Testosterone Replacement Therapy After Prostate Cancer: The Evidence Base Finally Catches Up

Testosterone Treatment in Prostate Cancer Survivors With Hypogonadism: A Randomized Clinical Trial | Trials | JAMA Internal Medicine | JAMA Network

IPCSG Newsletter — Clinical Update

A review of the SPIRIT trial, the 2026 FDA/HHS label reconsideration, and where the guidelines now stand

BLUF (Bottom Line Up Front): 

For decades, a history of prostate cancer was treated as an almost automatic disqualifier for testosterone replacement therapy (TRT), regardless of how low-risk the cancer was or how long a man had been disease-free. That position was never based on a randomized trial — it was based on fear, extrapolated from the fact that androgen deprivation shrinks advanced prostate cancer. The first placebo-controlled randomized trial designed to actually test the question, the SPIRIT trial, has now reported results: 12 weeks of TRT in men with low-grade, organ-confined disease who were disease-free after radical prostatectomy produced zero cases of biochemical recurrence in either arm, while significantly improving sexual activity, sexual desire, mood, lean mass, and aerobic fitness compared to placebo. Separately, and on its own timeline, the U.S. Department of Health and Human Services announced in June 2026 that it is asking the FDA to narrow the testosterone-product label's prostate cancer contraindication to metastatic disease only, easing decades-old restrictions. Neither development is a green light for unrestricted use — the SPIRIT trial was short and modestly sized, and the FDA's action is a labeling request, not yet a final rule — but together they mark the most significant evidence-based shift in this area in a generation. Men considering TRT after prostate cancer treatment should discuss candidacy, monitoring, and residual uncertainty with their treating urologist or oncologist.

Why This Question Has Mattered for So Long

Most men diagnosed with prostate cancer today have low-grade, organ-confined disease, and those treated with radical prostatectomy have a five-year disease-free survival rate above 99%. That excellent prognosis has shifted the clinical conversation from "can we cure this" to "how do these men live well afterward." Between 30% and 50% of prostate cancer survivors develop hypogonadism — low testosterone — and more than half report bothersome sexual or physical symptoms after surgery. Yet the same men have historically been told that testosterone therapy, the standard treatment for hypogonadism in men without a cancer history, was off the table for them.

The rationale traces to century-old physiology: androgen deprivation therapy shrinks advanced, androgen-sensitive prostate cancer, so raising testosterone was long assumed to do the reverse. That assumption was never tested in a randomized trial in prostate cancer survivors — a gap that essentially every major guideline (Endocrine Society, American Urological Association, and international bodies) has acknowledged for years while still recommending caution.

The SPIRIT Trial: First Randomized Evidence in This Population

The Sexual Health, Physical function, hormonal and QOL Improvement in Radical prostatectomy patients on Testosterone (SPIRIT) study, conducted at Brigham and Women's Hospital and Johns Hopkins Hospital and led by Dr. Shalender Bhasin's group, is the first randomized, placebo-controlled trial to test TRT's safety and efficacy specifically in prostate cancer survivors. Results were published in JAMA Internal Medicine in 2026.

Design

• 136 men aged 40+ with Gleason 6 (3+3) or 7 (3+4) disease, stage pT2N0M0 or cT2N0M0, undetectable PSA for at least two years after radical prostatectomy.
• Randomized 1:1 to weekly intramuscular testosterone cypionate (100 mg) or placebo for 12 weeks, with a further 12-week safety follow-up.
• Men on androgen deprivation therapy or radiation were excluded — this trial speaks only to post-surgical, low-grade disease.
• Primary safety endpoint: biochemical recurrence (two consecutive PSA readings ≥0.2 ng/mL). Primary efficacy endpoint: change in sexual activity, measured with a validated daily diary.

