Association of preoperative frailty with health-related quality of life and urinary function after robot-assisted radical prostatectomy

Introduction

Global population aging has resulted in an increasing number of older patients diagnosed with prostate cancer (1). As life expectancy rises, clinical decision-making has shifted from reliance on chronological age toward an emphasis on healthy life expectancy, with greater focus on oncological outcomes, as well as postoperative health-related quality of life (HRQOL) and functional status (2).

Frailty, defined as diminished physiological reserve and heightened vulnerability to stressors, has emerged as a practical indicator of biological age in older adults. There is growing evidence that frailty is a key determinant of postoperative complications, functional recovery, and long-term quality of life in surgical oncology (3,4).

Robot-assisted radical prostatectomy (RARP) has transformed the surgical management of localized prostate cancer by reducing operative invasiveness and enhancing perioperative and functional outcomes. These advantages suggest that RARP is an appropriate option for selected older patients, including individuals who might previously have been regarded as marginal surgical candidates (5,6).

To optimize patient selection, simple and objective frailty assessment tools are necessary (7). The G8 geriatric screening tool is a validated and widely adopted instrument for identifying frailty in older adults with cancer (8). Despite increasing interest in frailty evaluation, evidence remains limited regarding the relationship between preoperative G8-defined frailty and longitudinal postoperative outcomes after RARP (9). Specifically, most prior studies have relied on cross-sectional analyses, heterogeneous frailty instruments, or focused on perioperative morbidity rather than longitudinal patient-reported quality of life and urinary functional recovery (6).

This study aimed to investigate the association of preoperative frailty, assessed using the G8 screening tool, with longitudinal outcomes after RARP, with particular focus on patient-reported HRQOL and urinary status. We present this article in accordance with the STROBE reporting checklist (available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0589/rc).

Methods

Study design and patients

In total, 328 patients who underwent transperitoneal standard RARP at Kansai Medical University between January 2022 and December 2024 were retrospectively analyzed. Primary endpoints were the association between preoperative frailty, assessed using the G8 screening tool, and longitudinal changes in HRQOL measured with the Functional Assessment of Cancer Therapy-General (FACT-G) and Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaires (8,10). Previous studies have explored three-category G8 classifications to evaluate gradations of vulnerability, although the thresholds used have varied across studies (11,12). Accordingly, patients in the present study were stratified into three groups according to their G8 score: high (G8 ≥15), intermediate (G8 13–14), and low (G8 ≤12). This three-group classification was used to evaluate gradations of G8 status beyond the conventional binary classification, while retaining the conventional >14 versus ≤14 threshold at the upper boundary.

Patient demographic, clinical, and perioperative variables were collected and compared among the three G8 groups, including age, body mass index, preoperative prostate-specific antigen level, Instrumental Activities of Daily Living (IADL) score, diabetes mellitus, ischemic heart disease, neoadjuvant hormone therapy, clinical T stage, nerve-sparing status, console time, estimated blood loss, specimen weight, and follow-up duration. Secondary endpoints included the associations of preoperative G8 classification with (I) longitudinal subjective urinary status evaluated via the urinary incontinence subscale of the Expanded Prostate Cancer Index Composite (EPIC) (13), and (II) objective urinary continence recovery assessed using Question 5 of the EPIC questionnaire, which asks: “How many pads or adult diapers per day did you usually use to control leakage during the last 4 weeks?” Recovery was defined as the use of 0–1 pad per day. These assessments were administered preoperatively and at 1, 3, 6, 12, and 24 months postoperatively.

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. This study was approved by the Ethics Committee of Kansai Medical University (No. 2022137). All patients provided written informed consent to allow the use of their medical records for research. All consecutive patients who met the study eligibility criteria were included to minimize selection bias.

