Uncommon Histological Variants are Associated With Early Biochemical Recurrence After Robot-Assisted Radical Prostatectomy: A Retrospective Study With Exploratory Analysis of Postoperative PSA Outcomes.

INTRODUCTION

To evaluate the impact of uncommon histological (UH) variants on oncological outcomes after robot-assisted radical prostatectomy (RARP) in localized prostate cancer.

PATIENTS AND

METHODS

809 patients who underwent RARP between January 2019 and January 2024 were analyzed. Patients were classified into pure adenocarcinoma (PAC) and various UH subgroups, including glomeruloid structure, neuroendocrine (NE) differentiation, sarcomatoid differentiation, signet ring-like cells (SRC), mucinous feature, and cribriform architecture. The primary endpoint was biochemical recurrence (BCR)-free survival. Secondary endpoints included PSA persistence, overall survival, and treatment response after BCR. Kaplan-Meier and Cox regression analyses were performed.

RESULTS

At a median follow-up of 15 months, patients with NE/SRC/sarcomatoid differentiation had significantly higher BCR rates than those with PAC (42.9% vs. 13.5%, P < .05) and a lower 5-year BCR-free survival (HR 4.28; 95% CI, 2.10-8.72; P < .05). Following BCR, UH patients had longer time to PSA suppression (8.0 vs. 5.0 months, P < .05), though PSA ≤ 0.006 ng/mL was achieved in 80.0% of UH patients and 68.6% of PAC patients.

CONCLUSIONS

UH variants in localized prostate cancer were associated with heterogeneous postoperative outcomes after RARP. The adverse prognostic effect was mainly driven by NE/SRC/sarcomatoid differentiation, which was associated with earlier BCR. Exploratory postoperative treatment analyses suggest that short-term biochemical control may be observed in some patients with UH variants, but these findings require cautious interpretation and further validation.