Risk factors for peritoneal recurrence in serosa-negative gastric cancer.

19 Background: Peritoneal recurrence is often observed in gastric cancer patients without serosal invasion. It is difficult for pathologists to evaluate whether tumor cells penetrate serosa or not, because the subserosa layer is very thin. We evaluated the incidence and risk factors of peritoneal recurrence in serosa -negative gastric cancer patients to clarify the mechanism of peritoneal recurrence in these patients. Methods: A total of 1,745 gastric cancer patients underwent R0 resection from 2002 to 2009 were enrolled. The incidence of peritoneal recurrence according to tumor depth was analyzed. In serosa-nagative patients, the univariate and multivariate analysis were performed to identify the risk factors for peritoneal recurrence. Results: Peritoneal recurrence was observed in 64 (3.7 %) out of 1,745 patients. The incidence of peritoneal recurrence according to depth of tumor invasion was in 0 / 466 in T1a, 5 / 567 (0.88 %) in T1b, 4 / 187 (2.1 %) in T2, 31 / 360 (7.9 %) in T3, 20 / 108 (15.9 %) in ...