Feb. 15, 2011 -- Men who start to go bald by age 20 may have an increased risk for developing prostate cancer later in life, a study suggests.
Prostate cancer patients in the study were twice as likely to report that they began to lose their hair by this age as men who did not have the disease.
The findings appear to contradict research published last spring, which found early baldness to be protective against prostate cancer. But that study contradicted even earlier research suggesting just the opposite.
Cancer experts tell WebMD that the evidence linking baldness to prostate cancer remains inconclusive.
“This really just shows how much we don’t know,” American Cancer Society Director of Prostate and Colorectal Cancers Durado D. Brooks, MD, tells WebMD.
“Even if this research is corroborated, the message is not clear,” he explains. “If you are a 20-year-old man and you are balding, the most that can be said based on this latest study is that you might develop prostate cancer in 40 years.”
In the new study, published Tuesday in the Annals of Oncology, researchers found no evidence that specific patterns of hair loss were more closely linked to prostate cancer than others. The study also failed to show an association between early hair loss and the diagnosis of prostate cancer earlier in life.
The association between hair loss and prostate cancer was also not seen in men who reported that they began losing their hair at age 30 or 40.
“All that we can really say from this research is that men who are balding at age 20 appear to have an increased risk for prostate cancer,” radiation oncologist and study researcher Michael Yassa, MD, tells WebMD. “These other associations may exist, but we were not able to show them.”
About one in four men with male pattern baldness starts to lose his hair before age of 21 and two out of three will experience some hair thinning by age 35, according to the American Hair Loss Association.
Known medically as androgenic alopecia, male pattern baldness is caused by both genetics and hormones, but the specific relationship between the two is not completely understood.
It is believed that the androgen dihydrotesterone (DHT), which is a product of the male hormone testosterone, is produced in high amounts in genetically susceptible men. At these high levels DHT appears to cause the hair follicles to shrink over time, causing the hair to become weak and, eventually, stop growing.
DHT has also been implicated in the development and growth of prostate cancer.
The drug Propecia blocks the conversion of testosterone to DHT. Several widely publicized studies also suggest that it may prevent prostate cancer in high-risk men.