Impact of radiologic splenic vessel invasion in resectable left-sided pancreatic ductal adenocarcinoma: predictor of early systemic recurrence following upfront surgery.

Abstract

The aim of this study is to identify prognostic factors and the best candidates for neoadjuvant therapy among patients with resectable left-sided pancreatic ductal adenocarcinoma (PDAC) by analyzing the timing and pattern of recurrence following upfront surgery. This single-center retrospective study included patients with resectable left-sided PDAC who underwent upfront distal pancreatectomy from 2005 to 2015. A minimum P value approach was used to evaluate the optimal cutoff of early recurrence. The predictors of recurrence were assessed with Cox regression analysis. Among 311 included patients, 241 (77.5%) had a recurrence at a median follow-up of 29.3 months. Systemic recurrence occurred in 194 patients (80.5%) and isolated local recurrence in 47 patients (19.5%). A recurrence-free survival cutoff of 12 months was selected to distinguish between early and late recurrence. The patients with early recurrence had a shorter median overall survival (16.1 vs. 39.9 months, P<0.001) and post-recurrence survival (9.6 vs. 17.2 months, P<0.001) than those with late recurrence. The patients with systemic recurrence had a shorter median overall survival (19.6 vs. 29.1 months, P=0.007) and post-recurrence survival (11.0 vs. 15.3 months, P=0.024) than those with an isolated local recurrence. In multivariable analysis, preoperative CA 19-9 ≥500 U/mL [odd ratio (OR) 2.037, P=0.035], radiologic splenic vessels invasion (OR 5.014, P<0.001), positive radial resection margin (OR 2.638, P<0.001), and no adjuvant chemotherapy (OR 2.084, P=0.001) were predictors of an early systemic recurrence. Radiologic splenic vessels invasion may be considered to indicate a biologically borderline status in patients with anatomically resectable left-sided PDAC. Future clinical trials of neoadjuvant therapy targeting these patients should be conducted.