Balding Before 30 May Cut Prostate Cancer Risk
Early Hair Loss Reduced Later Prostate Cancer Risk Nearly 30% or More in Study
Balding and Prostate Cancer Risk: Findings
Men with any significant hair loss at age 30 had a 29% reduced risk of prostate cancer, the researchers found.
Then Wright's team looked at a smaller subgroup -- men who were balding in their 30s at both the top of the head and the forehead -- and were over age 60 at the reference date.
In this subgroup, he found a risk reduction of 45%.
Balding and Lower Prostate Cancer Risk: Why?
Previous studies have found conflicting results when looking at the relationship between baldness and prostate cancer risk, Wright says. Some studies found an increased risk with baldness and others found no change in risk, regardless of hair patterns.
But his study, unlike others that looked only at baldness close to the diagnosis date, looks back decades.
Even so, he says, ''Our findings are a little bit counterintuitive."
He can't explain the finding linking baldness and a reduction in prostate cancer risk. ''It's not as simple as DHT and testosterone levels," he tells WebMD. "There is a very complex environment going on."
Genetic differences may help explain the link, he says. For instance, he says, a genetic variant in the male hormone receptor gene can affect cancer development and male pattern baldness.
They will look next at genetic data from the men to try and understand the link.
Balding and Lower Prostate Cancer Risk: Other Views
The new findings fly in the face of traditional thinking, says Leonard Lichtenfeld, MD, deputy chief medical officer of the American Cancer Society, who reviewed the findings for WebMD.
''The old thinking is, the balder you are, the higher your risk of prostate cancer," he says, and that link was thought to be associated with testosterone levels, with both baldness and prostate cancer thought to be sensitive to hormone levels.
''This study is saying just the opposite," Lichtenfeld says. ''This concept doesn't fit the concept of the way things should work." But, he says, ''you always have to be willing to look at new evidence."
He agrees with Wright that the relationship between hormone levels and baldness and prostate cancer is complicated. "It may have to do with other genetic changes that we don't fully understand at this time," he says.