Men with a specific pattern of hair loss by age 45 are 40% more likely to be diagnosed with aggressive prostate cancer, according to a study conducted by researchers from the National Cancer Institute and published in the Journal of Clinical Oncology.
“Our study found an increased risk for aggressive prostate cancer only in men with a very specific pattern of hair loss, baldness at the front and moderate hair-thinning on the crown of the head, at the age of 45,” senior author Michael B. Cook, PhD, said. “But we saw no increased risk for any form of prostate cancer in men with other hair-loss patterns.”
Frontal baldness most dangerous
Previous research has shown that hair loss and prostate cancer share a number of risk factors, including a family history and elevated levels of the male sex hormone dihydrotestosterone (DHT).
A 2013 study by researchers from the University of Pennsylvania found that, among African American men between the ages of about 35 and 90, those with baldness were about 69% more likely to be diagnosed with prostate cancer. That study, however, included only about 500 participants.
The new study included 39,070 men between the ages of 55 and 74 (mostly in their 70s) who were asked to use a pictorial tool to demonstrate what their hair-loss patterns had been like at the age of 45. All participants were taking part in the US PLCO Cancer Screening Trial and had no history of cancer, with the exception of non-melanoma skin cancer, at the study’s start. Approximately half reported that they had experienced some form of hair loss already by age 45.
In three years of followup, 1,138 participants were diagnosed with prostate cancer, and 571 of these cases (51%) were classified as aggressive. The average age at diagnosis was 72.
The researchers found that men who reported frontal and moderate crown baldness at age 45 were 40% more likely to be diagnosed with prostate cancer than men without any hair loss at that age. Men with frontal baldness were actually twice as likely to be diagnosed with aggressive prostate cancer. There was no connection, however, between other forms of baldness and aggressive prostate cancer, or between any form of baldness and non-aggressive prostate cancer.
The study is the largest to date to show a connection between baldness and prostate cancer.
“While our data show a strong possibility for a link between the development of baldness and aggressive prostate cancer, it’s too soon to apply these findings to patient care,” Cook said. “There is a wide confidence in our estimated 40% increased risk. The lower confidence limit suggests just a 7% increased risk in these men.”
More research underway
The authors emphasized that further research is needed, both to confirm the connection and to explain it.
“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,” Cook said.
The researchers are already planning two followup studies, looking not just at the risk of developing prostate cancer but also at the risk of dying from it. One study will use a dermatological assessment to determine baldness, rather than using the less reliable self-reporting recall method.
Two other studies are currently underway to examine a potential connection between prostate cancer and baldness: 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.