Use of peritoneal washing cytology for the detection of free peritoneal cancer cells before and after surgical treatment of gastric adenocarcinoma.

Aim: Cytological detection of peritoneal-free gastric cancer cells is considered as the gold standard with variable sensitivity. Seeding of cancer cells after radical surgery for gastric cancer is a controversial issue. In this study, it was aimed to detect the rate of positive peritoneal washing cytology and the incidence of spreading of tumor cells after radical surgery.

Materials and Methods: Patients with pathologically proven and surgically treated gastric adenocarcinoma were enrolled. Three peritoneal washing samples were examined cytologically: at the beginning, after completion of resection, and before closure of the abdomen. Identification of peritoneal-free gastric cancer cells was regarded as the main outcome.

Results: Thirty-four patients with a mean age of 60.7 ± 12 years were enrolled. T3 and N0 were the most common stages seen in 16 (47%) and 12 patients (35.3%), respectively. There were two positive results (5.9%) as the first peritoneal sample. Considering T3- or N-positive patients, the incidence increased to 9.1%. There was no conversion of negative to positive cytology. Cytological positivity remained only in one case (2.9%) after the second and the third peritoneal samples.

Conclusion: Rate of positive peritoneal washing cytology in patients with gastric cancer is influenced by clinicopathological findings and the technique used. Use of cytology alone is thought to be failed to detect free cancers cells within the peritoneal cavity.