Yield of peritoneal cytology in staging patients with gastric and gastroesophageal cancer

Background: Guidelines for gastric and gastroesophageal (GE) cancer recommend staging laparoscopy (SL) with peritoneal cytology (PC). However, the reliability of PC is unknown. The primary purpose of this study was to determine the sensitivity of PC. Methods: We analyzed a prospectively maintained database of patients who underwent SL and PC for gastric and GE cancer. Test sensitivity of PC for detecting peritoneal disease was assessed. Survival analyses were used to examine the implication of PC. Results: There were 1186 patients that underwent SL and PC; 282 (24%) were found with carcinomatosis. PC was analyzed in 214 (76%) of these patients and 77 (36%) were found to have no malignant cells. In this setting, PC had a sensitivity of 64% for confirming peritoneal disease. Those with peritoneal disease had a poorer 5-year overall survival (5.8% vs 37.7%; P <.001). Those with positive PC without carcinomatosis had a similar survival to those with gross disease with and without cytological confirmation (both P >.05). Conclusions: PC has limited sensitivity for detecting peritoneal disease. Positive PC alone carries a similar poor survival as in patients with gross carcinomatosis. Improvements in the identification of microscopic disease in peritoneal washings are needed.