72.02 Unplanned Reoperation in Patients Undergoing Surgery for Rectal Cancer

Posted on January 18, 2018

L. V. Saadat1, A. C. Fields1, H. Lyu1, R. D. Urman1, E. E. Whang1, J. Goldberg1, R. Bleday1, N. Melnitchouk1  1Brigham And Women’s Hospital,Boston, MA, USA

Introduction: The rate of unplanned reoperation can provide information about surgical quality and the incidence and management of postoperative complications. There has been a paucity of studies assessing reoperation rates after rectal cancer surgery and the morbidity after such procedures remains largely unknown. The goal of this study was to determine the factors associated with unplanned reoperation following low anterior resection (LAR) and abdominoperineal resection (APR) for patients with rectal cancer and outcomes following these reoperations. 

 

Methods: The American College of Surgeons National Surgical Quality Improvement Program database was used to identify patients who underwent elective LAR and APR for rectal cancer from 2012-2014. The primary outcomes were 30-day reoperation rates and postoperative complications. Bivariate and multivariate analyses were conducted to assess risk factors for reoperation.

 

Results: A total of 11,297 patients were identified; 7,714 patients underwent LAR and 3,583 patients underwent APR. 454 LAR patients (5.9%) and 289 APR patients (8.1%) required reoperation within 30 days of their index operation. The most common reasons for reoperation were infection, bleeding, and bowel obstruction. The mean time to reoperation was 10.6 days and 13.1 days for LAR and APR, respectively. Multivariate analysis revealed that female sex (OR: 1.5, 95%CI: 1.19-2.01, p value: 0.001), poor functional status (OR: 2.2, 95%CI: 1.03-4.50, p value: 0.04), operation time (OR: 1.001, 95%CI: 1.00-1.002, p value: 0.01), and low preoperative albumin (OR: 0.79, 95%CI: 0.62-0.99, p value: 0.04) were independent risk factors for reoperation after LAR. Smoking (OR: 1.7, 95%CI: 1.2-2.4, p value: 0.001), COPD (OR: 1.8, 95%CI: 1.1-3.1, p value: 0.03), poor functional status (OR: 2.1, 95%CI: 1.1-4.3, p value: 0.032), operation time (OR: 1.003, 95%CI: 1.002-1.004, p value: <0.001), low preoperative albumin (OR: 0.69, 95%CI: 0.53-0.90, p value: 0.007), and laparoscopic approach (OR: 1.5, 95%CI: 1.1-2.1, p value: 0.02) were independent risk factors for reoperation after APR. Postoperative complication rates are high for those undergoing reoperation and patients are significantly more likely to have a non-home discharge (p <0.001) if reoperation takes place.  

 

Conclusion: Reoperation following LAR and APR for rectal cancer is not uncommon. This study highlights the common causes of reoperation, potentially modifiable preoperative risk factors for reoperation, and the morbidity associated with such operations.

 

 

72.01 PTEN Mutation Is Associated With Worse Prognosis In Stage III Colorectal Cancer

Posted on January 18, 2018

Y. Tajima1, Y. Shimada1, M. Nagahashi1, H. Ichikawa1, H. Kameyama1, M. Nakano1, J. Sakata1, T. Kobayashi1, H. Nogami2, S. Maruyama2, Y. Takii2, S. Okuda3, K. Takabe4,5, T. Wakai1  1Niigata University Graduate School Of Medical And Dental Sciences,Division Of Digestive And General Surgery,Niigata, NIIGATA, Japan 2Niigata Cancer Center Hospital,Department Of Surgery,Niigata, NIIGATA, Japan 3Niigata University Graduate School Of Medical And Dental Sciences,Division Of Bioinformatics,Niigata, NIIGATA, Japan 4Roswell Park Cancer Institute,Breast Surgery,Buffalo, NEW YORK, USA 5The State University Of New York,Department Of Surgery, University At Buffalo Jacobs School Of Medicine And Biomedical Sciences,Buffalo, NEW YORK, USA

Introduction:
he PI3K/AKT/mTOR pathway is related with cell proliferation and frequently activated in many human cancers. On the other hand, PTEN is a tumor suppressor gene inhibiting PI3K-initiated signaling. Loss of PTEN can be occurred in various types of tumor and associated with progression and worse prognosis. However, the association between PTEN mutation and prognosis in colorectal cancer (CRC) remains unclear. Our aim was to analyze the clinical impact of PTEN mutation in patients with colorectal cancer.

Methods:
Two-hundred-one Stage I–IV CRC patients who underwent colorectal resection were analyzed. We investigated genetic alterations associated with CRC using 415-gene panel. The association between PTEN mutation status and clinicopathological characteristics was analyzed using Fisher’s exact test. The association between PTEN mutation status and relapse-free survival (RFS) was analyzed using log-rank test and Cox proportional hazards model.

Results:
Fifty-five (27%) of 201 patients had PTEN mutation. Tumor diameter < 50 mm, lymphatic invasion, venous invasion, distant metastasis, poorly differentiated cluster grade 2/3 and Ki67 < 60 % were significantly associated with PTEN mutation (P < 0.001, P = 0.036, P = 0.003, P = 0.002, P = 0.009 and P = 0.003, respectively). Univariate analysis showed that PTEN mutation was significantly associated with the worse RFS in patients with Stage III CRC (P = 0.002) (Fig.1). On the other hand, PTEN mutation was not significantly associated with the RFS in patients with Stage I/II CRC and the overall survival in patients with Stage IV CRC (Fig.1). Of 415 genes, 18 genes had mutations in over 10% of patients with Stage III CRC. Those 18 genes were ACVR2A (10.9%), APC (71.7%), BRAF (10.9%), BRCA2 (10.9%), CDH1 (10.9%), CIC (10.9%), ERBB2 (13.0%), FAT1 (10.9%), FBXW7 (23.9%), KRAS (41.3%), PIK3CA (15.2%), PTEN (15.2%), RNF43 (19.6%), SMAD2 (10.9%), SMAD4 (21.7%), SPEN (13.0%), STK11 (15.2%), TP53 (78.3%). Among the 18 genes, PTEN mutation was significantly associated with CIC mutation (P = 0.020). Univariate analysis in patients with Stage III CRC showed that the RFS was significantly worse in mucinous type, CIC mutation, ERBB2 mutation and PTEN mutation (P = 0.005, P = 0.009, P = 0.037, P = 0.002, respectively). Multivariate analysis in patients with Stage III showed that only PTEN mutation was significantly affected the RFS (hazard ratio 6.18, 95% confidence interval 1.63–23.5, P = 0.007).

Conclusion:
PTEN mutation was associated with worse prognosis in Stage III CRC. We speculate that PTEN is one of potential driver genes in CRC.
 

