95.20 The Effect of Operative Time During Pancreaticoduodenectomy on Length of Stay

Posted on January 31, 2019

S. Parikh1, G. Sugiyama1, C. Choy1, G. Coppa1, P. Chung2,3  1Zucker School of Medicine Hofstra Northwell,Department Of Surgery,Manhasset, NY, USA 2SUNY Downstate Medical Center,Department Of Surgery,Brooklyn, NY, USA 3Coney Island Hospital,Department Of Surgery,Brooklyn, NY, USA

Introduction:
Cancer of the head of the pancreas is an aggressive disease with high rates of mortality. At this time surgical resection via a pancreaticoduodenectomy is the only potentially curative procedure. Although the procedure has in recent times become safer, the role that operative time has on postoperative outcomes is not well defined. Using the American College of Surgeons National Surgical Quality Improvement Program data, we sought to determine the role that operative time might play in length of stay.

Methods:
Using the 2010-2015 ACS NSQIP Participant Use Files (PUF) we identified cases in which pancreaticoduodenectomy was performed (CPT code 48150) in the setting of a postoperative diagnosis of pancreatic cancer (ICD9 code 157.0). We excluded cases that had emergency admissions, intraoperative wound classification of III or IV, and disseminated cancer. Cases with missing preoperative albumin, operative time, and total length of stay (LOS) data were excluded. We also excluded cases that had an operative time <15 minutes, and LOS >30 days. Multiple imputation for missing sex, race, functional status, and ASA classification was performed. Operative time was divided into quartiles (1st Quartile: <292.8 minutes; 2nd Quartile: 292.8 – 373.0 minutes; 3rd Quartile: 373.0 – 465.0 minutes; 4th Quartile: >465.0 minutes). Primary outcome was length of stay, for which negative binomial regression adjusting for age, sex, race, obesity, history of diabetes, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), dyspnea, bleeding disorder, ascites, hypertension, renal failure, dialysis dependent, functional status, smoking status, steroid use, weight loss, preoperative transfusion within 72 hours of surgery, preoperative albumin levels, ASA class, and operative time, was performed.

Results:
3,424 patients that met inclusion/exclusion criteria were identified. Of these, 1,758 (51.3%) were male, majority were White (88.1%), and mean age was 66.1 years. Median LOS was 9.0 (SD 5.4) days. Negative binomial regression showed that presence of bleeding disorder (IRR 1.17, p=0.0035), 4th vs 1st quartile operative time (IRR 1.16, p<0.0001), and history of COPD (IRR 1.10, p=0.022) were associated with increased LOS. Higher preoperative albumin status was associated with decreased LOS (IRR 0.88, p<0.0001).

Conclusion:
We performed a large observational study using a national database. We found that increased operative time, even after adjusting for multiple preoperative and intraoperative risk factors, is independently associated with increased LOS in patients that undergo pancreaticoduodenectomy for pancreatic cancer.  Further prospective studies are warranted to determine whether operative time should be used as a quality metric for patients undergoing pancreaticoduodenectomy.
 

95.19 Outcomes for Pancreaticoduodenectomy for Locally Advanced Right Colon Cancers

Posted on January 31, 2019

L. M. Daniels1, M. Khalili1, N. Grandhi1, A. Thandoni1, F. Burg1, L. Holleran1, E. M. Gleeson1, W. F. Morano1, W. B. Bowne1  1Drexel University College Of Medicine,Surgery,Philadelphia, Pa, USA

Introduction:  

Pancreaticoduodenectomy (PD) in conjunction with a right hemicolectomy (RH) has been performed to treat locally advanced right colon cancers (LARCC). Herein, we characterize clinicopathologic factors and evaluate outcomes of en bloc PD and RH for LARCC.

Methods:  

A systematic review of the world literature was conducted on PubMed using MeSH search terms [“pancreaticoduodenectomy” OR “pancreas/surgery” OR “duodenum/surgery” OR “colectomy”] AND [“colonic neoplasms”]. Data was extracted from patients who specifically underwent an en bloc PD and RH for primary colon cancer. Exclusion criteria included articles not published in English, those from which individual patient data could not be extrapolated, patients without primary colonic malignancy, and those with metastatic disease. Factors investigated included patient presentation, surgical and pathological parameters, postoperative complications, and disease recurrence and survival. Standard statistical tests were used.

Results:

Search yielded 28 articles from 1980-2017 with a cohort of 106 patients, including one case from our institution. Most patients were male (62.1%) with median age 58 years (range 34-83). Surgical procedures performed included en bloc RH with PD (n=91, 85.8%) and en bloc RH with pylorus-preserving pancreaticoduodenectomy (PPDP), (n=15, 14.2%). Median follow up was 21 months. R0 resection was reported in 63 patients. Of patients who experienced one or more complications (n=63, 52.4%), the most common included pancreatic fistula (n=15, 23.8%) and delayed gastric emptying (n=11, 17.5%). Fifty-three patients (50%) reportedly experienced no recurrence, 27 (25.5%) recurred, and 26 (24.5%) cases did not specify. Median recurrence free survival was not met. The average time to recurrence was 18.6 months; 60% of patients were disease free at 5 years. Median survival was 168 months. Survival after resection was 74.1% at 2 years and 63.2% at 5 years (Figure 1). Overall survival was improved with earlier diagnosis (IIC versus IIIC, p<0.005) and younger age at time of resection (<60 versus ≥ 60, p=0.031). Patients with stage IIC had an 84.9% 5 year survival versus 46.4% for patients with stage IIIC. Five year survival for patients <60 years was 70.9% versus 62.9% for patients ≥ 60 years. There were 2 postoperative mortalities.

Conclusion:

These data demonstrate that en bloc PD and RH is rarely performed, yet can be a safe procedure and potential treatment option in patients with LARCC. Patients less than 60 years of age and patients with less advanced disease had significantly improved outcomes. 

95.18 Outcomes of Gastric Resection in the Establishment of a Comprehensive Oncologic Robotic Program

Posted on January 31, 2019

J. T. Balbona1,2, M. Malafa1, S. Dineen1, R. Mehta1, J. M. Pimiento1  1Moffitt Cancer Center And Research Institute,Gastrointestinal Oncology,Tampa, FL, USA 2University Of South Florida College Of Medicine,Tampa, FL, USA

Introduction:
Robotic-assisted gastrectomy is increasingly utilized for the treatment of gastric malignancies. While minimally-invasive laparoscopic surgery has shown many advantages over open gastrectomy, the benefits of robotic surgery have been less defined. This study aims to describe short and long-term outcomes associated with the establishment of comprehensive robotic program for gastric malignancies.

