The clinical impact of portal venous patency ratio on prognosis of patients with pancreatic ductal adenocarcinoma undergoing pancreatectomy with combined resection of portal vein following preoperative chemoradiotherapy

We analyzed the significance of portal vein (PV) patency ratio (minimum diameter/maximum diameter) during preoperative chemoradiotherapy (CRT) on the outcomes of patients with pancreatic-ductal adenocarcinoma (PDAC). Methods: The 261 PDAC patients had been prospectively registered to our CRT protocol (Gemcitabine or S1+Gemcitabine) from 2005 to 2015. Among them, the subjects were the 84 PDAC- patients with preoperative PV contact who underwent pancreatectomy with PV resection. Results: The 3- and 5-year disease-specific survival (DSS) rates of all 84 patients were 44% and 39%, respectively. Pathological PV invasion (pPV) was seen in 22, and PV patency ratio after CRT (cut-off:0.62) was most relevant factor to predict pPV (sensitivity:54.8%, specificity:91.9%, accuracy:81.5%). Multivariate analysis revealed that PV patency ratio after CRT and improvement of PV patency ratio were selected as independent prognostic indicators. The 3- and 5-year DSS in 39 patients with PV patency ratio after CRT >0.6 were significantly higher than those in 45 patients <0.6: 65% and 60% vs. 24% and 20% (p = 0.0001). The patients with PV patency ratio >0.6, were significantly associated with the lower incidence of pPV, higher response for CRT, and better R0 resection rate. Even when severe PV strictures were seen before CRT, DSS of the patients whose PV patency ratio had recovered after CRT was excellent compared with those without improvement. Conclusions: The PV patency ratio and its improvement are new prognostic indicators for PDAC treated with preoperative CRT. Even when PV was severely constricted, patients could obtain favorable outcomes, if its patency had recovered after CRT.