Statistical analysis

Continuous variables were expressed as mean ± standard deviation or median with interquartile range, as appropriate. Categorical variables were summarized as number and percentage. Comparisons of baseline characteristics among the three G8 groups (high, intermediate, and low) were performed using the Kruskal-Wallis test for continuous variables and the chi-square test for categorical variables. Longitudinal changes in FACT-G and FACT-P scores were analyzed using linear mixed-effects models with patient-specific random intercepts. Time, G8 classification, and the time-by-G8 classification interaction were included as fixed effects. All available observations were included in the models, allowing patients with incomplete follow-up to contribute data at the assessment points for which measurements were available. To examine whether the association between G8 classification and postoperative HRQOL was independent of baseline HRQOL and chronological age, additional linear mixed-effects models restricted to postoperative assessments were adjusted for the corresponding baseline FACT score and age as a continuous variable. Sensitivity analyses were also performed by modeling the G8 score as a continuous variable and by dichotomizing the G8 score using the conventional cutoff (>14 vs. ≤14) to assess the robustness of the findings to alternative G8 specifications. Longitudinal changes in EPIC urinary incontinence scores were also analyzed using linear mixed-effects models with patient-specific random intercepts and fixed effects for time, G8 classification, and the time-by-G8 classification interaction. Additional models restricted to postoperative assessments were adjusted for the baseline EPIC urinary incontinence score and age as a continuous variable. Patients who had not yet reached a scheduled postoperative assessment were not considered to have missing data at that time point. Time to urinary continence recovery was estimated using the Kaplan-Meier method, and differences among G8 groups were assessed via the log-rank test. In addition, unadjusted Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for continence recovery according to G8 classification, with the high G8 group as the reference. All statistical analyses were conducted using SPSS software (version 28.0.1; IBM Corp., Armonk, NY, USA). All tests were two-sided, and P values <0.05 were considered statistically significant.

Results

Patient characteristics

G8 scores showed substantial overlap across age categories, with considerable variability within each age category (Figure 1).

Figure 1 Distribution of G8 scores by age category. Box-and-whisker plots display the distribution of G8 scores stratified by chronological age category (≤69, 70–74, and ≥75 years). Substantial overlap in scores was observed across age groups, with lower G8 scores present in some younger patients and preserved scores in some older patients. These findings suggest that chronological age alone does not adequately reflect frailty status. G8, Geriatric 8.

Baseline characteristics of the 328 patients stratified according to G8 classification (high, intermediate, and low) are summarized in Table 1. Patients with lower G8 scores had significantly lower body mass index and IADL scores, which assess independent daily functioning (P<0.001) (14). Age, preoperative prostate-specific antigen level, comorbidities, neoadjuvant hormone therapy, clinical T stage, nerve-sparing status, console time, estimated blood loss, specimen weight, and follow-up duration did not significantly differ among the three groups.

Longitudinal changes in HRQOL

Longitudinal changes in HRQOL, assessed by FACT-G and FACT-P, are shown in Figure 2 and summarized in Table 2. Linear mixed-effects models demonstrated significant effects of time on both FACT-G (P=0.004) and FACT-P (P<0.001). Significant main effects of G8 classification were also observed for both FACT-G and FACT-P (both P<0.001), indicating persistently lower HRQOL scores among patients with lower preoperative G8 scores throughout the follow-up period. However, no significant time-by-G8 interaction was observed for FACT-G (P=0.42) or FACT-P (P=0.14), indicating that the longitudinal patterns of HRQOL change did not significantly differ among the G8 groups. In additional models restricted to postoperative assessments and adjusted for the corresponding baseline FACT score and age, the time-by-G8 interaction remained nonsignificant for both FACT-G (P=0.31) and FACT-P (P=0.30), providing no evidence of differential postoperative HRQOL trajectories among the G8 groups after accounting for baseline HRQOL and age. Sensitivity analyses yielded consistent findings when G8 was modeled as a continuous variable or dichotomized using the conventional cutoff of ≤14. Lower G8 scores were associated with lower HRQOL levels, whereas no significant time-by-G8 interaction was observed under either specification, supporting the robustness of the finding that longitudinal HRQOL trajectories did not significantly differ according to preoperative G8 status. The number of evaluable patients decreased at later assessment points, primarily because some patients had not yet reached the corresponding scheduled postoperative follow-up assessment.

Figure 2 Longitudinal changes in health-related quality of life after RARP, stratified by preoperative G8 classification. Longitudinal changes in (A) FACT-G total score and (B) FACT-P total score from preoperative baseline (Pre) to 24 months after robot-assisted radical prostatectomy, stratified by preoperative G8 classification (high ≥15, intermediate 13–14, low ≤12). Patients with lower preoperative G8 scores consistently reported lower HRQOL before and after RARP. Values represent estimated marginal means, and error bars indicate ±1 standard error. Numbers of evaluable patients in the G8 high/mid/low groups were 175/109/40 preoperatively, 174/104/41 at 1 month, 167/104/39 at 3 months, 158/100/38 at 6 months, 149/95/34 at 12 months, and 90/58/17 at 24 months, respectively. FACT-G, Functional Assessment of Cancer Therapy-General; FACT-P, Functional Assessment of Cancer Therapy-Prostate; G8, Geriatric 8; HRQOL, health-related quality of life; RARP, robot-assisted radical prostatectomy.