Methods:
Data from 46 patients who underwent robotic-assisted gastric resections at Moffitt Cancer Center between April 2013 and May 2018 were retrospectively examined. Pre-operative measures as well as short and long-term outcomes were analyzed using descriptive statistics. A subgroup analysis of outcomes was conducted to evaluate the different surgical procedures performed in patients with gastric adenocarcinoma (GC).

Results:
This cohort consisted of 46 patients (pts.), 26 (56.5%) males, a median of 64 years (range: 29-87). Pathology included GC (70%), GIST (11%), neuroendocrine tumors (7%), metastatic lesions (2%), and benign processes (7%). 19 pts. underwent total gastrectomy, 16 distal gastrectomy, 4 subtotal gastrectomy and 7 wedge resection. As expected, distal gastrectomy (237.5 ± 71, p < 0.001) and wedge resection (126 ± 90, p < 0.001) had significantly shorter operative times than total gastrectomy (394 ± 110). Moreover, operative time in total gastrectomy decreased approximately 1h from the first half of GC cases to the latter half (426 ± 115 vs. 340 ± 92; p = 0.06). Overall, there was a median estimated intraoperative blood loss of 100 mL (range: 20-400). Post-operative length of stay (LOS) was shorter after distal (5 ± 1.5, p < 0.001), subtotal (6 ± 1.7, p < 0.001), and wedge gastrectomy (3 ± 2.2, p < 0.001) than after total gastrectomy (10 ± 4.7). 8.8% (4) of operations were converted to open and 28.2% (13) of pts. had post-operative complications, 8.7% (4) requiring readmission. The incidence of post-operative anastomotic leak, pneumonia, and ileus were 6.5% (3), 8.7% (4), and 10.9% (5), respectively. For pts. with GC, 69% received neoadjuvant therapy. The median lymph nodes removed were 20 (range: 14-46), 25.5 (range: 25-26) and 17 (range: 9-34) during total, subtotal and distal gastrectomy, respectively. All pts. underwent margin negative resection. The median follow-up for GC was 18m, and 60% of pts. received adjuvant therapy at a median of 59d (range: 23-106). GC recurred in 21% of pts.

Conclusion:
Our experience highlights the versatility of the robotic platform to tackle multiple pathologic diagnoses requiring oncologic total gastrectomies, from GIST, to metastatic disease, to adenocarcinoma. Our results compare adequately with previous series from our institution and are a good starting point to establish benchmarks to improve short and long-term outcomes, especially in relation to LOS and time to initiation of therapy.
 

95.17 Sarcopenia is Predictive of Negative Outcomes in Gastrointestinal Cancer Patients Undergoing Surgery

Posted on January 31, 2019

C. S. Lau1, R. S. Chamberlain1,2  1Abrazo Central Hospital, Abrazo Community Health Network,Phoenix, AZ, USA 2Cancer Surgical Services Division, Valley Surgical Clinics,Phoenix, AZ, USA

Introduction: Sarcopenia is the progressive loss of skeletal muscle mass and strength and has long been accepted as an age related process. Sarcopenia is also frequently observed among cancer patients and has been reported to affect as many as 57.7% of gastrointestinal (GI) cancer patients. This meta-analysis examines the impact of sarcopenia on surgical outcomes in GI cancer patients. 

Methods:  A comprehensive literature search of all published studies evaluating the impact of sarcopenia on GI cancer patients undergoing surgery was conducted using PubMed, Cochrane Central Registries of Controlled Trials, and Google Scholar. Keywords searched included combinations of ‘sarcopenia’, ‘gastrointestinal’, ‘gastric’, ‘colorectal’, ‘hepatic’, ‘pancreatic’, ‘cancer’, ‘surgery’, and ‘outcomes’. Outcomes analyzed included total complications, major complications (Clavien-Dindo grade ≥3), in-hospital/30-day mortality, 30-day readmission rates, length of stay, and hospital costs.

Results: Fifty studies including 14,531 patients (4,774 sarcopenia and 9,757 no sarcopenia) were analyzed. Patients with sarcopenia were 1.619 times more likely to develop complications (OR 1.619; 95% CI, 1.340-1.956; p<0.001), and 1.536 times more likely to develop major complications (Clavien-Dindo grade ≥3) (OR 1.536; 95% CI, 1.289-1.830; p<0.001) compared to those without sarcopenia. Sarcopenia was also associated with higher rates of mortality (OR 1.558; 95% CI, 1.145-2.120; p=0.005), 30-day readmissions (OR 1.425; 95% CI, 1.061-1.915, p=0.019) and longer lengths of stay (MD 1.450 days; 95% CI, 0.816-2.083; p<0.001). Total hospital costs were significantly higher among those with sarcopenia (MD = $1,478.85 USD; 95% CI, $106.21 – 2,851.49; p=0.035). Although poorer outcomes were seen among all types of cancers (gastric, colorectal, hepato-pancreatic), differences between sarcopenic and non-sarcopenic groups were greatest among those with gastric cancer.

Conclusion: Sarcopenia is associated with a significant increase in total complications, major complications, mortality, 30-day readmissions, length of stay, and hospital costs. Sarcopenia is a poor prognostic factor in GI cancer patients undergoing surgery, and preoperative muscle mass assessments may have significant value in predicting and improving patient outcomes.

 

95.16 Melanoma Patients Deficient in Vitamin D Exhibit Advanced Stage Disease

Posted on January 31, 2019

Z. L. Gentry2, E. Pruitt3, J. K. Kirklin3,4, C. Contreras1, T. Wang1  1University Of Alabama at Birmingham,Division Of Surgical Oncology,Birmingham, Alabama, USA 2University Of Alabama at Birmingham,School Of Medicine,Birmingham, Alabama, USA 3University Of Alabama at Birmingham,Kirklin Institute For Research In Surgical Outcomes,Birmingham, Alabama, USA 4University Of Alabama at Birmingham,Division Of Cardiothoracic Surgery,Birmingham, Alabama, USA

Introduction: The cumulative effect of sun exposure on melanoma risk is highly complex and difficult to predict. Although intermittent sun exposure sufficient to cause burning is a major risk factor for the development of melanoma, regular sun exposure may be protective due to the consequent higher levels of vitamin D. Multiple studies have confirmed that vitamin D induces growth arrest, triggers cell death and promotes differentiation of cancer cells. Higher levels of vitamin D correlate with better survival of patients with breast, colon, and prostate cancer. We hypothesize that melanoma patients with lower vitamin D levels exhibit more advanced stage disease than patients with normal vitamin D levels.

