Prognostic differences among Grade Group 4 subgroups in robotic-assisted radical prostatectomy.

To investigate whether the International Society of Urological Pathology Grade Group 4 (GG 4) subgroups have different oncological outcomes in Japanese prostate cancer (PCa) patients undergoing robotic-assisted radical prostatectomy (RARP).

We conducted a retrospective multicentre cohort study in PCa patients undergoing RARP at 10 institutions in Japan. Pre- and post-operative variables were collected from enrolled patients. We evaluated biochemical recurrence and clinical and pathological variables in the different GG 4 subgroups.

A total of 3195 patients were enrolled in the study. Among them, 298 patients with GG 4 tumours (pathological Gleason scores [GSs] of 3 + 5 [N = 37], 4 + 4 [N = 257] and 5 + 3 [N = 4]) based on RARP specimens were analysed. The median follow-up period was 25.2 months. The 3-year biochemical recurrence (BCR)-free survival (BCRFS) rate in the overall population was 74.5%. The 3-year BCRFS rates in the pathological GS 3 + 5, GS 4 + 4 and GS 5 + 3 subgroups were 93.8%, 71.9% and 50.0%, respectively (P = 0.01). In multivariate analysis, pathological GS based on RARP specimens, PSA levels at surgery, pathological T stage, pathological N stage and surgical margins were independent risk factors significantly associated with BCRFS. In particular, patients with pathological GSs 4 + 4 and 5 + 3 were at higher risk of BCR than patients with pathological GS 3 + 5 (hazard ratio 4.54, P = 0.03 and hazard ratio 11.2, P = 0.01, respectively). The study limitations include the lack of central pathological specimen evaluation.

For patients with localized PCa undergoing RARP, pathological GS 4 + 4 and GS 5 + 3 were significantly associated with worse BCRFS than pathological GS 3 + 5. Pathological GS 3 + 5 may be overrated in GG 4. This observation emphasizes that primary and secondary GS should be considered to accurately stratify the risk of BCR after RARP.

BJUI compass. 2022 Jun 02*** epublish ***

Takeshi Sasaki, Shin Ebara, Tomoyuki Tatenuma, Yoshinori Ikehata, Akinori Nakayama, Daiki Kato, Masahiro Toide, Tatsuaki Yoneda, Kazushige Sakaguchi, Jun Teishima, Kazuhide Makiyama, Hiroshi Kitamura, Kazutaka Saito, Takuya Koie, Fumitaka Koga, Shinji Urakami, Takahiro Inoue

Department of Nephro-Urologic Surgery and Andrology Mie University Graduate School of Medicine Tsu Japan., Department of Urology Hiroshima City Hiroshima Citizens Hospital Hiroshima Japan., Department of Urology Yokohama City University Yokohama Japan., Department of Urology University of Toyama Toyama Japan., Department of Urology Dokkyo Medical University Saitama Medical Center Koshigaya Japan., Department of Urology Gifu University Graduate School of Medicine Gifu Japan., Department of Urology Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital Tokyo Japan., Department of Urology Seirei Hamamatsu General Hospital Hamamatsu Japan., Department of Urology Toranomon Hospital Tokyo Japan., Department of Urology Kobe City Medical Center West Hospital Kobe Japan.