Ward MM - Whether lower rates of diagnosed prostate cancer are attributable to a reluctance to perform prostate biopsies in men who are anticoagulated, leading to an apparent protective influence, was investigated in a national population-based sample of elderly men. Between 17,815 men who received chronic oral anticoagulation for prosthetic heart valve thromboprophylaxis and 356,300 men from the general population, the trends in prostate cancer incidence were compared. A substantially lower incidence was found in the anticoagulation group among men registered in 2000-2001 and observed through 2015. Among men enrolled in 2008-2010, a decline in the incidence was reported over time in the general population group to approach that of the anticoagulation group. The researcher concluded that detection bias from lower rates of biopsies among men who are anticoagulated is likely responsible for the apparent protective effect of warfarin treatment on the risk of prostate cancer.