Low Testosterone and Cancer Risk: What a Major 2026 Study Found

For years, conversations about testosterone and cancer have largely focused on whether higher testosterone levels—particularly from testosterone replacement therapy—could increase cancer risk. A major 2026 analysis published in The Lancet Healthy Longevity offers another important perspective: very low testosterone may itself be an important marker of health risk in men.

What did researchers study?

The researchers combined long-term data from 11 prospective cohort studies involving more than 26,000 men from Australia, Europe, and the United States.

The men’s testosterone and other sex-hormone levels were measured at the beginning of the studies. Researchers then followed their health outcomes over time, examining:

• New cancer diagnoses

• Deaths from cancer

• New prostate cancer diagnoses

• Associations with testosterone, dihydrotestosterone (DHT), sex hormone-binding globulin (SHBG), and luteinizing hormone (LH)

The analysis accounted for several factors that could affect cancer risk, including age, body mass index, smoking, alcohol use, physical activity, diabetes, hypertension, and previous cancer.

What did the study find?

Men with testosterone levels in the lowest range had an 18% greater risk of dying from cancer compared with men in the highest range.

Cancer mortality began to increase when total testosterone fell below approximately:

• 8.6 nmol/L—or about 248 ng/dL

Researchers also found that the risk of developing cancer increased among men with very low testosterone, particularly at levels below:

• 7.3 nmol/L—or about 211 ng/dL

Lower DHT levels were also associated with a higher risk of cancer-related death.

What about prostate cancer?

One of the study’s most notable findings was that naturally occurring testosterone levels were not associated with a higher risk of developing prostate cancer.

Instead, lower levels of SHBG and LH were associated with increased prostate-cancer risk. This reinforces the importance of evaluating the complete hormonal picture rather than interpreting a single testosterone value in isolation.

Does this mean testosterone therapy prevents cancer?

No. This study identified an association, not a cause-and-effect relationship.

It does not prove that low testosterone causes cancer, and it does not show that testosterone replacement therapy prevents cancer or reduces cancer-related mortality.

Low testosterone may instead act as a biomarker of underlying health concerns. Obesity, diabetes, chronic illness, certain medications, sleep disorders, and other medical conditions can all contribute to lower testosterone levels and may independently influence cancer risk.

The study’s investigators specifically cautioned that these findings should not be interpreted as a reason for men to begin testosterone therapy solely to prevent cancer.

Why testosterone evaluation still matters

Persistently low testosterone should not automatically be dismissed as a normal part of aging. It may be a reason to take a closer look at a man’s overall health.

A comprehensive evaluation may include:

• Symptoms and medical history

• Two appropriately timed testosterone measurements

• Free testosterone when clinically appropriate

• SHBG

• LH and FSH

• Prolactin when indicated

• Metabolic and cardiovascular risk factors

• Sleep quality and possible sleep apnea

• Age-appropriate cancer screening

When testosterone deficiency is confirmed and accompanied by relevant symptoms, treatment may be considered after an individualized discussion of potential benefits, risks, monitoring, and contraindications.

The bottom line

This major analysis changes the conversation from “Is testosterone dangerous?” to a more nuanced question: “What might very low testosterone be telling us about a man’s overall health?”

Low testosterone does not mean that a man has cancer, and these findings do not establish testosterone therapy as a cancer-prevention strategy. They do suggest that significantly low testosterone deserves a thoughtful medical evaluation rather than being ignored.

If you are experiencing fatigue, reduced libido, loss of strength or muscle mass, mood changes, or other symptoms of testosterone deficiency, Morrell Wellness offers physician-led hormone evaluations through telemedicine across Texas.

Schedule your consultation at MorrellWellness.com.

This article is for educational purposes only and does not constitute medical advice. Testosterone therapy should be prescribed only after an appropriate medical evaluation and requires ongoing monitoring.

Reference: Marriott RJ, et al. “Associations of testosterone, sex hormone-binding globulin, and related hormones with risks of cancer death, incident cancer, and incident prostate cancer in men: individual participant data meta-analyses.” The Lancet Healthy Longevity. 2026;7(6):100857. Read the study (https://doi.org/10.1016/j.lanhl.2026.100857).