Long-Term Results and Prognostic Factors of Gastric Cancer Patients with Microscopic Peritoneal Carcinomatosis

BACKGROUND: Clinical significance of microscopic peritoneal carcinomatosis remained unclear. The aim of this study was to evaluate the prognostic value of microscopic peritoneal carcinomatosis in gastric cancer. METHODS: From 1996 to 2007, 4426 patients underwent gastrectomy for gastric cancer at Fudan University Shanghai Cancer Center. The clinical and pathological data were reviewed to identify patients with microscopic peritoneal carcinomatosis (group 1). The clinicopathological features and prognosis were examined. Additionally, 242 stage-matched gastric cancer patients without microscopic peritoneal carcinomatosis (group 2) and 118 with macroscopic peritoneal carcinomatosis (group 3) were selected as control groups. RESULTS: Microscopic peritoneal carcinomatosis was found in 121 patients. There were 85 males and 36 females (2.36:1). There was a higher incidence rate of large size tumor (≥5 cm) (P = 0.045), Borrmann IV (P = 0.000), and serosal invasion (P = 0.000) in gastric cancer with microscopic peritoneal carcinomatosis compared with the control group. The 5-year survival rate of gastric cancer with microscopic peritoneal carcinomatosis was 24%, significantly poorer than that of the stage-matched control group but better than that of patients with macroscopic peritoneal carcinomatosis. The independent prognostic factors identified included pathological stage and operative curability. CONCLUSIONS: The presence of microscopic peritoneal carcinomatosis was associated with worse prognosis for gastric cancer, but curative surgery showed potential to improve prognosis.