Men with prostate cancer are twice as likely to have had male pattern baldness starting at age 20, according to results of a study that found no increased risk among men who began balding in their 30s or 40s.
The findings, published Feb. 16 in Annals of Oncology (doi:10.1093/annonc/mdq695), suggest that men with early baldness may benefit from routine prostate cancer screening or preventive measures that could include the systematic use of 5-alpha reductase inhibitors, the researchers wrote.
(c) Smobserver Wikipedia/ Creative Commons
(c) Smobserver Wikipedia/ Creative CommonsAny balding present at age 20 was associated with an increased incidence of prostate cancer later in life.
For their research, Dr. Michael Yassa, who was a radiation oncology fellow at the Georges Pompidou European Hospital in Paris at the time of the study, and his associates studied 388 men with a diagnosis of prostate cancer, recruited from radiation oncology clinics in three French institutions. The study also included 281 matched controls with no history of cancer or hormonal pathologies, but with family histories similar to those of the cases. The mean age of the subjects was 67.2, and the controls, 66.4.
All study participants were asked to report any personal history of prostate cancer and their fathers' histories of the same, and to describe their balding pattern at ages 20, 30, and 40 along with their fathers', using a set of four images adapted from the Hamilton-Norwood scale of male pattern baldness. Case subjects' age at diagnosis, stage of disease at diagnosis, treatment, and other information were recorded.
The men with prostate cancer were twice as likely to have had male pattern baldness at age 20 (odds ratio [OR] 2.01). "This trend was lost at ages 30 or 40," the researchers wrote. No specific pattern of hair loss appeared to be a predictive factor for the development of prostate cancer.
Any balding present at age 20 was associated with an increased incidence of prostate cancer later in life. Cancer patients with early balding did not develop cancers younger – those with any pattern of balding by age 20 and 40 had a mean age of diagnosis of 64.4 and 64.5 years, respectively, compared with 64.3 years for patients with no balding by age 40. The researchers also found no associations between early balding and more aggressive types of tumors.
Dr. Yassa, now with the University of Montreal, and colleagues cited a number of earlier studies with conflicting evidence on the links between baldness and cancer. One Duke University study (Cancer Epidemiol. Biomarkers Prev. 2000;9:325-8) showed that men who developed vertex baldness by age 30 had nearly a twofold increase in risk of developing prostate cancer, but a more recent population-based study (Cancer Epidemiol. [doi:10.1016/j.canep.2010.02.003]) showed baldness at age 30 to be associated with 29% relative risk reduction for prostate cancer.
The investigators in the current study speculated that androgens might be implicated in any link between early balding and cancer. "Finasteride blocks the conversion of testosterone to dihydrotestosterone, the active metabolite of testosterone, slowing the progression of androgenic alopecia and decreasing the incidence of prostate cancer," they wrote.
They also acknowledged that their own study was limited by its small size and a case-control design involving self-reporting, that could allow for recall and selective recall bias, and a lack of controlling for factors including African heritage and dietary differences.
Neither Dr. Hassa nor his coauthors declared conflicts of interest.