Urinary status outcomes

Changes in urinary status assessed using the EPIC urinary incontinence subscale score are presented in Figure 3 and Table 2. Linear mixed-effects modeling demonstrated a significant effect of time on EPIC urinary incontinence scores (P<0.001). In the unadjusted model, the G8 group effect was not statistically significant (P=0.24), whereas a significant time-by-G8 interaction was observed (P=0.002). However, in the model restricted to postoperative assessments and adjusted for baseline EPIC urinary incontinence score and age, the overall time-by-G8 interaction was no longer statistically significant (P=0.29). Thus, after accounting for baseline urinary status and age, there was no clear evidence of different postoperative urinary incontinence trajectories among the three G8 groups. For pad-based continence recovery, in an unadjusted Cox proportional hazards model using the high G8 group as the reference, the hazard ratio for continence recovery was 1.05 [95% confidence interval (CI), 0.81–1.36] for the intermediate G8 group and 1.05 (95% CI, 0.71–1.55) for the low G8 group (Table S1). Although these estimates were consistent with the nonsignificant log-rank comparison, the confidence interval was relatively wide in the low G8 group, and potentially clinically meaningful differences cannot be definitively excluded.

Figure 3 Longitudinal changes in EPIC urinary incontinence scores after robot-assisted radical prostatectomy according to preoperative G8 classification. Estimated marginal means of EPIC urinary incontinence scores from baseline to 24 months after robot-assisted radical prostatectomy according to preoperative G8 classification. Error bars indicate ±1 standard error. Numbers of evaluable patients in the G8 high/mid/low groups were 177/109/40 preoperatively, 170/100/41 at 1 month, 167/103/39 at 3 months, 158/99/38 at 6 months, 149/95/34 at 12 months, and 91/58/17 at 24 months, respectively. G8 classification: high ≥15, intermediate 13–14, low ≤12. EPIC, Expanded Prostate Cancer Index Composite; G8, Geriatric 8; RARP, robot-assisted radical prostatectomy.

Urinary continence recovery

Objective urinary continence recovery is illustrated in Figure 4. Cumulative continence recovery rates rapidly rose during the early postoperative period and continued to increase with longer follow-up. No significant difference in time to continence recovery was observed among the three G8 groups (log-rank test, P=0.82).

Figure 4 Kaplan-Meier curves for recovery of urinary continence after RARP stratified by G8 classification. Urinary continence was defined as use of 0–1 pad per day, stratified by preoperative G8 classification. No significant difference in continence recovery was observed among the three G8 groups (log-rank test, P=0.82). The decrease in the number at risk over time reflected both continence-recovery events and censoring during follow-up and should not be interpreted as missing data or loss to follow-up alone. G8 classification: high ≥15, intermediate 13–14, low ≤12. G8, Geriatric 8; RARP, robot-assisted radical prostatectomy.

Discussion

In this single-center cohort study of patients who underwent RARP, patients with lower preoperative G8 scores consistently reported lower overall and prostate cancer-specific quality of life before and after RARP. Despite these persistent differences in patient-reported outcomes, after accounting for baseline urinary status and age, there was no clear evidence of different postoperative urinary recovery trajectories among the G8 groups, and time to continence recovery did not significantly differ among groups. The substantial overlap in G8 scores across age categories further indicated that chronological age does not adequately approximate frailty status. This distinction suggests that treatment decisions should incorporate both chronological age and individual biological vulnerability to better guide preoperative counseling and risk evaluation.

Frailty is increasingly recognized as an important determinant of postoperative outcomes in older patients with cancer (3,4,15,16). In the present study, lower G8 scores were associated with lower FACT-G and FACT-P scores across the assessment period. However, after adjustment for the corresponding baseline HRQOL score and chronological age, no significant time-by-G8 interaction was observed for either FACT-G or FACT-P. This finding suggests that the lower postoperative HRQOL observed in patients with lower G8 scores largely reflected differences already present before surgery, rather than a differential postoperative recovery trajectory. This observation aligns with the concept of frailty as an indicator of reduced physiological reserve, rather than a measure of postoperative recovery dynamics (17,18).

