Balding Before 30 May Cut Prostate Cancer Risk
Balding and Lower Prostate Cancer Risk: Why? continued...
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.
The factors triggering male pattern baldness and prostate cancer may be the same process or may be different, Lichtenfeld says. "Testosterone and DHT may not be the whole story. More subtle genetic changes within the scalp and the prostate may actually explain these findings."
Another expert says more research is needed.
"I think it's going to take a lot of data to show an easy link between baldness and prostate cancer," says Peter Galier, MD, staff physician at Santa Monica-UCLA & Orthopaedic Hospital in Santa Monica, Calif., and associate professor of medicine at the University of California Los Angeles David Geffen School of Medicine.
Like other experts, he says there may be tissue-specific effects of hormones. It's known, he says, that men with high levels of DHT can lose their hair and also have enlarged [but not necessarily cancerous] prostates. ''If you lower DHT, he grows hair and the prostate shrinks."
But perhaps, Galier says, a man somehow has higher levels of DHT in the scalp than in the prostate, explaining the reduced risk found among bald men in Wright's study. More study is needed to replicate and clarify the link, he says.


