Androgenetic alopecia and risk of prostate cancer: A systematic review and meta-analysis

Background: Androgenetic alopecia (AGA) is a genetically determined skin condition strongly age dependent and androgens are assumed to play an important role in its development. A link between AGA and prostate cancer has been hypothesized because of their similar risk factors. Objective: We sought to systematically review the evidence available on the association between AGA and risk of prostate cancer. Methods: We searched the electronic databases MEDLINE and Cochrane for studies examining the association between AGA and risk of prostate cancer. We estimated pooled odds ratios (OR) and 95% confidence intervals. We also analyzed the OR for individual hair loss patterns, as defined by the Hamilton scale. Results: A total of 7 case-control studies including 8994 patients-4078 cases and 4916 controls-were reviewed. One cohort study was identified but did not meet our inclusion criteria. There was statistically significant association between vertex baldness and prostate cancer (OR 1.25; 95% confidence interval 1.09-1.44; Z = 3.13; P = .002). No statistically significant association between AGA (any pattern) and prostate cancer was identified (OR 1.03; 95% confidence interval 0.93-1.13; Z = 0.55; P = .58). Limitations: Only case-control studies, which may be subject to bias, met the inclusion criteria for this meta-analysis. Conclusions: Vertex pattern AGA was associated with a significant increased risk of prostate cancer. Any pattern AGA did not show a significant increase in the risk of prostate cancer.