Pathologic complete response following neoadjuvant chemotherapy in pancreatic ductal adenocarcinoma: Impact on survival and recurrence

Background: Pathologic complete response after neoadjuvant treatment in pancreatic ductal adenocarcinoma is a rare occurrence. Similar to other malignancies, achieving a pathologic complete response in pancreatic ductal adenocarcinoma seems to correlate with improved survival. However, because of the rarity of such events, the true significance of pathologic complete response in pancreatic cancer remains unclear. The aim of the present study was to investigate the impact of pathologic complete response on survival and recurrence. Methods: In a single-center retrospective study, pathologic complete response was defined as no evidence of viable tumor cells in resected specimen entirely sampled according to a rigorous protocol and in which a residual tumor bed was identified. Disease-specific survival and disease-free survival were measured from surgery. Independent predictors for disease-specific survival and disease-free survival were examined. Results: Overall, 403 patients were included. Pathologic complete response was found in 15 patients (3.8%), after chemotherapy alone. After a median follow-up of 42 months (95% CI 38-45), 3-year disease-specific survival was 87% in pathologic complete response patients vs 43% in those without pathologic complete response (P = .014). The recurrence rate was 40% (n = 6/15) in the pathologic complete response group compared with 69.8% (n = 271/388) in those without pathologic complete response. Disease-free survival was longer in the pathologic complete response group, with higher 1- and 3-year rates compared with the no-pathologic complete response group (80% vs 60% and 48% vs 24%, respectively). Pathologic complete response was found to be an independent protective factor for disease-specific survival (P = .035) but not for disease-free survival (P = .052). Conclusion: Pathologic complete response in pancreatic ductal adenocarcinoma is not synonymous of cure but ensure a prolonged survival. Nevertheless, recurrence remains a significant concern, with high rates observed even among these exceptional responders.