Methods: A database of 497 patients from a single institution treated for melanoma from 2010-2017 was retrospectively reviewed. Serum 25-hydroxyvitamin D levels were measured in 129 patients at a time near their diagnosis. Patients were categorized as Low VD if their 25-hydroxyvitamin D levels were <30 ng/ml and Normal VD if their 25-hydroxyvitamin D levels were >30 ng/ml. Patient vitamin D assessment categories were then compared to their melanoma stage at diagnosis. Each patient’s melanoma was categorized as Early Stage or Late Stage based on their AJCC classification. Early Stage was defined as local disease (stages 0, I, II). Late Stage was defined as lymph node and distant metastatic disease (stages III and IV). Chi-squared analysis was used to determine the association between the categorical variables. Medians with interquartile ranges were calculated for vitamin D levels and compared by Wilcoxon rank sum test.

Results: There were 63 Low VD patients and 66 Normal VD patients. Low VD patients were more likely to present with Late Stage disease than Normal VD patients (27.0% vs. 10.6%, p=0.02). The median 25-hydroxyvitamin D level of Early Stage melanoma patients was significantly higher than Late Stage melanoma patients (30.1 and 25.4 ng/ml, respectively; p=0.02).

Conclusion: Melanoma patients deficient in vitamin D exhibit more advanced disease when compared to melanoma patients with normal vitamin D levels. Sun exposure may confer a protective advantage against melanoma by increasing levels of vitamin D necessary for inhibiting cancer progression. Further research to elucidate the inhibitory effects of vitamin D in carcinogenesis will provide more effective means of prevention and treatment of melanoma.

95.15 Neutrophil to Lymphocyte Ratio in Thick Melanoma Is Not Predictive of Recurrence

Posted on January 31, 2019

J. T. Cohen1, A. Blakely1, D. Comissiong1, M. Vezeridis1, T. J. Miner1  1Brown University School Of Medicine,Department Of Surgery,Providence, RI, USA

Introduction:

Serum neutrophil-to-lymphocyte ratio (NLR) has recently gained increasing attention as a readily available biomarker, providing prognostic information in various malignancies including melanoma, breast cancer, non-small cell lung cancer, and hepatocellular carcinoma. An elevated NLR has been demonstrated to be a poor prognostic marker in stage I-II melanoma and high-risk non-metastatic melanoma. In metastatic melanoma, high NLR may predict disease responsiveness to anti-PD-1 immunotherapy. Here, we investigate the NLR in thick melanoma (≥4 mm), in an attempt to elucidate the role of NLR as a marker of immunologic privilege.

Methods:

This is a retrospective review of all patients who underwent wide local excision of melanoma between June 2005 and December 2016 at a single tertiary academic medical center. Patients with thick melanoma (≥4 mm) were selected for analysis. NLR was calculated for patients who had a complete blood count with differential following diagnosis of melanoma but prior to excision. Patients were excluded if they had leukocytosis, neutrophilia, or lymphopenia. A high NLR was defined as >3, as has been described in the literature for high-risk non-metastatic melanoma.

Results:

Of 1,714 patients, 103 (6%) were identified as having thick melanoma. Of these, 39 patients had available laboratory data meeting the inclusion criteria. Fourteen of 39 (35.9%) had High NLR (>3), while 25 of 39 (63.1%) had Low NLR (≤3). The mean NLR in the High group was significantly elevated compared to the Low group (4.83 vs. 2.08 p < 0.0001).  There was no significant difference in patient gender, age, location of tumor, tumor thickness, mitotic rate, or positivity of SLNB between the two groups.  Median follow up time was 503 days, which did not vary significantly between the cohorts. Margins of excision were <2 cm in 3 patients, all of whom were in the High group. There was no significant difference in number of SLNBs performed. In both univariate and multivariate analysis, NLR was not predictive of overall recurrence, recurrence type, wound complications, or lymphovascular invasion. Median time to recurrence was not significantly different (p=0.2) in the Low group compared with the High (260 vs 174 days).

Conclusion:

NLR is an important prognostic marker in a variety of patients with both local and metastatic melanoma. This may represent an environment in which neutrophils enriched with PD-L1 down-regulate cytotoxic lymphocytes, providing an optimal environment for melanoma cell survival and ultimately recurrence or metastasis. 

In this scenario, a high NLR serves as a marker for the degree of immunologic privilege afforded to the melanoma cell at the time of excision. Here we demonstrate NLR is not predictive of recurrence in thick melanoma, which is consistent with aggressiveness of the tumor and suggests that thick melanoma may not require the same degree of immunologic privilege to recur.  

95.14 Implementation of Robotic Surgery into a Complex General Surgical Oncology Practice

Posted on January 31, 2019

M. Tsao1, M. Alvarez1, P. Dickson1, E. Glazer1, R. S. Daugherty1, J. Deneve1  1Univeristy Of Tennessee Health Science Center,Surgical Oncology,Memphis, TN, USA

Introduction:

Minimally invasive surgery has reduced hospital length of stay (LOS) with low morbidity and equivalent oncologic outcomes to open surgery. Robotic surgery (RS) is increasingly used as a minimally invasive approach for complex gastrointestinal operations. We examined our early experience with RS in a complex general surgical oncology practice.

Methods:
Retrospective review of patients undergoing RS was performed. Patient characteristics, operative details, pathology data, and short-term postoperative outcomes were analysed.

Results:
One-hundred and three robotic procedures were performed for gastric (N=28), rectal (N=18), colon (N=19), gallbladder (N=13), pancreas (N=8), liver (N=6), adrenal (N=4), duodenal (N=3) and other pathology (N=4).  Median patient age was 60 years, average BMI was 29.2 and 28% had prior laparotomy.  Indications for resection were for malignant (64%) and benign (36%) pathology. Overall median operative time was 229 minutes (72-582), median blood loss was 50 mL (5-2500) and 4% of patients required transfusion.  Operative time was significantly longer for rectal procedures than gastric or colon procedures (348 vs 218 vs 229 minutes, p<0.001, respectively).  Conversion to laparotomy was necessary in 15% (N=16), most commonly for difficulty with visualization (N=5) or failure to progress (N=4).  The median hospital LOS was 5 days (0-20 days) and hospital re-admission was required in 12%.  A complication occurred in 28% with a major complication in 12% and no 30-day mortality.  Short-term oncologic outcomes for malignant gastric and colorectal procedures revealed R0 resection for all cases aside from an R1 resection in a gastric gastrointestinal stromal tumor, and median gastric lymph node harvest was 15 while median colon and rectal lymph node harvest were 20 and 14 respectively.

