National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD.
Int J Cancer. 2020 Jun 1;146(11):3022-3025. doi: 10.1002/ijc.32712. Epub 2019 Oct 23.
Warfarin treatment has been associated with lower risks of prostate cancer, without a specified biological mechanism. Our study tested the hypothesis that reluctance to perform prostate biopsies in men who are anticoagulated results in lower rates of diagnosed prostate cancer, leading to an apparent protective effect. Rates of prostate biopsies have decreased from 2000 to 2015, allowing calendar time to be used as the intervention. In a national population-based sample of elderly men, our study compared trends in prostate cancer incidence between 17,815 men treated with chronic oral anticoagulation for prosthetic heart valve thromboprophylaxis and a general population comparison group of 356,300 men. Cancer events were based on administrative claims. Among men enrolled in 2000-2001 and followed through 2015, prostate cancer incidence was substantially lower in the anticoagulation group (adjusted incidence rate ratio [IRR] 0.70; 95% confidence interval [CI] 0.62-0.80). Incidence decreased over time in the general population group to approach that of the anticoagulation group among men enrolled in 2008-2010 (IRR 0.86; 95% CI 0.71-1.04). Rates of prostate biopsies also decreased over time in the general population group to match the rate in the anticoagulation group. These results indicate that the apparent protective effect of warfarin treatment on the risk of prostate cancer is likely the result of detection bias from lower rates of biopsies among men who are anticoagulated.
华法林治疗与前列腺癌风险降低相关，但目前尚不清楚其具体的生物学机制。我们的研究检验了这样一个假设，即对于正在接受抗凝治疗的男性，如果不愿意进行前列腺活检，那么前列腺癌的诊断率会降低，从而产生一种明显的保护作用。从 2000 年到 2015 年，前列腺活检的比例下降，这使得我们可以使用日历时间作为干预因素。在一项基于全国人群的老年男性样本中，我们比较了在接受慢性口服抗凝治疗以预防人工心脏瓣膜血栓形成的 17815 名男性和 356300 名普通人群比较组中，前列腺癌发病率的趋势。癌症事件基于行政索赔数据。在 2000-2001 年入组并随访至 2015 年的男性中，抗凝组的前列腺癌发病率明显较低（调整后的发病率比 [IRR] 0.70；95%置信区间 [CI] 0.62-0.80）。在普通人群组中，发病率随时间的推移而下降，在 2008-2010 年入组的男性中接近抗凝组（IRR 0.86；95%CI 0.71-1.04）。在普通人群组中，前列腺活检的比例也随时间的推移而下降，与抗凝组的比例相匹配。这些结果表明，华法林治疗对前列腺癌风险的保护作用可能是由于抗凝治疗男性活检率较低导致的检测偏差所致。
