PROTEUS substudy results add context on testosterone recovery and erectile dysfunction after prostate cancer treatment, with key limits and questions for care.
On October 24, 2026, Urology Times published a report on the PROTEUS substudy in men with high-risk localized or locally advanced prostate cancer. The report included a median testosterone-recovery time of 20.7 months and similar reported erectile-dysfunction rates between treatment groups.
Dana-Farber described the findings, presented at the 2026 European Society for Medical Oncology Congress, as an additional comparison with standard care. For men and their partners, the update brings a laboratory measure and sexual-function reporting into the same conversation.
According to Urology Times, the open-label randomized study assigned 408 patients in a 1:3 ratio. The combination-treatment arm included 102 men and the surgery-alone arm included 306. Participants had high-risk localized or locally advanced prostate cancer.
The surgical approach was radical prostatectomy and pelvic lymph-node dissection. Men assigned to the combination arm also received apalutamide plus androgen-deprivation therapy, or ADT. This regimen was perioperative, meaning it was given before and after surgery.
The report described six cycles before surgery and six afterward. Median follow-up was 37.8 months. These details establish the treatment sequence and observation period behind the results.
The study asked a specific treatment question: how the combined drug regimen plus surgery compared with surgery alone in this patient population. It also reported hormone recovery and adverse events alongside its cancer-control findings.
Urology Times reported that testosterone recovery was defined as reaching at least 200 ng/dL. In the apalutamide-plus-ADT arm, the median time to that threshold was 20.7 months. The report described this as about nine months after treatment ended.
That timing deserves careful reading. The reported recovery timeline includes the treatment period; it was not described as 20.7 months after the drugs stopped. Keeping those time points separate makes the result easier to understand.
In the same report, erectile dysfunction was recorded in 56% of the apalutamide-plus-ADT group and 62% of the surgery-alone group. These are the observed percentages behind the description of similar rates.
Urinary incontinence was reported in 63% and 66%, respectively. Other reported adverse events included hot flashes in 64% of the combination group versus 0.7% of the surgery-alone group. Fatigue occurred in 22% versus 2.8%.
The broader adverse-event picture matters when reading a report focused on sexual function. Erectile dysfunction was one reported outcome within a treatment comparison that also recorded urinary symptoms and other effects.
At a median follow-up of 37.8 months, median event-free survival was not reached in the combination arm. It was 19.1 months in the surgery-alone arm, according to Urology Times. At 36 months, 63.0% of the combination group and 41.4% of the surgery-alone group were event-free.
These cancer-control results help explain why the substudy matters in treatment discussions. The sexual-function findings add another type of information to that assessment.
This was a randomized experimental comparison rather than an observational study. However, its open-label design and uneven allocation between groups are important features when assessing the findings. Its population also limits generalization: these results concern a specific high-risk cancer setting rather than all men with prostate cancer or age-related sexual changes.
The study did not isolate apalutamide’s effect. It compared apalutamide plus ADT and surgery with surgery alone. The results therefore cannot separate the contribution of each drug or procedure to the reported sexual outcomes.
The testosterone threshold was a study definition. Reaching it does not necessarily mean returning to a person’s pretreatment level. The group median is also not a promise that an individual will recover on that schedule.
The erectile-dysfunction percentages do not show severity, duration or pretreatment function. Available reporting also lacks the detail needed to understand patient-perceived impact and sexual recovery over time. Similar observed rates do not establish that the added regimen has no sexual effects or that the approaches are equivalent for sexual function.
Event-free survival is a cancer-control measure. Improvement in that outcome is not evidence of better desire, erections or intimacy.
In an October 2026 commentary in Hematology & Oncology, an expert called for more quality-of-life data on the main PROTEUS trial. The commentary also noted that the main trial did not compare the regimen with radiation-based approaches. Those gaps matter when placing the findings within the full range of treatment decisions.
The main PROTEUS phase 3 trial compared apalutamide plus ADT with placebo plus ADT. The substudy added the surgery-alone comparison that was absent from the main trial, according to Urology Times.
That distinction explains why the substudy is an addition to the evidence. Comparing treatments when both groups receive ADT addresses a different question from comparing an added systemic regimen with surgery alone. Readers should keep the two comparisons distinct when encountering headlines about PROTEUS.
Dana-Farber’s summary emphasized improved event-free survival and a lower risk of metastasis or death in the substudy. That emphasis places the update within the larger cancer-treatment discussion rather than making sexual recovery its sole purpose.
Presenting author Alberto Briganti described the perioperative regimen as a potential option for selected patients who choose surgery and are fit for both surgery and systemic treatment. This is a statement about a defined treatment setting. It is not a general recommendation for everyone facing a prostate-cancer diagnosis.
Read alongside the main trial, the substudy adds information for weighing treatment. Its hormone and sexual-function reporting belongs within that wider assessment rather than being treated as a separate verdict on the regimen.
For readers weighing treatment, the practical value is in the questions the report helps identify. A discussion can give cancer-control goals and sexual wellbeing their own space. Neither subject needs to be treated as an afterthought.
The research supports bringing the following topics to the treating team. These are discussion points rather than a treatment plan.
For related educational context, Sexential’s discussion of sexual wellbeing after prostate-cancer treatment addresses the wider subject of intimacy. Its article on interpreting testosterone results in context provides another starting point for understanding hormone-related questions.
The laboratory figure and the sexual-function percentages introduced in this update belong in the same conversation. Their value is not in reducing recovery to a scorecard. It is in helping readers discuss cancer treatment with room for their experience of life afterward.
Weighing hormone-recovery data alongside sexual-function results is an evidence-reading task, where Sexential supplies context rather than a treatment decision. For readers uncertain about what influences sexual function, its educational coverage considers hormones and relationships together to support clearer understanding without personalised medical advice.
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