1. Krieg M, Nass R, Tunn S. Effect of aging on endogenous level of 5 alpha-dihydrotestosterone, testosterone, estradiol, and estrone in epithelium and stroma of normal and hyperplastic human prostate. J Clin Endocrinol Metab. 1993;77(2):375–81.
2. Walsh PC. Screening for prostate cancer: an update of the evidence for the U.S. Preventive Services Task Force. J Urol. 2003;170(1):312–3.
3. American Cancer Society. Cancer facts and figures 2014. Atlanta: American Cancer Society; 2014.
4. Rohrmann S, Nelson WG, Rifai N, Brown TR, Dobs A, Kanarek N, et al. Serum estrogen, but not testosterone, levels differ between black and white men in a nationally representative sample of Americans. J Clin Endocrinol Metab. 2007;92(7):2519–25.
5. Wu AH, Whittemore AS, Kolonel LN, John EM, Gallagher RP, West DW, et al. Serum androgens and sex hormone-binding globulins in relation to lifestyle factors in older African-American, white, and Asian men in the United States and Canada. Cancer Epidemiol Biomark Prev: Publ Am Assoc Cancer Res cosponsored by the Am Soc Prev Oncol. 1995;4(7):735–41.