L. Miller1,2, E. Papai1,2, J. Fredette3, M. Taylor1,2, J. Hwang2, A.M. Villano1,2, S.S. Reddy2 1Temple University, Lewis Katz School Of Medicine, Philadelpha, PA, USA 2Fox Chase Cancer Center, Division Of Surgical Oncology, Philadelphia, PA, USA 3Fox Chase Cancer Center, Division Of Biostatistics And Bioinformatics, Philadelphia, PA, USA
Introduction: For those with pancreatic cancer, preoperative treatment with chemotherapy or radiation has become prominent. The Center for Disease Control (CDC) drafts a national index based on home address every census year called the social vulnerability index (SVI). Studies have utilized this metric as proxy to predict treatment and health outcomes in illnesses. This study aims to analyze the connection between SVI and duration of neoadjuvant therapy (NAT).
Methods: In this retrospective cohort study, medical records an NCI-designated center were reviewed for 1078 pancreatic ductal adenocarcinoma (PDAC) patients. Subjects were filtered for PDAC-specific disease with post-2012 surgical resection. The remaining 193 subjects were stratified based on five SVI measures: overall vulnerability (OV), socioeconomic status (SES), household characteristics (HC), racial & ethnic minority status (RE), and housing type & transportation (HTT). The CDC categorizes SVI into high and low-risk based on a score of >=0.75 and <0.75 respectively. Scores were obtained utilizing patient home address and tract level SVI. Our primary outcome was NAT duration measured in days (end date-start date). Duration of NAT was assessed with ordinary least squares regression on SVI score while controlling for sex, age, BMI, ECOG performance status, and year of resection. High and low risk were compared using a Kruskal Wallis Test. Treatment course was compared between the two SVI categories using Fisher’s Exact Test.
Results: Of 193 subjects, median age was 67 years (38-86 years) and 56% (108) were male. Median BMI was 26.25 (15.36-60.36) and 51.6% (99) of subjects had smoking history. Subject ECOG status at diagnosis was documented as 0 (115, 59.6%) or greater (56, 29%). Twenty-four (12.4%) subjects qualified as high-risk OV and 169 (87.6%) qualified as low-risk. Mean OV was found to be 0.3975; median 0.3490. While 57 (29.5%) underwent surgery first, 72 (37.3%) received TNT and 64 (33.2%) completed single modality neoadjuvant therapy (SMNT). Treatment course was not associated with OV risk group (p=0.063). Median neoadjuvant therapy (NAT) duration was 83 days (0 – 361 days) and was not predicted by OV risk group (p=0.796). Adjusted analysis of the relationship between OV and NAT duration was also unsubstantiated (p= 0.218). There is a negative correlation between increasing OV and duration of NAT, where roughly a 2.69-day decrease is noted for a 10% increase in SVI score. Duration of NAT was not significantly predicted by SES (p=0.359), RE (0.345), or HTT (p=0.712), but HC neared significance (p=0.059) and suggested a 4.42 day decrease in NAT duration per 10% increase in SVI score.
Conclusion: This study suggests there is limited application for SVI in predicting length of neoadjuvant chemotherapy treatment. The relationship is also absent when accounting for confounders. Further research into the impact of HC on those with PDAC and receipt of NAT is advised.