Stacy Loeb, MD
In a Swedish study reported in the Journal of Clinical Oncology, Stacy Loeb, MD, of New York University, and colleagues found that use of testosterone replacement therapy was not associated with an increased risk of prostate cancer and was associated with a lower risk of aggressive cancer among men developing the disease.
The study was a nested case-control study in the National Prostate Cancer Register of Sweden, including all 38,570 prostate cancer cases diagnosed between 2009 to 2012, and 192,838 age-matched men without prostate cancer.
Prescriptions for testosterone replacement therapy were filled by 284 patients with prostate cancer (1%) and 1,378 control cases (1%). In multivariate analysis, there was no association between the use of testosterone replacement therapy and overall prostate cancer risk (odds ratio [OR] = 1.03, 95% confidence interval [CI] = 0.90–1.17). Among patients with prostate cancer, those receiving testosterone replacement therapy were more likely to have favorable-risk disease (OR = 1.35, 95% CI = 1.16–1.56) and less likely to have aggressive disease (OR = 0.50, 95% CI = 0.37–0.67). The increase in favorable-risk prostate cancer was evident within the first year of testosterone replacement therapy (OR = 1.61, 95% CI = 1.10–2.34); in contrast, the reduction in risk for aggressive prostate cancer became evident only with testosterone replacement therapy exposure beginning more than 1 year before diagnosis (OR = 0.44, 95% CI = 0.32–0.61).
Men who received testosterone replacement therapy were more likely to have undergone prostate biopsy than men who did not, and patients with prostate cancer who underwent biopsy were more likely to have favorable-risk vs aggressive disease. After adjusting for previous biopsy findings, testosterone replacement therapy remained significantly associated with greater likelihood of favorable-risk prostate cancer and a lower risk of aggressive prostate cancer among men developing the disease.
The investigators concluded: “The early increase in favorable-risk prostate cancer among patients who received [testosterone replacement therapy] suggests a detection bias, whereas the decrease in risk of aggressive prostate cancer is a novel finding that warrants further investigation.” ■
The study was supported by the Swedish Research Council, the Swedish Cancer Society, Louis Feil Charitable Lead Trust, and Laura and Isaac Perlmutter Cancer Center at New York University Langone Medical Center.