High testosterone linked to prostate cancer risk

Men with naturally high concentrations of testosterone in their blood face an elevated risk of prostate cancer, according to data collected since 1961. If testosterone concentrations that have been artificially elevated carry the same danger, then men who use hormone supplements to combat age-related problems could be in for trouble, says a group of Baltimore researchers.

J. Kellogg Parsons of Johns Hopkins Medical Institutions in Baltimore and his colleagues used nearly 40 years of test results from 794 men to assess the relationship between prostate cancer and variations in blood concentrations of testosterone. All the volunteers were healthy and living in Baltimore when they joined the study decades ago, and each underwent multiple testosterone tests.

The scientists found that men with the highest concentrations of what’s known as free testosterone were 2.6 times as likely to get prostate cancer as were men with the lowest concentrations of that sex hormone.

The link was less strong in men older than 45. Within that demographic, the subgroup with the highest free testosterone faced 1.9 times as great a cancer risk as the subgroup with the least of the hormone did. Physicians are most concerned about the effects of testosterone among older men because they’re the group most likely to take synthetic testosterone for symptoms such as declining libido (SN: 5/10/03, p. 296: Unproven Elixir).

“[O]lder men receiving testosterone therapy should be carefully monitored for the development of … prostate cancer,” the researchers say in the September Cancer Epidemiology Biomarkers & Prevention.