Conclusion:
RS use in a complex general surgical oncology practice with heterogeneous pathology and operative indications was feasible and safe with acceptable morbidity and short-term oncologic outcomes.  Operative time, conversion and technical proficiency learning curves will likely improve with additional RS experience.

95.13 CRS/HIPEC in the palliative treatment of peritoneal carcinomatosis: a single institution experience

Posted on January 31, 2019

E. A. Strong1, M. V. Hembrook1, S. Tsai1, K. K. Christians1, H. D. Mogal1, T. C. Gamblin1, C. N. Callisia1  1Medical College of Wisconsin,Surgical Oncology,Milwaukee, WI, USA

Introduction:  Palliation is a controversial indication for cytoreductive surgery (CRS) and hyperthermic intraperitoenal chemotherapy (HIPEC) in patients with peritoneal carcinomatosis (PC). However, with more effective systemic therapies, patients with metastatic disease are living longer and the role of palliative surgery is increasingly challenged. The purpose of this study is to evaluate the indications for surgery, morbidity, and symptom improvement from CRS/HIPEC in patients with advanced PC.  

Methods:  We performed a retrospective review of a prospectively maintained clinical registry of patients undergoing CRS/HIPEC at the Medical College of Wisconsin from February 2008 to February 2018. Patient undergoing surgeries with palliative intent were included in this study. Indications for surgery, clinical and pathological factors, operative details, and postoperative course were analyzed. Main endpoints included symptom improvement, discharge to home, progression-free (PFS), and overall survival (OS).   

Results: 277 patients were referred for CRS/HIPEC at our institution over this 10-year period. 18 patients underwent 19 procedures with palliative intent. 10 patients (56%) were female, 8 (44%) were male with a median age at surgery of 57 years (IQR:7).  All patients had an ASA class of 3 (68%) or 4 (32%).  Metastatic colorectal cancer was the most common malignancy treated [n=7 (39%)], followed by appendiceal cancer [n=6 (33%)], peritoneal mesothelioma [n=3 (17%)], gastric cancer [n=1 (6%)], and sarcoma [n=1 (6%)]. At time of surgery, 4 (21%) patients had an ECOG performance status of 0, 11 (58%) ECOG of 1, 3 (16%) ECOG of 2, and 1 (5%) ECOG of 3. Median preoperative serum albumin and prealbumin levels were 3.3 g/dL (IQR:0.6) and 13 mg/dL (IQR:7.5). Indications for palliative surgery were ascites 8 (42%), obstruction 5 (26%), abdominal pain 4 (21%), GI bleed 1 (5%), and other 1 (5%). 5 (26%) patients required preoperative admission for nutritional optimization. 9 (47%) patients underwent CRS and HIPEC, 1 (5%) underwent HIPEC only, 9 (47%) underwent CRS only. 30-day mortality was n=2 (10.5%). 11 (58%) patients had postoperative complications; 6 (32%) minor (Clavien I/II) and 5 (26%) major (Clavien ≥III) complications. Median hospital LOS was 11 days (IQR=12). 30-day readmission rate was 10.5%. 2 patients (11%) were discharged to hospice and subsequently died from their disease. 1 (5%) patient was discharged to a skilled nursing facility, the remaining 16 (84%) were discharged home. 17 (89%) had at least partial of symptom improvement at 30 postoperative days. Median PFS was 2.9 months (IQR:5.6), and median OS was 8.2 months (IQR:12).

Conclusion: Palliative CRS and/or HIPEC achieves adequate symptom palliation in patients with advanced peritoneal carcinomatosis. However, these interventions are associated with high morbidity and mortality.

 

95.12 Complications of Gastrectomy with Cytoreductive Surgery – Hyperthermic Intraperitoneal Chemotherapy

Posted on January 31, 2019

A. Z. Paredes1, F. A. Guzman-Pruneda1, S. Abdel-Misih1, J. Hays2, M. E. Dillhoff1, T. M. Pawlik1, J. M. Cloyd1  1Ohio State University,Department Of Surgery, Division Of Surgical Oncology,Columbus, OH, USA 2Ohio State University,Department Of Internal Medicine, Division Of Medical Oncology,Columbus, OH, USA

Introduction: Formal gastrectomy, at times, is required in order to achieve complete cytoreduction for patients with peritoneal surface malignancies. In addition, the role of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with gastric cancer is increasingly being explored. Nevertheless, data on the safety of gastrectomy at the time of CRS-HIPEC is limited.

Methods:  The ACS-NSQIP databases from 2005-2016 were used to identify patients who underwent CRS-HIPEC. Demographic, clinical, and perioperative outcomes were compared between patients who underwent CRS-HIPEC with and without gastrectomy.

Results: Among 1,168 patients who underwent CRS-HIPEC, 43 (4%) underwent partial (n=20) or total (n=23) gastrectomy. Patients who underwent gastrectomy at the time of CRS-HIPEC had a longer operative time (529.3 vs, 457.6 min, P=0.004), were more likely to need an intraoperative transfusion (32.6% vs. 14.3%, P=0.001), experienced a longer length of stay (19.0 vs. 11.3d, P<0.001), and had a significantly greater complication rate (60.5% vs. 27.9%, P<0.001) whereas postoperative mortality was not statistically significantly different (4.7% vs. 1.4%, P=0.09). On multivariate logistic regression, gastrectomy (OR 3.52, P<0.001) was the strongest predictor of postoperative morbidity, in addition to ASA class 4 (OR 2.82, P=0.001), malnutrition (OR 1.63, P=0.01), liver resection (OR 1.88, P=0.01) and colectomy (OR 2.04, P<0.001).

Conclusion: Patients undergoing gastrectomy at the time of CRS-HIPEC experience a substantial postoperative complication rate (60%) and extended length of stay (mean 19 days). These findings highlight the need for cautious patient selection and preoperative counseling prior to performing concomitant gastrectomy and CRS-HIPEC. Future clinical trials investigating the role of HIPEC for gastric cancer should continue to stringently evaluate short-term morbidity in addition to long-term oncologic outcomes.

95.11 Liquid Biopsy, Histopathology, and Outcomes in Mutation(-) versus Mutation(+) Lung Cancer Patients

Posted on January 31, 2019

S. Zhang2, T. Boyle1,2, C. Williams1,2, S. Antonia1,2, A. Chiappori1,2, J. Gray1,2, T. Tanvetyanon1,2, B. Creelan1,2, E. Haura1,2, M. Shafique1,2, J. Fontaine1,2, J. Cox1,2, F. Kaszuba1,2, R. Keenan1,2, V. Nair1,2, E. Toloza1,2  1Moffitt Cancer Center And Research Institute,Tampa, FL, USA 2University Of South Florida College Of Medicine,Tampa, FL, USA

Introduction:   Liquid biopsy of peripheral blood circulating tumor DNA (ctDNA) and protein can capture genetic and proteomic data that represents the molecular state of tumors.  We sought to investigate whether liquid biopsy can correlate histopathologic factors, treatment, or outcomes with ctDNA mutations and proteomic signatures.

