Intraperitoneal free cancer cells exfoliated from the gastric tumors are thought to be responsible for peritoneal carcinomatosis. Peritoneal recurrence is the foremost pattern of failure after potentially curative resection for gastric cancer. The prognostic value of positive cytology has been seldom investigated in the Western patients.

AIM:
To evaluate the prognostic value of intraperitoneal free cancer cells (IFCC) in peritoneal lavage of patients who underwent potentially curative surgical treatment for gastric carcinoma.

METHODS:
322 patients with gastric cancer stage I, II or III according to UICC classification were prospectively evaluated with peritoneal lavage and cytologic examination at the time of gastric resection. Aspirated fluid from the abdominal cavity was centrifuged and subjected to cytological examination through Papanicolaou staining method.

RESULTS:
The mean age was 60.9 years (range = 27 to 86 years) and 62.5% were men. IFCC were detected in 7.7% of the patients; suspected in 2%, and negative in 87.8%. No judgment could be given in 2.5% of the cases. Invasion of the gastric serosa (pT3) was observed in all positive cytology patients. Lymph node involvement was also detected in all positive cytology patients, 60% of the positive tumors were pN1 and 40% pN2. Survival curves using Kaplan-Meier method revealed a significant reduction in overall survival for patients with IFCC. Patients with IFCC had a mean survival time = 10.5 months, while those with negative IFCC had a mean survival time = 61 months, p=0.0001. None of the positive patients survived more than 20 months. There was no correlation between the presence of IFCC and tumor size, histology or degree of differentiation.

CONCLUSIONS:
1. Positive cytology indicates a poor prognosis in patients who underwent potentially curative resection; 2. Intraoperative cytologic evaluation of peritoneal lavage adds sensitivity in assessing patients with potentially curative gastric carcinoma and may alter their therapeutic approach.