Studies on platelet function in patients with prostatic cancer. Preliminary report.

Platelet function was evaluated as an index of the thromboembolic tendency in patients with untreated, advanced prostatic cancer. Patients with benign prostatic hypertrophy (BPH) and similar age distribution served as a comparison group. Platelet aggregations were elevated in both groups, but not significantly different from each other. Platelet serotonin level in patients with prostatic cancer was lower than in patients with BPH (p less than 0.01), whereas plasma serotonin level in patients with prostatic cancer (within normal ranges in our series) was lower than in patients with BPH (p less than 0.001). Levels of 2 intraplatelet proteins, beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) in the two groups of patients were similar. However, levels of beta-TG were elevated significantly in both groups of patients compared with those of healthy individuals. These studies revealed that the platelet serotonin levels in advanced prostatic cancer patients differed significantly from those in patients with BPH. The platelet serotonin level thus may provide an index of platelet activation in patients with prostatic cancer.