Methods:   We retrospectively analyzed data from all non-small cell lung cancer (NSCLC) patients who underwent liquid biopsy analysis of ctDNA and proteins on peripheral blood samples from August 2016 to June 2018.  The ctDNA analysis detected presence of targetable mutations, and proteomic analysis grouped patients into Good or Poor status.  Patients with proteomic Poor were excluded.  Liquid biopsy results were then correlated with histopathologic factors, such as tumor histology, grade of differentiation, tumor (T) status, nodal (N) status, metastasis (M) status, pathologic stage (pStage), and treatment.  Student’s t-test, Kruskal-Wallis test, or Chi-square test were used to compare these factors between groups, and Kaplan-Meier curves were used to compare survival.  Statistical differences were significant at p≤0.05.

Results:  Of 522 patients analyzed by liquid biopsy, 62 (11.9%) proteomic-Poor patients were excluded.  Of 460 (88.1%) proteomic-Good patients, 376 (81.7%) were mutation-negative [mutation(-)], and 84 (18.3%) were mutation-positive [mutation(+)].  Mean age were similar between mutation(-) and mutation(+) groups (83.4 yr vs. 67.5 yr; p=0.462).  Mean primary tumor size differed between mutation(-) and mutation(+) groups (3.0 cm vs. 4.7 cm; p=0.002).  Histology (i.e. adenocarcinoma, squamous cell carcinoma, neuroendocrine carcinoma, etc.) differed between the two groups, with mutation(-) patients having proportionately more squamous histology (p<0.01).  Tumor grade of differentiation, N status, M status, and pStage differed between mutation(-) and mutation(+) groups, with the mutation(+) group having more patients with poorly-differentiated (G3) tumors (p<0.01), N2 and N3 status (p<0.01), M1 status (p<0.01), and pStage III and IV cancers (p< 0.01).  Treatment differed between mutation(-) and mutation(+) groups, with the mutation(-) group more likely to have surgery or radiation and the mutation(+) group more likely to receive systemic therapy (p<0.01).  In Kaplan-Meier survival analysis, the mutation(-) group had 1-year overall survival (1-yr OS) of 88.5% compared to a 1-yr OS of 45.2% for the mutation(+) group (p<0.01).

Conclusion:  A commercially-available peripheral blood liquid biopsy kit identified NSCLC patients as mutation(-) or mutation(+) by ctDNA analysis and as Good status by proteomic analysis.  While age did not correlate with mutation status, mutation(+) patients had larger tumors, more poorly-differentiated tumors, more N2 and N3 status, more distant metastases, and higher pStaged cancers, required systemic therapy more often, and had worse 1-yr OS than mutation(-) patients.

95.10 Impact of AJCC Staging Changes Among Racial and Ethnic Groups Undergoing Surgery for Gastric Cancer

Posted on January 31, 2019

S. Paul1, S. C. Wang1, M. R. Porembka1  1University Of Texas Southwestern Medical Center,Dallas, TX, USA

Introduction: Gastric cancer is a heterogeneous disease with variable presentation and outcome based on histologic subtype and race. A recent revision to the American Joint Committee on Cancer (AJCC) staging classification for gastric cancer introduced increased subclassification based on the degree of nodal involvement.  The impact of race on the prognostic ability of the various staging systems has not been assessed.

Methods:  Using the National Cancer Database, we selected patients with gastric adenocarcinoma who underwent upfront surgery between 2006 and 2013 and extracted clinicopathologic data. Stage was assigned in accordance with the 7th and 8th editions of the AJCC pTNM staging systems. Race was classified into Non-Hispanic Whites (NHW), Hispanic (HS), African American (AA) and Asian (AS). Overall survival was estimated using the Kaplan–Meier method and compared using log-rank tests. Multivariable Cox regression was used to estimate factors associated with survival and chi-square analysis was performed to determine effect of race on staging.

Results: We identified 15641 patients. Median age was 67 years (IQR: 57-76) and 60% were male. There were 8970 NHW (57%), 1987 HS (13%), 3153 AA (20%), and 1531 AS (10%) patients. AS patients had significantly more lymph nodes examined (median lymph nodes: AS 17, WNH 14, HS 15, AA 14; p<0.05). The 7th edition system discriminated well between stages, but was not prognostic for Hispanic patients with Stage 3 disease (log-rank p=0.16). Migration between stages was similar between races (2B +1.5%, 3A +4.4%, 3B -3.2%, 3C -2.2%; p>0.05).  Discrimination was improved among all races and stages, including Hispanic patients with Stage 3 disease (p<0.001). Adequate lymph node harvest improved the accuracy of both staging systems; however, only the 8th edition was able to discern HS patients with Stage 3 disease.

Conclusion: In a retrospective study of patients undergoing upfront resection for gastric cancer, classification of patients under the 8th edition AJCC staging resulted in better discernment and separation of staging groups among racial groups.

 

95.09 Incidence and Long-Term Outcomes of Patients Requiring Early Reoperation Following HIPEC

Posted on January 31, 2019

T. C. Lee1, M. C. Morris1, L. K. Winer1, K. Wima1, J. Sussman1, S. Ahmad1, S. H. Patel1  1University Of Cincinnati,Surgery,Cincinnati, OH, USA

Introduction:  Hyperthermic intraperitoneal chemotherapy (HIPEC) remains a formidable operation associated with considerable morbidity.  It is unclear how often these patients require reoperation for post-operative complications and if the need for reoperations leads to worse long-term outcomes.

Methods: The Peritoneal Malignancy Database at a single center in the U.S. was retrospectively queried. Out of 149 entries, 141 HIPECs performed between 2012-2018 met the inclusion criteria. Patient and tumor factors were studied using univariate analyses. Reoperation details were studied on an individual case level. Recurrence data was calculated for patients with completeness of cytoreduction of 0. Overall survival analysis was also performed.

Results: There were 15 reoperations after 141 HIPECs (10.6%). Median number of days after HIPEC to reoperation was 18. Reasons for reoperation included intra-abdominal infection (n=5), bowel obstruction (n=4), wound infection (n=3), bleeding (n=2), evisceration (n=1). There were no identified patient or tumor related risk factors for reoperation, including neoadjuvant chemotherapy, prior abdominal surgery, length of surgery, peritoneal cancer index, completeness of cytoreduction, number of anastomoses, primary tumor origin, or grade of tumor. Reoperations were associated with longer hospital length of stay (19 days vs 9 days, p=0.005) and 30-day readmissions (46.7% vs 12.8%, p=0.003). There was no significant difference in recurrence rate (13.3% vs 34.9%, p=0.14) or in 3-year recurrence free survival (95.1% vs 90.0%, p=0.77), but there was a significant difference in 3-year overall survival (97.5% vs 84.4%, p=0.03).

