Tumor manipulation during pancreatic resection for pancreatic cancer induces dissemination of tumor cells into the peritoneal cavity: a systematic review

Intraoperative tumor manipulation may induce the dissemination of occult peritoneal tumor cells (OPTC) into the peritoneal cavity. A systematic review was performed in the PubMed, Embase and Cochrane databases from inception to March 15, 2017. Eligible were studies that analyzed the presence of OPTC in peritoneal fluid, by any method, both before and after resection in adults who underwent intentionally curative pancreatic resection for histopathologically confirmed pancreatic ductal adenocarcinoma in absence of macroscopic peritoneal metastases. Four studies with 138 patients met the inclusion criteria. The pooled rate of OPTC prior to tumor manipulation was 8% (95% CI 2%-24%). The pooled detection rate of OPTC in patients in whom OPTC became detectable only after tumor manipulation was 33% (95% CI 15-58%). Only one study (28 patients) reported on survival, which was worse in patients with OPTC (median 11.1 months versus 30.3 months; p = 0.030). This systematic review suggests that tumor manipulation induces OPTC in one third of patients with pancreatic cancer. Since data on survival are lacking, future studies should determine the prognostic consequences of tumor manipulation, including the potential therapeutic effect of 'no-touch' and minimally invasive resection strategies