The parameters of coagulation hemostasis in 37 patients with gastric cancer, 65 patients with colon cancer, 17 patients with prostate cancer and in 8 patients with lung cancer were analyzed. The aggregation of platelets in 119 patients with tumors of the breast, 17 — stomach cancer, 11 — colon cancer, 17 — prostate cancer and 8 — lung cancer also were analyzed. It was found that cancer patients have hyperthrombinemia, hyperfibrinogenemia, violation of the protein C system, reduction of the antithrombin III concentration, increase of induced platelet aggregation, which contributes to the formation of the thrombophilic status in cancer patients, is significant in the progression of the tumor and its metastasis. The use of anticoagulants and antiplatelets by these patients can not only lead to a decrease in the risk of thrombotic complications, but also to improve the survival of cancer patients.