Testosterone replacement therapy and prostate cancer risk

A new article in the Journal of Clinical Oncology has further undermined the long-held belief that there was an inherently increased risk for prostate cancer among men who received treatment with testosterone replacement therapy (TRT) for low testosterone levels.

The new paper by Loeb et al. is based on an analysis of data from the National Prostate Cancer Register of Sweden, including data from all the 38,000+ men in Sweden who were diagnosed with prostate cancer between 2009 and 2012 and comparable data from > 192,000 age-matched “control” patients who were free of prostate cancer over the same time frame.

Here are the basic findings of the study:

  • 38,570 men in Sweden were diagnosed with prostate cancer between 2009 and 2012.
  • Data from these patients were compared to data from 192,838 age-matched men who were free of prostate cancer.
  • Prescriptions for TRT had been filled by
    • 284/38,570 men diagnosed with prostate cancer (1 percent)
    • 1,378/192,838 men who were free of prostate cancer (1 percent)
  • Based on a multivariable analysis, the authors found that
    • There was no association between treatment with TRT and overall risk for prostate cancer (odds ratio [OR] = 1.03.
    • Men treated with TRT had
      • More favorable-risk prostate cancer (OR = 1.35)
      • A lower risk of aggressive prostate cancer (OR = 0.50)
    • The increase in risk for favorable-risk prostate cancer could be observed within the first year of TRT (OR = 1.61).
    • The reduction in risk for aggressive prostate cancer was observed after > 1 year of TRT (OR = 0.44).
  • After adjusting for previous biopsy findings as an indicator of diagnostic activity, TRT remained significantly associated with more favorable-risk prostate cancer and lower risk of aggressive prostate cancer.

Loeb and her colleagues conclude that

The early increase in favorable-risk prostate cancer among patients who received TRT suggests a detection bias, whereas the decrease in risk of aggressive prostate cancer is a novel finding that warrants further investigation.

It is important to appreciate that a study like this doesn’t “prove” that there is no association between TRT and risk for clinically significant prostate cancer. However, as indicated above, it does add to the accumulating evidence that TRT is probably not a major risk factor for clinically significant prostate cancer for the majority of men who were previously undiagnosed.

Note that this paper provides no information about the risks associated with the use of TRT in men who have previously been diagnosed and treated for prostate cancer, which is a different situation entirely.

One Response

  1. This certainly does appear to be the trend. Slowly putting that old beast to pasture … :-)

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