Large study confirms that positive peritoneal cytology predicts poor disease-specific survival for patients with gastric cancer

Although long-term survival in patients with positive peritoneal cytology is extremely uncommon, those who convert to negative cytology after chemotherapy exhibit significant improvement in disease-specific survival

Positive peritoneal cytology is a poor predictor of survival in patients with gastric cancer. The aim of the study presented at 2010 Gastrointestinal Cancers Symposium (22-24 January, Orlando, USA) by Dr James J Mezhir of the Memorial Sloan-Kettering Cancer Center, New York, USA was to more clearly define the natural history of this cohort of patients. The authors analyzed 1241 patients with gastric cancer who have been underwent to laparoscopy with peritoneal washings; 291 (23%) had positive cytology. Findings from the study have confirmed that positive peritoneal cytology predicts poor disease-specific survival (DSS), even in the absence of visible peritoneal or visceral metastases. Independent predictors at initial staging laparoscopy of worse DSS were disease with peritoneal or visceral metastases discovered at laparoscopy, tumor location, and poor performance status. Additionally, 72 patients were selected for resection of their primary tumor; resected patients were presented more often with no visible visceral or peritoneal metastases (72% vs. 19%, p < 0.0001). Of the 261 patients who were treated initially with chemotherapy, 48 (18%) had a repeat laparoscopy for re-evaluation. Of these, 21 had persistent positive cytology (median DSS 1.4 years) and 27 converted to negative cytology (median DSS 2.5 years, p = 0.0003). The authors concluded that although long-term survival in patients with positive cytology is extremely uncommon, those who convert to negative cytology after chemotherapy exhibit significant improvement in DSS. Four medical specialty societies co-sponsored 2010 Gastrointestinal Cancers Symposium, including the American Gastroenterological Association Institute, the American Society of Clinical Oncology, the American Society for Radiation Oncology and the Society of Surgical Oncology.