Role of radiotherapy in the chemotherapy-containing multidisciplinary management of patients with resected pancreatic adenocarcinoma

Background To analyze prognostic factors associated with long-term outcomes in patients with resected pancreatic cancer treated with chemotherapy (CT) and surgery with or without external beam radiotherapy (EBRT). Patients and methods From January 1995 to December 2012, 95 patients with adenocarcinoma of the pancreas and locoregional disease [clinical stage IB-IIA ( n = 45; 47 %), IIB-IIIC ( n = 50; 53 %)] were treated with curative resection [R0 ( n = 52; 55 %), R1 ( n = 43, 45 %)] and CT with ( n = 60; 63 %) or without ( n = 35; 37 %) EBRT (45–50.4 Gy). Additionally, 29 patients (48 %) also received a pre-anastomosis IOERT boost (applicator diameter size, 7–10 cm; dose, 10–15 Gy; beam energy, 9–18 MeV). Results With a median follow-up of 17.2 months (range, 1–182), 2-year overall survival (OS), disease-free survival (DFS), and locoregional control were 28, 20, and 53 %, respectively. Univariate analyses showed that IIB-IIIC stage (HR, 2.23; p = 0.04), R1 margin resection status (HR, 2.09; p = 0.04), no vascular resection (HR, 0.42; p = 0.02), and not receiving external beam radiotherapy (HR, 2.70; p = 0.004) were associated with locoregional recurrence. In the multivariate analysis, only R1 margin resection status (HR, 2.63; p = 0.009) and not receiving EBRT (HR, 2.91; p = 0.002) retained significance with regard to locoregional recurrence. We observed no difference in toxicity between patients treated with or without EBRT ( p = 0.44). Overall treatment mortality was 3 %. No long-term treatment–related death occurred. Conclusions Although adjuvant CT is still the standard of care for resected pancreatic tumors, OS remains modest owing to the high risk of distant metastases. Locoregional treatment needs to be tested in the context of more efficient systemic therapy.