1. ¹Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan
2. ²Division of Oncological Pathology, Aichi Cancer Center Research Institute, Nagoya, Japan
3. ³Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, Nagoya, Japan
4. ⁴Department of Surgery II, Nagoya University School of Medicine, Nagoya, Japan

Correspondence: Dr H Nakanishi, Division of Oncological Pathology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan. E-mail: hnakanis@aichi-cc.jp

Received 31 May 2005; Revised 22 August 2005; Accepted 22 August 2005; Published online 4 October 2005.

Abstract

Prediction of peritoneal relapse is extremely important for gastric cancer patients after curative surgery. The present study prospectively validates the prognostic ability of quantifying carcinoembryonic antigen (CEA) mRNA in peritoneal washes by real-time reverse transcriptase–polymerase chain reaction. Based on a retrospective study of 197 curatively resected gastric cancer patients (training set), we determined a cutoff value of CEA mRNA using receiver-operating characteristic curve. We used this cutoff value to validate the risk of peritoneal recurrence in a new cohort of 86 gastric cancer patients (validation set) between July 2000 and December 2002 in a prospective study. During the median 30 months of postoperative surveillance, 20 of the 86 patients died, and 13 of the 20 developed peritoneal metastases. Peritoneal recurrence-free survival as well as overall survival was significantly worse in patients with positive CEA mRNA (P<0.0001). Multivariate analysis with the Cox proportional hazards model showed that positive CEA mRNA was a significant independent risk factor with both survival (P=0.0130) and peritoneal recurrence-free survival (P=0.0006) as end points. These results indicate that quantitation of CEA mRNA in peritoneal washes is a reliable prognostic indicator of peritoneal recurrence in the clinical setting.