Conclusion: These data demonstrate, for the first time, that complications requiring reoperation are more common after HIPEC than other major abdominal surgeries. These complications lead to increased short-term morbidity, longer hospital length of stay and most importantly reduced overall survival.
 

95.08 Neutrophil-Lymphocyte Ratio is associated with post-opeartive readmissions and overall survival

Posted on January 31, 2019

P. Bou-Samra1, M. Axline1, C. Shen1, A. Tsung1  1University Of Pittsburg,Hepatobiliary And Pancreatic Surgery,Pittsburgh, PA, USA

Introduction: Post-operative complications and the surgical stress are inductive to inflammation, that has been shown to affect outcomes. The Neutrophil-Lymphocyte Ratio (NLR) is a surrogate of perioperative inflammation. Given the potential advantage of an early intervention whenever patients have an elevated NLR, this study aims to evaluate the impact of postoperative NLR on 30-day and 90-day readmissions, and survival in that cohort.

Methods:  Patients who underwent liver tumor resection for metastatic CRC at the UPMC Liver Cancer Center between the year 2011-2015 were evaluated. The absolute neutrophil and lymphocyte counts for patients for several post-operative days (POD) were extracted from their charts and used to calculate the NLR. It was analyzed for an association with 30-day and 90-day readmissions by using the multivariate logistic analysis and for overall survival using the Cox proportional-hazards regression analysis.

Results: 262 patients were included in our study. 126 (48.09%) patients were readmitted within 30-days and 245 (93.50%) patients within 90-days. POD 5 NLR was correlated with 30-day readmission (OR:1.07; 95%CI 1.00-1.14; p=0.047). POD 3 NLR was correlated with 90-day readmission (OR: 1.06; 95% CI 1.00-1.12; p=0.04). POD 0 NLR was correlated with survival (HR: 1.102; 95%CI 1.00-1.034; p=0.012).

Conclusion: Post-operative NLR is correlated with an increased 30-day and 90-day readmission and a poorer long-term survival after surgery for metastatic CRC. Having a high NLR postoperatively could be predictive of post-operative outcomes and instigate preventative interventions. 

 

 

95.07 Is There a Role for PET/CT in High-risk Stage II Melanoma Patients?

Posted on January 31, 2019

C. T. Mayemura1, S. O’Brien1, E. A. O’Halloran1, G. Gauvin1, E. E. McGillivray1, K. Liang1, K. Loo1, A. J. Olszanski2, S. Movva2, B. Luo5, H. Wu4, J. Q. Yu3, S. Reddy1, J. M. Farma1  1Fox Chase Cancer Center,Department Of Surgical Oncology,Philadelphia, PA, USA 2Fox Chase Cancer Center,Department Of Hematology/Oncology,Philadelphia, PA, USA 3Fox Chase Cancer Center,Department Of Diagnostic Imaging,Philadelphia, PA, USA 4Fox Chase Cancer Center,Department Of Pathology,Philadelphia, PA, USA 5Fox Chase Cancer Center,Molecular Diagnostics Laboratory,Philadelphia, PA, USA

Introduction:  While current guidelines do not recommend the use of PET/CT scans in the initial evaluation of stage 1 and 2 melanoma, recent studies have shown that in certain subsets of cases, preoperative PET/CT may be beneficial. We report our experience with high-risk stage II melanoma patients who underwent PET/CT prior to surgery and their clinical outcomes.

Methods: Using our prospectively maintained melanoma database at our tertiary referral center, we identified and selected clinically staged II patients who underwent preoperative PET/CT between 2004 and 2018. We specifically evaluated any change in their treatment course, defined as any additional biopsy, imaging, consult, or change in surgical planning. We calculated the average time from diagnosis (initial biopsy date) to surgery, between those who underwent PET and those who did not to look for any associated delay, compared by unpaired t-test.

Results: Of 290 stage II melanoma patients, 106 patient received preoperative PET scans. Of these, 63% were male, and were stage IIA (N=30), stage IIB (N=43), and stage IIC (N=33). The median age was 71.5 years, median tumor thickness was 3.5 mm, median mitotic rate was 6 (per mm2), and 62 were ulcerated. Twenty-three patients (22%) had a change in treatment. In 12 patients, the PET was concerning for metastatic melanoma: 7 underwent additional biopsies (1 positive for metastatic melanoma to the femur, 2 for lymphoma, 1 for recurrent Merkel Cell carcinoma, and 3 false positives), 1 had an additional lymph node basin dissection, and 4 underwent lymph node dissection instead of sentinel lymph node biopsy after positive biopsy for metastatic melanoma of PET positive lymph node. In total, of these 12, 5 were confirmed to have advanced melanoma, and 3 went on to systemic therapy. Eleven cases had incidental findings: 3 had additional consults (2 urology, 1 gastroenterology), 3 underwent colonoscopy, 2 had additional imaging (1 led to diagnosis of squamous cell carcinoma of the lungs), and 3 had thyroid evaluation (1 positive for papillary thyroid carcinoma). The average time from diagnosis to surgery for the patients who underwent PET was 48.89 days, and 34.30 days for those without PET (p=0.019).

Conclusion: Approximately one in five patients (22%) with high risk stage 2 melanoma who had a preoperative PET scan had their treatment course changed, although this was associated with a clinically non-significant 14-day delay from diagnosis to surgery. However, fourteen of the positive PET findings ended up being unrelated to melanoma and 26% (N=6) changed melanoma specific management. A second cancer was discovered in 5 patients. These findings are important and further larger studies in this specific group are warranted.
 

