Hyperaggregability Of Platelets In Cancer, Especially In Reference To Genesis Of DIC
To clarify the role of platelets in the genesis of DIC in cancer, platelets of cancer patients with and without DIC were examined. Patients studied were 29 cases with cancer in stomach, 17 in lung, 7 in pancreas, 6 in liver (hepatoma), 6 in throat, nose and jaw, 2 in the gall bladder and bilary duct, 2 in uterus and 1 each in the small bowel, rectum and prostate, and 1 each with osteosarcoma, mesothelioma and chorionepithelioma. All patients were in stage 3 or 4. 105 healthy controls were also studied. They were evaluated on a scale of coagulation abnormalities, one point was given for each of the following criteria full-filled, and the score (0 to 4) was used. 1. Platelet count<150xl03Anl. 2. Prothrombin time prolonged more than 1 sec over control and/or activated partial thromboplastin time prolonged more than 10 sec over control. 3. Fibrinogen<250 mg/dl (mean fibrinogen value of the cancer patients minus 1 SD). 4. FDP>20 µg/ml. The patients were distributed with 27 % for score 0, 38 % for 1, 20 % for 2, 7 % for 3 and 8 % for 4. Degrees of abnormality in groups with scores of 3 and 4 were significant when compared to scores 0 and 1, but score 2 was not clearly distinguishable. Platelet mode volume in score 4 was smaller than the other groups. Platelet aggregation by adrenaline and ADP decreased in score 3 and 4, while it increased significantly in score 0 and 1 respectively (P<0.01 -0.05). The mean value of plasma β-TG in the cancer patients as a whole (44±24 ng/ml) was significantly higher than that of control (22±13 ng/ml)(P<0.01). PF4 showed the same tendency. During the time course of the disease, hyperaggrega- bility of platelets associated with increases in β-TG and PF4 was observed before an appearance of DIC syndrome in several cases. The results suggest the existence of hyperfunction of platelets in cancer patients and the possibility of triggering mechanism of such activated platelets in the genesis of DIC in cancer.