Disparities in Receipt of Adjuvant Therapy after Upfront Surgical Resection for Pancreatic Ductal Adenocarcinoma

Background. A multimodal approach of surgery and chemotherapy, with or without radiation, is the mainstay of therapy with curative-intent for resectable pancreatic ductal adenocarcinoma (PDAC). This study compared utilization trends and outcomes of upfront surgery with and without adjuvant therapy. Methods. The National Cancer Database was queried for patients with a diagnosis of stage 1 or 2 PDAC who underwent upfront resection. Multivariable regression was applied to identify factors associated with initiation of adjuvant therapy. Results. Of the 39,128 patients in the study, 67% initiated adjuvant therapy after resection, whereas 33% received upfront surgery alone. Receipt of adjuvant multimodal therapy increased from 59% in 2006 to 69% in 2017 (P < 0.0001). Non-white race was associated with lower odds of receiving adjuvant therapy after adjustment for income status, education attainment, and other variables (Hispanic/Spanish [odds ratio {OR}, 0.77; 95% confidence interval {CI}, 0.69-0.86] and non-Hispanic black [OR 0.84; 95% CI 0.78-0.91 vs non-Hispanic white; P < 0.001). The variables that contributed to receipt of adjuvant therapy were place of residence in high versus low education attainment area (OR 1.30; 95% CI 1.18-1.44; P < 0.0001) and lower odds for initiation of adjuvant therapy with increasing distance from the treating facility (> 50 miles [OR 0.51; 95% CI 0.47-0.54] vs P < 0.0001). The median unadjusted overall survival (OS) time was 18.2 months (95% CI 17.7-18.8 months) for upfront surgery alone and 25.3 months (95% CI 24.9-25.8 months) for surgery with adjuvant therapy. Conclusions. The patients who underwent upfront surgical resection for PDAC showed wide socioeconomic disparities in the use of adjuvant therapy independent of insurance status, facility type, or travel distance.