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

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

doi:10.1002/bco2.160

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

BJUI Compass. 2022 Jun 2;3(5):392-399. doi: 10.1002/bco2.160. eCollection 2022 Sep.

Authors

Takeshi Sasaki¹, Shin Ebara², Tomoyuki Tatenuma³, Yoshinori Ikehata⁴, Akinori Nakayama⁵, Daiki Kato⁶, Masahiro Toide⁷, Tatsuaki Yoneda⁸, Kazushige Sakaguchi⁹, Jun Teishima¹⁰, Kazuhide Makiyama³, Hiroshi Kitamura⁴, Kazutaka Saito⁵, Takuya Koie⁶, Fumitaka Koga⁷, Shinji Urakami⁹, Takahiro Inoue¹

Affiliations

¹ Department of Nephro-Urologic Surgery and Andrology Mie University Graduate School of Medicine Tsu Japan.
² Department of Urology Hiroshima City Hiroshima Citizens Hospital Hiroshima Japan.
³ Department of Urology Yokohama City University Yokohama Japan.
⁴ Department of Urology University of Toyama Toyama Japan.
⁵ Department of Urology Dokkyo Medical University Saitama Medical Center Koshigaya Japan.
⁶ Department of Urology Gifu University Graduate School of Medicine Gifu Japan.
⁷ Department of Urology Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital Tokyo Japan.
⁸ Department of Urology Seirei Hamamatsu General Hospital Hamamatsu Japan.
⁹ Department of Urology Toranomon Hospital Tokyo Japan.
¹⁰ Department of Urology Kobe City Medical Center West Hospital Kobe Japan.

Abstract

Objectives: 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).

Patients and methods: 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.

Results: 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.

Conclusions: 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.

Keywords: Gleason score; grade group; prostate cancer; radical prostatectomy; robotic‐assisted.