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Early Balding Found to Double Prostate Cancer Risk
Major Finding: The men with prostate cancer were twice as likely to have had male pattern baldness at age 20 (OR 2.01).Data Source: Men with a...
NEW ORLEANS – Men infected with genital herpes as young adults are at a twofold increased risk of developing prostate cancer by middle age, according to a nested case-control study conducted in the U.S. military.
The prostate cancer study findings have important practical implication for physicians. "When you diagnose genital herpes in someone who's 17, hook him up with a urologist pretty quickly. He needs to start having urologic exams and PSA screening at an early age," Dr. Theodore Rosen said at the annual meeting of the American Academy of Dermatology.
Dr. Theodore Rosen
"Seventeen percent of American men get prostate cancer, and we've never really known what the risk factors are. This study very strongly suggests herpes simplex virus-2 infection is an important one," added Dr. Rosen, professor of dermatology at Baylor College of Medicine, Houston.
The study, led by investigators at the University of Iowa in Iowa City, utilized stored sera obtained from the U.S. Department of Defense Serum Repository, a one-of-a-kind facility containing multiple samples from all active-duty military personnel.
The study population consisted of 267 military men diagnosed with prostate cancer at a median age of 48 years – two full decades younger than the median age at diagnosis in the general population – and an equal number of controls matched for age, race, branch of service, rank, marital status, and serum collection dates.
The investigators analyzed two stored serum specimens from each participant for antibodies to three common sexually transmitted infections (STIs): herpes simplex virus-2 (HSV-2), human papillomavirus, and Chlamydia trachomatis. One serum sample was collected a year before diagnosis of prostate cancer, the other about 8 years prior to diagnosis.
There was no association between prostate cancer and serologic evidence of infection with any of the pathogens in the more recent sample. In the older sample, however, serologic evidence of HSV-2 infection was associated with an adjusted twofold increased odds of subsequent diagnosis of prostate cancer (Cancer Epidemiol. Biomarkers Prev. 2009;18:2665-71).
"If this association is causal, then our findings would suggest a long latency period for prostate cancer development after HSV-2 infection," the investigators noted.
They pointed out that infectious agents have previously been associated with a wide range of other cancers, including malignancies of the liver, stomach, bladder, and cervix, as well as with Kaposi sarcoma.
The investigators chose to look at the association between STIs and prostate cancer in a military population because prostate-specific antigen screening is a covered benefit in the U.S. military, so undiagnosed prostate cancer is less likely than in civilian populations. Access to stored sera overcame a major limitation of most epidemiologic studies of STIs and cancer risk, namely the reliance upon self-report of STIs and resultant vulnerability to recall bias.
Dr. Rosen noted that GlaxoSmithKline has announced it is halting all further development of its long-awaited herpes simplex vaccine, known as Simplirix.
The impetus for the corporate announcement was the finding that the vaccine proved ineffective in an 8-year, phase III clinical trial cosponsored by the National Institute of Allergy and Infectious Diseases in which more than 8,300 women were vaccinated.
The STI/prostate cancer study was funded by the Department of Defense. Dr. Rosen declared having no relevant financial interests.