70.09 The Association Between Travel Distance, Institutional Volume, and Outcomes for Rectal Cancer Patients

Posted on January 18, 2018

M. Cerullo1, M. Turner1, M. A. Adam1, Z. Sun1, J. Migaly1, C. Mantyh1  1Duke University Medical Center,Department Of Surgery,Durham, NC, USA

Introduction: Though the relationship between surgical volume and outcomes has been well studied, travel to higher-volume centers remains a significant barrier for patients. Though travel to higher-volume centers is associated with improved outcomes for other cancers, it remains unclear whether travel to higher volume centers is associated with improved 30- and 90-day mortality, better long-term survival, or a higher likelihood of undergoing appropriate surgery in patients with rectal cancer.

Methods: Patients with rectal adenocarcinoma (stages I-III) with a single primary tumor were identified in the 2011-2014 National Cancer Database (NCDB). Patients were further categorized into quartiles by distance traveled, while centers were categorized into volume quartiles. Multivariable logistic regression and Cox proportional hazards regression models were used to compare outcomes between patients in the highest quartile of travel distance treated at the highest volume centers (travel) with patients in the lowest quartile of travel distance treated at the lowest volume centers (local).

Results: Exactly 3,088 patients in the lowest quartile of travel distance treated at low-volume centers and 3,071 patients in the highest quartile of travel distance treated at high-volume centers were identified. Overall, 38.2% of patients had stage III disease (35.3% of short-distance/low-volume patients vs. 41.1% of greater-distance/high-volume patients, p<0.001), and 63.6% received neoadjuvant radiation (57.7% of short-distance/low-volume patients vs. 69.6% of greater-distance/high-volume patients, p<0.001). After adjustment for disease severity and receipt of adjuvant therapy, patients who traveled greater distances to high-volume centers had a 71% lower 30- and 61% lower 90-day mortality (30-day: OR=0.29, 95% CI: 0.15–0.57, p<0.001; 90-day: OR=0.39, 95% CI: 0.24–0.62, p<0.001), as well as lower risk of overall mortality (Hazard ratio=0.78, 95% CI: 0.68–0.88, p<0.001). These patients also were more likely to have adequate lymph node harvest (OR=1.83, 95% CI: 1.64–2.05, p<0.001) and less likely to have positive margins (OR=0.76, 95% CI: 0.59–0.96, p=0.02). However, these patients also had 42% greater odds of being readmitted after surgery (OR: 1.42, 95% CI: 1.14–1.75, p=0.001).

Conclusion: Traveling greater distances to high-volume centers improves 30- and 90-day mortality, overall risk of death, and pathologic surrogates for appropriate surgery in rectal cancer patients. As patients may often be faced with choosing to obtain care at local lower-volume centers or traveling to higher-volume centers, these findings provide an impetus for facilitating travel for patients to higher-volume centers.

70.06 Neoadjuvant Radiation for Locally Advanced Colon Cancer: A Good Idea for a Bad Problem?

Posted on January 18, 2018

A. T. Hawkins1, T. M. Geiger1, M. Ford1, R. L. Muldoon1, B. Hopkins1, L. A. Kachnic1, S. Glasgow2  1Vanderbilt University Medical Center,Nashville, TN, USA 2Washington University,Colon And Rectal Surgery,St. Louis, MO, USA

Introduction: Compared with lower tumor stages, resection of locally advanced colon cancer (LACC) is associated with poor survival. Few strategies are available to address this disparity. Data on the effect of neoadjuvant radiation therapy (NRT) to improve resectability and survival is lacking. We hypothesized that NRT will result in increased R0 resection, decreased multivisceral resection rates and improved overall survival in patients with LACC.  

Methods: The National Cancer Database (NCDB 2004-2014) was queried for adults with clinical evidence of LACC (defined as clinically evident T4 disease prior to surgery) who underwent curative resection. Patients with metastatic disease or in whom clinical staging data was unavailable were excluded.  Patients were divided into two groups – those who underwent NRT and those that did not.  Bivariate and multivariable analyses were used to examine the association between NRT and R0 resection rate, multivisceral resection and overall survival.  

Results: 15,207 patients with clinical T4 disease who underwent resection were identified over the study period.  195 (1.3%) underwent NRT.  The majority of patients in the NRT group underwent 4500 cGy of radiation in 25 fractions over five weeks (range: 3900- 5040 cGy). Rate of NRT utilization did not change by year. Factors associated with the use of NRT included younger age, male gender, private insurance, lower Charlson comorbidity score, and treatment at an academic/research program.  NRT was associated with superior R0 resection rates (NRT 87.2% vs. No NRT 79.8%; p=0.009) but not lower multivisceral resection rates (NRT 45.6% vs. No NRT 21.5%; p< 0.001).  Five-year overall survival was increased in the NRT group (NRT 62.0% vs. No NRT 45.7%; p< 0.001; PLEASE SEE FIGURE).  The benefit of NRT persisted in a Cox proportional hazard multivariable model containing a number of confounding variables including comorbidity, multivisceral resection and postoperative chemotherapy (OR 1.30; 95%CI 1.01-1.69; p=0.04).  

Conclusion: Younger age, male gender, private insurance, lower Charlson comorbidity score, and treatment at an academic/research program were associated with increased rates of NRT utilization. Although radiation is rarely used in locally advanced colon cancer, this NCDB analysis suggests that the use of neoadjuvant radiation for clinical T4 disease may be associated with superior R0 resection rates and improved overall survival.  NRT should be considered on a case-by-case basis in locally advanced colon cancer. Further research is necessary to identify patients that will benefit the most from this approach. 

 

70.04 Enhanced Recovery Pathway for Colorectal Surgery Improves Outcomes in Private and Safety Net Settings

Posted on January 18, 2018

T. J. Roberts1, J. L. Anandam1,3, P. K. Brown1, J. R. Lysikowski1, J. L. Rabaglia1,2,3  1University Of Texas Southwestern Medical Center,Dallas, TX, USA 2VA North Texas Health Care System,Dallas, TX, USA 3Parkland Health & Hospital System,Dallas, TX, USA

Introduction:  Although it is known that Enhanced Recovery Pathways (ERP) decrease length of stay (LOS) and improve outcomes in colorectal surgery, these studies predominantly represent the private health care setting. There is a paucity of information regarding the effectiveness of ERP in the public arena, comprised of the under or un-insured who may have different social determinants of health. This study aims to compare the effect of an ERP on LOS and readmission for colorectal surgery across the private and safety net settings in a large urban academic medical center.

Methods:  A multidisciplinary panel of experts utilized professionally recognized standards and evidence-based best practice to create a comprehensive ERP for elective colorectal surgery. The ERP included standardization of patient education, optimization of co-morbidities, multimodal analgesia, carbohydrate loading, intraoperative goal-directed fluid therapy, minimization of opioids, and early ambulation, removal of urinary catheter, and resumption of diet. There were no social interventions. The ERP was implemented in the safety net hospital (SNH) in 9/2014 and in the private University hospital (PUH) in 12/2014. Process and outcome metrics from 100 consecutive patients having surgery in the 18 months prior to ERP at each institution were compared to a similar group post ERP. Surgeons and discharge criteria remained constant. Primary end points were LOS and readmissions.

