Time to Adjuvant Systemic Therapy Following Pancreatic Cancer Resection and Effect on Outcome.

Abstract

The appropriate timing of chemotherapy following surgery for resectable pancreatic adenocarcinoma is controversial. Using the National Cancer Database we evaluated time to initiation of chemotherapy postresection and correlated with outcome.We identified stage I-III pancreatic adenocarcinoma treated surgically with adjuvant chemoradiotherapy. Receiver operator curve analysis identified an interval of 66 days as the a priori value for largest discrepancy in outcome. Multivariable logistic regression analysis identified variables associated with increased time to chemotherapy postoperatively (>66 days). Propensity matching was performed to account for indication bias.In total, 6873 and 3348 patients received chemotherapy before and after the 66-day cutoff, respectively. Predictors of expedited chemotherapy included lower comorbidity, treatment outside a community program in an urban location, having insurance, white race, and treatment after 2009. Propensity-matched median survival was 21.8 months for all patients, and of these, 6462 were stage 1. Five-year survival was 20% in patients receiving chemotherapy within 66 days and 18% in those not (P = 0.0266). In stage 1 patients, 5-year survival was 23% versus 21% (P = 0.0116) in favor of expedited chemotherapy.The present propensity-matched analysis showed a significant association with survival for earlier delivery of chemotherapy in the adjuvant setting.