Is there an increased risk of prostate cancer with taking testosterone replacement therapy?

Should you have a PSA test? And when? Dr Benjamin Davis discusses whether an increased risk of prostate cancer is one of the risks of taking testosterone replacement therapy.

Some basic facts about prostate cancer:

It’s the most common cancer in men. Over 50,000 men are diagnosed with prostate cancer in the UK each year, and 12,000 die from it.1 However, a lot of men live with prostate cancer for a long time and it never causes them any problem. In fact, over 78% of men in the UK diagnosed with prostate cancer survive over 10 years. Some men, particularly those with a family history or those of Black ethnicity are at higher risk. The risk of prostate cancer changes with age. The graph below shows that there are virtually no cases of prostate cancer in men under 45, but the risk of prostate cancer increases as men get older.2 This means in men under 45 we don’t need to be worried about prostate cancer, but once over 45 or 50 years old we need to be more aware of the possibility.

risks of testosterone replacement therapy - histogram depicting rate of prostate cancer in men.

Should I have a PSA test?

A PSA or Prostate Specific Antigen test is a blood test that can help diagnose prostate cancer. However, it’s not a perfect test. 75% of men with a raised PSA (a level over 3) will not have prostate cancer, and equally a small proportion of men with a low PSA will later be found to have prostate cancer. A PSA can be raised for lots of different reasons as the image below shows:3

risks of testosterone replacement therapy - infographic about PSA levels

Having a PSA done is an individual decision. It is included in the Advanced TRT blood tests we recommend from Medichecks. If you are having a PSA blood test, it is best to avoid vigorous exercise including cycling and sex for 2 days before the test as this can affect the level.

The risk of having a raised PSA is that you might need further investigation including an ultrasound scan or MRI and then possibly a prostate biopsy to look for cancer cells even when no cancer is present. The use of more advanced MRI techniques has reduced the need for prostate biopsy by about 25% and so the risk of a raised PSA leading to invasive prostate biopsy has decreased in recent years. 

Is an increased risk of prostate cancer one of the risks of taking testosterone replacement therapy?

There is an understandable concern that increasing your testosterone level might increase your risk of prostate cancer. After all, men who have prostate cancer are treated with drugs that block or reduce testosterone levels in the body. So surely increasing your testosterone must increase your risk of prostate cancer?

The evidence from multiple studies seems to be that testosterone replacement doesn’t increase the risk of prostate cancer.4 Guidance from the European association of urology, the British Society of Sexual Medicine conclude there is no compelling evidence that testosterone therapy is associated with an increased risk of prostate cancer.5 Multiple studies have shown that testosterone levels do not correlate with risk of prostate cancer.

Why might this be? Decreasing your testosterone treats prostate cancer, but increasing it through testosterone replacement therapy doesn’t increase prostate cancer risk? Studies have shown that the prostate gets saturated with testosterone at around 8-8.5nmol/L, so increasing your testosterone above this level, doesn’t lead to higher levels of testosterone in the prostate.6

It is therefore possible that if your total testosterone is less than 8.5nmol/L, you may be more likely to see a rise in your PSA when you start testosterone therapy; and possibly have a higher risk of prostate cancer which has stayed quiet when your testosterone level is low, growing when you start testosterone therapy and your level goes over 8.5nmol/L.

The Testosterone Trials were a trial of testosterone therapy done in the USA. One study from this trial compared men over the age of 65 taking testosterone with a placebo (non-active drug) group. 7 4.4% of men taking testosterone had a rise in the PSA by 1 year which necessitated referral to a urologist vs 1.7% in the placebo group. Twenty-two out of 743 men in total between the two arms were seen by a Urologist and 6 of these ended up having prostate biopsies – 4 men in the testosterone arm, and two in the placebo arm. Of the four men taking testosterone who had a prostate biopsy, three had prostate cancer, two of which were high grade (more high risk). Of the two men who had a biopsy in the placebo group, one had cancer. These were men aged over 65 and so had a higher risk of prostate cancer. You can see that the risk of needing a biopsy from PSA monitoring is low, and those who did have a biopsy were highly likely to have prostate cancer, particularly in the men taking testosterone replacement therapy

It can all seem a bit confusing but the take aways are:

  • There is no convincing evidence that an increased risk of prostate cancer is one of the risks of taking testosterone replacement therapy. However, an absence of evidence doesn’t totally rule out the risk of prostate cancer after starting testosterone. To be on the safe side, for men over the age of 50, checking your prostate through examination and monitoring of your PSA is recommended before starting testosterone replacement therapy and with a repeat PSA test at 3 – 6 and 12 months, and yearly after that.

All of the clinical team at the Leger Clinic are experienced in discussing these issues and are more than happy to talk through PSA monitoring at any point. 


1. Cancer Research UK. Prostate cancer statistics. Published 2022. Accessed December 8, 2022.

2. Cancer Research UK. Prostate cancer incidence statistics . Published December 2022. Accessed December 8, 2022.

3. GOV.UK. PSA testing: advice for men without symptoms aged 50 and over – GOV.UK. Published March 2022. Accessed December 8, 2022.

4. Cui Y, Zong H, Yan H, Zhang Y. The effect of testosterone replacement therapy on prostate cancer: a systematic review and meta-analysis. Prostate Cancer Prostatic Dis. 2014;17(2):132-143. doi:10.1038/PCAN.2013.60

5. Hackett G, Kirby M, Edwards D, et al. British Society for Sexual Medicine Guidelines on Adult Testosterone Deficiency, With Statements for UK Practice. Journal of Sexual Medicine. 2017;14(12):1504-1523. doi:10.1016/j.jsxm.2017.10.067

6. Marks LS, Mazer NA, Mostaghel E, et al. Effect of Testosterone Replacement Therapy on Prostate Tissue in Men With Late-Onset HypogonadismA Randomized Controlled Trial. JAMA. 2006;296(19):2351-2361. doi:10.1001/jama.296.19.2351

7. Cunningham GR, Ellenberg SS, Bhasin S, et al. Prostate-Specific Antigen Levels during Testosterone Treatment of Hypogonadal Older Men: Data from a Controlled Trial. Journal of Clinical Endocrinology and Metabolism. 2019;104(12):6238-6246. doi:10.1210/jc.2019-00806

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