PROGNOSTIC VALUE AND CLINICAL IMPLICATIONS OF DISSEMINATED CANCER-CELLS IN THE PERITONEAL-CAVITY DETECTED BY REVERSE TRANSCRIPTASE-POLYMERASE CHAIN-REACTION AND CYTOLOGY

Free cancer cells exfoliated from the cancer-invaded serosa contribute to peritoneal dissemination, the most frequent pattern of recurrence in gastric carcinoma patients. This study was designed to evaluate the prognostic relevance of such free cells in peritoneal washes detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and cytol ogy. RT-PCR analysis with primers specific for carcinoembryonic antige n and conventional cytologic examination by Papanicolaou staining were performed on peritoneal washes, collected at laparotomy from 148 gast ric carcinoma patients. Prognostic analyses were performed with 1) dea th due to cancer recurrence and 2) peritoneal dissemination as endpoin ts. RT-PCR was found to be more sensitive than cytologic examination f or detection of free cancer cells in the peritoneal washes, with a hig her detection rate for each of the T categories in the tumor-node-meta stasis (TNM) classification. Five patients with synchronous or recurre nt peritoneal dissemination were found among 17 patients with positive RT-PCR and negative cytologic results. Both positive cytologic result s and positive RT-PCR results had significant influences over the surv ival of patients with advanced gastric carcinomas (n = 75, p < .002). Detection of free cancer cells in peritoneal washes, most reliably by RT-PCR, is promising as a predictor of peritoneal dissemination in pat ients with gastric carcinoma. (C) 1998 Wiley-Liss, Inc.