Prognostic Factors for Gastric Cancer with Cancer Cells in the Peritoneal Cavity

Aim: To identify the prognostic factors for gastric cancer with positive peritoneal cytology (CY1) or peritoneal metastasis (P1).

Patients and methods: We retrospectively analyzed clinicopathological and survival data of 78 patients who had undergone gastrectomy and/or S-1 based chemotherapy for CY1 or P1 gastric cancer.

Results: The median overall survival (OS) did not differ significantly between patients with CY1P0, CY0P1 and CY1P1 disease (24, 17 vs. 14 months, respectively). Among 12 clinicopathological factors, clinical N3 (odds ratio [OR]=2.18; 95% confidence interval [CI]=1.22-4.00; p=0.01) and gastrectomy not performed (OR=1.80; 95% CI=1.29-2.51; p<0.01) were significant independent prognostic factors. The median OS significantly differed between patients who had undergone gastrectomy plus chemotherapy versus chemotherapy alone (22 vs. 10 months, respectively; p<0.01).

Conclusion: Gastrectomy and perioperative chemotherapy may both be indicated in CY1 or P1 gastric cancer patients with clinical N0-2.