Minneapolis VA Center for Chronic Disease Outcomes Research, Minneapolis, MN 55417, USA.
BJU Int. 2010 Nov;106(10):1444-51. doi: 10.1111/j.1464-410X.2010.09714.x.
• To estimate the benefits and harms of 5-α-reductase inhibitors (5-α-RIs) in preventing prostate cancer.
• We searched MEDLINE and the Cochrane Collaboration Library through June 2010 to identify randomized trials. • We included articles if they examined 5-α-RI vs control, were ≥ 1 year in duration and provided clinical outcomes. • Our primary outcome was prostate cancer period-prevalence 'for-cause'.
• Eight studies met inclusion criteria but only the Prostate Cancer Prevention Trial and the Reduction by Dutasteride of Prostate Cancer Events were designed to assess the impact of 5-α-RIs on prostate cancer period-prevalence. The mean age of enrolees was 64 years, 92% were White, and mean PSA level was 3.1 ng/mL. For-cause prostate cancers comprised 54% of all cancers detected in placebo-controlled studies. • Compared with placebo, 5-α-RI resulted in a 25% relative risk (RR) reduction in prostate cancers detected for-cause [RR 0.75, 95% confidence interval (CI) 0.67-0.83; 1.4% absolute risk reduction (3.5% vs 4.9%)]. One BPH trial reported that the risk of prostate cancers detected for-cause was significantly reduced with dutasteride and combined dutasteride plus tamsulosin compared with tamsulosin monotherapy. • Six trials vs placebo assessed prostate cancers detected overall. There was a 26% RR reduction favouring 5-α-RI [RR 0.74, 95% CI 0.55-1.00; 2.9% absolute risk reduction (6.3% vs 9.2%)]. There were reductions across categories of age, race and family history of prostate cancer. • One placebo-controlled trial of men that investigators considered at greater risk for prostate cancer (based on age, elevated PSA level and having a previous suspicion of prostate cancer leading to a prostate biopsy) reported that dutasteride did not reduce prostate cancers detected for-cause based on needle-biopsy but did reduce risk of overall incident prostate cancer detected by biopsy by 23%[RR 0.77, 95% CI 0.70-0.85; absolute reduction 16.1% vs 20.8%]. There were reductions across age, family history of prostate cancer, PSA level, and prostate volume subgroups. • Incidences of erectile dysfunction, ejaculate volume, decreased libido, and gynaecomastia were greater with 5-α-RI vs placebo.
• 5-α-RIs reduce the risk of being diagnosed with prostate cancer among men who are screened regularly for prostate cancer. • Information is inadequate to assess the effect of 5-α-RIs on prostate cancer or all-cause mortality. • 5-α-RIs increase sexual and erectile dysfunction.
评估 5-α 还原酶抑制剂（5-α-RIs）在预防前列腺癌方面的获益和危害。
我们检索了 MEDLINE 和 Cochrane 协作图书馆，检索时间截至 2010 年 6 月，以确定随机试验。如果试验比较了 5-α-RI 与对照组、试验持续时间≥ 1 年并提供了临床结局，则纳入研究。我们的主要结局为前列腺癌的“因癌就诊”期患病率。
共有 8 项研究符合纳入标准，但只有前列腺癌预防试验和度他雄胺减少前列腺癌事件研究旨在评估 5-α-RIs 对前列腺癌期患病率的影响。入组患者的平均年龄为 64 岁，92%为白人，平均 PSA 水平为 3.1ng/mL。在安慰剂对照研究中，因癌就诊的前列腺癌占所有检出癌症的 54%。与安慰剂相比，5-α-RI 使因癌就诊的前列腺癌的相对风险（RR）降低了 25%[RR 0.75，95%置信区间（CI）0.67-0.83；绝对风险降低 1.4%（3.5% vs 4.9%）]。一项良性前列腺增生（BPH）试验报告称，与单独使用坦索罗辛相比，度他雄胺和度他雄胺联合坦索罗辛治疗可显著降低因癌就诊的前列腺癌风险。有 6 项试验与安慰剂比较了总的前列腺癌检出率。5-α-RI 组的 RR 降低了 26%，有统计学意义[RR 0.74，95%CI 0.55-1.00；绝对风险降低 2.9%（6.3% vs 9.2%）]。在年龄、种族和前列腺癌家族史等分类中均观察到 RR 降低。一项针对研究者认为处于更高前列腺癌风险的男性（基于年龄、升高的 PSA 水平和之前怀疑患有前列腺癌导致前列腺活检）的安慰剂对照试验报告称，度他雄胺并没有降低因癌就诊的前列腺癌检出率，但确实降低了通过活检检出的总体前列腺癌发病风险 23%[RR 0.77，95%CI 0.70-0.85；绝对降低率 16.1% vs 20.8%]。在年龄、前列腺癌家族史、PSA 水平和前列腺体积亚组中均观察到 RR 降低。与安慰剂相比，5-α-RI 组发生勃起功能障碍、精液量减少、性欲降低和女性型乳房的发生率更高。
5-α-RIs 可降低定期筛查前列腺癌男性被诊断为前列腺癌的风险。目前尚无足够信息评估 5-α-RIs 对前列腺癌或全因死亡率的影响。5-α-RIs 增加了性功能和勃起功能障碍的发生风险。