Results: Patients in the post ERP cohorts at both facilities were significantly older than pre ERP (p=0.047, 0.034), with no significant difference in gender and BMI. The rate of open versus minimally invasive was similar at SNH (p=0.067), while more post ERP patients at PUH underwent open surgery (p=0.002). 96% of PUH patients were funded through private insurance or Medicare, verses only 6% at the SNH. ERP implementation reduced total LOS at both facilities, while readmission and reoperation remained constant. LOS at PUH fell from 8.1 to 5.9 days (p=0.028), and at SNH from 7.0 to 5.1 days (p=0.004). 30-day all-cause readmission and return to surgery were stable (PUH p=0.634; SNH p=1) and (PUH p=0.610; SNH p=0.066) respectively. Surgical site infection rate was unchanged at PUH (p=0.485) and significantly reduced at SNH (p=0.021, OR 0.39). Mean time to ambulation and mean time to first bowel movement were reduced at SNH (p=0.002, 0.001). Mean time to resumption of solids was reduced at both PUH and SNH (p<0.001).

Conclusion: Implementation of ERP is similarly effective across private and safety net settings, without interventions to address social determinants of health. Both cohorts experienced reduced LOS without increasing readmission or reoperation. The data suggest ERP may have a more dramatic impact on outcomes in the safety net setting, perhaps through standardization in a group with more varied baseline health status. Utilization of ERP appears to be advantageous for all populations regardless of funding.

 

7.20 Decision Tree Analysis to Identify Key Factors Predicting ICU Admission After Colorectal Surgery

Posted on January 18, 2018

D. E. Wang1, Y. Fang2, S. E. Sherman2, E. Newman1, G. Ballantyne1, H. Pachter1, M. Melis1  1New York University School Of Medicine,Department Of Surgery,New York, NY, USA 2New York University School Of Medicine,Department Of Population Health,New York, NY, USA

Introduction: Currently, there are no standard criteria for admission to an intensive care unit (ICU) following colorectal surgery and rates of ICU admission fluctuate widely across various healthcare settings. Undertriage can lead to preventable complications. Over-triage can cause iatrogenic harm to the patient alongside unnecessary costs and misutilization of resources. We sought to identify predictors for appropriate ICU triage following colorectal surgery.

Methods:  We performed a retrospective analysis of patients undergoing colorectal surgery (2011-2015). Objective criteria (e.g. prolonged hypotension, reintubation, new onset of cardiac arrhythmia) were used to identify appropriate ICU admissions. Patient demographics, underlying conditions, and common surgical risk scores such as Charlson Comorbidity Index (CCI), Surgical Apgar Score (SAS), and Revised Cardiac Risk Index (RCRI) were utilized in a decision tree model to identify factors correlating with objective criteria for ICU admission. The accuracy and overall quality of the model was assessed by examining the test misclassification rate achieved after separating the dataset into training and validation sets. The model was then compared to other approaches including bivariate analysis and multiple logistic regression analysis.

Results: Events requiring ICU care were observed in 41 of 104 patients who underwent colorectal surgery. Decision tree analysis identified the lowest intraoperative heart rate, CCI, and eGFR as the 3 most important predictors for ICU admission with an overall misclassification rate of 21.2% (Figure 1a). SAS, CCI, age, history of solid tumor, and preoperative hematocrit were also predictors of need for ICU. Using 65 patients who were randomly selected as training set to build a model and the remaining 39 patients to test the model, a simpler decision tree was achieved utilizing CCI and lowest intraoperative heart rate with an overall misclassification rate of 20.5% (Figure 1b). Bivariate analysis of the top 9 predictors identified through the decision tree model revealed significant differences (p<0.05) in lowest heart rate, CCI, SAS, RCRI, and history of a solid tumor but insignificant differences in eGFR, age, and preoperative hematocrit. Multiple logistic regression analysis of these 9 variables resulted in an overall misclassification rate of 23.1%.

Conclusion: Many patients are unnecessarily admitted to the ICU following colorectal surgery. Using decision tree modeling, we found that lowest intraoperative heart rate and CCI represent the two most important predictors for ICU admission. Further analysis with larger datasets will be necessary to develop clinical tools to enhance postoperative triage after colorectal surgery.

 

7.19 Finding the Surgical “Sweet Spot” in Colorectal Cancer: Timing Affects Survival.

Posted on January 18, 2018

R. J. Kucejko1, T. Holleran1, D. E. Stein1, J. L. Poggio1  1Drexel University College Of Medicine,Surgery,Philadelphia, PA, USA

Introduction:  Surgical resection is the mainstay of definitive treatment for colon and rectal cancer.  Prior studies have shown that earlier surgery for other malignancies can improve long-term survival.  Research has shown that emergent treatment for colorectal cancer leads to lower long-term survival, but the effect of timing for elective surgery has not been well studied.  Quality metrics have been established for the administration of chemotherapy in colorectal surgery, but none exist for the timing of surgery.  This study aims to determine the optimal timing of elective surgical resection of colon and rectal cancer.

Methods:  A retrospective review was performed on the National Cancer Database (NCDB) on patients between 2004 and 2013 with a primary site corresponding to colon or rectum.  Patients were included if the entry was for their first and only malignancy, and if definitive surgical treatment was performed prior to other modalities.  Patients were excluded if the number of days to diagnosis was unknown, or diagnosis was made on autopsy.  Patients were separated into 15-day strata and post-operative outcomes were assessed by chi-squared and Mann-Whitney U tests.  Overall survival was evaluated by Cox regression.

Results: 595,174 patients were analyzed, with 78.7% having colon cancer and 21.3% having rectal cancer.  62.4% of all patients were operated on between 0 to 15 days after definitive diagnosis, with 30.2% having an operation the same day as diagnosis.  Cox regression analysis controlling for age, stage, and Charlson comorbidity score showed the lowest overall survival rate in patients operated on within the first 15 days of diagnosis.  When days 0 through 15 were analyzed individually, a significantly lower survival was noted between days 2 through 6.  The highest survival was seen in patients operated on between 16 and 90 days after definitive diagnosis.

Conclusion: The timing of surgery in colon and rectal cancer significantly affects overall survival.  Patients operated on the same day of diagnosis may represent those in need of emergent surgery, yet those patients did not have the lowest overall survival when controlling for disease stage, age, and comorbidities.  The high percentage of patients receiving definitive operations within the first 15 days suggest patients may be receiving definitive operations too soon.  They would likely benefit from pre-operative optimization of medical comorbidities, nutrition, and social support, as no benefit is seen from rushing to surgery.  There is a need for further analysis of pre-operative variables to determine why the lowest survival exists between days 2 to 6 after definitive diagnosis. 

