A pooled analysis of more than 26,000 men found that those with the lowest testosterone levels faced an 18% higher risk of dying from cancer than men with the highest levels. The data came from 11 long-running studies in Australia, the United States and Europe, and the work was published in The Lancet Healthy Longevity. Nothing in it shows that taking testosterone lowers that risk, and the authors do not recommend supplements for cancer prevention.
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Professor Bu Yeap of the University of Western Australia, who leads the international Androgens In Men Study collaboration, said the men’s later risk of dying from cancer stayed higher even after allowing for age and other health factors. Yeap added that there is no evidence yet that giving men testosterone will reduce that risk. ScienceDaily posted the story on Nov. 8, while the university’s own announcement is dated June 23.
Lowest fifth versus highest fifth, and the 8.6 nmol/L threshold
The paper, Associations of testosterone, sex hormone-binding globulin, and related hormones with risks of cancer death, incident cancer, and incident prostate cancer in men, runs in volume 7, issue 6 of the journal and lists 29 authors, with Ross J. Marriott first and Yeap last. According to the University of Western Australia’s announcement, blood hormone levels measured earlier in life were matched to later cancer outcomes for the same men, over follow-up spanning decades. The hormones examined were testosterone, dihydrotestosterone, sex hormone-binding globulin and luteinizing hormone.
The 18% figure compares the lowest one-fifth of testosterone levels with the highest one-fifth, after adjusting for age and other health factors. Cancer risk began rising when baseline testosterone fell below 8.6 nmol/L. For context, ScienceDaily’s version of the story notes that healthy younger men typically sit between 10 and 30 nmol/L and that levels generally decline with age.
Prostate cancer and the other hormones in the analysis
Prostate cancer behaved differently from cancer death overall. Testosterone was not associated with prostate cancer risk, but men with low levels of sex hormone-binding globulin and of luteinizing hormone did have higher prostate cancer risk. So the study does not say that low testosterone makes prostate cancer more likely, and the signal it found sits in other hormones for that particular disease.
Hormone levels were taken at baseline.
That design has a built-in limit. A single blood draw early in follow-up says where a man stood on that day, not how his levels moved over the following decades, and the analysis ties the baseline reading to what happened afterward. It is also why the 8.6 nmol/L point is best read as a place where the pattern began to bend in this pooled group, not as a diagnostic cutoff for any individual patient walking into a clinic.
The association comes with the usual observational warnings. Body mass index, physical activity and conditions such as diabetes can all affect testosterone, which means low levels may be a marker of poorer general health instead of a direct cause of cancer deaths. The authors adjusted for age and other health factors, but adjustment cannot remove every difference between men whose hormone levels sit at opposite ends of the range, and the news summary cautions that the full paper should be checked for effect sizes, confidence intervals and methods.
The scale of the pooled data is its main strength. Gathering more than 26,000 men from 11 cohorts across three continents gives far more statistical weight than any single cohort could, and it let the researchers examine several hormones side by side, not testosterone alone. The size does not change the study’s nature, though. Pooled individual-participant data still describe association, and the men were not assigned to different testosterone levels.
Testosterone treatment is a separate question
The hormone-level finding says nothing yet about whether replacing testosterone changes anything. The largest trial of testosterone replacement in men with low levels, TRAVERSE, examined cardiovascular safety rather than cancer. A Cleveland Clinic account of the trial reports major adverse cardiac events in 7.0% of men on testosterone and 7.3% of men on placebo over a mean of 22 months, alongside higher rates of atrial fibrillation, acute kidney injury and venous blood clots on testosterone. Senior author Steven Nissen cautioned that the results should not justify widespread prescription.
Healio’s coverage adds that fractures were more frequent on testosterone, 154 confirmed versus 97 on placebo, and that prostate cancer cases were similar in the two groups, at 12 and 11. None of that tells a man whether testosterone pills or other supplements would cut his risk of dying from cancer, which is why the Australian authors decline to recommend supplements for that purpose.
What Yeap does recommend is practical and narrower. Men whose testosterone is low should get a full medical checkup, because the finding may point to other health issues or risk factors even when there is no sign of testicular disease. The unanswered question is whether correcting low levels in a randomized trial would change cancer deaths at all, and none of the sources read for this report describes one.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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