預防攝護腺癌的實證醫學

Prevention of Prostate Cancer from the Perspectives of Evidence-Based Medicine

攝護腺癌在近年來已躍居台灣男性發生率第五名的癌症，本文從實證醫學角度來介紹有關批量元素、維生素、藥物及飲食預防攝護腺癌的功效。目前共計有三個第三期、雙盲、且受安慰劑控制的攝護腺癌預防研究已完成並發表，分別是Selenium and Vitamin E Cancer Prevention Trial (SELECT)、ProstateCancer Prevention Trial (PCPT)、及Reduction by Dutasteride ofProstate Events (REDUCE)。SELECT的結論為抽（Selenium）及維生素E，不論單獨使用或併用，均無法降低攝護腺癌的發生率，甚至單獨給予維生素E的族群發生攝護腺癌的機率上升17%。PCPT及DERUCE的結論為長期服用5α還原酶阻斷劑finasteride或dutasteride可分別減少24.8%及22.8%攝護腺癌的發生，但長期服用finasteride會引起發生高度惡性攝護腺癌的機率輕披上升。有關飲食及生活型態調整以預防攝護腺癌的議題則缺乏能提供較高等級實證醫學證據的文章。未來仍須更多大型的隨機分布試驗以提供攝護腺癌的預防策略建議。

Prostate cancer has become the fifth most common cancer among Taiwanese men. This article aims to introduce the strategies of preventing prostate cancer from the perspectives of evidence-based medicine. To date there are three Phase III, double-blinded, placebo-controlled studies that had been published, which are: The Selenium and Vitamin E Cancer Prevention Trial (SELECT), Prostate Cancer Prevention Trial (PCPT), and Reduction by Dutasteride of Prostate Events (REDUCE). The SELECT study concluded that selenium and vitamin E, no matter used alone or in combination, could not prevent prostate cancer. Moreover, vitamin E supplementation significantly increases the risk of prostate cancer by 17%. The PCPT and REDUCE studies showed that long-term use of finasteride or dutasteride can decrease the relative risk of prostate cancer development by 24.8% and 22.8%, respectively. However, long-term use of finasteride was associated with a significantly increased risk of high-grade prostate cancer. There is a lack of articles with higher level of evidence that deal with the dietary agents and lifestyle change for prostate cancer prevention. Further large randomized control trials are needed to draw more solid conclusions about prostate cancer prevention.