Our recent studies indicate that omental milky spots are frequently involved in the early stage of peritoneal cancer dissemination. We have used carcinoembryonic antigen (CEA)-specific RT-PCR for omental milky spots to predict peritoneal recurrence in gastric cancer patients. CEA mRNA was found to be positive in both 10 peritoneal washes and 16 greater omenta of 30 gastric cancer patients, including all 6 patients who showed positive results for both cytology and RT-PCR of peritoneal wash and omentum. Three of the 6 cases with positive RT-PCR in the greater omentum but not in the peritoneal wash showed recurrence of peritoneal carcinomatosa within 2 years after operation. Micrometastasis on omental milky spots was histologically confirmed in 6 of 30 gastric cancer cases. Non-specific band was detected only in the omentum of 1 case of 15 benign disease (7%), but not in peritoneal washes (0%), probably due to weak expression of CEA in mesothelial cells. Our results show that CEA-specific RT-PCR targeting micro-metastases on omental milky spots is more sensitive than targeting the peritoneal wash or conventional cytology, and suggest that this method is useful for the prediction of peritoneal recurrence in gastric cancer patients.
Copyright 2001 Wiley-Liss, Inc.