Potential role of platelets and coagulation factors in the metastasis of prostatic cancer.

One of the common surgical procedures used in the management of prostate cancer is transurethral resection of the prostate in which the possibility of the escape of tumor cells and their encounter with the hemostatic system is reported to contribute to the threat of hematogenous dissemination. We are reporting about the role of the hemostatic system involving the platelets and coagulation factors in the dissemination process in a tumor model carrying Dunning's R3327 AT3 adenocarcinoma of the prostate whose metastatic behavior is similar to that of human prostatic cancer. Our data revealed that the number of circulating platelets dropped and their aggregation activity increased in tumor-bearing rats as compared to controls. Normal platelets when treated with tumor effusions and reacted with the exogenous aggregating agent collagen exhibited a significant increase in the aggregating activity suggesting that the tumor and its microenvironment were capable of activating the hemostatic system. Out of eight coagulation factors measured only factors XI and XII were significantly decreased in tumor-bearing rats. The role of platelets in the metastatic process is discussed.