“We had a whole escape plan,” the prostate cancer cells admit, huddled in the locker room like a team down by six with 30 seconds left. “Then somebody gave the defense apalutamide, and suddenly our offense looked like a clipboard with coffee spilled on it.”
That, in a tiny dramatic jersey, is the PROTEUS story.
For high-risk localized or locally advanced prostate cancer, surgery can be a curative play. The surgeon goes in for a radical prostatectomy, removes the prostate, checks the nearby lymph nodes, and everyone hopes the tumor got tackled behind the line of scrimmage. But high-risk prostate cancer has a nasty habit of acting like that one player who refuses to stay down. Even after surgery, relapse within 5 years can happen in up to about half of patients.
PROTEUS asked a very sports-radio question: what if we do not wait until after surgery to bring in the big defensive lineup?
The Pregame Blitz
The trial tested perioperative therapy, which is medicine given before and after surgery. That word sounds like something a hospital invented to make normal people feel underdressed, but the idea is simple: hit the cancer early, operate, then keep hitting any stragglers afterward.
In PROTEUS, 2,109 patients were randomly assigned to one of two teams. One group got androgen-deprivation therapy, or ADT, plus apalutamide. The other got ADT plus placebo. Both groups received treatment for six 28-day cycles before surgery and six cycles after surgery.
ADT lowers androgen signals, especially testosterone, that many prostate cancers use like premium fuel. Apalutamide blocks the androgen receptor, the cellular antenna that hears those growth signals. If ADT cuts the stadium power, apalutamide tells the quarterback the headset is broken.
The Scoreboard Actually Moved
The first big scoreboard stat was pathologic complete response or minimal residual disease at surgery. Translation: when the pathologist inspected the removed tissue, how often was the cancer gone or nearly gone?
With apalutamide plus ADT, that happened in 8.9% of patients. With ADT plus placebo, it happened in 1.0%. That is not a casual box-score improvement. That is the underdog suddenly discovering a three-point shot.
The second main endpoint was metastasis-free survival, meaning patients were alive without the cancer spreading. At 5 years, 78.2% of patients in the apalutamide group were metastasis-free, compared with 73.5% in the placebo group. The hazard ratio was 0.80, meaning a 20% lower risk of distant metastasis or death with apalutamide.
That may sound modest if you are thinking in movie-trailer terms. But in high-risk prostate cancer, keeping the cancer from traveling is the whole defensive game plan. Once prostate cancer starts setting up shop elsewhere, the season gets much harder.
The Bench Was Not Empty Before This
PROTEUS did not appear from the mist wearing a lab coat and sunglasses. The field has been moving toward treatment intensification for a while.
The STAMPEDE platform trial showed that adding abiraterone, with or without enzalutamide, improved outcomes for high-risk non-metastatic prostate cancer treated with standard therapy. Reviews in Nature Reviews Urology and European Urology have also been tracking the rise of neoadjuvant hormonal therapy before prostatectomy, along with more experimental approaches such as lutetium-PSMA radioligand therapy.
So PROTEUS fits into a bigger trend: prostate cancer care is becoming less “remove it and wait nervously” and more “pressure the tumor from multiple angles while the clock is still friendly.”
The Injury Report
No serious trial gets a victory parade without checking the injury report.
Grade 3 or 4 adverse events happened in 39.6% of patients who received apalutamide plus ADT, compared with 31.0% in the placebo group. The main difference was more rash with apalutamide. That matters. A treatment can win on the scoreboard and still make life harder for patients in the stands.
The real-world question is not just “Does this work?” It is “Who benefits enough to justify the extra treatment, side effects, clinic visits, cost, and hassle?” Oncology, bless its complicated heart, rarely hands out free touchdowns.
Why This One Has People Leaning Forward
The exciting part is not that every patient should now get the same play called from the sideline. It is that PROTEUS gives doctors stronger evidence that earlier systemic therapy can change the long-term trajectory for some patients with high-risk localized disease.
If these results shape practice, future care may become more tailored. Imaging such as PSMA PET, surgical pathology, genomic risk, and early treatment response could help identify who needs the full-court press and who can avoid overtreatment. That is the dream: fewer metastases, fewer relapses, fewer emergency “the cancer is back” meetings that nobody wants on their calendar.
PROTEUS does not end the season. It changes the scouting report. The tumor thought surgery was the opening whistle. Turns out, the defense was already on the field.
References
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O'Leary K. PROTEUS trial heralds perioperative therapy for prostate cancer. Nature Medicine. 2026. DOI: 10.1038/d41591-026-00032-4
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Taplin ME, Gleave M, Shore ND, et al. Perioperative apalutamide in high-risk localized prostate cancer. New England Journal of Medicine. 2026. DOI: 10.1056/NEJMoa2603878
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Attard G, Murphy L, Clarke NW, et al. Abiraterone acetate and prednisolone with or without enzalutamide for high-risk non-metastatic prostate cancer. The Lancet. 2022;399:447-460. DOI: 10.1016/S0140-6736(21)02437-5. PMCID: PMC8811484
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Devos G, Devlies W, De Meerleer G, et al. Neoadjuvant hormonal therapy before radical prostatectomy in high-risk prostate cancer. Nature Reviews Urology. 2021;18:739-762. DOI: 10.1038/s41585-021-00514-9
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Oing C, Kolinsky MP, Retz M, et al. Neoadjuvant lutetium PSMA, the TIME and immune response in high-risk localized prostate cancer. Nature Reviews Urology. 2024. DOI: 10.1038/s41585-024-00913-8
Disclaimer: The image accompanying this article is for illustrative purposes only and does not depict actual experimental results, data, or biological mechanisms.