Pathological tumor size is an independent prognostic factor in pancreatic cancer patients undergoing curative resection followed by adjuvant chemotherapy with S-1

Abstract

Background: The objective of this retrospective study was to clarify prognostic factors in pancreatic cancer patients treated with curative resection followed by adjuvant chemotherapy with S-1. Methods: Both overall survival (OS) and recurrence-free survival (RFS) were examined in 76 pancreatic cancer patients who underwent curative surgery and received adjuvant chemotherapy with S-1 after surgery between 2007 and 2014. Results: When the length of OS was evaluated according to the log-rank test, significant differences were observed in the pathological tumor size. In addition, univariate and multivariate Cox’s proportional hazards analyses demonstrated that the pathological tumor size was the only significant independent prognostic factor for both OS and RFS. The 5-year OS was 0% in the pathological tumor size ≥ 60 mm group and 30.4% in the pathological tumor size < 60 mm group (p=0.010). Moreover, similar results were observed for recurrence-free survival (p=0.008). Conclusions: The pathological tumor size is the most important prognostic factor for OS and RFS in patients with pancreatic cancer treated with curative resection followed by adjuvant chemotherapy with S-1. The present results suggest that adjuvant chemotherapy with S-1 is not sufficient, especially in patients with relevant risk factors.