Neighborhood-level socioeconomic status and outcomes in patients with localized pancreatic adenocarcinoma treated with first-line FOLFIRINOX

Abstract

Presenter: Douglas S Swords MD, MS | The University of Texas MD Anderson Cancer Center Background: National data demonstrate that neighborhood-level low socioeconomic status (SES) is associated with shorter overall survival (OS) in patients with localized pancreatic ductal adenocarcinoma (PDAC). No previous studies have focused on the impact of SES in patients initially treated with chemotherapy at high-volume institutions. We aimed to assess the associations between SES and receipt of surgery, pathologic/postoperative outcomes, and OS in this population. Methods: We performed a single-center retrospective cohort study of patients who completed ≥ 1 cycle of FOLFIRINOX for non-metastatic PDAC from 2012-2019. Among 519 eligible patients, we excluded those living outside the US (n = 6), residing in areas with suppressed area deprivation index (ADI) values (n = 5), variant histology (n = 5), and unknown surgical status (n = 4). The exposure was ADI, a SES composite constructed using 17 variables measured at the census block group-level. SES was dichotomized as high (ADI values of 1-40th percentile) and low (41-100th percentile). We assessed the associations of SES with resection, pathologic/postoperative outcomes, and OS. Results: Among 499 patients, median age was 64 years (IQR 58, 69), 42.9% were female, and 80.8% were White. The population was skewed towards high SES patients (median ADI 40, scale 0-100[IQR 23, 64]). The resection rate was 31.2% in low SES vs. 39.3% in high SES patients (p = 0.06). When stratified by stage, low SES was associated with lower resection rates in potentially resectable (PR) patients (48.2% vs. 71.8%, p = 0.002) but not in borderline resectable (BR) (38.9% vs. 36.4%, p = 0.75) and locally advanced (LA) (9.8% vs. 15.5%, p = 0.24) patients. Among low vs. high SES resected patients, rates of R1 margins (10.5% vs. 10.5%, p = 1.0), hospital stay (mean 7.9 vs. 6.9 days, p = 0.14), 90-day readmissions (29.0% vs. 19.0%, p = 0.13), major complications (21.3% vs. 14.1%, p = 0.22), and postoperative chemotherapy (64.9% vs. 72.5%, p = 0.29) did not differ significantly. In the overall cohort, median OS in low SES patients was 19 months (95% CI 17, 22) vs. 29 months (95% CI 23, 34) in high SES patients (Figure A, p<0.001). In a multivariable model in the overall cohort, low SES was independently associated with shorter OS (adjusted HR 1.46, 95% CI 1.14, 1.89). Low SES was associated with shorter OS in PR patients (Figure B) but OS did not differ significantly in BR (not shown, p = 0.09) and LA (not shown, p = 0.12) patients. Low SES was associated with similar OS in resected patients (Figure C) but was associated with a modest survival decrement in unresected patients (Figure D). Conclusion: In this cohort of 499 patients with newly diagnosed non-metastatic PDAC who were selected to receive first-line FOLFIRINOX, low SES patients had similar postoperative outcomes and OS to high SES counterparts, reinforcing the value of multimodal therapy at specialized centers. The finding of shorter OS in low SES patients appears to be partially driven by lower rates of being oncologically and medically appropriate for surgery at the conclusion of neoadjuvant therapy. If these findings are confirmed in multi-center studies then it would be appropriate to view low SES patients as a high-risk group deserving of additional supportive resources during first-line therapy.