95.06 Variability in Chemotherapy Use for Metastatic Low Grade Mucinous Appendiceal Adenocarcinoma

Posted on January 31, 2019

P. Lu1,2, G. Shabat1,3, A. C. Fields1, R. Bleday1, J. Goldberg1, N. Melnitchouk1,2  1Brigham And Women’s Hospital,Department Of Surgery,Boston, MA, USA 2Center for Surgery and Public Health,Brigham And Women’s Hospital,Boston, MA, USA 3Ivano-Frankivsk National Medical University,Department Of Surgery,Ivano-Frankivsk, IVANO-FRANKIVSK, Ukraine

Introduction: Appendiceal cancer is a rare malignancy that exhibits a wide range of histology and treatment response.  Studies have suggested that while cytoreductive surgery with intraperitoneal chemotherapy can improve survival, there is little efficacy in systemic chemotherapy use for metastatic mucinous appendiceal adenocarcinoma with low grade histology. It is posited that the indolent, slow growing nature of low grade disease diminishes the effect of cell cycle based systemic chemotherapy regimens.  No guidelines currently exist for treatment of appendiceal cancers. Despite lack of evidence, the use of systemic chemotherapy in low grade metastatic mucinous appendiceal adenocarcinoma continues to vary. We evaluated the treatment of patients with metastatic low grade mucinous appendiceal adenocarcinoma at two large cancer referral centers.

Methods:  Patients diagnosed with metastatic low grade mucinous adenocarcinoma at two cancer referral centers between the years 2000 and 2017 were identified. Chart review was performed and information regarding patient demographics, cancer specific details, perioperative outcomes, and treatment histories were collected, and descriptive statistics were performed

Results: 94 patients had mucinous, histologically low grade, stage IV appendiceal adenocarcinoma. Of these patients, a total of 93.6% of patients underwent at least 1 surgery for cytoreduction, and 51.1% of patients successfully completed hyperthermic intraperitoneal chemotherapy. 6.4% of patients underwent systemic chemotherapy treatment prior to surgery- the regimens included FOLFOX, Capecitabine, or combination. After surgery, a large subset of patients underwent additional chemotherapy. Many of them went on to receive multiple different lines of systemic treatment and experienced a wide range of chemotherapy related complications including neuropathy, fatigue, gastrointestinal distress, and neutropenia (Table 1). Chemotherapy treatments were highly variable as well. The most frequently used regimens were CAPOX, FOLFOX, or 5FU regimens with or without Bevacizumab.

Conclusion: Despite lack of evidence supporting the use of systemic chemotherapy in treatment of metastatic low grade mucinous appendiceal adenocarcinoma, a large proportion of patients received variable systemic chemotherapy regimens and experienced related adverse effects.

 

95.05 Feasibility of a Randomized Trial of Appropriate Margins for Intermediate Thickness Melanoma

Posted on January 31, 2019

D. Nold1, J. M. Mammen1  1University Of Kansas,Surgery,Kansas City, KS, USA

Introduction:

The primary treatment of localized malignant melanoma is wide local excision in which a predetermined margin of skin and subcutaneous tissue is removed around the pigmented lesion. The margins for thin (1mm or less) and thick (greater than 2mm) melanoma are well known and validated. The standard of care margin for intermediate thickness (1.01mm to 2mm Breslow thickness) melanomas by NCCN and other treatment guidelines is 1cm or 2cm. While retrospective studies have attempted to settle the issue of margins for intermediate thickness melanomas, no randomized clinical trial is available for guidance. Currently, the MelmarT clinical trial is accruing patients in New Zealand and Australia and is scheduled to complete accrual in 2029 with a total of 400 subjects planned. The authors have started an clinical trial to determine the feasibility of randomizing eligible melanoma patients in the United States

Methods:
Institutional Review Board permission was obtained for a feasibility trial that randomizes 1:1 eligible intermediate thickness (1.01mm to 2mm Breslow thickness) melanoma patients to 1cm or 2cm margins. Total accrual goal for this 2 year study is 60 patients. Exclusion criteria include location of the melanoma (head and neck, hands, feet), residual pigmentation suggesting additional thickness, and a positive deep margin.

Results:
The "Pilot Study of 1cm versus 2cm Margins for the Surgical Treatment of cT2N0M0 Melanoma" was opened at the University of Kansas on January 30, 2017. All eligible patients who presented to the Melanoma Surgical Oncology clinic were evaluated for this trial. A total of 146 new localized melanoma patients were seen from January 30, 2017 to October 30, 2017. During that time period, 41 (28%) of the new patients had cT2N0M0 melanomas. Of that group, 12 (29.2%) of the patients had melanomas at sites excluded by the study. Ultimately, 9 patients enrolled in the study during this time period (one enrollee monthly on average). A variety of patient preferences and physician preferences (for example, avoiding a skin graft in locations like the distal anterior leg) led to additional eligible patients not enrolling.

Conclusion:
A clinical trial to randomize intermediate thickness melanoma patients to 1cm or 2cm margins appears to be feasible in the United States. Currently, a single institution feasibility trial is accruing one patient monthly, though two additional patients monthly appear to be eligible
 

95.03 Merkel Cell Carcinoma Outcomes in Three Distinct Immunosuppressed Groups

Posted on January 31, 2019

C. Contreras1, T. N. Canavan2, E. Malone1, J. Richman1, R. Pearlman1, C. A. Elmets3, C. Huang3, C. Contreras1  1University Of Alabama at Birmingham,Surgical Oncology,Birmingham, Alabama, USA 2New York University School Of Medicine,The Ronald O. Perelman Department of Dermatology,New York, NY, USA 3University Of Alabama at Birmingham,Dermatology,Birmingham, Alabama, USA

Introduction:   Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine carcinoma that disproportionately afflicts elderly Caucasian and immunosuppressed patients. Immunosuppression correlates with worse MCC outcomes. This study compared MCC outcomes between immunocompetent patients and those with immunosuppression from various etiologies, including solid organ transplant recipients (SOTRs), those with hematologic malignancies, and therapeutic immunosuppression for other causes.

Methods:   We conducted a single institution retrospective review examining the MCC disease course for all patients at our institution from 2000 to 2017. Treatments were reviewed for all patients. Stage at diagnosis was compared between immunosuppressed and immunocompetent patients. Kaplan Meier curves were generated, and hazard ratios estimated for disease-free survival and overall survival by immunosuppression status.

