Importance of positive peritoneal lavage cytology findings in the stage grouping of gastric cancer

Although peritoneal lavage cytology is widely performed during surgery for gastric cancer and the results have been reported to be one of the accurate prognostic factors, the cancer stage is determined independent of the resu lts of lavage cytology according to the First English Edition of Japanese C lassification of Gastric Carcinoma. In this study we demonstrated the valid ity of lavage cytology for accurately staging gastric cancer. Between 1988 and 1996, peritoneal lavage cytology was performed in 347 patients with res ectable gastric cancer. Among them, cytology was positive in 29 cases (8.4% ), The survival rate of the cytology-positive patients in each stage was wo rse than that of all patients in the same stage. The prognosis of patients with positive cytology findings and serosa-exposed gastric cancer was signi ficantly worse than that of negative cytology findings and serosa-exposed g astric cancer, and similar to that of negative cytology findings and serosa -infiltrating gastric cancer. Our data indicated that positive cytology fin dings thus indicated a poor prognosis, and the prognostic difference betwee n positive and negative cytology findings was approximately a one-stage dif ference in the Japanese stage grouping. Based on our findings, the results of peritoneal lavage cytology should thus be included in the factors for st aging gastric canter.