In contrast to the quality-of-life outcomes, EPIC urinary incontinence scores significantly improved over time. Although differences according to G8 status were observed in the unadjusted longitudinal analysis, the time-by-G8 interaction was no longer statistically significant after adjustment for baseline EPIC urinary incontinence score and age. This finding suggests that the observed longitudinal differences were substantially influenced by differences in urinary status already present before surgery, without clear evidence of different postoperative recovery trajectories among the three G8 groups after baseline adjustment. Similarly, no significant difference in pad-based continence recovery was observed among the G8 groups. These findings should be interpreted cautiously, as the absence of statistically significant differences does not exclude the possibility of clinically meaningful differences between groups. Togashi et al. examined the relationship between frailty and lower urinary tract symptoms after RARP and similarly reported no statistically significant association between frailty and lower urinary tract symptoms or continence rates (9).

Previous studies have demonstrated acceptable functional outcomes of RARP in older patients when appropriate selection criteria are applied (19,20). For instance, Yamada et al. reported favorable urinary outcomes in older patients (age ≥75 years) undergoing RARP (19). Our findings suggest that lower G8 scores were not associated with a statistically significant difference in time to pad-based urinary continence recovery in this cohort of carefully selected patients undergoing RARP.

Overall, our findings indicate that preoperative G8 screening may help identify patients with lower HRQOL before surgery who may continue to experience lower HRQOL after RARP. The integration of frailty assessment into shared decision-making may allow clinicians to tailor preoperative counseling and perioperative care according to individual vulnerability, rather than chronological age thresholds.

Several limitations of this study should be acknowledged. First, this was a single-institution retrospective analysis, which may limit generalizability. Surgical candidacy was determined by clinician judgment rather than predefined criteria, potentially introducing selection bias. Second, the number of evaluable patients decreased at later assessment points, particularly at 24 months, primarily because some patients had not yet reached the corresponding scheduled postoperative follow-up assessment. Therefore, the smaller sample size at later time points should not be interpreted solely as loss to follow-up or questionnaire nonresponse. Nevertheless, the reduced number of evaluable patients at later assessments may have decreased the precision of the longitudinal estimates. Similarly, the small number of patients remaining at risk at later time points in the Kaplan-Meier analysis may have reduced the precision of the late continence-recovery estimates. Third, although the additional longitudinal models were adjusted for baseline outcome scores and chronological age, they were not comprehensively adjusted for other potential confounding factors, including patient characteristics and perioperative factors that may be associated with HRQOL or urinary recovery. Residual confounding therefore cannot be excluded. Fourth, the study primarily focused on urinary outcomes and did not fully assess other functional domains, such as sexual or bowel function. Future multicenter prospective studies that incorporate comprehensive geriatric assessments and broader patient-reported outcome measures are warranted to clarify the role of frailty in long-term recovery and survivorship among older patients undergoing RARP.

Conclusions

Lower preoperative G8 scores were associated with persistently lower HRQOL before and after RARP, without evidence of a significantly different longitudinal HRQOL trajectory. After accounting for baseline urinary status and age, there was no clear evidence of different postoperative urinary recovery trajectories among the G8 groups, and time to pad-based continence recovery did not significantly differ among groups. The substantial overlap in G8 scores across age categories suggests that G8 screening may provide information complementary to chronological age. Incorporating preoperative frailty evaluation into routine practice may provide clinically meaningful information for shared decision-making and perioperative counseling for older patients undergoing RARP.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0589/rc

Data Sharing Statement: Available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0589/dss

