New data support a potential link between early-onset androgenic alopecia, which is popularly referred to as “male pattern baldness,” and the development of prostate cancer.
Michael Yassa, MD, and colleagues at European Georges Pompidou Hospital in Paris, France, queried men with and without prostate cancer about their balding patterns at ages 20, 30, and 40 years. The results revealed that any balding at age 20 was associated with an increased incidence of prostate cancer later in life.
Also, men with prostate cancer were twice as likely to have signs of alopecia at age 20 (odds ratio, 2.01; P
= .0285; 95% CI, 1.07-3.79) compared with controls without prostate cancer. This trend did not persist at ages 30 or 40.
The study included 388 consecutive patients with a diagnosis of prostate cancer seen at a radiation oncology follow-up clinic and 281 controls selected from the same hospital databases who had no history of prostate cancer or hormonal pathologies.
Participants scored their hair-loss pattern at the 3 different time points using the widely validated modified Hamilton-Norwood scale. The physicians of all respondents completed a separate questionnaire to confirm or rule out a history of prostate cancer in their patients.
The study found that the pattern of hair loss (frontal vs vertex vs both) was not a predictive factor for the development of cancer.
There was no association between early-onset alopecia and an earlier diagnosis of prostate cancer. Nor was early-onset alopecia associated with a diagnosis of more aggressive prostate cancer as defined by T3/T4 tumors, a Gleason score ≥7, or prostate-specific antigen >20.
Men with prostate cancer were twice as likely to have signs of alopecia at age 20 compared with controls without prostate cancer.
Yassa and colleagues said that while androgens appear to be implicated in the development of male pattern baldness and prostate cancer, a direct link between the 2 has not been identified. The type II 5-alpha reductase inhibitor finasteride blocks the conversion of testosterone to dihydrotestosterone, the active metabolite of testosterone, thereby slowing the progression of androgenic alopecia and reducing the incidence of prostate cancer. The investigators emphasize, however, that they do not yet know whether men with early-onset male pattern baldness can benefit from routine prostate cancer screening or the routine use of 5-alpha reductase inhibitors as primary prevention.
They cautioned that their results may be limited by recall bias, although they note that retrospective self-reporting of male balding patterns has been validated. Also, they say that most men would probably remember developing baldness, especially early-onset baldness.
The study’s failure to control for prostate cancer risk factors such as African heritage and dietary differences may represent an additional limitation.
Yassa M, Saliou M, De Rycke M, et al. Male pattern baldness and the risk of prostate cancer [published online ahead of print February 15, 2011]. Ann Oncol. 2011. 22(8):1824-1827.