Methods: In a multicenter trial using a two-by-two factorial design, we randomly assigned 73 patients with resected pancreatic ductal adenocarcinoma to treatment with chemoradiotherapy alone (20 Gy over a two-week period plus fluorouracil), 75 patients to chemotherapy alone (fluorouracil), 72 patients to both chemoradiotherapy and chemotherapy, and 69 patients to observation.

Results: The analysis was based on 237 deaths among the 289 patients (82 percent) and a median follow-up of 47 months (interquartile range, 33 to 62). The estimated five-year survival rate was 10 percent among patients assigned to receive chemoradiotherapy and 20 percent among patients who did not receive chemoradiotherapy (P=0.05). The five-year survival rate was 21 percent among patients who received chemotherapy and 8 percent among patients who did not receive chemotherapy (P=0.009). The benefit of chemotherapy persisted after adjustment for major prognostic factors.

Conclusions: Adjuvant chemotherapy has a significant survival benefit in patients with resected pancreatic cancer, whereas adjuvant chemoradiotherapy has a deleterious effect on survival.