Peer Review File: Available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0589/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0589/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. This study was approved by the Ethics Committee of Kansai Medical University (No. 2022137). All patients provided written informed consent to allow the use of their medical records for research.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Teoh JYC, Hirai HW, Ho JMW, et al. Global incidence of prostate cancer in developing and developed countries with changing age structures. PLoS One 2019;14:e0221775. [Crossref] [PubMed]
2. Boyle HJ, Alibhai S, Decoster L, et al. Updated recommendations of the International Society of Geriatric Oncology on prostate cancer management in older patients. Eur J Cancer 2019;116:116-36. [Crossref] [PubMed]
3. Molina-Garrido MJ, Guillén-Ponce C. Use of geriatric assessment and screening tools of frailty in elderly patients with prostate cancer. Review. Aging Male 2017;20:102-9. [Crossref] [PubMed]
4. Liu X, Sun W. Frailty Assessment for Outcome Prediction of Patients With Prostate Cancer Receiving Radical Prostatectomy: A Meta-Analysis of Cohort Studies. Clin Nurs Res 2022;31:1136-47. [Crossref] [PubMed]
5. Gurung PMS, Wang B, Hassig S, et al. Oncological and functional outcomes in patients over 70 years of age treated with robotic radical prostatectomy: a propensity-matched analysis. World J Urol 2021;39:1131-40. [Crossref] [PubMed]
6. Yamada Y, Taguchi S, Kume H. Surgical Tolerability and Frailty in Elderly Patients Undergoing Robot-Assisted Radical Prostatectomy: A Narrative Review. Cancers (Basel) 2022;14:5061. [Crossref] [PubMed]
7. Kostakopoulos N, Bellos T, Malovrouvas E, et al. Robot-Assisted Urological Oncology Procedures, Outcomes, and Safety in Frail Patients: A Narrative Review of Available Studies. Urol Res Pract 2024;50:36-41. [Crossref] [PubMed]
8. Bellera CA, Rainfray M, Mathoulin-Pélissier S, et al. Screening older cancer patients: first evaluation of the G-8 geriatric screening tool. Ann Oncol 2012;23:2166-72. [Crossref] [PubMed]
9. Togashi K, Hatakeyama S, Kojima Y, et al. The effect of frailty on the quality of life and lower urinary symptoms following robot-assisted radical prostatectomy: A longitudinal analysis (FRARP-QL Study). Urol Oncol 2021;39:192.e7-192.e14. [Crossref] [PubMed]
10. Esper P, Mo F, Chodak G, et al. Measuring quality of life in men with prostate cancer using the functional assessment of cancer therapy-prostate instrument. Urology 1997;50:920-8. [Crossref] [PubMed]
11. Deluche E, Leobon S, Lamarche F, et al. First validation of the G-8 geriatric screening tool in older patients with glioblastoma. J Geriatr Oncol 2019;10:159-63. [Crossref] [PubMed]
12. Yajima S, Nakanishi Y, Umino Y, et al. Value of Geriatric Assessment Using the G8 to Predict Postoperative Urinary Tract Infections in Patients Undergoing Radical Cystectomy. Turk J Urol 2022;48:278-86. [Crossref] [PubMed]
13. Kakehi Y, Takegami M, Suzukamo Y, et al. Health related quality of life in Japanese men with localized prostate cancer treated with current multiple modalities assessed by a newly developed Japanese version of the Expanded Prostate Cancer Index Composite. J Urol 2007;177:1856-61. [Crossref] [PubMed]
14. Barberger-Gateau P, Commenges D, Gagnon M, et al. Instrumental activities of daily living as a screening tool for cognitive impairment and dementia in elderly community dwellers. J Am Geriatr Soc 1992;40:1129-34. [Crossref] [PubMed]
15. Shinall MC Jr, Arya S, Youk A, et al. Association of Preoperative Patient Frailty and Operative Stress With Postoperative Mortality. JAMA Surg 2020;155:e194620. [Crossref] [PubMed]
16. Aceto P, Bassi P, Sollazzi L, et al. Implementation of frailty preoperative assessment to predict outcome in patients undergoing urological surgery: a systematic review and meta-analysis. BJU Int 2021;127:507-17. [Crossref] [PubMed]
17. Clegg A, Young J, Iliffe S, et al. Frailty in elderly people. Lancet 2013;381:752-62. [Crossref] [PubMed]
18. Panayi AC, Orkaby AR, Sakthivel D, et al. Impact of frailty on outcomes in surgical patients: A systematic review and meta-analysis. Am J Surg 2019;218:393-400. [Crossref] [PubMed]
19. Yamada Y, Teshima T, Fujimura T, et al. Comparison of perioperative outcomes in elderly (age ≧ 75 years) vs. younger men undergoing robot-assisted radical prostatectomy. PLoS One 2020;15:e0234113. [Crossref] [PubMed]
20. Islamoglu E, Aksaray EE, Tas S, et al. Elderly Patients' Outcomes After Robot-Assisted Radical Prostatectomy: A Single Center Experience. J Laparoendosc Adv Surg Tech A 2023;33:1097-101. [Crossref] [PubMed]