Tumor marker recovery rather than major pathological response is a preferable prognostic factor in patients with pancreatic ductal adenocarcinoma with preoperative therapy

Background/Purpose: A pathological response of the primary tumor by preoperative therapy is a prognostic factor in various malignancies, and several histologic grading systems have been proposed for pancreatic ductal adenocarcinoma (PDAC). However, the prognostic value remains unclear. We explored the clinical implication of a major pathological response following preoperative therapy in patients with PDAC. Methods: Of 415 patients with resected PDAC, 137 who had undergone preoperative therapy were examined. Cox proportional hazards models were used to determine the predictors of a major pathological response, and survival analyses were performed. Results: Twenty patients exhibited a major pathological response (≥90% tumor reduction). Significant associations were observed between a major pathological response and resectability (P =.001), the period of preoperative therapy (P <.001), RECIST best response (P <.001), the tumor size after preoperative therapy (P =.02), and tumor marker recovery (P <.001). Multivariate analysis of progression-free survival (PFS) revealed that both body mass index (≥20 kg/m²) (P =.035) and tumor marker recovery (P =.046) were independent prognostic factors. The median survival time (MST) of PFS for a ≥90% pathological response was better than that of a <90% response (P =.25); however, the MST for tumor marker recovery was significantly better than that without tumor marker recovery (P =.0054). Conclusions: In our study, a major pathological response was not extracted as a prognostic factor. Rather, tumor marker recovery was a preferable prognostic factor in patients with PDAC who had undergone preoperative therapy.