Purpose: The role of peritoneal washing cytology in determining further treatment strategies after gastric cancer surgery is still unclear. One reason for this is that optimal procedures to increase the accuracy of predicting peritoneal metastasis have not been established. The aim of this study was to evaluate the efficacy of cytology using samples harvested from 2 different abdominal cavity sites during gastric cancer surgery.
Materials and Methods: We prospectively recruited 110 patients who were clinically diagnosed with locally advanced gastric cancer (higher than cT1 stage disease). Peritoneal washing fluids were collected from the Douglas pouch and the subphrenic area. Patients were prospectively followed up for 2 years to determine the rates of recurrence and survival.
Results: Thirty-three patients dropped out of the study for several reasons, and 75 patients were finally included in the analysis. Seven patients (9.3%) showed positive cytology, of whom, 3 patients showed peritoneal recurrence. Tumor size was the only factor associated with positive cytology (P = 0.043). The accuracy and specificity of cytology for predicting peritoneal recurrence were 90.1% and 94.2%, respectively, whereas the sensitivity was 50.1%. The survival rate did not differ between patients with positive and those with negative cytology (P = 0.081).
Conclusions: Peritoneal washing cytology was not able to predict peritoneal recurrence or survival in gastric cancer patients. Thus, conventional cytology during gastric cancer surgery seems to be a superfluous procedure
