Outcomes of conversion surgery following chemotherapy for initially unresectable metastatic pancreatic ductal adenocarcinoma: a retrospective cohort study in Taiwan

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a high mortality rate. For patients with metastatic PDAC (mPDAC) initially deemed unresectable, systemic chemotherapy followed by conversion surgery may offer an improvement in survival. This study aimed to compare survival between mPDAC patients undergoing conversion surgery versus chemotherapy alone, and identify factors associated with recurrence following conversion surgery. Methods: We conducted a retrospective cohort study of patients with mPDAC treated with systemic chemotherapy at National Cheng Kung University Hospital, Taiwan, between September 2020 and January 2023. Patients who subsequently underwent conversion surgery were analyzed to identify factors associated with recurrence. Clinicopathologic, treatment, and surgical variables were extracted from medical records. Recurrence-free survival (RFS) was defined from the date of conversion surgery to recurrence or death. Survival outcomes were estimated using the Kaplan–Meier method and compared with the log-rank test. Cox proportional hazards regression with stepwise selection was applied to identify independent predictors of recurrence. Results: Among 151 patients who underwent chemotherapy, 33 subsequently received conversion surgery. In the patients who received conversion surgery, male sex (HR 4.33, 95% CI 1.60–11.72), tumor location in the head/uncinate process (HR 2.79, 95% CI 1.03–7.58), and regression grade 2 (HR 4.65, 95% CI 1.41–15.30) were significantly associated with worse RFS. Conclusion: Among patients with mPDAC who underwent conversion surgery after chemotherapy, several factors were independently associated with shorter RFS, including male sex, tumor location in the pancreatic head/uncinate process, and histologic regression grade 2.