 

7.18 ERAS Protocol Validation in a Propensity Matched Cohort of Patients Undergoing Colorectal Surgery.

Posted on January 18, 2018

P. Vinsard3, A. C. Spaulding2, J. M. Naessens2, Z. Li5, A. Merchea1, J. E. Crook5, D. W. Larson4, R. G. Landmann1, D. T. Colibaseanu1,2  1Mayo Clinic,Department Of General Surgery,Jacksonville, FL, USA 2Mayo Clinic,Center For The Science Of Health Care Delivery,Rochester, MN, USA 3University Of Connecticut,Department Of Surgery,Farmington, CT, USA 4Mayo Clinic,Division Of Colorectal Surgery,Rochester, MN, USA 5Mayo Clinic,Department Of Health Sciences Research,Jacksonville, FL, USA

Introduction: Enhanced Recovery after Surgery (ERAS) has been shown to decrease length of stay, postoperative pain, morbidity, and cost of care. Implementation of the various elements of ERAS is variable, and limited data exists regarding protocol validation. We aim to describe the implementation and validation of a previously described ERAS protocol.

Methods: A retrospective review with propensity score matching of all patients undergoing elective colorectal surgery from 2009 – 2016 was undertaken.  Patient demographics, length of stay (LOS), pain scores, and perioperative morbidity (30-day readmissions, unplanned reoperations, surgical site infections, anastomotic leaks and bleeding) are described. Patients enrolled in the ERAS protocol and those undergoing standard of care were compared for the above outcomes.

Results:From the initial 1,556 patients identified in the initial, nonmatched cohort, 1398 were propensity matched, 698 in each group.  After propensity matching, there was no significant difference in age, Charlson Comorbidity Index, American Society of Anaesthesiologists (ASA) score, Body Mass Index (BMI), sex, operative approach (minimally invasive or open), and surgery duration.  Overall postoperative complications were the same in both groups, with postoperative bleeding slightly lower in the ERAS group. The median LOS in ERAS and non-ERAS groups was 3 vs 5 days, respectively (p <0.001).  From the time of implementation, the 2-day decrease in LOS stabilized after approximately 6 months. Mean pain scores were always lower in the ERAS group, measured at discharge from post anesthesia unit (4.8 vs 3.4; p<0.0001), on Post Operative Day (POD)1 (3.8 vs 3.3; p 0.002) , and on POD 2 (3.1 vs 2.8; p 0.024), but were the same on discharge (2.0). 

Conclusion:This ERAS protocol was successfully validated at our institution, using the same protocol and a similar population of patients as the institution that developed the protocol.   The primary outcome, LOS, decreased by 2 days as at the original institution.   In this study, the time to achieve a 2-day decrease in LOS from the moment of implementation was 6 months.  Secondary outcomes were also very similar as the original institution; in particular pain scores were observed to be statistically significant and lower in the ERAS group.  Different than most other retrospective studies was the use of propensity matching which ensured that – to the best of the authors’ ability-  the groups are as evenly matched as possible. This study adds to the body of literature showing that ERAS is beneficial to the patients, but is the only validation ERAS study in a propensity matched cohort of patients undergoing elective colorectal surgery. Limitations of this study include the retrospective design and that this is a single institution experience, reliant on its surgical mix and electronic clinical systems to capture some of the outcomes described. Further validation from other institutions would be beneficial. 

7.17 Frequency and Timing of Complications Following Abdominoperineal Resection: A NSQIP Analysis

Posted on January 18, 2018

L. A. Sceats1, J. E. Tooley3, D. D. Bohl2, B. Read1, A. Trickey4, C. Kin1  1Stanford University,Surgery,Palo Alto, CA, USA 2Rush University Medical Center,Orthopedic Surgery,Chicago, IL, USA 3Stanford University,Internal Medicine,Palo Alto, CA, USA 4Stanford University,S-SPIRE Center,Stanford, CA, USA

Introduction:
Abdominoperineal resection (APR) is primarily used for low rectal cancers and is historically associated with a high rate of complications. Though the majority of APRs are performed as open procedures, laparoscopic APRs have increased in popularity. The differences in short-term complications between open and laparoscopic APR are poorly characterized. The purpose of this study was to determine the differences in frequency and timing of onset of postoperative complications between laparoscopic and open APR.  

Methods:
A retrospective cohort study was completed using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. All patients in the ACS-NSQIP database who underwent laparoscopic or open APR between 2011 and 2015 were identified by Current Procedure Terminology (CPT) codes. Selected patients’ demographic data and comorbidities were compared using Pearson’s χ2 tests. Utilization of the laparoscopic approach over time was evaluated with χ2 tests for trend. The 30-day occurrence rates of common postoperative complications were determined. Cox proportional hazard models were created to compare timing of complication onset between open and laparoscopic procedure groups while controlling for baseline demographics and comorbidities. Hazard ratios and hazard curves for postoperative day of onset were calculated for each complication. Differences in length of stay were analyzed using multivariate robust regression. Statistical analyses were conducted using Stata v14.2.   

Results:
A total of 7681 patients undergoing laparoscopic or open APR were identified. The total complication rate for APR was high (45.4%). APRs were commonly complicated by blood transfusion (20.1%), surgical site infection (19.3%), and readmission (12.3%). The percentage of APRs completed laparoscopically increased from 26% in 2011 to 40% in 2015 (p<0.001). Laparoscopic APR was associated with a lower total complication rate compared to open APR (36.0% vs. 50.1%, p<0.001). This was primarily driven by a decreased rate of transfusion (10.7% vs. 24.9%, p<0.001) and surgical site infection (15.5% vs. 21.2%, p<0.001). Laparoscopic APR was associated with a shorter length of stay (7.4 vs. 9.8 days, p<0.001) and decreased reoperation rate but similar rates of readmission and death. Laparoscopic patients were readmitted earlier, corresponding with earlier discharge date. Cardiopulmonary complications occurred earlier in the postoperative period while infectious complications occurred later. Wounds dehisced later (16.5 vs. 13.2 days, p=0.001) and strokes occurred later in laparoscopic surgical patients (12.2 vs. 8.8 days, p=0.027). 

Conclusion:
Short-term complications following APR are common. Compared to open APR, laparoscopic APR is safe and has a shorter hospitalization, decreased rate of complications, and lower reoperation rate. Laparoscopic APR may be the preferable method for surgeons with the appropriate training and skill set.
 

7.16 Medicaid Patients Less Likely to Receive Emergent Procedures for Colorectal Cancer

Posted on January 18, 2018

Y. A. Zerhouni1,3, E. B. Schneider2, N. Melnitchouk1  1Brigham And Women’s Hospital,C,Boston, MA, USA 2Ohio State University,Columbus, OH, USA 3UCSF- East Bay,Surgery,Oakland, CA, USA

Introduction:
Disparities in referral to surgical intervention for cancer exist for Medicaid patients. Emergent surgical procedures, both curative and palliative, play a major part in the management of patients with colorectal cancer (CRC), and carry worse outcomes. We evaluated the disparity of procedures by insurance coverage in the management of CRC patients who present to the emergency department (ED) for care of CRC.

