Re-evaluating conventional wisdom on testosterone therapy

12 March 2016

“In the 1980s, testosterone was the devil when it came to prostate cancer. High testosterone levels were seen as feeding a hungry tumour, or even throwing gasoline on a bonfire.” As the final speaker of Plenary Session 1, Dr. Abraham Morgentaler (Boston, USA) chose to give a first-hand account of his re-assessment of Nobel Prize-winning research that had become conventional wisdom in the decades since. In his own words: “Everything we once learned about testosterone is wrong.”

Morgentaler chronicled his experiences of treating men with testosterone injections in 1988. The men were all healthy, apart from low testosterone levels. Men reported improved erections, libido and orgasms, with the added benefit of greater feelings of wellbeing and mood. At the time, this defied standard practice, as conventional wisdom was that low testosterone protected against PCa.

“From the early 1990s, I began performing sextant prostate biopsies prior to testosterone therapy to rule out PCa. All men had low testosterone, PSA values below 4.0ng/ml. Cancers were nevertheless diagnosed in 11 of the first 77 men, a similar cancer rate as men with an elevated PSA.”

Morgentaler decided to examine the origin of the concerning association between high testosterone levels and the onset of prostate cancer, searching Harvard basements for Charles Huggins’ “Studies on Prostate Cancer”, published in Cancer Research in 1941. Huggins was awarded the Nobel Prize in 1966 for his research, which concluded that “cancer of the prostate is activated by testosterone injections.”

“But how strong was Huggins’ conclusion regarding the dangers of testosterone injections?” Morgentaler asked. “Only three men received testosterone injections for fourteen days, two men had results reported and one had been previously castrated and androgen-deprived. His conclusion was based on one patient, treated for only 14 days.”

Renewed research

Upon this realisation, Morgentaler conducted fresh research into the correlation between PCa and testosterone levels. “For the first time since Huggins in 1941 did someone bother to look at what testosterone does to prostate cancer!” Morgentaler proceeded to present results from twenty years’ worth of subsequent studies, all indicating that the relationship between high testosterone levels and the development of PCa is anything but a certainty.

On the contrary, placebo-controlled trials have since revealed that PCa rates do not differ in men receiving testosterone therapy vs. placebo. Morgentaler then explained the concept of “saturation” on a molecular basis, pointing out the finite amount of androgen receptors in the target cell, limiting the amount of DHT reaching the cell’s nucleus.

“A more accurate and effective metaphor of the relationship between testosterone and PCa, rather than feeding an endlessly hungry and growing tumour is watering a thirsty plant. “You can give it water for days, but a small plotted plant will never become a redwood tree.”

“In conclusion: everything we once learned about testosterone is wrong. There is no evidence that high levels contribute to increased PCa risk, low levels are not protective. The important exception is androgen-deprived men.”

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