Does Testosterone Increase Prostate Cancer Risk? TRAVERSE Study Says No

The idea that testosterone fuels prostate cancer has long been a concern—both among doctors and men exploring testosterone therapy. After all, one of the mainstays of prostate cancer treatment is lowering testosterone through hormone-suppressing therapies. But does that mean boosting testosterone in men without cancer puts them at risk?

Thanks to new data from the TRAVERSE trial—the largest and most rigorous testosterone study to date—we finally have a more confident answer. This study took a hard look at whether testosterone replacement therapy (TRT) increases the risk of prostate cancer, including high-grade types, and whether it worsens urinary symptoms. The results? Both reassuring and highly informative.

Why testosterone and prostate cancer have long been linked

Prostate cancer is hormonally sensitive. Many prostate tumors shrink when testosterone levels are reduced, which is why androgen deprivation therapy (ADT) is a key treatment for advanced cases. That link has fueled fears that giving testosterone—especially to older men—might cause or accelerate prostate cancer.

However, this logic oversimplifies hormone biology. The belief that “more testosterone equals more cancer” doesn’t account for how testosterone receptors work or how prostate tissue responds at different life stages. Researchers have long suspected that the relationship is not linear—and now the data is backing them up.

What the TRAVERSE trial actually studied

The TRAVERSE trial was designed to evaluate testosterone safety in men with or at risk for cardiovascular disease, but one of its secondary endpoints was prostate health. Over 5,000 men were enrolled, with an average age of 63. All had either confirmed heart disease or multiple risk factors.

Participants were randomized to receive either testosterone gel (applied daily to the arm, buttocks, or abdomen) or a placebo gel. Importantly, men had to have:

• Two low testosterone readings (<300 ng/dL)
• At least one symptom of low testosterone (fatigue, low libido, erectile dysfunction, etc.)

Their testosterone levels were maintained in a range of 350–750 ng/dL during treatment.

How the study was designed and who qualified

The TRAVERSE trial followed participants for an average of 33 months. To avoid overreacting to temporary PSA changes (which are common during early TRT), the study established strict criteria for prostate biopsy referrals. This avoided unnecessary interventions due to expected PSA fluctuations.

Criteria included:

• PSA increase ≥1.4 ng/mL from baseline
• PSA >4 ng/mL if not on medications, or >2 ng/mL if on 5-alpha reductase inhibitors (like finasteride)
• PSA >3 ng/mL for men under 55
• Abnormal digital rectal exam (DRE) findings

Eligible men were informed through shared decision-making and asked if they wished to proceed with biopsy—an approach that reflects real-world urology care.

Understanding high-grade prostate cancer: the main concern

Not all prostate cancers are created equal. Many are low-grade, slow-growing, and unlikely to cause harm. The primary endpoint in TRAVERSE was high-grade prostate cancer, defined as Gleason score 4+3 or higher—the types of tumors that are more aggressive and potentially deadly.

The study also tracked secondary outcomes:

• Any prostate cancer diagnosis
• Urinary retention requiring catheterization
• Prostate-related surgery
• New medications for urinary symptoms
• Prostate biopsies performed

What were the results on cancer and urinary outcomes?

After nearly three years of follow-up, the differences between the testosterone group and placebo group were negligible:

• High-grade prostate cancer: 0.19% in TRT group vs. 0.12% in placebo
• Any prostate cancer: no significant difference
• Urinary complications: no significant increase in the testosterone group

These findings were plotted on a forest plot, showing that none of the endpoints crossed the line of statistical significance. In plain terms: testosterone therapy did not increase risk of prostate cancer or urinary issues.

Only a small percentage of men—fewer than 20% in either group—ultimately underwent biopsy. This reflects both the strict referral criteria and the shared decision-making model, which empowers patients to make informed choices.

PSA changes and the shared decision-making approach

One known effect of TRT is a modest rise in PSA (prostate-specific antigen) levels, especially in men starting with very low testosterone. But this rise reflects androgen receptor saturation, not necessarily a pathological process.

The TRAVERSE trial researchers anticipated this, setting evidence-based thresholds for biopsy referrals. And rather than reacting reflexively to any rise, physicians used education, shared discussions, and patient choice to determine whether a biopsy was appropriate.

This mirrors the shift in modern prostate cancer screening—moving away from fear-based testing toward risk-aware, patient-centered decision-making.

What this means for men considering testosterone therapy

For years, fear of prostate cancer has cast a long shadow over testosterone therapy. But the TRAVERSE trial offers strong reassurance: Testosterone therapy does not increase the risk of high-grade prostate cancer or worsen urinary symptoms, at least over the medium-term (~3 years).

That doesn’t mean TRT is right for everyone. Men should still be:

• Screened appropriately
• Monitored for PSA changes and symptoms
• Evaluated for cardiovascular and other risks

But if you’re dealing with classic low testosterone symptoms and meet clinical criteria, this new data supports safe, informed use of TRT without disproportionate fear about prostate cancer.

Citations

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2813293
https://grandroundsinurology.com/testosterone-and-cardiovascular-risk-traverse-trial-and-new-fda-label-change
https://en.wikipedia.org/wiki/Testosterone