Prognostic significance of peritoneal washing cytology in Thai patients with gastric adenocarcinoma undergoing curative D2 gastrectomy

Background. The aim of the present study was to determine the prognostic significance of peritoneal washing cytology (PWC) among Thai patients with gastric adenocarcinoma. Methods. Medical charts of 97 patients with gastric adenocarcinoma who underwent curative D2 gastrectomy between October 1995 and September 2005 were reviewed. Results. A total of 22 patients (23%) had positive PWC. Factors significantly associated with positive PWC included tumor location, macroscopic findings, histology, depth of tumor invasion, nodal involvement, TNM stage, and angiolymphatic invasion. Positive PWC was found only in tumors invading the serosa. All patients with positive PWC developed peritoneal recurrence. The sensitivity and specificity of positive PWC in predicting peritoneal recurrence were 61% and 100%, respectively. The overall 5-year survival rates for patients with positive and negative PWC were 0% and 75%, respectively. Conclusion. Gastric adenocarcinoma with positive PWC should be considered stage IV disease. PWC should be included in the staging of gastric adenocarcinoma.