Preoperative Predictors of R0 Resection after Neoadjuvant Treatment for Pancreatic Ductal Adenocarcinoma

Abstract

Background: R status plays a major role in Pancreatic Ductal Adenocarcinoma(PDAC) survival, even if there aren’t preoperative predictors of R0 after neoadjuvant treatment(NAT). We aim to identify preoperative predictors of R0 resection. Methods: All the patients underwent curative-intent(R0-R1) resection following NAT for PDAC between 2010 and 2020 were identified. Baseline and restaging characteristics, including radiology, blood tests and tumor markers, along with surgical and pathological features were collected. OS was estimated using the Kaplan-Meier method and compared using the log-rank test. A uni- and multivariable regression was used to determine the predictors of R0 and OS. Results: Among 158 patients FOLFIRINOX and Gemcitabine+nab-Paclitaxel were used in 68(50%) and 42(31%), and radiotherapy in 43(27%). After NAT median Ca19-9 dropped from baseline 180.7 U/mL(40.9-473.7) to 25.5(10.0-62.9). At radiological restaging, persistence of vascular invasion were reported in 65%, whereas vascular resection was performed in 27% of patients. R0 was reached in 118 (75%) of the patients, R1 in 39(25%), whereas ypN+ were found in 92(58%). One-, 3- and 5-year OS was 82.6,52.0, 34.0 and 67.4, 34.3, 8.8% in R0 and R1(log-rank p=0.006). At multivariable analysis, none of the preoperative factors resulted as independent predictor of R0, whereas preoperative Ca19.9(OR 1.12 95%CI 1.04-1.20 p=0.002), yN+(OR 2.20 95%CI 1.11-4.34 p=0.03), and recurrence(OR 7.61 95%CI 2.58-22.43 p<0.001) were independent predictors of OS. Conclusions: R0 resection is confirmed to have an increased OS, and should be the goal of resection after NAT, even if currently there aren't independent preoperative predictors of R0 resection. OS Kaplan-Meier Curves