Preoperative Therapy for Unresectable Locally Advanced Pancreatic Cancer for ≥6 Months Improves Prognosis After Pancreatectomy.

Abstract

This study aimed to identify the optimal duration of pretreatment for unresectable locally advanced (UR-LA) pancreatic cancer and analyze its effect on the prognosis. This retrospective study included 39 patients with UR-LA pancreatic cancer after pancreatectomy. The cutoff period of preoperative therapy was determined using a receiver operating characteristic curve. We investigated the relationship between preoperative and intraoperative clinical variables and overall survival (OS) in univariate and multivariate analyses. The relationship between the preoperative therapy duration and the clinicopathological variables was investigated. OS was compared according to preoperative therapy duration and the presence or absence of adjuvant surgery. After pretreatment, 15 patients underwent adjuvant surgery and 24 patients continued on chemotherapy without surgery. The multivariate analysis demonstrated preoperative therapy duration ≥6 months was an independent prognostic factor [hazard ratio (HR)=0.10, p=0.04]. No significant difference in the clinicopathological variables was observed between the two groups according to preoperative therapy duration. The OS was significantly better in patients who underwent adjuvant surgery after preoperative therapy duration ≥6 months than in those after preoperative therapy duration <6 months and in those without adjuvant surgery (5-year OS rates: 80% vs. 0%; p=0.01 and 5-year OS rates: 80% vs. 0%; p=0.004, respectively). The OS was not significantly better in patients with adjuvant surgery after preoperative therapy duration <6 months than in those without adjuvant surgery (2-year OS rates: 45.7% vs. 38.1%; p=0.98). Preoperative therapy for UR-LA pancreatic cancer for ≥6 months is necessary to improve prognosis after adjuvant surgery.