by ecancer reporter Janet Fricker

Vertex androgenetic alopecia (baldness affecting the crown) at the age of 40 years may be a marker of increased risk for early onset prostate cancer, finds an Australian study published in the journal “Cancer Epidemiology, Biomarkers and Prevention”.

Prostate cancer and androgenetic alopecia (also known as male pattern baldness) are both age-related conditions considered to be androgen dependent.

However, while some studies have suggested that androgenetic alopecia (especially when it occurs in younger men) might be a marker of increased risk of prostate cancer in later life, others have found it to be associated with a lower risk.

In the current study, David Muller and colleagues from the University of Melbourne set out to retrospectively assess whether androgenetic alopecia at the ages of 40 and 20 years was associated with the risk of prostate cancer.

The investigators undertook the study using a subset of men participating in the Melbourne Collaborative Cohort Study (MCCS), a prospective cohort study that was set up to investigate the role of diet and life style factors in chronic diseases including prostate, breast and bowel cancers. Altogether over 40,000 people aged between 27 and 81 years have been recruited to the MCCS study from the Melbourne metropolitan area.

For the sub-study 9,448 men were asked to retrospectively assess their hair patterns at the ages of 20 and 40 years relative to a set of eight pictures.

When they developed cases of prostate cancer were notified to the Victorian Cancer Registry (VCR). Flexible parametric survival models were used to estimate age-varying HRs and predicted cumulative probabilities of prostate cancer by androgenetic alopecia categories.

During a median follow-up of 11 years 4 months, 476 cases of prostate cancer were identified. At younger ages, the investigators found that the hazard was greater for those with vertex androgenetic alopecia, whereas at older ages those with no androgenetic alopecia had a greater hazard of prostate cancer.

At age 55 years, the hazard of prostate cancer is 1.81 (95% CI, 1.13–2.90) times higher for those with vertex androgenetic alopecia at 40 years than those with no androgenetic alopecia; between the ages of 60 and 70 years the HR was not discernible from 1, and at the age of 75 years the vertex androgenetic alopecia group had a 44% lower hazard than those with no androgenetic alopecia (HR 0.56; 95% CI, 0.33–0.95).

“In summary, we found that vertex androgenetic alopecia at age 40 years was associated with earlier age at onset of prostate cancer, and increased cumulative probability of prostate cancer up to age 76 years,” write the authors. Much of the earlier inconsistency in the literature, argue the authors, may have resulted from the previous studies failing to “adequately model the age varying nature of the association”.

Reference

D Muller, G Giles, R Sinclairs, et al. Age-Dependent Associations between Androgenetic Alopecia and Prostate Cancer Risk. doi: 10.1158/1055-9965.EPI-12-0860.