Testosterone therapy and risk for prostate cancer (redux)

The question of whether long-term exposure to testosterone therapy is associated with a significant increase in risk for a diagnosis of prostate cancer (and particularly clinically significant or high-risk prostate cancer) remains a matter of debate. A new paper by Baillargeon et al. in the Journal of Urology has added to our knowledge on this topic … but it has not resolved the issue, as the authors themselves are very careful to note.

The authors sought to determine whether treatment with testosterone therapy (for hypogonadism or other reasons) for a 5-year period was associated with an increase in the likelihood of a diagnosis of  high-grade prostate cancer (i.e., the patient had a cancer with a Gleason score of 7 or higher or received primary treatment with androgen deprivation therapy). To do this they used data from the US Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database for the period January 1, 2001 through December 31, 2006.

Now it should be pointed out that the use of this database over the 2001 to 2006 time frame immediately presents certain problems in knowing how to interpret the data:

  • It is limited almost exclusively to men of 65 years and older at the time they may have started on testosterone supplementation.
  • Because the patients had to have medical records available for a minimum of 5 years prior to diagnosis with prostate cancer, it is limited exclusively to men diagnosed with prostate cancer at age 70 or older.
  • The vast majority of men in this study were being treated with supplemental testosterone through the use of testosterone injections of some type (whereas most men getting testosterone supplements today are using things like oral testosterone supplements, testosterone patches, etc.).

With that said, and with the recognition that this type of retrospective epidemiological analysis can only give is insight to “associations” as opposed to helping us understand cause and effect, here is what Baillargeon and his colleagues were able to show:

  • There were 52,579 men diagnosed with prostate cancer during the study period and recorded in the SEER-Medicare database.
  • Of these 52,579 men with prostate cancer
    • 564 (1.1 percent) had a 5-year history of testosterone use.
      • 448 (0.9 percent) had a low or moderate Gleason score.
      • 116 (0.2 percent) had a high Gleason score.
    • 51,945 (98.8 percent) had no history of testosterone use.
      • 37,922 (72.1 percent) had a low or moderate Gleason score.
      • 14,023 (26.7 percent) had a high Gleason score.
  • Compared to non-users, testosterone users had
    • A higher degree of co-morbid disease (i.e., a Charlson score of ≥ 3)
    • A higher prevalance of conditions for which testosterone therapy is indicated
    • A greater number of PSA tests in the 2 years prior to diagnosis
  • Compared to non-users, testosterone users had no increase in risk for diagnosis with high-grade prostate cancer (odds ratio [OR] = 0.84).
  • There was no increase in risk for diagnosis with high-grade prostate cancer among men who had received an increasing number of injections of testosterone therapy.

The authors conclude only that:

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.

It is important to note that they make no comment about the risk-benefit assessment of men who do not have any clear evidence of testosterone deficiency. They are also very careful to state that:

Because our study was restricted to a sample of patients with prostate cancer, we could not make any inferences about whether testosterone therapy was associated with an increased risk of prostate cancer in general.

So, what this study does certainly appear to confirm is that among older men on Medicare who require testosterone therapy for good medical reasons, there is no increase in risk for diagnosis with high-grade prostate cancer at up to 5 years of follow-up. This is certainly useful and important information for clinicians treating such older men. The broader question of whether using testosterone supplementation as a kind of physiological “booster” — without supporting evidence of medical need — remains unanswered.

5 Responses

  1. Seems like a good time to keep beating my drum re this; low T (and the things that cause it) is the evil, not normal levels of T, properly administered to truly hypogonadal men. TRT is a life saver!

  2. Can we assume that the objective of the therapy was typically to bring testosterone for these patients up to the normal range? That seems likely. If so, then the men in this study were likely not having testosterone raised above the normal range; in other words, they were apparently becoming more like the average man, not like a man with elevated and arguably more risky testosterone.

  3. Jim, yes, correct assumption. TRT is to do just that; bring T levels to normal amounts.

  4. Jim (and others):

    It is extremely important to understand the distinctions between four different uses of testosterone supplementation:

    (a) The normal and entirely appropriate use of TRT in hypogonadal men who have low testosterone levels for common and less common clinical conditions (which was the case for almost all of the men in this study as far as I can tell)

    (b) The use of TRT among (normally older) men who have testosterone levels in the normal range and who believe that boosting their testosterone levels will boost their level of energy and vigor (which has become increasingly common over the past 5-10 years and which may be associated with risks for a variety of disorders, of which prostate cancer is just one)

    (c) The use of TRT among younger males as a way to boost their athletic performance, build additional muscle, etc. (which is generally not a very good idea for a variety of reasons, but we know that it goes on)

    (d) The use of TRT by prostate cancer patients whose testosterone levels have been dropped into a very low range through the use of androgen deprivation therapy (which may be beneficial but may come with risks that are still not well established in at least some men)

  5. Item (b) is the one that is causing the most controversy, I believe. It’s masking other issues (obesity, poor diet, lack of exercise, etc.).

    Item (c) is illegal as far as I know, but yes, of course it goes on. Think body building, etc.

    Re item (d), we do know the harms ADT does to the male body: weight gain, bone loss, increased risk of cardiovascular disease, etc.

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