Postoperative Treatment of Resectable Pancreatic Cancer With Positive Peritoneal Lavage Cytology: A Multicentre Retrospective Study

Background/Aim: We aimed to evaluate pancreatic cancer (PC) with positive peritoneal lavage cytology (CY1) outcomes following a change in adjuvant therapy. Patients and Methods: The clinicopathological data of patients with pancreatic adenocarcinoma with CY1 at 14 institutions, between 2007 and 2015, were collected and analyzed. Results: Of the 124 eligible patients, 114 underwent macroscopically curative resection. Of the 114 patients, 80 (70%) did not have early recurrence and received postoperative chemotherapy that was S-1 in 43 (54%), gemcitabine in 31 (39%), and others in six (7%). The median overall survival was 21.0 months in S-1 and 19.2 in gemcitabine therapy (p=0.23), whereas the median relapse-free survival was 10.2 and 7.1 months (p=0.03), respectively. Conclusion: Following the change in adjuvant therapy, most PC patients with CY1 who underwent macroscopically curative resection received S-1; however, it was insufficient. Further development of postoperative chemotherapy is required.