Adjuvant therapy (AT) following resection of pancreatic ductal adenocarcinoma (PDAC): Are patients from rural, remote areas disadvantaged?

Abstract

373 Background: AT with chemotherapy (CT) + radiation (RT) has been shown to improve PDAC survival over surgery alone. Although race and socioeconomic status can affect outcomes in PDAC, the impact of rural or remote residence on the delivery and effect of AT has not been studied. Methods: Patients undergoing pancreatectomy for PDAC were identified from the National Cancer Data Base between 2006 and 2013. Individuals were classified as living in a metro area, urban/rural adjacent to metro area (URA), and urban/rural remote area (URR). Patients with less than 6 months follow-up were excluded. Logistic regression was performed to assess residence as a predictor of receiving AT. Overall survival (OS) as a function of inhabitance was estimated by the method of Kaplan and Meier and prognostic factors were identified by Cox regression. Results: A total of 32,521 individuals underwent pancreatectomy for PDAC. The majority of AT was delivered in academic research facilities in 56% of patients while only 29% of patients received both CT and RT. Univariate analysis demonstrated individuals in URR were less likely to receive CT (55% vs 58%, p < 0.01) but not RT (30% vs 31%, p < 0.261) and had a longer interval to AT (82 vs 75 days, p < 0.009) than those in metro areas. However on multivariate analysis URR inhabitance was no longer predictive of any form of AT (OR = 0.892, 95% CI: 0.792-1.006, p = 0.062). Hispanic ethnicity, Medicaid insurance, uninsured status, and lower education were all predictive of decreased likelihood of receiving AT. Median OS was inferior for URR dwellers with pathologic T2 and T3 tumors compared to those in metro areas (19.8 vs. 24.4 months, p = 0.044 and 17.5 vs. 19.4 months, p < 0.001). Cox regression revealed URR location remained independently associated with poorer OS (HR 1.076, 95% CI: 1.008-1.149, p < 0.029). Conclusions: While living in a URR does not lead to reduced access to AT, it is associated with a worse OS in resected PDAC. This may be due to inadequate AT or other socioeconomic factors present in URR patients. Attention must be focused on improving oncologic care for groups susceptible to treatment disparities.