Androgenetic Alopecia and Risks of Overall and Aggressive Prostate Cancer: An Updated Systematic Review and...

Androgenetic alopecia, also known as male pattern baldness (MPB), is a common hair loss disorder among middle-aged men. MPB shares similar risk factors with prostate cancer (PrCa), including advancing age, family history, and sex hormones. Several studies have examined the associations between MPB and PrCa; however, the evidence remains unclear. We carried out an updated meta-analysis of epidemiological studies that examined the relationship between age at onset and patterns of MPB (either frontal, vertex, or both) and their associations with risks of total and aggressive PrCa.

A literature search was performed using PubMed and Web of Science databases for epidemiological studies published between 1 January 2000 and 31 December 2024 that examined the associations between MPB and PrCa. From each eligible study, relevant data were extracted on study design and population, sample size, prevalence of MPB at various ages, and their association with PrCa. Pooled relative risks (RR) and corresponding 95% confidence intervals (CI) were calculated using the Der-Simonian and Laird random-effects models. Heterogeneity across studies was assessed by I² statistics, while the quality of studies was evaluated using the Newcastle-Ottawa Scale.

A total of 19 observational studies, including 17,810 cases and 146,806 controls/non-cases, were analyzed. The prevalence of MPB increased from 5% to 65% with aging and varied across the studies. Both frontal and vertex MPB were associated with a pooled RR of 1.08 (95% CI 1.02-1.14) for total PrCa, but there was no association with frontal-only MPB. Younger-onset MPB (<40 years old) was also associated with an RR = 1.13 (95% CI 0.96-1.31) for PrCa, although results were not statistically significant. Vertex-only MPB was associated with more aggressive PrCa (pooled RR = 1.14; 95% CI 1.02-1.25); however, there was substantial heterogeneity in the definition of aggressive PrCa across the studies.

Men with both frontal and vertex MPB have a modestly elevated risk of PrCa. However, most studies were conducted in Caucasian men and they did not evaluate effect modifications by genetic variations in androgen metabolism pathway genes or changes in serum levels of androgens with aging. Large prospective cohort studies with more accurate longitudinal assessment of hair loss patterns are needed to better understand the complex relationship between genetic susceptibility, endogenous hormones, MPB, and subsequent risk of PrCa.