Methods:
We queried the 2008-2014 Healthcare Cost and Utilization Project Nationwide Emergency Department Sample (NEDS), a 20% stratified sample of United States ED visits, to identify all visits with a primary ICD-9-CM diagnosis of CRC. CRC patients who underwent a colon resection, ostomy creation, colon dilation, or colon stenting were identified (PROC). Comparisons were done between Medicaid and private insurance PROC patients and those who did not have a procedure (NOPROC). Using coarsened exact matching controlling for age, sex, cancer site, hospital region, zip-code median income, year of presentation, and discharge weight within the NEDS, a one-to-one match was made between Medicaid and private insurance patients. Descriptive analyses were done to compare the matched cohorts.

Results:

Medicaid and private insurance patients accounted for 12.7% and 20.1% respectively of an estimated 312,105 ED visits for a primary diagnosis of CRC. In the unmatched analysis, Medicaid patients were noted to be younger (mean age NOPROC 53.5 vs. 57.3 and PROC 54.9 vs. 57.9, p<0.001). Both Medicaid and private insurance patients were more likely to be male (NOPROC 55.8% vs 57.9%, p=0.092; PROC 55.0% vs 51.6%, p<0.001). Both groups of Medicaid patients were more likely to have more comorbidities than private patients, notably tobacco use, malnutrition, COPD, liver disease, and AIDS. Private NOPROC patients were significantly more likely to be obese, have a history of myocardial infarction, congestive heart failure, peripheral vascular disease, and chronic renal disease. Private PROC patients were more likely to be obese than Medicaid patients (14.0% vs. 10.0%, p<0.001). Medicaid patients were more likely to receive an ostomy only as their procedure (15.4% vs. 8.5%, p<0.001).  4,087 matched pairs were made. After matching, Medicaid patients were still less likely to have a procedure (p=0.021) and died at a higher rate after a procedure but this did not meet statistical significance (2.6% vs. 1.7%, p=0.055).

Conclusion:
After matching, Medicaid patients continue to be less likely to be treated with a surgical procedures. Medicaid patients presenting for emergent care of CRC have more co-morbidities and rectal disease than private patients. Medicaid patients were more likely to undergo ostomy creation as their sole procedure.

7.15 Trends and Outcomes for Minimally Invasive Surgery for Inflammatory Bowel Disease

Posted on January 18, 2018

C. H. Davis1, T. Gaglani2, H. R. Bailey1,2, M. V. Cusick1,2  1Methodist DeBakey Heart And Vascular Center,Department Of Surgery,Houston, TX, USA 2University Of Texas Health Science Center At Houston,Department Of Surgery,Houston, TX, USA

Introduction:
The relapsing and remitting nature of Inflammatory Bowel Disease (IBD) predisposes patients to the development of fibrotic strictures, which must often be managed surgically. Laparoscopy provides the potential for enhanced perioperative care. Previous studies comparing morbidity and trends of open versus laparoscopic resection in IBD have been constrained by length of study and sample size. The aim of this study was to assess the trends of laparoscopic utilization over time and to compare operative outcomes with between open vs. laparoscopic technique.

Methods:
Using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, patients with primary diagnosis of IBD undergoing surgical resection from 2005-2015 were identified using a combination of ICD-9 and CPT codes. Utilization as well as morbidity and mortality rates were then compared between open and laparoscopic resections.

Results:
A total of 29,266 resections were performed on IBD patients; 4,856 (16.6%) performed laparoscopically. The mean age in the open and laparoscopic groups was 43.8 and 38.9 years, respectively. The mean BMI in the open and laparoscopic groups was 25.7 and 25.2 kg/m2. The use of laparoscopy increased over time from 5.9% in 2005 to 23.2% in 2015. Comparing laparoscopic versus open, postoperative complication rates favored laparoscopy in each of the 16 categories. (Table 1) The most common complications in both laparoscopic and open methods were organ space infection (5.4% vs. 6.9%), superficial surgical site infection (4.6% vs. 7.1%), and urinary tract infection (1.3% vs. 3.4%). Length of stay was also markedly reduced in the laparoscopic group (6.4 vs. 9.3 days).

Conclusion:
These data indicate that the number of laparoscopic resections for IBD have been increasing over time. Favorable complication rates, operating time and hospital stay suggest that laparoscopy may be a safer option and should be preferred for fibrotic bowel resection. There are various limitations of this study that stem from the use of the NSQIP database. Skill or training level of surgeons and outcome data past 30 postoperative days are not captured. Furthermore, there was limited information about the clinical complexity of each case as the database did not contain inflammatory markers such as C-reactive protein or sedimentation rates. Future analyses should be conducted about the relative efficacy of robotic surgery as well as single incision laparoscopic surgery.
 

7.14 Perineural Invasion is a Significant Prognostic Factor in Non-Metastatic Colon Cancer.

Posted on January 18, 2018

L. G. Leijssen1,2, A. M. Dinaux1,2, H. Kunitake1,2, L. G. Bordeianou1,2, D. L. Berger1,2  1Massachusetts General Hospital,General And Gastrointestinal Surgery,Boston, MA, USA 2Harvard School Of Medicine,Brookline, MA, USA

Introduction:  ?Perineural invasion (PNI) is associated with adverse oncological outcomes in colorectal cancer. However, it’s often underreported and not considered in the TNM staging system. The aim of this study is to clarify the role of PNI in patients with non-metastatic colon cancer.?

Methods:  Patients with stage I-III colon cancer who underwent elective surgery at our tertiary center between 2004-2014 were extracted from a prospectively maintained database (n=1090). Long-term outcomes were compared, and differences were determined by multivariable Cox regression models adjusted for stage and potential confounders. ?

Results: PNI was identified in 168 (15.4%) patients and associated with left-sided tumors, greater tumor size, and advanced disease. Histopathological features including extramural vascular invasion, large and small vessel involvement, and poor differentiation were correlated with PNI. Furthermore, recurrence rates were significantly higher in patients with PNI presence (P<0.001). This was mainly explained by a higher rate of distant recurrence (8.7% vs. 30.4%, P<0.001), with liver (14.9%), peritoneum (8.9%), and lung (8.3%) as the main sites of metastasis. The estimate 5-year overall (OS) and disease-free survival (DFS) were both worse in the PNI positive group (OS: 79.7% vs. 55.1%; DFS: 87.9% vs. 60.8%, both P<0.001). Patients with stage-II disease and PNI presence had significantly worse OS than stage-III patients with no PNI (P<0.001). However, adjuvant therapy reversed this adverse outcome to comparable OS (P0.205). Multivariate analysis demonstrated PNI as an independent predictor for both overall (HR 1.77, 95% CI: 1.31-2.40, P<0.001) and disease-free survival (HR 1.72, 95% CI: 1.20-2.54, P0.004).?

Conclusion: Our study supports the benefits of adjuvant therapy in stage-II colon cancer with PNI positivity. PNI presence is an independent and poor prognostic factor in non-metastatic colon cancer and should be considered as a factor in disease stratification.?

