Clinical Studies On Platelet Aggregation In Patients With Carcinoma Of Gastrointestinal Tract

Platelet aggregation was studied in 73 patients with carcinoma of gastrointestinal tract. Control group was composed of 45 patients with non malignant diseases. Aggregation was induced by adding 10μg/ml of Collagen, 1μ or 2μM at final concentration of ADP to that platelet rich plasma. Using aggregometer of Bryston, aggregation curves were recorded. The estimation of platelet aggregation was determined by aggregation rate, disaggregation rate and maximum aggregation rate. Patients with carcinoma were divided into two groups according to the presence of peritoneal dissemination, liver metastasis, lymphnode involvement as well as the depth of cancer invasion ( limited within submucosa layer or invaded below proper muscle ) and the size ( ≤ 5 cm or > 5 cm ). Moreover after resection of tumor, alteration in parameters of platelet aggregation was evaluated. Maximum aggregation rate was higher and disaggregation rate was lower in patients with carcinoma than in control group. There was significant differences in the intensity of platelet aggregation according to the rate of invasion and the size of the tumor, although peritoneal dissemination, liver metastasis, or lymphnode involvement did not affect platelet aggregation. Maximum aggregation rate and aggregation rate were higher and disaggregation rate was lower in the group with deeper invasion of tumor as well as in the group with larger tumors. After removal of tumor, platelet aggregation decreased. These results suggested that a substance or substances which activate platelet aggregation would be released from tumor tissue.