Pathological Response Predicts Survival after Pancreatectomy following Neoadjuvant FOLFIRINOX for Pancreatic Cancer

SIMPLE SUMMARY: In pancreatic cancer, complete pathologic response (cPR) after neoadjuvant treatment (NAT) has been rarely reported and its clinical course is not well known. Since the introduction of FOLIFIRINOX in clinical practice, the efficacy of chemotherapy has shown a dramatic improvement and these regimens have become the mainstay of chemotherapy. However, prior studies on cPR with various neoadjuvant regimens do not reflect the current trend. The aim of this study was to investigate the clinical course of patients according to pathological response, including cPR, who underwent resection following FOLIFIRNOX in advanced pancreatic cancer. We identified the value of pathological response as the prognostic factor for overall survival (OS) and disease-free survival (DFS). ABSTRACT: Background: The clinical course of complete pathologic response (cPR) in pancreatic cancer after neoadjuvant chemotherapy is not well known. The aim of this study was to investigate the clinical course of patients according to pathological response, including cPR, who received only FOLIFIRNOX in advanced pancreatic cancer. Methods: Patients who underwent pancreatectomy after FOLFIRINOX for pancreatic ductal adenocarcinoma (PDAC) from 2017 to 2019 were retrospectively reviewed. cPR was defined as an absence of residual tumor on pathologic report. A nearly complete pathologic response (ncPR) was defined as a tumor confined to pancreas parenchyma, less than 1 cm without lymph-node metastasis. cPR and ncPR were assigned into a favorable pathologic response group (fPR). Kaplan–Meier method and Cox proportional hazard models were used for analysis. Results: Of a total 64 patients, 8 (12.5%) had a cPR and 8 (12.5%) had a ncPR. In the fPR group, median OS and DFS were superior to those of non-pathologic response group (more than 60 months vs. 38 months, p < 0.001; more than 42 months vs. 10 months, p < 0.001). On multivariable analyses, fPR and adjuvant therapy were independent prognostic factors for OS (HR: 0.12; 95% CI: 0.02–0.96, p = 0.05; HR: 0.26; 95% CI: 0.09–0.74, p = 0.01) and DFS (HR: 0.31; 95% CI: 0.12–0.86, p = 0.02; HR:0.31; 95% CI: 0.13–0.72, p = 0.01). Conclusions: pathologic response predicts survival after pancreatectomy following neoadjuvant FOLFIRINOX for pancreatic cancer, and adjuvant chemotherapy following neoadjuvant treatment might be beneficial for OS and DFS.