 

7.13 Pre-operative Predictors of Prolonged Length-of-Stay with Enhanced Recovery After Surgery (ERAS)

Posted on January 18, 2018

T. S. Wahl1, J. D. Owen1, L. E. Goss1, J. S. Richman1, M. S. Morris1, G. D. Kennedy1, J. A. Cannon1, D. I. Chu1  1University Of Alabama At Birmingham,Department Of Surgery,Birmingham, AL, USA

Introduction: ERAS decreases post-operative length-of-stay (pLOS) and cost following colorectal surgery. It remains unclear, however, which patients will fail ERAS based on pre-operative assessments. We hypothesized that patient-level factors, such as social determinants of health (SDOH), would predict prolonged post-operative length-of-stay.

Methods: All adult patients undergoing colorectal surgery with ERAS from 2015 at a single-institution were identified. ERAS failure was defined as an observed pLOS greater-than-the-expected pLOS calculated using the ACS-NSQIP Risk Calculator. Patients were stratified by ERAS success or failure. Pre-operative patient-level characteristics including SDOH were compared. Backwards step-wise logistic regression identified independent predictors of ERAS failure.

Results: Of 210 patients, 39 (18.6%) patients were ERAS failures. No differences in SDOH or ERAS compliance rates were observed between groups. Compared to non-ERAS failures, ERAS failure patients experienced a median pLOS 12 days (IQR 8-14) compared to 3 days (IQR 3-4) (p<0.001). ERAS failure was associated with active smoking, white race, and emergency surgery. On adjusted analysis, pre-operative smoking status (OR 2.4 95%CI 1.1-5.6, p=0.03) and emergency surgery (OR 5.0 95%CI 1.9-13.5, p<0.01) were independently associated with ERAS failure. On adjusted analysis of elective surgery patients, the presence of pre-operative opioid prescriptions was independently associated with ERAS failure (OR 4.8 95%CI 1.7-13.7, p=0.03).

Conclusion: Pre-operative patient characteristics associated with ERAS failure are smoking status, emergency surgery, and having outpatient opioid prescriptions. These factors represent potential targets for future interventions to prevent ERAS failure.
 

7.12 Risk Factors Associated with Readmission after Ileal Pouch-Anal Anastomosis: An ACS-NSQIP Analysis

Posted on January 18, 2018

N. P. McKenna1,4, E. B. Habermann3,4, A. E. Glasgow4, K. L. Mathis2, A. L. Lightner2  1Mayo Clinic,Department Of Surgery,Rochester, MN, USA 2Mayo Clinic,Division Of Colon And Rectal Surgery,Rochester, MN, USA 3Mayo Clinic,Department Of Health Science Research,Rochester, MN, USA 4Mayo Clinic,Robert D. And Patricia E. Kern Center For The Science Of Health Care Delivery,Rochester, MN, USA

Introduction: While the increased risk for readmission after ileal pouch-anal anastomosis (IPAA) relative to other colorectal surgery operations is known, reasons and risk factors for readmission remain poorly understood. The purpose of this study was to identify preventable reasons for readmission and to delineate risk factors for readmission in the perioperative period.

Methods: Patients with a diagnosis of chronic ulcerative colitis (CUC) undergoing either total proctocolectomy with IPAA (two-stage) or proctectomy with IPAA (three-stage) were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2012 to 2015.  Reasons for unplanned readmission within 30 days of procedure were reviewed and categorized as infectious, dehydration/electrolyte abnormalities, small bowel obstruction/ileus, venous thromboembolism, ostomy related, pouch related, pain, bleeding, and other/missing. The primary outcome rate measured was readmission within 30 days of discharge as calculated by person-years method. Cox Proportional Hazard models determined independent risk factors for readmission overall and for specific categories.  

Results: 3473 patients met inclusion criteria with an overall readmission rate of 33% per 30 person days. Identified reasons for readmission included infectious complications (32%), dehydration/electrolyte abnormalities (23%), small bowel obstruction/ileus (15%) and venous thromboembolism (VTE) (5%). Multivariable analysis found race/ethnicity of Hispanic white and black/African American (both versus non-Hispanic white, HR: 1.5, p=0.02 and HR: 1.4, p=0.02, respectively) to be independently associated with thirty-day readmission. When looking at specific reasons for readmission, age 57+ (versus age 18-32, HR: 2.3, p<0.01) and hypertension requiring medication (HR: 1.5, p=0.04) were associated with readmission for dehydration/electrolyte abnormalities; two stage IPAA was associated with readmission for VTE (HR 6.5, p=0.01), while obesity (HR 1.5, p<0.01), operative time 330+ minutes (versus <189 minutes, HR: 2.2, p<0.01), and Hispanic white race/ethnicity (versus non-Hispanic white, HR: 2.0, p<0.01) were associated with readmission for infectious complications.

Conclusions: One-third of patients were readmitted after IPAA, with infectious complications and dehydration making up the majority of reasons for readmission. Targets for quality improvement include potentially preventable reasons for readmission such as dehydration and VTE. The development of pathways to prevent dehydration after discharge in high-risk patients and consideration of extended VTE prophylaxis after two-stage IPAA could help reduce the high readmission rate after IPAA. 

7.11 Disparity of Colon Cancer Outcomes in Rural America: Making the Case to Travel the Extra Mile

Posted on January 18, 2018

V. Raman1, M. A. Adam1, M. Turner1, H. Moore1, C. Mantyh1, J. Migaly1  1Duke University Medical Center,Department Of Surgery,Durham, NC, USA

Introduction:
Rural disparity in colon cancer care may exist, with potential compromised outcomes for rural dwellers. However, it is unclear if this disparity could be mitigated by traveling to high-volume centers, given concerns for travel burden and wait times. The objectives of this study were to characterize outcomes from colon cancer patients based on rurality and compare the outcomes of rural patients who traveled to high-volume centers to urban patients who traveled to high-volume centers.

Methods:
Patients treated for colon cancer were identified from the National Cancer Database (2004-2014). Travel distance to treatment centers and annual hospital volume were divided into quartiles. Overlaying rural status with the upper quartiles of travel distance with hospital volume status was employed to identify 2 groups: (1) rural patients who traveled to high-volume hospitals, (2) urban patients who traveled to high-volume hospitals. Outcomes were compared after adjustment for clinicopathologic tumor characteristics, and surgical therapy.

Results:
A total of 503,438 patients were included; 492883 patients from urban areas and 10555 patients from rural areas. Rural vs urban patients more often were White, had lower income, more comorbid conditions, and received treatment at non-academic centers (all p<0.05).  While extent of surgery was not different between groups, rural patients had higher 90-day mortality (7% vs 6%, p=0.002). Unadjusted 10-year overall survival was significantly shorter for the rural group (37% vs 39%, p<0.0001). After adjustment, survival remained significantly compromised among rural patients (HR 1.06, p=0.0003). There were 31499 urban patients who travel a long distance (mean 40 miles) to high-volume centers (mean137 cases/yr) and 701 rural patients who travel a long distance (mean 108 miles) to high-volume centers (139 cases/yr). Unadjusted 10-year survival was equivalent between rural vs urban patients who travelled to high-volume centers (42% vs 45%, p<0.39), even after adjustment for patient and tumor characteristics (HR 1.097, p=0.25).

