Relationship between the cytologic characteristics of intraperitoneal free cancer cells and the prognosis in patients with gastric cancer.

The presence of free cancer cells in the peritoneal cavity of 387 patients with gastric cancer was analyzed using specimens obtained by intraoperative lavage of the pouch of Douglas. If cancer cells were found in the specimen, the case was classified with respect to the number and arrangement (clustered or isolated) of the cancer cells found. Study of the relationship between the histologic type of cancer and the presence of free cancer cells showed that poorly differentiated adenocarcinomas and signet ring-cell carcinomas were associated with a higher incidence of free cancer cells than were other types of cancer. The relationships between the characteristics of the free cancer cells and the postoperative survival rate were also studied. Patients whose free cancer cells were present in clusters were associated with a more favorable prognosis than were those with no such clusters. Patients with small numbers of free cancer cells survived longer than did those with large numbers of free cancer cells.