Increased Warfarin Sensitivity as an Early Manifestation of Occult Prostate Cancer with Chronic Disseminated Intravascular Coagulation

Increased sensitivity to warfarin anticoagulation is usually attributed to liver disease, vitamin K deficiency, or drug interactions. We describe a patient with unexplained sensitivity to warfarin and mildly elevated prostate-specific antigen levels in whom subsequent developments indicated that warfarin sensitivity was the first manifestation of occult prostatic cancer. A review of all published cases of coagulopathy associated with cancer of the prostate shows that, unlike other solid tumors with secondary disseminated intravascular coagulation (DIC), in prostate cancer increased bleeding is more common than thrombotic phenomena. Chronic DIC due to occult prostate cancer should be included in the differential diagnosis of excessive prothrombin time prolongation in patients receiving anticoagulants.