A large trial found that men with moderate baldness at age 45 had an increased risk of developing aggressive prostate cancer compared with men with no baldness.
In the largest single prospective trial to date evaluating a possible link between prostate cancer and male pattern baldness, researchers found that men who had moderate baldness in the front and crown of the head at age 45 had up to a 40% increased risk of developing aggressive prostate cancer compared with men who had no baldness. Other types of baldness patterns were not linked to increased prostate cancer risk. The study is published in the Journal of Clinical Oncology.
Still, these results are not practice-changing and should be interpreted conservatively, lead study author Michael B. Cook, PhD, a researcher in the Division of Cancer Epidemiology and Genetics at the National Cancer Institute in Bethesda, Maryland told CancerNetwork. “There is a wide confidence in our estimated 40% increased risk. The lower confidence limit suggests just a 7% increased risk in these men.”
“Men with any pattern of male pattern baldness at age 45 years should not be additionally concerned about their individual risk of prostate cancer,” said Cook.
Cook acknowledged that while in the future, male pattern baldness might play a small role in estimating a man’s risk of prostate cancer and contributing to a decision on screening, further studies are needed to validate the connection.
In a released statement, Charles Ryan, MD, an associate clinical professor who specializes in prostate cancer at the Helen Diller Family Comprehensive Cancer Center at the University of California San Francisco, agreed. "Previous research linking baldness and prostate cancer has been inconclusive, but this large study suggests a significant link between high-risk prostate cancer and hair loss-and suggests that men with hair loss may need to be followed more closely. More evidence is needed, however, before we can routinely consider baldness in prostate cancer screening recommendations."
The researchers analyzed a cohort of 39,070 men between the ages of 55 and 74, who took part in the prospective Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. After a median follow-up of 2.78 years, 1,138 men were diagnosed with prostate cancer-and of these case, 571 (51%) were aggressive. The average age at diagnosis was 72. Male pattern baldness by age 45 was self-reported by 53.4% of men in the study. Among this group, 46.4% had frontal baldness and 23.5% had frontal plus mild crown balding and 18.1% had frontal plus moderate crown balding.
Prior research has shown that male pattern baldness shares pathologic mechanisms with prostate cancer-advanced age, heritability, and endogenous hormone levels-yet epidemiologic studies have so far been inconclusive about the connection. Two cohort studies as well as a meta-analysis of seven case-controlled studies appear to support the connection, according to Cook. Still, he cautions that direct comparisons of studies can be difficult for many reasons, including different ages when baldness is assessed and different types of baldness patterns that are evaluated.
Dihydrotestosterone (DHT) is associated with prostate cancer progression and has also been linked to male pattern baldness, as these men have higher circulating levels of this androgen.
“If the association between frontal plus moderate vertex balding and increased aggressive prostate cancer risk is replicated in other studies, then mechanistic studies may be warranted to help understand the links underlying this association,” said Cook. Cook and his colleagues are now working to understand the relationship between prostate cancer risk and baldness.
Two other cohort studies currently assessing the association between prostate cancer and baldness are the Vitamins and Lifestyle (VITAL) Cohort Study by researchers at the Fred Hutchinson Cancer Research Center, and the National Health and Nutrition Examination Survey (NHANES) I follow-up study (NHEFS) by the Centers for Disease Control.