In case you haven’t noticed, there has been a massive surge in the use of testosterone supplements by older men in the past 10 years or so (as we seek to maintain the bizarre illusion that we are really still in our early 30s and might still be able to win an Olympic gold medal in [pick your sport]).
Now come some far from surprising findings published in a report by Hyde et al., and based on data from a large, Australian study of healthy aging (the so-called Health in Men Study).
The goal of this specific element of the Health in Men Study was to investigate whether serum levels of testosterone and related hormones are associated with incident prostate, lung, and colorectal cancers. Between 2001 and 2004, the research team had collected a wide variety of data (including blood samples) from a cohort of 3,635 apparently healthy men living in the community and aged between 70 and 88 years of age (with an average age of 77 years). They subsequently obtained notifications of diagnoses of cancer among this group of men via linkages to their electronic medical records (through December 31, 2010).
Here are the key study findings:
- The average (mean) follow-up period was 6.7 ± 1.8 years.
- During that follow-up period, the researchers identified
- 297 cases of prostate cancer
- 104 cases of colorectal cancer
- 82 cases of lung cancer
- Through the use of sophisticated statistical models it was shown that
- Each one-point increase in the standard deviation above the average in free testosterone level was associated with a 9 percent increase in risk for diagnosis of prostate cancer.
- Other hormone levels were not significantly associated with any increase in risk for diagnosis of prostate cancer.
- There were no significant associations between hormonal levels and risk for diagnosis of colorectal cancer.
- Men with higher total testosterone levels appeared to be at increased risk for diagnosis of lung cancer.
- Men with higher free testosterone levels also appeared to be at increased risk for diagnosis of lung cancer.
- The apparent increases in risk for diagnosis of lung cancer were still evident after exclusion of data from current smokers.
Hyde and her colleagues conclude that elevated levels of free testosterone were associated with an increased risk for diagnosis of prostate cancer and that elevated testosterone levels “may also” be associated with increased risk for diagnosis of lung cancer.
Now it needs to be clearly stated that “associations” are not the same as “cause and effect”. In other words, we cannot be certain that elevated testosterone levels are a direct cause of increased levels of diagnosis of prostate and lung cancer in men > 70 years of age. However, there is a clear warning here to men about the possible risks asociated with testosterone supplementation. … Raising serum testosterone levels above normal, healthy levels may significantly increase risk for diagnosis of some cancers (prostate cancer included) as one ages.
This is not a new idea. In America, where advertising of prescription drugs on television and in magazines is commonplace, many of us will have see advertising for testosterone supplments, and (ideally) noted the warning that use of such supplements may be associated with increased risk for prostate cancer.
Hyde is quoted in The Financial Express as saying that, while higher levels of testosterone were unlikely to actually cause cancer, they might make an existing cancer grow faster, and that “We need to conduct large-scale, long-term trials of testosterone therapy to see if this risk applies to men receiving testosterone.”