(NewsTarget) Merck's popular hair loss drug Propecia may alter the results of the prostate-specific antigen (PSA) prostate cancer screening test, which could prevent detection of the disease, according to a new study appearing in the Dec. 5 online edition of the journal Lancet Oncology.
The active ingredient in Propecia -- finasteride -- was initially developed to treat enlarged prostate by targeting an enzyme that causes the prostate to grow. That formulation of finasteride eventually became Proscar, a drug aimed at lowering rates of prostate cancer. Propecia -- which contains one-fifth the amount of finasteride as Proscar -- was later marketed as a drug to prevent hair loss.
While doctors have known for years that Proscar can falsely lower PSA levels -- an indicator of prostate health -- they were unsure whether or not Propecia caused the same alteration.
Researchers led by Dr. Anthony D'Amico, chief of genitourinary radiation oncology at Boston's Brigham and Women's Hospital, split 355 men with male pattern baldness between the ages of 40 and 60 into two groups. The first group took Propecia, while the second group was given a placebo. The researchers then tested each group's PSA levels over 48 weeks, searching for possible changes.
The researchers found that PSA levels in men aged 40 to 49 in the Propecia group dropped by 40 percent during the study, while men 50 to 60 in the Propecia group experienced a 50 percent drop in PSA. Men taking placebo experienced a 13 percent PSA increase.
D'Amico warned men who regularly use Propecia that they "should be aware that their PSA will be falsely lowered," and called on physicians to re-assess how they evaluate PSA tests in men who take Propecia.
According to consumer advocate Mike Adams, author of "How to Prevent and Reverse Prostate Cancer," a number of FDA-approved drugs have unintended side effects that can mask or exaggerate symptoms of disease. However, Adams said, the PSA test for indicating prostate cancer has been declared inaccurate by its own founder.
"The fact that this hair loss drug conceals PSA test results is not as significant as many people fear," Adams said. "In reality, prostate cancer is easily prevented through nutritional therapies that include healing foods and supplements combined with regular physical exercise."
Adams encourages men to research foods and herbs to consume for prostate health at www.HealingFoodReference.com.