The Adequacy of Pelvic Lymphadenectomy During Radical Cystectomy for Carcinoma Urinary Bladder: A Narrative Review of Literature

Pembrolizumab monotherapy for high-risk non-muscle-invasive bladder cancer without carcinoma in situ and unresponsive to BCG (KEYNOTE-057): a single-arm, multicentre, phase 2 trial

BACKGROUND

The KEYNOTE-057 trial evaluated activity and safety of pembrolizumab in patients with BCG-unresponsive high-risk non-muscle-invasive bladder cancer who were ineligible for or declined radical cystectomy. In cohort A (patients with carcinoma in situ, with or without papillary tumours) of the KEYNOTE-057 study, pembrolizumab monotherapy led to a complete response rate of 41% at 3 months, and 46% of responders maintained a response lasting at least 12 months. Here, we evaluate pembrolizumab monotherapy in cohort B of patients with papillary tumours without carcinoma in situ.

METHODS

KEYNOTE-057 is a single-arm, phase 2 study in 54 sites (hospitals and cancer centres) in 14 countries. Cohort B eligible patients were aged 18 years and older, had an Eastern Cooperative Oncology Group performance status of 0-2, and had BCG-unresponsive high-risk non-muscle-invasive bladder cancer with papillary tumours (high-grade Ta or any-grade T1) without carcinoma in situ. Transurethral resection of bladder tumour within 12 weeks of first pembrolizumab dose was required. Patients received pembrolizumab 200 mg intravenously every 3 weeks for a maximum of 35 cycles. Primary endpoint was 12-month disease-free survival of high-risk non-muscle-invasive bladder cancer or progressive disease as assessed by cystoscopy, cytology, and central pathology and radiology review. Activity was assessed in all patients who received at least one dose of the study drug and had a baseline evaluation. Safety was assessed in all patients who received at least one dose of the study drug. This trial is registered with ClinicalTrials.gov number, NCT02625961, and is ongoing.

FINDINGS

Between April 12, 2016, and June 17, 2021, 132 patients (104 [79%] men and 28 [21%] women) who had received a median of ten (IQR 9-15) previous BCG instillations were enrolled into cohort B of the study. Patients received a median of 10 cycles (IQR 6-27) of pembrolizumab. At data cutoff date, Oct 20, 2022, median follow-up was 45·4 months (IQR 36·4-59·3) and five (4%) of 132 patients remained on treatment. The 12-month disease-free survival was 43·5% (95% CI 34·9-51·9). Treatment-related adverse events occurred in 97 (73%) of 132 patients; 19 (14%) had a grade 3 or 4 treatment-related adverse event; the most common grade 3 or 4 treatment-related adverse events were colitis (in three [2%] patients) and diarrhoea (in two [2%]). 17 (13%) of 132 patients experienced serious treatment-related adverse events, of which colitis (three patients [2%]) was most common. No treatment-related deaths occurred.

INTERPRETATION

Pembrolizumab monotherapy showed antitumour activity and manageable toxicity in patients with BCG-unresponsive high-risk Ta or T1 bladder cancer without carcinoma in situ and could potentially be a suitable treatment option for patients who decline or are ineligible for radical cystectomy. Findings will need to be confirmed in a randomised controlled trial.

FUNDING

Merck Sharp & Dohme.

The Role of Lymph Node Dissection in Patients With Muscle-Invasive Bladder Cancer Who Underwent Radical Cystectomy Following Neoadjuvant Chemotherapy

BACKGROUND

The interaction between lymph node dissection (LND) during radical cystectomy (RC) and neoadjuvant chemotherapy (NAC) remains unclear. This study aimed to evaluate the role of LND in patients undergoing RC after NAC.

PATIENTS AND METHODS

We retrospectively analyzed 259 patients with muscle-invasive bladder cancer (MIBC) who underwent RC following NAC at Fujita Health University Hospital and Fujita Health University Okazaki Medical Center between 2010 and 2022. Baseline characteristics, pathological outcomes, recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were compared between propensity score (PS)-matched cohorts.

RESULTS

PS matching analysis resulted in 94 matched pairs from the adequate (standard or extended template) and inadequate (limited template or unilateral- or no-LND) LND groups. The median number of dissected nodes was significantly higher in the adequate LND group than in the inadequate LND group (19 vs. 5, P < .001). Similarly, a higher pathological node-positive rate (ypN+) was observed in the adequate group than in the inadequate group (18.1% vs. 7.4%, P = .03). The adequate LND group identified more ypN+ with ≤ ypT1 cases than the inadequate group (4 vs. 1). There were no statistically significant differences between the adequate and inadequate groups in RFS (P = .94), CSS (P = .54), and OS (P = .65). Subgroup analysis also showed comparable survival rates, even in patients with ≥ pT3 or cN+ disease. ypN+ was an independent predictor of OS in the Cox regression analysis, while adequate LND and the number of lymph nodes removed (≥10 or ≥15) were not associated with survival.

CONCLUSIONS

Although adequate LND did not show a significant therapeutic effect in RC after NAC, adequate LND may have an important diagnostic role in detecting ypN+, which is a robust predictor, and is a useful biomarker to perform appropriate adjuvant immunotherapy especially in ≤ ypT1 cases.