Conclusion:
This national study suggests that rural disparity exists in colon cancer, with compromised outcomes for rural patients. Despite concerns for travel burden and the potential for longer wait times, rural patients who travel to high-volume centers appear to have similar survival to urban patients who travel to high-volume centers. This data may encourage rural providers, patients and policymakers to facilitate referral to high-volume centers for this disadvantaged population. 
 

7.09 Readmission Risk Factors For Colorectal Patients Under Enhanced Recovery After Surgery Pathways

Posted on January 18, 2018

J. D. Owen1, L. E. Goss1, G. D. Kennedy1, J. A. Cannon1, M. S. Morris1, J. S. Richman1, D. I. Chu1  1University Of Alabama at Birmingham,Department Of Surgery,Birmingham, AL, USA

Introduction:  Enhanced Recovery After Surgery (ERAS) pathways decrease length-of-stay and readmissions after colorectal surgery. While risk factors such as ostomies have been associated with 30-day readmissions under traditional recovery pathways, it is unclear if these readmission factors remain the same with ERAS pathways. We hypothesized that risk factors for 30-day readmissions under ERAS would differ from pre-ERAS risk factors. 

Methods: Using a single-institution colorectal database, we identified all patients who underwent ERAS in 2015 and matched to pre-ERAS patients from 2010-2014 by age, sex, race/ethnic group and procedure type. Patient/procedure-specific characteristics were obtained. The primary outcome was 30-day readmissions. Pre-ERAS and ERAS patients were each stratified by readmission status and univariate and bivariate comparison were made. Multivariate regression was used to identify independent predictors of 30-day readmissions for each cohort. 

Results:Of 395 patients, 198 patients underwent ERAS and were matched to 197 Pre-ERAS patients. Overall, the 30-day readmission rate was 15.7% and similar between ERAS and Pre-ERAS patients (16.2 vs. 15.2%, p>0.05). Among ERAS patients, readmitted and non-readmitted patients were similar by matched characteristics and smoking status (28.1 vs 17.5%), minimally-invasive approaches (37.5 vs 44.6%) and BMI (mean 28.9 vs 28.3 (p>0.05). Compared to non-readmitted ERAS patients, readmitted ERAS patients had more ostomies (43.3% vs 22.8%), higher ASA classification scores and more government insurance (p<0.05). Among Pre-ERAS patients, readmitted and non-readmitted patients were similar by female status (53.3 vs. 43.7%), smoking status (23.3 vs 22.2%), and hypertension (43.3 vs 48.5%) (p>0.05). Compared to non-readmitted Pre-ERAS patients, readmitted Pre-ERAS patients had a higher proportion of total colectomies (30.0 vs 5.4%) and more ostomies (36.7 vs. 15.6%) (p<0.01). On adjusted comparisons (Table), risk factors for 30-day readmissions for Pre-ERAS patients included procedure type such as total colectomy (Odds Ratio [OR] 7.0, 95%Confidence-Interval [CI] 1.1-41.6) and presence of an ostomy (OR 2.6, 95%CI 1.1-6.1). For ERAS patients, risk factors for 30-day readmissions included government insurance (OR 4.2, 95%CI 1.7-10.6) and presence of an ostomy (OR 3.1, 95%CI 1.5-6.4). 

Conclusion:Independent risk factors for readmission varied between the pre-ERAS and ERAS cohorts. The presence of an ostomy, however, remained an important and common risk factor for 30-day readmissions even under ERAS pathways. Improving our post-discharge care of patients with an ostomy may represent an immediately actionable opportunity to reduce readmissions. 

 

7.10 Patterns of Opioid Prescribing and Patient Use for Outpatient Anorectal Operations

Posted on January 18, 2018

A. Swarup1, K. A. Mathis1, M. V. Hill1, S. J. Ivatury1  1Dartmouth Medical School,General Surgery,Lebanon, NH, USA

Introduction:

Surgery for anorectal diseases is commonly thought to cause significant pain in the postoperative setting. There is little known regarding standardized opioid prescribing trends and patient use following surgery for anorectal disorders. With the ongoing opioid epidemic posing a significant health problem, we aimed to evaluate and analyze opioid prescribing trends and patient use for outpatient anorectal operations.

Methods:

All patients who underwent outpatient anorectal surgery performed over a one year period at a single institution were eligible. Procedures included hemorrhoidectomy, anal fistula repair/seton, anal fissure treatment with sphincterotomy, and transanal excision of rectal tumors. Demographic, operative and postoperative data was obtained. Patients were given a survey to determine postoperative pain control with opioid and non-narcotic analgesia use; respondents were included in analysis.

Results:

42 outpatient anorectal surgery patients were included: 13 had hemorrhoidectomy, 22 anal fistula repair/seton, 1 sphincterotomy and 6 transanal excisions. All patients had multimodality treatment with an anal block and postoperative Tylenol and/or ibuprofen. 90% were prescribed opioids postoperatively with a median of 20 pills (range: 0 – 120 pills). 43% (18/42) did not fill their prescription. For those who used opioids, the median number of pills taken was four. 80% of pills prescribed were not used. One patient required a refill. Greater than 60% of respondents reported good to excellent pain control on a five-point scale.

Conclusion:

There is large variability in the amount of opioids prescribed for patients undergoing outpatient anorectal surgery. When used with a multimodality pain treatment approach, opioids are minimally needed for most patients. We intend to standardize our prescribing opioid quantities for outpatient anorectal operations to reflect this reduced use. 
 

7.08 Coping Strategies Among Colorectal Cancer Patients Undergoing Surgery: A Qualitative Study

Posted on January 18, 2018

J. S. Abelson1, A. Chait2, M. J. Shen3, M. Charlson4, A. Dickerman2, H. L. Yeo1,5  2Weill Cornell Medical College,Psychiatry,New York, NY, USA 3Weill Cornell Medical College,Psychology,New York, NY, USA 4Weill Cornell Medical College,Integrative Medicine,New York, NY, USA 5Weill Cornell Medical College,Healthcare Policy And Research,New York, NY, USA 1Weill Cornell Medical College,Surgery,New York, NY, USA

Introduction: Distress is common among cancer patients and is associated with worse post-operative outcomes. Surgeons are often the first physicians to have in-depth conversations with patients about new diagnoses of colorectal cancer. As a result, it is important for them to understand ways patients cope with their diagnosis in order to offer them support as needed to minimize distress.  However, there are no clear data on how these patients cope with their diagnoses, surgery and recovery.  We performed qualitative in-depth interviews trying to explore their coping mechanisms throughout the surgical experience.