Results:  Our cohort included 78 immunocompetent patients and 22 immunosuppressed (4 SOTR, 11 hematologic, and 7 other). There was no statistically significant difference between the presenting stages of our immunosuppressed patients (suppressed vs. competent: IA: 23% vs. 24%; IB: 23% vs. 19%; II: 9% vs. 8%; IIIA: 5% vs. 14% ; IIIB: 23% vs. 15%; IV: 18% vs. 18%; p=0.80).  Of patients who had a sentinel lymph node biopsy at the time of initial staging, 30% of immunosuppressed patients had positive nodes compared to 46% of immunocompetent patients (p=0.49). Overall, 35% of the cohort was treated with resection alone, 44% were treated with the combination of surgery and radiation therapy, and 3% were treated with a combination of radiation and/or chemotherapy.  All immunosuppression etiologies were associated with decreased overall and disease-free survival rates compared to immunocompetent patients in aggregate, and by type of immunosuppression: Overall: SOTR: HR=1.6 (95% CI: 0.5-5.2), Heme Malignancy: HR=2.5 (95% CI: 1.1-5.7), Other: HR=2.3 (95% CI: 1.0-5.4); Disease-free: SOTR: HR=1.2 (95% CI: 0.4-3.9), Heme Malignancy: HR=2.0 (95% CI: 0.9-4.3), Other: HR=1.2 (95% CI: 1.2-5.8). In multivariate models controlling for age, gender and stage at presentation, immunosuppression was predictive of decreased survival (Overall: HR=3.2 (95% CI: 1.6-6.1); Disease-free: HR=1.9 (95% CI: 1.1-3.5)). Immunosuppressed patients had a median disease free-survival of 8 months compared to 17 months in immunocompetent patients, p=0.03.

Conclusion:  Immunosuppressed groups had worse MCC-specific outcomes relative to immunocompetent patients overall and by reason for immunosuppression. Despite heterogeneity solid organ transplant, hematologic malignancy, and iatrogenic etiology all imparted a similar risk for decreased disease free and overall survival. The modest cohort size in this single center retrospective review is inherent to this rare malignancy; further study involving multiple institutions is important to confirm these findings.

95.02 Feasibility of Axillary Lymph Node Localization Using Radar Reflector Localization

Posted on January 31, 2019

S. A. Morris1, D. Henry2, W. Sun2, C. Laronga2, M. C. Lee2  1University Of South Florida College Of Medicine,Tampa, FL, USA 2Moffitt Cancer Center And Research Institute,Breast Surgical Oncology,Tampa, FL, USA

Introduction: Radar reflector localization (RRL) has been identified as an effective means of guiding excision of non-palpable breast lesions compared to traditional wire localization (WL). With increasing data supporting selective or targeted axillary dissection for node positive breast cancer after neoadjuvant chemotherapy (NAC), we sought to evaluate the feasibility of RRL to assist the excision of biopsy-proven or suspected metastatic axillary lymph nodes.

 

Methods: A retrospective chart review of all suspected or biopsy-proven node positive patients who underwent RRL of an axillary lymph node to guide surgical extirpation as a selective axillary nodal excision (SANE), targeted axillary dissection (TAD) or axillary lymph node dissection (ALND) between 1/2017 and 5/2018 was conducted. Clinical and demographic data were collected. Descriptive statistics were performed.

 

Results: A total of 42pts had a radar reflector placed in/adjacent to a biopsy-proven or suspected metastatic axillary lymph node a median of 7.5 days prior to surgery (range: 1-139 days). 33 (79%) nodes had a clip placed at the time of diagnostic biopsy, if one was performed. At the time of surgery, the median pt age was 56 years (range: 21-75 years), with 41 (98%) having ductal histology, 18 (43%) with hormone-positive only breast cancer and 21 (50%) undergoing mastectomy. A total of 9pts (21%) had surgery first, 29pts (69%) after NAC, and 4pts (9.5%) for an axillary recurrence (ipsilateral and contralateral). TAD was performed in 34pts (81%) using dual-tracer sentinel lymph node (SLN) biopsy concurrent with RRL; in 33/34 (97%) specimens the RRL node was also identified as a SLN. One pt failed SLN mapping. Of the remaining pts, 4 (9.5%) underwent ALND alone and 4 (9.5%) underwent RRL SANE. The median number of nodes in a RRL specimen was 1 (range: 1-6). The median number of SLNs removed was 3 (range: 0-9). The radar reflector was recovered in all cases, and surgeons did not report any intraoperative or postoperative complications. The median number of positive nodes in the RRL surgical specimen was 1 (range: 0-3). One pt had a discordant FNA of a suspicious axillary lymph node, final pathology was negative. Of the 29pts having NAC, 29 (100%) RRL nodes were positive or showed treatment effect and 11/29 (38%) had a complete pathologic response.

 

Conclusion: RRL is feasible to guide excision of suspected or biopsy proven lymph nodes in the axilla of a breast cancer patient and can be utilized with minimal risk of complications. Further investigation is warranted to compare RRL to WL.

95.01 Radiation Therapy For Patients With Soft Tissue Sarcomas: Who Benefits?

Posted on January 31, 2019

N. Nagarajan1, J. Singh2, K. Giuliano1, F. Gani1, C. Wolfgang1, T. Pawlik3, E. Schneider4, J. Canner1, F. Johnston1, N. Ahuja5  1Johns Hopkins University School Of Medicine,Department Of Surgery,Baltimore, MD, USA 2Johns Hopkins Bloomberg School of Public Health,Baltimore, MD, USA 3The Ohio State University,Department Of Surgery,Columbus, OH, USA 4School of Medicine at the University of Virginia,Department Of Surgery,Charlottesville, VA, USA 5Yale University School of Medicine,Department Of Surgery,New Haven, CT, USA

Introduction:
Soft tissue sarcomas (STS) are heterogeneous tumors necessitating multipronged treatment approaches by multidisciplinary teams. However, the evidence for using radiation therapy in STS is variable. Therefore, we studied the association of radiation with survival in patients with STS.

Methods:

STS cases were identified in the Surveillance Epidemiology and End Results (SEER) Program (2002-2012) and categorized into 12 histological subtypes (ICD-O-3). Relative times to cause-specific mortality (censored at 10 years) were examined across patients undergoing surgery only, radiation only, or combination (surgery plus radiation accounting for interaction) using generalized gamma parametric survival functions stratified by histological subtype and controlling for age, sex, race, location, grade, size, local extension, lymph node and distant metastasis.

Results:
A total of 42,409 patients were included. Risk-adjusted survival analyses revealed that surgery alone was associated with significantly increased survival (1.9-5.9 times) compared to no treatment among all histological subtypes (p<0.05). Radiation alone was associated with significantly increased survival (1.4-2.5 times) in aggressive subtypes including leiomyosarcoma (p<0.05). Combination therapy was also associated with significantly increased survival (1.6-5.6 times) across all subtypes compared to no treatment (p<0.05). Compared to surgery alone, combination therapy showed incremental increases in survival for leiomyosarcoma, liposarcoma, angiosarcoma, and synovial sarcoma with only rhabdomyosarcoma showing statistically significant longer survival [Time Ratio:1.5 (95%CI:1.2-1.8),p=0.001](Figure).

Conclusion:
This study demonstrated that combination therapy is similar to surgery alone in most STS subtypes. Combination therapy with radiation appears to be beneficial in aggressive subtypes of STS with up to 50% incremental increase in survival compared to surgery alone.