Study analysis · Asian Journal of Andrology · 2015

Testosterone therapy might not worsen prostate cancer in men on active surveillance, challenging a 70-year-old medical dogma.

In men with low-risk prostate cancer who are closely monitored, taking testosterone for low testosterone levels did not significantly increase the chance of cancer progression over about three years.

Reading level
Moderate certainty
Level 2b · Individual cohort studyAssociation, not causationNo causal claims

Overview

What the study found

The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.

In simple terms

This study looked back at medical records of men with low-risk prostate cancer who were not getting treatment right away. Some of these men got testosterone therapy because they had low testosterone, and others didn't. The study found that the men who got testosterone did not seem to have their cancer get worse faster than the men who didn't. But because this was not a carefully controlled experiment, we can only say there might be a connection—we can't be sure testosterone therapy is safe or that it doesn't cause harm.

What’s the bottom line?

Men with low testosterone and low-risk prostate cancer can keep an eye on their cancer instead of treating it right away. This study checked if taking testosterone would make their cancer grow faster. Over about 3 years, men who took testosterone did not have a higher chance of their cancer getting worse than men who didn't take it.

How strong is this study?

Even though the study had a comparison group, it was not as fair as a randomized experiment. The two groups were from different clinics and had slightly different follow-up procedures (like different numbers of biopsy samples taken). Also, there were only 28 men in the testosterone group, which is a small number. Because of these issues, we should not fully trust the study's results to make important decisions without more research.

Reporting

40 / 100

  • COI disclosure+40/40
  • Data availabilitydata not shared
  • Code availabilitycode not shared
Methodology

43 / 100

  • Randomizationnot randomized
  • Blindingblinding unclear
  • Control group+15/15
  • Sample size (n=124)+9.2/20
  • Follow-up+10/10
Publication

100 / 100

Statistical

77 / 100

  • P-values+15/15
  • Effect size+20/20
  • Confidence intervals+15/15
  • Pre-registrationnot pre-registered

Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.

Where it sits

RCT reviews

Max 100

Randomized Trials

Max 90

Reviews of Cohort Studies

Max 85

Cohort Studies

Max 72

Reviews of Case-Control Studies

Max 63

Case-Control Studies

Max 58

Cross-Sectional & Case Series

Max 50

Expert Opinion

Max 5
StrongerWeaker
Cohort Studies
Level 2b
62

62 / 100

Probability of being correct

Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.

This design cannot establish causation — the findings describe an association, not a cause. This is a retrospective cohort study without randomization. Differences between groups (e.g., inclusion of Gleason 3+4 in T group, different biopsy protocols) introduce potential confounding and selection bias. Causal relationships cannot be established; only associations can be observed.

No Conflicts

No conflicts of interest identified

Not Disclosed

No conflicts identified.

Undisclosed — Suspicious

No conflict of interest or funding information provided in the text.

Key takeaways

  1. 01

    About 32% of men taking testosterone had their cancer progress (get a bit worse) compared to 45% of men not taking it.

  2. 02

    Only 11% of men on testosterone had a more serious cancer grade, versus 9% of the others.

  3. 03

    These differences were not big enough to be sure they weren't just due to chance.

  4. 04

    The small number of men in the study means we can't be certain that testosterone is safe, but it suggests it might not be harmful in the short term.

Surprising findings

  • Testosterone therapy did not increase biopsy progression rates despite the long-standing belief that testosterone fuels prostate cancer.The 'androgen hypothesis' from 1941 suggested testosterone accelerates prostate cancer, and many physicians still consider prostate cancer an absolute contraindication.
  • Men with slightly more aggressive cancer (Gleason 3+4) on testosterone showed no upgrading beyond 3+4 over 2 years.Even in men with a higher baseline risk, testosterone did not appear to worsen their cancer grade.

Practical takeaways

Men with low-risk prostate cancer on active surveillance who have symptoms of low testosterone should discuss testosterone therapy with their doctor, considering the potential benefits and uncertainties.

This study is small and retrospective; individual risks may vary. The study excluded men with higher-volume or higher-risk disease.

low confidence

If you are on testosterone therapy and diagnosed with low-risk prostate cancer, you may not need to automatically stop testosterone; discuss staying on active surveillance with your urologist.

The study had short follow-up (mean ~3 years); long-term safety is not established.

low confidence

Why this study matters

No significant increase in cancer progression

Among 28 men on testosterone therapy, 32.1% had biopsy progression compared to 44.7% of 96 untreated men. This difference was not statistically significant (p=0.280).

This reassures men with low testosterone and low-risk prostate cancer that testosterone therapy may not be as dangerous as once thought.

Gleason upgrading rates were similar

Only 10.7% of treated men had an increase in Gleason score versus 9.4% of untreated men (p=0.732).

Gleason score is a key indicator of cancer aggressiveness, and this study suggests testosterone doesn't make the cancer more aggressive.

All treated men reported symptom improvement

Every man in the testosterone group reported improved libido, erectile function, and/or energy levels.

Quality of life improvements are a major reason men seek testosterone therapy, and these benefits occurred without apparent harm.

Want the whole report?

Detailed mode opens the full scientific breakdown — every score component, the methodology, conflicts of interest, the evidence analysis behind each claim, and the raw study data.