Key Results

Measure	Finding
Biochemical recurrence	Zero cases in either group through 12 weeks of treatment and 12 weeks of follow-up (upper bound of 95% CI: 5.3%)
Sexual activity	TRT group improved 0.91 events/day more than placebo (P<.001)
Sexual desire	Significant improvement over placebo (P<.001)
Erectile function	Small improvement in the TRT group but not significantly different from placebo — consistent with prior TRT literature showing testosterone alone rarely restores erections after nerve-sparing surgery
Negative mood (PANAS)	Significantly reduced with TRT vs. placebo
Lean body mass	+2.56 kg whole-body vs. placebo
Peak aerobic capacity (VO2 peak)	+0.16 L/min vs. placebo — an ~8% gain, comparable in magnitude to improvements linked with reduced mortality in cardiac rehabilitation literature
Stair-climb power	+33 watts vs. placebo, exceeding the threshold considered clinically meaningful
Adverse events	Similar overall rates between groups; erythrocytosis (elevated red blood cell count) occurred in 3 testosterone-treated men and none on placebo — the expected class effect requiring routine hematocrit monitoring

What the trial does not show: Twelve weeks is not long enough to detect a cancer recurrence that might take years to manifest, and 136 participants is not a large enough sample to rule out a modest increase in recurrence risk. The authors are explicit that this was a "proof-of-concept" trial intended to justify a larger, longer study — not a final verdict on long-term oncologic safety. The findings also do not extend to men with high-grade cancer, men treated with radiation, or men who received or are receiving androgen deprivation therapy.

Corroborating Evidence From Other Recent Studies

The SPIRIT trial doesn't stand alone. Several other lines of evidence published or updated in 2025–2026 point the same direction:

• VA cohort study (Veterans Affairs Informatics and Computing Infrastructure): An analysis of nearly 70,000 men with localized prostate cancer treated with surgery or radiation between 2001 and 2015 found that testosterone therapy after definitive treatment was not associated with increased biochemical recurrence or mortality, over median follow-up exceeding seven years — considerably longer observation than any randomized trial to date.
• Scoping review, International Journal of Impotence Research (Nov. 2025): Across 12 studies published between 2005 and 2025 covering men treated with definitive therapy for prostate cancer, TRT was not associated with increased biochemical recurrence or progression risk, while consistently improving hypogonadal symptoms.
• British Society for Sexual Medicine consensus statement (2026): International specialists concluded TRT can be offered to symptomatic, disease-free men after treatment for low-risk prostate cancer under appropriate monitoring, citing the "saturation model" — the concept that prostate tissue androgen receptors saturate at fairly low testosterone concentrations, so additional testosterone above that threshold may have little further effect on cancer growth.
• Ongoing trials: New randomized studies are extending this question to men on active surveillance rather than post-prostatectomy — a more cautious population. Roswell Park Cancer Institute is currently recruiting for one such trial (NCT06733350), and the University of Miami has registered a related study (NCT07278362) expected to begin in mid-2026. A separate Seattle-based trial (NCT04049331) is examining testosterone replacement across cancer survivors broadly, including prostate cancer survivors, with results anticipated in 2027.

Regulatory Movement: FDA/HHS Proposes Narrowing the Label

Independent of the SPIRIT results, the regulatory landscape has been shifting quickly. In February 2025, the FDA removed the cardiovascular boxed warning from testosterone products, informed by the large TRAVERSE cardiovascular safety trial (over 5,200 men), which found no significant increase in major cardiac events with TRT compared to placebo.

On June 18, 2026, HHS — through the FDA — announced it is requesting further class-wide labeling updates for testosterone products. The proposal has three parts:

1. Removing the long-standing limitation of use stating that TRT's safety and effectiveness "have not been established" in men with age-related (as opposed to organic) hypogonadism.
2. Narrowing the prostate cancer contraindication so that testosterone products would be contraindicated only in men with metastatic prostate cancer — rather than any known or suspected prostate cancer history, as current labels state.
3. Revising warnings about benign prostatic hyperplasia (enlarged prostate), based on evidence that TRT does not appear to worsen symptoms in men with mild-to-moderate BPH.

