Survival impact of pancreatic resection for metastases in the pancreas: A retrospective multi-center study.

BACKGROUND:Pancreatic metastases from other primary malignancies are rare. There is no clear evidence for a treatment strategy for this condition. The purpose of this study was to assess the clinical outcomes, including prognostic factors for pancreatic resection of metastatic tumors in the pancreas, through a retrospective review. METHODS:Data of 35 patients who underwent pancreatic resection for pancreatic metastasis between 2005 and 2020 in eight Japanese institutions were included in this study. Survival analyses were performed using the Kaplan-Meier method, and comparisons were made using the Cox proportional hazards model. RESULTS:The median follow-up period was 35 months (range, 5-102 months). Median duration from resection for primary tumor to resection for metastatic pancreatic tumor was 10.6 years (range, 0.6-29.2 years). The 3- and 5-year survival rates after resection for metastatic tumors in the pancreas were 89% and 69%, respectively. In contrast, the 3- and 5-year disease-free survival rates after resection for metastatic tumors in the pancreas were 48% and 21%, respectively. Performance status ≥1 at the time of resection for metastatic tumors in the pancreas (HR: 7.56, p = 0.036) and pancreatic metastasis tumor diameter >42 mm (HR: 6.39, p = 0.02) were significant poor prognostic factors only in the overall survival. CONCLUSIONS:The prognosis of pancreatic resection for metastatic tumors in the pancreas is relatively good for selected patients. However, because it is prone to recurrence after radical surgery, it should only be considered in patients with good PS.