When farmers in the 1800s learned that crop rotation could beat exhausted soil better than just planting the same thing over and over, they were not doing oncology, obviously, though if you squint hard enough over your coffee, the idea feels familiar: sometimes you win by changing the field before the trouble gets comfortable.
That is the homespun logic behind a new prostate cancer study called PROTEUS. The question was simple enough to fit on a diner napkin: if high-risk prostate cancer often comes back after surgery, what happens if doctors treat it hard before and after the operation, instead of waiting for bad news to knock on the door?
The answer: adding apalutamide to standard hormone therapy improved several cancer-control outcomes in men with high-risk localized or locally advanced prostate cancer undergoing radical prostatectomy. Not magic. Not a cure-all. But a meaningful nudge in the right direction, and in cancer medicine, meaningful nudges are how the furniture gets rearranged.
The Tumor’s Favorite Snack
Many prostate cancers grow with help from androgens, hormones like testosterone. Think of testosterone as fertilizer. Perfectly normal in the right garden, but if weeds are taking over, you may want to lock the shed.
Androgen-deprivation therapy, or ADT, lowers that hormonal fuel. Apalutamide goes one step further. It blocks the androgen receptor, the little “mail slot” prostate cancer cells use to receive growth instructions. ADT cuts down the mail. Apalutamide tells the mail slot to stop being so helpful.
That combination has already mattered in more advanced prostate cancer. The newer question is whether using it earlier, around surgery, can stop microscopic escape artists before they become visible metastases. Cancer cells, bless their rotten little hearts, are very good at leaving crumbs behind.
What PROTEUS Actually Did
The PROTEUS trial enrolled 2,109 patients with newly diagnosed high-risk localized or locally advanced prostate cancer. Everyone was headed for radical prostatectomy with pelvic lymph-node dissection. Half received ADT plus apalutamide. Half received ADT plus placebo. Treatment ran for six 28-day cycles before surgery and six cycles after surgery.
Researchers looked at two main outcomes. First, did the removed prostate show either no remaining cancer or only minimal residual disease? Second, did patients remain free of metastasis?
The pathology result was striking: 8.9% of patients in the apalutamide group had a complete or near-complete pathological response, compared with 1.0% in the placebo group. That is still a small fraction overall, but the difference is not small. It is the difference between “we swept the porch” and “we found the broom closet.”
At five years, metastasis-free survival was 78.2% with apalutamide versus 73.5% with placebo. The hazard ratio for distant metastasis or death was 0.80, meaning a 20% relative reduction in that combined risk. Event-free survival, time to next treatment, and time to distant metastasis also favored the apalutamide group Taplin et al., 2026.
Why This Is More Than a Bigger Hammer
For years, doctors have known that surgery can cure many patients with localized prostate cancer. But high-risk disease is the ornery patch of weeds that may grow back even after you pull hard. Prior reviews have found that older neoadjuvant hormone approaches could shrink tumors and improve surgical pathology, but they did not clearly improve long-term outcomes like survival or spread Devos et al., 2021.
That is why PROTEUS gets attention. It connects a better-looking surgical specimen with a better metastasis-free survival signal. A phase 2 trial called ARNEO had already suggested that adding apalutamide before surgery could improve pathological response in high-risk patients Devos et al., 2023. PROTEUS is the larger phase 3 “all right, prove it at the grown-up table” version.
There are still practical questions. Which patients benefit most? How should doctors weigh the extra side effects? Will this change choices between surgery and radiation-based approaches? Current prostate cancer guidelines already treat high-risk localized disease as a place where careful staging, multimodal therapy, and patient preference matter a great deal Cornford et al., 2024. PROTEUS adds a new card to that hand.
The Catch, Because Biology Charges Sales Tax
More treatment usually means more side effects. Grade 3 or 4 adverse events occurred in 39.6% of patients receiving apalutamide versus 31.0% receiving placebo, mainly driven by rash. Hormone therapy can also bring hot flashes, fatigue, sexual side effects, bone and metabolic concerns, and the general indignity of making the body feel like it has misplaced its thermostat.
So this is not “everyone gets the extra drug and we all go for pie.” It is a conversation. For a patient with especially aggressive localized disease, a better chance of delaying or preventing metastasis may be worth a tougher treatment year. For someone else, the tradeoff may feel different.
The Takeaway
PROTEUS suggests that high-risk prostate cancer may be better handled by treating the whole problem early: weaken the cancer before surgery, remove the main tumor, then keep pressure on any microscopic leftovers afterward. Soap and water, not just water.
If future follow-up confirms durable benefit and clinicians learn who gains the most, perioperative apalutamide plus ADT could become a serious option for patients choosing surgery for high-risk localized or locally advanced prostate cancer. Not because cancer has suddenly become polite. Because doctors may have found a better way to meet it at the gate before it wanders down the road.
References
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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. https://doi.org/10.1056/NEJMoa2603878
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Devos G, Tosco L, Baldewijns M, et al. ARNEO: A Randomized Phase II Trial of Neoadjuvant Degarelix with or Without Apalutamide Prior to Radical Prostatectomy for High-risk Prostate Cancer. European Urology. 2023;83(6):508-518. https://doi.org/10.1016/j.eururo.2022.09.009
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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. https://doi.org/10.1038/s41585-021-00514-9
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Cornford P, van den Bergh RCN, Briers E, et al. EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer - 2024 Update. Part I: Screening, Diagnosis, and Local Treatment with Curative Intent. European Urology. 2024;86(2):148-163. https://doi.org/10.1016/j.eururo.2024.03.027
Disclaimer: The image accompanying this article is for illustrative purposes only and does not depict actual experimental results, data, or biological mechanisms.