Abstract
To obtain an early diagnosis of peritoneal dissemination of gastric cancer, the usefulness a novel method employing the release of carcinoembryonic antigen (CEA) from cancer cells via peritoneal irrigation with phosphatidylinositol phospholipase C (PI-PLC) was evaluated experimentally and clinically. Experimental study: 1) The CEA value was increased about 1.7 fold by PI-PLC against KATO-III CEA secreting cancer cells. 2) The CEA value increase depended on the duration of incubation with PI-PLC and the number of target cells. 3) The CEA value was increased by combination with trypsin. Clinical study: Three kinds of irrigation cytology were performed at laparotomy on 81 gastric cancer patients, that is irrigation cytology (IR), cell CEA stain (cCEA) and PI-PLC. 1) The positive rate for 12 patients with macroscopic peritoneal dissemination (P) was 91% for IR, 75% for cCEA and 83% for PI-PLC, while corresponding values were 2.9%, 4.3% and 7.2%, respectively, in 69 cases without P. 2) CEA sensitivity ranged from 1.8 times to 600 times, and the characteristic of showing positivity on PI-PLC suggested microscopic peritoneal dissemination reflected by clinico-pathological findings, From the above results, it is suggested that PI-PLC is a potentially useful method of objectively detecting early peritoneal dissemination.