HHS Secretary Robert F. Kennedy Jr. and FDA officials framed the move as bringing labeling in line with newer trial data; outside experts quoted in trade and consumer press broadly agreed the science supports narrowing the warning, while cautioning that this is a proposed labeling change working through FDA's standard process, not yet finalized, and that it does not amount to an endorsement of testosterone therapy in men with active, non-metastatic prostate cancer. A December 2025 FDA expert panel also floated the idea of reclassifying testosterone out of Schedule III controlled-substance status, and the agency opened a formal public-comment docket (FDA-2025-N-6743) that drew more than 2,000 submissions by its February 2026 deadline. No final rule has yet been issued as of this writing.

"Testosterone therapy still requires a clear diagnosis based on both symptoms and consistently low testosterone levels, and men on therapy require ongoing monitoring with appropriate laboratory follow-up." — Urology commentary on the 2026 FDA proposal

What This Means for IPCSG Readers

If you are a prostate cancer survivor with symptoms of low testosterone — low libido, fatigue, loss of muscle mass, low mood — and you have been told TRT is simply off-limits, the evidence base underlying that blanket rule is weaker than many patients have been led to believe, particularly if your disease was low-grade, organ-confined, and treated surgically, and you have been free of biochemical recurrence for an extended period. That said, several practical points bear emphasis:

• This is not a green light for everyone. The strongest evidence applies to men with Gleason 6–7 disease treated with prostatectomy, disease-free for two or more years. It does not extend to men with high-grade disease, men treated with radiation or androgen deprivation therapy, or men with detectable PSA.
• Monitoring matters. Every study in this area — SPIRIT included — paired testosterone treatment with close PSA surveillance. That is not optional; it is the safety mechanism that makes cautious use defensible.
• Long-term safety remains genuinely unknown. No trial to date has followed men on TRT after prostate cancer for the 5–10+ years it might take a slow-growing recurrence to appear. The VA cohort data are reassuring but observational, not randomized, and subject to the selection biases inherent in any cohort study (physicians likely chose lower-risk men for TRT in the first place).
• This is a conversation for your own urologist or oncologist, ideally one who is current on both the SPIRIT trial data and the evolving FDA labeling — not a decision to make from an online pharmacy or telehealth testosterone platform without cancer-specific oversight.

