Men with very low testosterone levels may face an increased risk of developing cancer and dying from the disease later in life, according to a major international study. The findings suggest that testosterone levels could provide an early clue to future health risks, potentially years or even decades before cancer is diagnosed.
Researchers found that men with low testosterone had an 18 percent higher risk of dying from cancer. However, the relationship was not the same for every type of cancer. Surprisingly, testosterone levels were not associated with prostate cancer risk. Instead, prostate cancer was more closely linked to low levels of two other hormones, sex hormone-binding globulin (SHBG) and luteinizing hormone.
The research comes from the Androgens In Men Study (AIMS), an international collaboration led by Professor Bu Yeap at The University of Western Australia. The project investigates how different sex hormones relate to cancer risk and other health outcomes in men.
Study Tracks Testosterone and Cancer Risk in 26,000 Men
Published in the journal Lancet Healthy Longevity, the study examined data from more than 26,000 men participating in 11 long-running studies across Australia, the United States, and Europe.
Researchers analyzed hormone concentrations in blood samples collected earlier in the men’s lives. They then compared those measurements with cancer diagnoses and deaths recorded over the following decades, allowing them to investigate whether hormone levels were associated with future cancer outcomes.
The analysis included testosterone, dihydrotestosterone (DHT), SHBG, and luteinizing hormone. Luteinizing hormone is produced by the pituitary gland and signals the testes to produce testosterone.
“We wanted to know whether the concentration of these hormones in the blood was related to the risk of men being diagnosed with, or dying from, cancer into the future,” Professor Yeap said.
“What we saw was that if a man had low testosterone levels – in the lowest one-fifth compared to the highest one-fifth of the range – their subsequent risk of dying from cancer was higher, even after allowing for age and other health-related factors.”
Cancer Risk Increased Below a Key Testosterone Level
The researchers identified a testosterone concentration below which cancer risk began to rise. According to Professor Yeap, testosterone levels in healthy younger men typically range from 10 to 30 nanomoles per liter (nmol/L), although concentrations generally decrease with age.
Testosterone levels can also be influenced by factors that people may be able to change, including body mass index and physical activity. Certain medical conditions, such as diabetes, can affect testosterone concentrations as well.
“We saw that when baseline testosterone was below 8.6 nmol/L, subsequent cancer risk started increasing,” Professor Yeap said.
“This suggests low testosterone is an important biomarker, so it’s possible that looking at testosterone levels could help us identify men who might do poorly if they get cancer down the track.”
These findings raise the possibility that testosterone measurements could help doctors recognize men who may face greater health risks in the future. However, the results show an association and do not establish that low testosterone itself causes cancer.
A Surprising Finding About Prostate Cancer
Because testosterone plays an important role in male reproductive health, researchers also investigated whether naturally occurring testosterone levels influenced the likelihood of developing prostate cancer.
The question has particular medical significance because lowering testosterone is an established treatment for prostate cancer. However, the new analysis found no evidence that a man’s natural testosterone concentration was associated with his risk of developing the disease.
“Since reducing testosterone levels is a treatment for prostate cancer there’s always been a question of whether the amount of testosterone your own body makes relates to your risk of prostate cancer but based on our findings there’s no evidence they are related,” Professor Yeap said.
“We did find, however, that men with low levels of SHBG and luteinizing hormone were at higher risk of prostate cancer.”
The results highlight an important distinction between testosterone and other hormones involved in male reproductive function. Although low testosterone was associated with higher overall cancer risk and mortality, prostate cancer showed a different pattern of hormonal associations.
Why Low Testosterone Does Not Mean Men Need Supplements
Despite the connection between low testosterone and cancer outcomes, Professor Yeap emphasized that the findings should not be interpreted as a recommendation to take testosterone supplements to prevent cancer.
“While we’ve shown low levels are associated with increased risk, we haven’t got any evidence yet that actually giving men testosterone will reduce that risk,” he said.
Instead, unexpectedly low testosterone could be a reason to investigate a person’s overall health. A medical evaluation may uncover underlying conditions or risk factors that require attention, even when there is no evidence of a problem affecting the testes.
“What we would say to men is if they are found for whatever reason to be low in testosterone, it’s important to go to the doctor for a full checkup. It may not show any sign of testicular disease, but it might show other health issues or risk factors they need to address.
“It could be a wake-up call and encouragement for men to engage in more healthy lifestyle behaviors, and to get regular, holistic checkups to stay on top of their health.”