Exposure to testosterone therapy over a 5-year period does not increase the risk of aggressive prostate cancer, according to a new population-based study. Also, the risk of high-grade prostate cancer does not increase according to the total number of testosterone injections.
“Given the slow growth of prostate cancer development, this investigation offers novel and important information to physicians, patients, and the general public,” said lead author Jacques Baillargeon, PhD, Professor of Epidemiology in the Department of Preventative Medicine and Community Health at the University of Texas Medical Branch at Galveston.
Many longitudinal studies have shown there is no increased risk of prostate cancer incidence associated with testosterone use. Prostate cancer incidence in men who are receiving testosterone therapy is considered to be similar to that in men who are not. A large meta-analysis of 18 prospective studies that included more than 3500 men found no association between serum androgen levels and the risk of prostate cancer development.
However, no population-based studies have examined the association of high-grade prostate cancer with testosterone exposure beyond 1 year.
Using Surveillance, Epidemiology and End Results-Medicare linked data, the researchers identified 52,579 men who received a diagnosis of prostate cancer between January 2001 and December 2006. The men had a minimum of 5 years continuous enrollment in Medicare before their cancer diagnosis.
In the 5 years before their diagnosis, 574 men had a history of testosterone use. The distributions of age, ethnicity/race, year of diagnosis, and marital status were comparable between testosterone users and nonusers.
The study analyzed data from diagnosis codes included in charges for outpatient and hospitalization services and physician claims.
After adjusting for demographic and clinical characteristics, a logistic regression analysis found that exposure to testosterone therapy was not associated with an increased risk of high-grade prostate cancer (OR, 0.84) or receipt of primary androgen deprivation therapy after diagnosis (OR, 0.97).
In addition, the risk of high-grade prostate cancer did not increase according to the total number of testosterone injections.
“We examined whether exposure to testosterone during a 5-year period was associated with an increased risk of high grade prostate cancer and whether this risk increased in a dose-response fashion with the cumulative number of testosterone injections,” said Dr Baillargeon.
“Our finding that testosterone therapy was not associated with an increased risk of high-grade prostate cancer may provide important information regarding the risk-benefit assessment for men with testosterone deficiency considering treatment.”