Intensity-modulated radiotherapy with systemic chemotherapy improves survival in patients with nonmetastatic unresectable pancreatic adenocarcinoma: A propensity score-matched, nationwide, population-based cohort study.

Abstract

In the era of intensity-modulation radiation therapy (IMRT), no prospective randomized trial has evaluated the efficacy of IMRT exclusively, such as concurrent chemoradiotherapy (CCRT), sequential induction chemotherapy followed by radiotherapy (CT-RT), and systemic chemotherapy (CT) alone, for treating unresectable pancreatic adenocarcinomas (PAs) without metastasis. Through propensity score matching, we designed a nationwide, population-based, head-to-head cohort study to determine the effects of various treatments on unresectable PAs. We minimized the confounding effects of various treatment outcomes in patients with unresectable PAs from the Taiwan Cancer Registry database by dividing them as follows: group 1, CCRT; group 2, sequential CT-RT; group 3, nontreatment; and group 4, CT alone. The matching process yielded a final cohort of 2960 patients (740 patients each in groups 1, 2, 3, and 4). In both univariate and multivariate Cox regression analyses, the adjusted hazard ratios (95% confidence interval) derived for the definitive CCRT and sequential CT-RT groups compared with the CT alone group were 0.443 (0.397-0.495) and 0.633 (0.568-0.705), respectively. A combination of IMRT and systemic CT for the treatment of unresectable PAs might increase survival compared with CT alone.