Short‐Term Longitudinal Changes in Quality of Life Among Japanese Patients With Prostate Cancer After Single‐Port Robot‐Assisted Radical Prostatectomy: A Preliminary Prospective Study

In Japan, the incidence of prostate cancer (PCa), particularly localized PCa, has increased among patients aged over 70 years since 2000 [1]. Transperitoneal multiport (MP) robot-associated radical prostatectomy (RARP) is the gold standard treatment for localized PCa [2]. Recently, a single-port (SP) robotic platform (Intuitive Surgical Inc., California, USA) was proposed as a minimally invasive option for RARP [3]. The Da Vinci SP received manufacturing and marketing approval from the Ministry of Health, Labor, and Welfare in Japan in September 2022. Compared with the MP platform, which predominantly uses the transperitoneal approach, the SP system allows insertion of multiple forceps through a single port, enhancing maneuverability in confined spaces and accounting for 38.2% of extraperitoneal RARP procedures [4]. Chavali et al. demonstrated that extraperitoneal SP-RARP achieves comparable oncological and functional outcomes to transperitoneal MP-RARP [2]. Moreover, SP-RARP offers benefits such as reduced postoperative pain, faster recovery, and earlier discharge. Previous studies on perioperative outcomes following SP-RARP in other countries have been limited regarding oncological outcomes, pain scores, complications, continence, and potency [4]. In this study, we assessed perioperative outcomes and short-term longitudinal changes in quality of life (QOL) using the International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score (OABSS), Geriatric 8 (G8), 8-item Short-Form Health Survey (SF-8), and Expanded Prostate Cancer Index Composite (EPIC) up to 6 months after SP-RARP at our institution. This study was approved by the Institutional Ethical Review Board of our hospital (IRB number H2024-143). Our institution performed the first case of SP-RARP in February 2024. A prospective QOL study was performed in 23 consecutive patients with localized PCa who underwent SP-RARP performed by four surgeons at our institution between February and September 2024. All four surgeons had sufficient experience with MP-RARP, and held Japanese Society of Endourology and Robotics (JSER) proctor certification. All patients underwent extraperitoneal SP-RARP, as previously described [3], without pelvic lymph node dissection. During the same period, MP-RARP was performed for cases requiring lymph node dissection. For SP-RARP, no limitations on surgical eligibility were applied based on tumor location, prostate volume, and surgical history. For preoperative staging, all patients underwent chest-pelvic computed tomography, bone scans, pelvic magnetic resonance imaging, and the International Society of Urological Pathology (ISUP) biopsy Grade Group (bGG) was recorded. Pathological assessments included T and N staging, pathological ISUP Grade Group (pGG), extraprostatic extension (EPE), positive surgical margins (PSMs), and lymphovascular invasion (LVI). QOL status, including IPSS, OABSS, G8, SF-8, and EPIC scores, was assessed at baseline (pre-treatment) and at 1, 3, and 6 months after SP-RARP. Longitudinal changes in QOL were evaluated using the Friedman test for multiple and paired comparisons, with Bonferroni correction applied across periods. All statistical analyses were conducted using SPSS software version 28 (IBM Corporation, Armonk, NY, USA). Figure 1a,b show patient characteristics and pathological findings. The median age at surgery was 66 years (range, 52–78), and the median preoperative PSA level was 7.9 ng/mL (range, 3.9–16). The median operating time was 173 min (range, 106–274), console time 131 min (range, 75–242), and estimated intraoperative blood loss was 100 mL (range, 0–1336). Pelvic drains were placed in 13 of 23 cases. However, those cases were early-phase cases in which SP-RARP was launched, and drains were no longer routinely placed. Perioperative complications included one case of surgical site infection (Clavien–Dindo classification Grade II) and one case of liver dysfunction (Clavien–Dindo classification Grade I). The median (range) of urethral catheter placement and the length of hospital stay were 6 days (range: 5–7) and 9 days (range: 8–10), respectively. Histopathological examination revealed pathological stages T2, T3a, and T3a in 16, 5, and 2 patients, respectively. Figure 1c–k illustrate QOL changes: IPSS (Figure 1c), OABSS (Figure 1d), G8 (Figure 1e), SF-8 physical component summary (PCS) (Figure 1f), SF-8 mental component summary (MCS) (Figure 1g), and EPIC domain summary scores (Figure 1h–k) assessed at baseline (pre-treatment) and at 1, 3, and 6 months after SP-RARP. IPSS and OABSS scores increased at 1 month after SP-RARP and subsequently decreased (Figure 1c,d). G8 and SF-8 scores remained unchanged (Figure 1e–g). EPIC urinary and sexual summary scores decreased at 1 and 3 months after SP-RARP (Figure 1h,j). Furthermore, in the subscales analysis, the EPIC urinary incontinence scores significantly decreased at 1 and 3 months after SP-RARP; the EPIC sexual function scores significantly decreased at 1, 3, and 6 months after SP-RARP (data not shown). In nerve-sparing SP-RARP (n = 14), the EPIC sexual function scores at 6 months were higher than in non-nerve-sparing SP-RARP (n = 9) (p = 0.02), but there was no difference between the two groups regarding the EPIC urinary incontinence scores, IPSS, and OABSS (data not shown). The first study comparing QOL between SP-RARP and MP-RARP was published in 2022 and found no difference in surgical satisfaction (SSQ-8) scores [5]. The present study differs in using an extraperitoneal approach and assessing QOL longitudinally at baseline and 1, 3, and 6 months postoperatively. No previous studies had evaluated SF-8, EPIC, and G8 scores longitudinally after SP-RARP. Therefore, this preliminary study had been conducted with a small number of cases and had not statistically determined the sample size. Similar longitudinal changes in SF-8, EPIC, G8, IPSS, and OABSS scores, as observed in our study, have been reported in Japanese patients following MP-RARP [6, 7]. Interestingly, in our study, the SF-8 PCS scores at 1 month postoperatively did not decline, suggesting that SP-RARP may be less physically demanding than MP-RARP in the early postoperative period. Focusing on this point, we are planning a prospective study on postoperative QOL comparing SP-RARP and MP-RARP. Further prospective study may reveal that SP-RARP improves postoperative QOL. Takeshi Sasaki: writing – original draft, resources, data curation. Shinichiro Higashi: conceptualization, resources, data curation. Taketomo Nishikawa: resources. Yusuke Sugino: resources. Kouhei Nishikawa: resources. Takahiro Inoue: conceptualization, writing – review and editing, supervision. We thank Dr. Toru Ogura (Department of Clinical Research Support Center, Mie University) for his assistance with statistical analyses. We would like to thank Editage (www.editage.com) for their English language editing. The protocol for this research project was approved by the appropriate ethics committee at Mie University [approval number: H2024-143] and complied with the provisions of the Declaration of Helsinki. The need for informed consent was waived due to the retrospective study design. However, the ability to opt out is provided on our institution's website. The authors declare no conflicts of interest. Takeshi Sasaki and Takahiro Inoue are the Editorial Board members of the International Journal of Urology and the co-authors of this article. To minimize bias, they were excluded from all editorial decision-making related to the acceptance of this article for publication.