Men who start to lose hair at the age of 20 are more likely to develop prostate cancer in later life and might benefit from screening for the disease, according to a new study published online in the cancer journal, Annals of Oncology today.
The French study compared 388 men being treated for prostate cancer with a control group of 281 healthy men and found that those with the disease were twice as likely as the healthy men to have started going bald when they were 20. However, if the men only started to lose their hair when they were 30 or 40, there was no difference in their risk of developing prostate cancer compared to the control group. The study found no association between early hair loss and an earlier diagnosis of prostate cancer, and nor was there any link between the pattern of hair loss and the development of cancer.
Until now there has been conflicting evidence about the link between balding and prostate cancer; this is the first study to suggest a link between going bald at the young age of 20 and the development of prostate cancer in later life.
Professor Philippe Giraud (M.D., PhD), Professor of Radiation Oncology at the Paris Descartes University (Paris, France) and at the European Georges Pompidou Hospital (Paris, France), who led the research, said: "At present there is no hard evidence to show any benefit from screening the general population for prostate cancer. We need a way of identifying those men who are at high risk of developing the disease and who could be targeted for screening and also considered for chemo-prevention using anti-androgenic drugs such as finasteride. Balding at the age of 20 may be one of these easily identifiable risk factors and more work needs to be done now to confirm this."
Androgenic alopecia, sometimes known as male pattern baldness, is common in men, affecting 50% throughout their lifetime. A link has been established between baldness and androgenic hormones, and androgens also play a role in the development and growth of prostate cancer. Finasteride blocks the conversion of testosterone to an androgen called dihydrotestosterone, which is thought to cause hair loss, and the drug is used to treat the condition. It has also been shown to decrease the incidence of prostate cancer.
From September 2004 Prof Giraud and his colleagues asked the men in their study to answer a questionnaire about their personal history of prostate cancer (if any) and to indicate on four pictures any balding patterns that they had at ages 20, 30 and 40. The pictures showed four stages of hair loss: no balding (stage I), frontal hair loss (receding hairline around the temples), vertex hair loss (a round bald patch at the top of the head), or a combination of both types of hair loss (stage IV). The men's doctors were also asked to provide a medical history of their patients, including any diagnosis of prostate cancer, age at diagnosis, stage of the disease and treatment. The study ran for 28 months. The men with prostate cancer were diagnosed with the disease between the ages of 46 and 84.
Dr Michael Yassa (M.D.), currently Assistant Professor at the University of Montreal (Montreal, Canada) and a radiation oncologist at the Maisonneuve-Rosemont Hospital in Montreal, but who previously worked as a radiation oncology Fellow at the European Georges Pompidou Hospital, said: "There were only three men with stage III and none with stage IV hair loss at the age of 20, but the data revealed that any balding at stages II-IV (37 cases and 14 controls) was associated with double the risk of prostate cancer later in life. This trend was lost at ages 30 and 40.
"We were unable to find an association between the type or pattern of hair loss and the development of cancer. This might be due to the very low prevalence of stage III and IV hair loss at the ages of 20 and 30 in our study."
The researchers say the link between baldness and the development of prostate cancer is still unclear. "Further work should be done, both at the molecular level and with larger groups of men, to find the missing link between androgens, early balding and prostate cancer," said Dr Yassa.
"Male pattern baldness and the risk of prostate cancer". Annals of Oncology. doi:10.1093/annonc/mdq695