• Cindy Ke Zhou, Ruth M. Pfeiffer, and Michael B. Cook, National Cancer Institute, Bethesda, MD; Cindy Ke Zhou, Sean D. Cleary, Heather J. Hoffman, and Paul H. Levine, George Washington University, Washington, DC; and Lisa W. Chu and Ann W. Hsing, Cancer Prevention Institute of California, Fremont, CA.
• Cindy Ke Zhou, Ruth M. Pfeiffer, and Michael B. Cook, National Cancer Institute, Bethesda, MD; Cindy Ke Zhou, Sean D. Cleary, Heather J. Hoffman, and Paul H. Levine, George Washington University, Washington, DC; and Lisa W. Chu and Ann W. Hsing, Cancer Prevention Institute of California, Fremont, CA. cookmich@mail.nih.gov.

PURPOSE: Male pattern baldness and prostate cancer appear to share common pathophysiologic mechanisms. However, results from previous studies that assess their relationship have been inconsistent. Therefore, we investigated the association of male pattern baldness at age 45 years with risks of overall and subtypes of prostate cancer in a large, prospective cohort—the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.

METHODS: We included 39,070 men from the usual care and screening arms of the trial cohort who had no cancer diagnosis (excluding nonmelanoma skin cancer) at the start of follow-up and recalled their hair-loss patterns at age 45 years. Hazard ratios (HRs) and 95% CIs were estimated by using Cox proportional hazards regression models with age as the time metric.

RESULTS: During follow-up (median, 2.78 years), 1,138 incident prostate cancer cases were diagnosed, 571 of which were aggressive (biopsy Gleason score ≥ 7, and/or clinical stage III or greater, and/or fatal). Compared with no baldness, frontal plus moderate vertex baldness at age 45 years was not significantly associated with overall (HR, 1.19; 95% CI, 0.98 to 1.45) or nonaggressive (HR, 0.97; 95% CI, 0.72 to 1.30) prostate cancer risk but was significantly associated with increased risk of aggressive prostate cancer (HR, 1.39; 95% CI, 1.07 to 1.80). Adjustment for covariates did not substantially alter these estimates. Other classes of baldness were not significantly associated with overall or subtypes of prostate cancer.

CONCLUSION: Our analysis indicates that frontal plus moderate vertex baldness at age 45 years is associated with an increased risk of aggressive prostate cancer and supports the possibility of common pathophysiologic mechanisms.