Outcomes of Neoadjuvant Radiotherapy Followed by Robotic Radical Prostatectomy in High-Risk Locally Advanced Prostate Cancer: A Prospective Pilot Study.

PURPOSE: Neoadjuvant radiotherapy (RT) in prostate cancer remains investigational. This prospective pilot study evaluated the feasibility, perioperative safety, and preliminary outcomes of neoadjuvant RT combined with androgen-deprivation therapy (ADT), followed by robot-assisted radical prostatectomy (RP), in high-risk locally advanced disease.

METHODS

Patients with high-risk locally advanced prostate cancer (clinical stage T3a-T3b, Gleason score ≥8, or prostate-specific antigen [PSA] ≥ 20 ng/mL) were prospectively enrolled. All patients received neoadjuvant RT (50 Gy in 25 fractions) with 3 months of ADT, then robot-assisted RP with pelvic lymph node dissection. A retrospective contemporaneous RP-alone cohort served as controls. Primary outcomes included perioperative safety, pathological response, and postoperative PSA levels. Secondary endpoints included oncological outcomes, functional outcomes, and MRI-derived imaging biomarkers.

RESULTS

In total, 10 patients received neoadjuvant RT, and 11 patients served as controls. The median PSA at diagnosis was 19.46 ng/mL in the neoadjuvant group and 15.52 ng/mL in controls. No major complications occurred. Pathological downstaging was observed in 60% of the neoadjuvant group, whereas none occurred in controls (4/11 showed upstaging). At 12 months, urinary continence was achieved in four patients. After a median follow-up of 16.4 months, five patients developed biochemical recurrence, and one progressed to bone metastasis. Post-treatment changes in apparent diffusion coefficient values and T2-weighted MRI signals were associated with improved pathological outcomes, suggesting potential predictive value.

CONCLUSIONS

Neoadjuvant RT with ADT followed by RP is feasible and well tolerated in high-risk locally advanced prostate cancer. Although pathological downstaging was observed, this pilot study does not support definitive conclusions regarding oncologic benefit, and larger prospective studies are warranted.