Metastatic tumors to the pancreas: a systematic review and meta-analysis.

INTRODUCTION Metastases to the pancreas from other primary tumors are increasingly recognized in clinical practice, but the real role of surgery remains unclear. This study was designated to evaluate by a meta-analytic approach the results of surgical treatment for the most common malignancies metastasizing to the pancreas. EVIDENCE ACQUISITION MEDLINE, PubMED, Scopus and Web of Sciences were searched from January 2000 to December 2015. Studies reporting postoperative complications, postoperative mortality, disease-free and overall survival of patients undergoing resection for secondary tumours of the pancreas, were included. EVIDENCE SYNTHESIS Fourteen publication with 281 patients met the inclusion criteria and were subjected to the analysis. Operative morbidity and mortality were 34% and 1.3% respectively. Pancreatic resection for renal cell cancer showed better survival compared to other non-renal cell cancer (ratio of mean 1.83; 95% CI: 1.42-2.36, I2=74.52%, P<0.001). Disease-free interval was longer for metastatic renal cell carcinoma patients (mean difference 6.36, 95% CI: 3.803-8.912 years, I2=76:54%, P<0.001). A meta-regression was used to correlate the two endpoints and showed that a longer DFI is associated to a longer survival. CONCLUSIONS Pancreatic resection for metastasis should be reserved to patients in good health conditions, with isolated disease from renal cell cancer. For other types of tumor, surgery should be performed only in individual basis. There is a need of studies evaluating the role of chemotherapy in the neoadjuvant setting or the best sequential use of multimodality treatment (targeted therapy, radiotherapy, surgery, etc.).