Surgical maneuvers enhance molecular detection of circulating tumor cells during gastric cancer surgery

Objective To evaluate the relation between the presence of cancer cells in blood according to the time course during a surgical procedure and liver me tastases in patients with gastric cancer. Summary Background Data Several studies have reported on the detection of c irculating cancer cells in blood by reverse transcriptase-polymerase chain reaction (RT-PCR). However, few reports have examined the relation between molecular detection of circulating cancer cells according to the time cours e during a surgical procedure and blood-borne metastases. Methods Blood samples from 57 patients with gastric cancer were obtained fr om the portal vein, peripheral artery, and superior vena cava before and af ter tumor dissection. After total RNA was extracted from each blood sample, carcinoembryonic antigen (CEA)-specific RT-PCR was performed. Results CEA-mRNA was detected in the blood of 21 (36.8%) of the 57 patients . CEA-mRNA was not detected in the blood obtained from 15 healthy volunteer s and 15 patients with benign disease. The positive rate increased in propo rtion to the depth of tumor. The incidence of positive CEA-mRNA did not dif fer among the various sites of blood sampling. The appearance of circulatin g cancer cells was related to the surgical maneuver. A significant relation was found between the detection of CEA-mRNA and blood-borne metastases. Conclusions A high incidence of positive CEA-mRNA was found in the blood du ring gastric cancer surgery. Surgical maneuvers are a possible cause of hem atogenous metastasis. The authors found that patients with positive CEA-mRN A had a high risk of blood-borne metastasis even after curative resection.