Verified Sources

1. Bhasin S, Burnett AL, Gagliano-Jucá T, et al. Testosterone Treatment in Prostate Cancer Survivors With Hypogonadism: A Randomized Clinical Trial (SPIRIT). JAMA Internal Medicine. Published online May 11, 2026 (corrected July 6, 2026). doi:10.1001/jamainternmed.2026.1343. ClinicalTrials.gov Identifier: NCT03716739.
2. Valderrábano RJ, Pencina K, Storer TW, et al. Testosterone replacement in prostate cancer survivors with testosterone deficiency: study protocol of a randomized controlled trial. Andrology. 2023;11(1):93-102. doi:10.1111/andr.13299. https://pmc.ncbi.nlm.nih.gov/articles/PMC9771994/
3. Testosterone Replacement Therapy in Hypogonadal Men with a Prostate Cancer Diagnosis: A British Society for Sexual Medicine Consensus Statement. World Journal of Men's Health. 2026. https://wjmh.org/DOIx.php?id=10.5534%2Fwjmh.250086 (mirrored at PMC12798415)
4. Testosterone replacement therapy following definitive treatment for prostate cancer: a scoping review of safety and efficacy. International Journal of Impotence Research. Published online November 26, 2025. doi:10.1038/s41443-025-01206-3. https://www.nature.com/articles/s41443-025-01206-3
5. Testosterone Therapy Does Not Increase the Risks of Prostate Cancer Recurrence or Death After Definitive Treatment for Localized Disease (VA cohort study, 69,984 patients). PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC11220914/
6. Lincoff AM, Bhasin S, Flevaris P, et al. Cardiovascular Safety of Testosterone-Replacement Therapy (TRAVERSE trial). New England Journal of Medicine. 2023;389(2):107-117. doi:10.1056/NEJMoa2215025.
7. Pencina KM, Travison TG, Cunningham GR, et al. Effect of Testosterone Replacement Therapy on Sexual Function and Hypogonadal Symptoms in Men With Hypogonadism (TRAVERSE substudy). Journal of Clinical Endocrinology & Metabolism. 2024;109(2):569-580. doi:10.1210/clinem/dgad484.
8. U.S. Department of Health and Human Services. HHS Announces Requested Updates to Testosterone Therapy Product Labels. Press release, June 18, 2026. https://www.hhs.gov/press-room/fda-requests-updates-testosterone-therapy-labeling.html
9. HHS requests testosterone therapy label updates, citing new safety data. Urology Times. Published ~June 2026. https://www.urologytimes.com/view/hhs-requests-testosterone-therapy-label-updates-citing-new-safety-data
10. Mammoser G. Prostate Cancer: HHS to Update Testosterone Therapy Warning Labels. Healthline. June 23, 2026. https://www.healthline.com/health-news/hhs-updates-testosterone-therapy-warning-labels
11. What men should know about the US government's latest move on testosterone therapy. CNN. June 20, 2026. https://www.cnn.com/2026/06/20/health/testosterone-therapy-warning-label-changes-wellness
12. Vohnoutka E. Testosterone Therapy Labels And Limits May Change Under FDA Proposal. HealthDay, via U.S. News & World Report. June 23, 2026. https://www.usnews.com/news/health-news/articles/2026-06-23/testosterone-therapy-labels-and-limits-may-change-under-fda-proposal
13. How testosterone therapy use in men with prostate cancer has evolved. Urology Times. 2026. https://www.urologytimes.com/view/how-testosterone-therapy-use-in-men-with-prostate-cancer-has-evolved
14. Testosterone and prostate cancer: What's the connection? Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/prostate-cancer/in-depth/testosterone-and-prostate-cancer/art-20589655
15. ClinicalTrials.gov. Safety of Intramuscular Testosterone Replacement Therapy in Hypogonadal Patients With Prostate Cancer Under Active Surveillance. NCT07278362 (University of Miami; not yet recruiting as of Feb. 2026). https://clinicaltrials.gov/study/NCT07278362
16. ClinicalTrials.gov. Investigating the Effect of Testosterone Replacement Therapy Among Hypogonadal Men With Localized Prostate Cancer on Active Surveillance. NCT06733350 (Roswell Park Cancer Institute; recruiting). https://clinicaltrials.gov/study/NCT06733350
17. ClinicalTrials.gov. Improving Patient-Important Outcomes With Testosterone Replacement in Hypogonadal Men With a Prior History of Cancer. NCT04049331 (Seattle Institute for Biomedical and Clinical Research; active, not recruiting). https://clinicaltrials.gov/study/NCT04049331
18. FDA. FDA Issues Class-Wide Labeling Changes for Testosterone Products. Press release, February 28, 2025. https://www.fda.gov/drugs/drug-safety-and-availability/fda-issues-class-wide-labeling-changes-testosterone-products

Disclaimer: This article is intended for informational and patient-education purposes as part of IPCSG's ongoing coverage of prostate cancer research and is not a substitute for individualized medical advice. Decisions about testosterone replacement therapy require direct discussion with your treating urologist or oncologist, particularly regarding your specific cancer grade, stage, treatment history, and PSA monitoring plan. No court filings or litigation specific to TRT-and-prostate-cancer causation were identified as part of this review as of the publication date; readers should note that regulatory and legal developments in this area are moving quickly and this summary reflects the best available information as of early July 2026.

Prepared for the IPCSG Newsletter — July 2026.