Methods:  Patients diagnosed with colorectal cancer were recruited from an outpatient surgery clinic at a single academic medical center. Purposive sampling was used to recruit both patients who were planning to undergo surgery or had undergone surgery within six months. Validated qualitative methods were used, including in-depth, open-ended, individual interviews; demographic data were also collected. Constant comparative methodology and grounded theory were used to develop themes regarding patients’ coping strategies and beliefs regarding patients’ view of the role of the surgeon in helping them cope. 

Results: A total of 24 patients were interviewed. Most participants were interviewed during the post-operative period (n=15; 62%), were White (n=18; 75%), and had a diagnosis of rectal cancer (n=15; 62%). Three major themes emerged from the data that described how patients with colorectal cancer cope throughout the surgical experience. First, patients cited their own internal coping strategies such as problem-focused, emotion-focused, and meaning-focused techniques. Second, patients cited their social support network including family, friends, and cancer support groups as being helpful. Third, patients believed surgeons and their teams should be involved in helping patients cope with the cancer diagnosis and surgical experience, especially if patients were experiencing high levels of distress or had inadequate coping skills. They did not believe surgeons themselves should be primarily responsible.

Conclusion: This is the first study to evaluate coping strategies used by colorectal cancer patients as they undergo surgical treatment. These findings are important for surgeons to guide initial management of distress in patients with a new diagnosis of colorectal cancer, as mandated by the National Comprehensive Cancer network and the American College of Surgeons Commission on Cancer. Surgeons should screen patients for distress, identify and strengthen a patient’s own coping strategies, facilitate a strong social support network, and provide patients with the option to obtain further support from the surgeon’s office. Future research should evaluate the impact of a comprehensive strategy to enhance coping strategies in colorectal cancer patients undergoing surgery on post-operative outcomes.

 

 

7.07 Primary Tumor Sidedness Differentially Affects Overall Survival for Stage I-IV Colon Adenocarcinoma

Posted on January 18, 2018

J. Watson1, M. Turner1, Z. Sun1, D. Becerra1, J. Migaly1, C. Mantyh1, D. Blazer1  1Duke University Hospital,Department Of General Surgery,Durham, NC, USA

Introduction: Recent studies have observed differences in overall survival and response to chemotherapy in left compared to right-sided colon cancer. This suggests biologic differences within tumor laterality. We evaluated the impact of left compared to right-sided primary tumors on overall survival for patients with stage I-III and stage IV colon cancer in both operative and non-operative cohorts, utilizing a large national cancer database.

Methods: The 2006-2013 National Cancer Data Base was queried for patients with single primary, stage I-IV colon adenocarcinoma. Patients were grouped by stage and tumor location based on embryologic boundaries. Left side was defined as splenic flexure to the sigmoid colon, and right side was defined as cecum to transverse colon. Patients with appendiceal, overlapping, or unspecified tumor locations were excluded. Overall survival was compared using Cox Proportional Hazard modeling while adjusting for demographic, clinical, and tumor characteristics. The analysis was conducted separately for patients who had operative and non-operative management (stage IV) of the primary tumor.

Results: For stage I-II tumors, 114,839 patients underwent resection, 62% for right and 38% for left-sided tumors. After adjustment for patient and tumor characteristics, patients with right-sided tumors had superior survival compared to those with left-sided tumors (HR for left-sided tumors, right-sided reference [HR]: 1.13, p<0.001). For Stage III tumors, 71,024 patients underwent resection (59% right-sided, 41% left-sided tumors). Of 60,788 patients with stage IV tumors, 41,371 (68%) patients underwent resection (57% right-sided, 43% left-sided). For the 19,417 patients with stage IV cancer who did not undergo surgery, 56% were right-sided tumors, and 44% were left-sided tumors. After adjustment for patient and tumor characteristics, left-sided tumors had superior survival compared to right-sided tumors in Stage III tumors, Resected Stage IV tumors, and Unresected  Stage IV Tumors with respective Hazard Ratios of Stage III 0.90, p<0.001, Stage IV Resected HR 0.71, p<0.001, and Stage IV Unresected HR 0.77, p<0.001.

Conclusion: Primary tumor laterality affects overall survival across stages for colon adenocarcinoma. In this analysis, patients with right-sided tumors have superior survival for stage I-II disease. However, left-sided tumors have superior survival in advanced disease, stage III-IV. These results from a large, national cancer database reinforce and extend previous subgroup analyses of large cooperative group trials.  These findings provide investigators better prognostication tools and provide a possible avenue to better understand the molecular mechnisms in patients with colon adenocarcinoma.

7.06 The Effect of State Rurality on Colorectal Cancer Screening and Death Rate

Posted on January 18, 2018

E. Benzer1, S. Tolefree1, C. DeRoche2, Z. Wu1, J. Mitchem1  1University Of Missouri,Department Of Surgery,Columbia, MO, USA 2University Of Missouri,Medical Research Office,Columbia, MO, USA

Introduction:
Colorectal cancer is the second leading cancer killer in the US.  Screening significantly decreases the death rate from colorectal cancer, which has led to standard screening recommendations from multiple professional and government organizations. Despite this well-established data, adherence to colorectal cancer screening is poor. One reason for this may be access to care, as adherence to colorectal screening has previously been shown to be worse in rural populations.  We used a population based data set combined with state level data on rurality to test the effect of rurality on screening and death rate from colorectal cancer.

Methods:
Publicly accessible data was downloaded from the American Cancer Society website compiled from the Center for Disease Control regarding colorectal cancer death rate average from 2010-2014 and Behavioral Risk Factor Surveillance System regarding colorectal cancer screening from 2014. Data regarding rural and urban populations, race, and socioeconomic status was downloaded from the US Census website. Data analysis was performed using SPSS.

Results:
The median percent of population residing in rural and urban areas in each state was 25.8% (0-61.3) and 73.8% (38.6-100), respectively. Median percent of patients screened was 67.6% (58-76), and the median death rate (per 100,000) from colorectal cancer per state was 14.6 (11.3-19.4). To establish that screening correlates with decreased death from colorectal cancer, each state’s percent screened was compared with death rate from colorectal cancer. This demonstrated significant negative correlation (-0.500, p< 0.001). Each state’s percent of population living in rural areas was then compared with death rate from colorectal cancer. This demonstrated a significant positive correlation (0.43, p= 0.002). To test our hypothesis, we then compared percent rural population with screening rate. We found no correlation between rural population and screening rate (-0.153, p=0.29).  There was no difference between males or females. We then performed multivariate linear regression to factors associated with death rate from colorectal cancer. After this analysis, percent rural, percent African-American, and percent screened remained significant (p<0.05).

Conclusion:
State level data from the Behavioral Risk Factor Surveillance System, Center for Disease Control, and the US Census were used to determine whether increased rural population correlates with colorectal cancer death and screening. Both screening rate and state rurality correlate significantly with death rate from colorectal cancer; however, screening and rurality did not correlate. Based on this result, future interventions aimed at rural populations should focus not only on screening, but also what to do after screening results are obtained. Further analysis is warranted to delve deeper into this issue to improve outcomes from colorectal cancer in rural populations.
 

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