Clinical Implication of Peritoneal Cytology in Gastric Cancer

Abstract

Purpose : Peritoneal cytology has been reported to be a useful tool for the detection of peritoneal dissemination in several studies, and in the 7 th edition of the AJCC staging, positive peritoneal cytology is classified as metastatic disease. This study evaluated the presence of free cancer cells through the peritoneal cytology in gastric cancer patients and analyzed their clinical and prognostic values.Materials and Methods : Total 125 gastric cancer patients who underwent gastrectomy with intraoperative peritoneal cytology were enrolled in this study, and they were categorized into two groups; cytology negative (Cy-) and cytology positive (Cy+).Results : 16 of total 125 patients (12.8%) were Cy+, and they had more advanced T, N, and M stages, as well as histologically undifferentiated carcinomas. The difference of the overall survival rates between Cy-and Cy+ group was not significant (p =0.106), but the disease free survival rates of patients with Cy+ were significantly shorter than those with Cy-(p <0.001). The survival curves of patients with positive cytology but no gross metastasis (Cy+/M0) showed no significant difference, compared to those with gross metastasis (M1) (p =0.076).Conclusions : Peritoneal lavage cytology may be a useful marker of tumor progression and a strong predictor of recurrence in gastric cancer patients. However, it should be questioned whether this novel marker is an independent prognosticator in survival and recurrence.