Chen Chu, Lamharzi Najib, Weiss Noel S, Etzioni Ruth, Dightman Douglas A, Barnett Matt, DiTommaso Dante, Goodman Gary
Program in Epidemiology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
Cancer Epidemiol Biomarkers Prev. 2002 Oct;11(10 Pt 1):1033-40.
The human androgen receptor gene contains polymorphic CAG and GGC repeats in exon 1. We investigated whether the number of CAG and/or GGC repeats is related to prostate cancer risk in a case-control study nested within the beta Carotene and Retinol Efficacy Trial. Among 300 cases and 300 controls, we did not observe any increase in risk associated with fewer CAG or GGC repeats. We observed a nonsignificant decrease in risk associated with each unit of decrease in CAG length [odds ratio (OR), 0.98; 95% confidence interval (CI), 0.93-1.03). Men with CAG <22 had a relative risk of prostate cancer of 0.89 (95% CI, 0.65-1.23) compared with men with CAG > or =22. There was no appreciable difference in the mean number of GGC repeats between cases and controls; the estimated change in the risk of prostate cancer associated with one fewer GGC repeat was 0.97 (95% CI, 0.88-1.06). The risk in men at or below the mean number of GGC repeats (17) was 0.80 (95% CI, 0.57-1.12). In contrast to prior reports, men with both short CAG (<22) and short GGC (< or =17) repeats were not at increased risk of prostate cancer (OR, 0.56; 95% CI, 0.32-0.98), compared with men with > or =22 CAG repeats and >17 GGC repeats. Our results do not support the hypothesis that a small number of CAG or GGC repeats in the androgen receptor gene increases a man's risk of prostate cancer.
人类雄激素受体基因的第1外显子包含多态性的CAG和GGC重复序列。我们在一项嵌套于β-胡萝卜素与视黄醇功效试验中的病例对照研究中，调查了CAG和/或GGC重复序列的数量是否与前列腺癌风险相关。在300例病例和300例对照中，我们未观察到CAG或GGC重复序列数量减少与风险增加之间存在任何关联。我们观察到CAG长度每减少一个单位，风险有非显著的降低[比值比（OR）为0.98；95%置信区间（CI）为0.93 - 1.03]。与CAG≥22的男性相比，CAG<22的男性患前列腺癌的相对风险为0.89（95%CI为0.65 - 1.23）。病例组和对照组之间GGC重复序列的平均数量没有明显差异；GGC重复序列每减少一个，前列腺癌风险的估计变化为0.97（95%CI为0.88 - 1.06）。GGC重复序列数量处于均值（17）及以下的男性的风险为0.80（95%CI为0.57 - 1.12）。与之前的报告相反，与CAG重复序列≥22且GGC重复序列>17的男性相比，CAG重复序列短（<22）且GGC重复序列短（≤17）的男性患前列腺癌的风险并未增加（OR为0.56；95%CI为0.32 - 0.98）。我们的结果不支持雄激素受体基因中少量的CAG或GGC重复序列会增加男性患前列腺癌风险这一假说。
