Balding middle-aged men have a greater chance of getting aggressive prostate cancer later in life than those with a full head of hair, say researchers who suggest the result may one day help doctors predict the disease.
The study reviewed the cases of 39,070 men 55 to 74-years-old who were asked to use a pictorial to identify their own baldness at age 45. Those with moderate hair loss on the front and crown of the head were 39 percent more at risk of getting fast-growing, aggressive prostate cancer, the study found.
The results, published yesterday in the Journal of Clinical Oncology, need to be affirmed by more study, said Michael Cook, the paper’s author and a researcher at the National Cancer Institute in Rockville, Maryland. If they are, doctors may one day use the hairline to help determine treatment strategies for a malignancy that kills almost 30,000 Americans a year.
The finding “suggests men with hair loss may need to be followed more closely,” said Charles Ryan, a professor of medicine at the University of California in San Francisco, in a statement.
Prostate cancer and male pattern baldness are both tied to increased levels of male sex hormones called androgens, which are mainly produced by the testicles. High levels of androgens can affect hair follicles, causing thinning and loss of hair, Cook said. Androgens can also cause prostate cancer cells to grow. The prostate is a gland in the male reproductive system found between the bladder and the rectum.
Prostate cancer is the second most common malignancy in men behind skin cancer, according to the American Society of Clinical Oncology.
The study subjects were taken from the NIH’s Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. About 53 percent had male-pattern baldness at age 45 with 18 percent showing frontal baldness plus moderate hair loss on the crown. There were 1,138 diagnosed prostate cancer cases among the men in the study. Of those, about half were considered aggressive.
The average age at diagnosis was 72 years.
The researchers only found an increased risk of aggressive prostate cancer in men with frontal baldness and moderate hair loss on the crown, compared with men who had no baldness. No link was seen between prostate cancer and other types of baldness, the researchers said.
The research reported yesterday is the largest to suggest the biological link between baldness and cancer, Cook said.
“If we do have replication of these results and if we can understand the mechanism that links this, it could be that male pattern baldness could help us either predict prostate cancer or it may contribute to the decisions and discussion between a patient and his doctor about whether to opt for prostate cancer screening,” Cook said.