Impact of surgical margin and extent of lymphadenectomy on oncologic outcomes in plasmacytoid urothelial carcinoma

OBJECTIVE

Guideline recommendations disagree on template boundaries for pelvic lymph node dissection (PLND) in conventional urothelial carcinoma. Less is known about PLND in variant histology. We aimed to analyze the role of LND in plasmacytoid urothelial carcinoma (PUC).

METHODS

A retrospective review of patients with cTanyNanyM0 PUC who underwent radical cystectomy (RC) with PLND was performed from 2012 to 2022. Lymph node count (LNC) was a surrogate for extent of lymph node dissection and dichotomized based on maximally selected rank statistics. Multivariable cox hazard regression analysis (MVA) for overall survival (OS) corrected for age, perioperative chemotherapy, soft tissue margin status, and stage ≥pT3 and/or pN+ was performed. Disease free survival (DFS) and OS were estimated using Kaplan-Meier (KM) analysis.

RESULTS

Sixty-seven patients with median age of 71, who were 79.1% male were included. Neoadjuvant and adjuvant chemotherapy were administered in 61.2% and 19.4% of patients, respectively. At RC, 70.1% were ≥pT3. Median LNC was 22 (IQR 14-27) with 43.3% of patients being pN+. Calculated optimal-LNC cut point for DFS and OS was 19. Grouping by optimal (≥20) vs. suboptimal-LNC (<20), no significant clinicodemographic differences were found. Optimal-LNC provided improved DFS (P = 0.05) and OS (P = 0.02). Optimal-LNC (HR 0.47, 0.24-0.93 CI 95%, P = 0.03) and negative soft tissue margin (HR 0.38, 0.19-0.76 CI 95%, P = 0.01) was associated with improved OS on MVA. Receipt of perioperative chemotherapy did not improve OS (P = 0.46).

CONCLUSION

In PUC, complete surgical extirpation achieving negative soft tissue margins and removing ≥20 lymph should be prioritized if operative intervention is pursued.

Minimizing the learning curve for robotic-assisted radical cystectomy A single-surgeon, retrospective, cohort study

INTRODUCTION

Studies published to date have suggested non-inferiority of robotic-assisted radical cystectomy (RARC) compared to open radical cystectomy (ORC), while few centers in Canada have adopted this approach. Though multifactorial, the learning curve and operative time are often discussed barriers. Herein, we present outcomes from the largest Canadian cohort of RARC performed to date.

METHODS

We conducted a retrospective chart review of all patients undergoing RARC by a single surgeon with greater than 1500 robot-assisted radical prostatectomy (RARP) experience at our institution from May 2020 to December 2021. Clinicopathological, intraoperative, and postoperative data, as well as complications in the first 90 days, were collected. Regression analysis was used to determine the relationship between case volume and operative time/lymph node yield.

RESULTS

A total of 31 patients underwent RARC during the study period, 26 of which were male. The median length of stay was six days (Q1-Q3 5-10), while days alive and out of hospital at 90 days were 83 days (Q1-Q3 80-85). Soft tissue margins were positive in 9.6% (3/31) of patients. Median lymph node yield was 17.0 lymph nodes (Q1-Q3 11-23). Median operative time was 241 minutes (Q1-Q3 228-252) in the ileal conduit group and 320 minutes (Q1-Q3 302-337) in the neobladder group. We observed four Clavien-Dindo grade >3 complications. The 90-day readmission rate and mortality rate were 17.2% (5) and 0% (0), respectively. There was no correlation between case volume and any outcome variables.

CONCLUSIONS

Previous high-volume experience performing RARP reduces the learning curve for performing RARC, with similar short-term outcomes to high-volume centers.

Extended pelvic lymph node dissection in muscle invasive bladder cancer

PURPOSE OF REVIEW

Bilateral pelvic lymph node dissection (PLND) at the time of radical cystectomy (RC) provides important staging information and oncologic benefit in patients with bladder cancer. The optimal extent of the PLND remains controversial. Our aim is to highlight nodal mapping studies and the data that guides optimization of both staging and oncologic outcomes. We then review contemporary randomized trials studying the extent of PLND.

RECENT FINDINGS

A recent randomized trial (RCT) powered for a 15% improvement in recurrence-free survival (RFS) of extended (e) over limited (l)PLND was completed but failed to identify this large difference in outcome. Concerns over study design limit the ability to interpret the oncologic results. Importantly, ePLND minimally changed surgical morbidity. An ongoing, similar RCT (SWOG S1011) powered to detect a 10% difference in RFS has completed accrual, but no published outcomes are available.

SUMMARY

RC and ePLND can provide cure in 33% of LN positive bladder cancer patients. Current data support a 5% improvement in RFS if ePLND is routinely used in MIBC patients. Two randomized trials powered to identify much larger (15 and 10%) improvements in RFS are unlikely to identify such an ambitious benefit by extending the PLND.

Extent of lymph node dissection and impact on survival in radical cystectomy for advanced bladder cancer

PURPOSE OF REVIEW

In patients with muscle invasive bladder cancer (MIBC) or unresectable non-MIBC, radical cystectomy is routinely combined with bilateral pelvic lymph node dissection (LND) owing to the oncological benefits found in recurrence-free survival (RFS), overall survival (OS) and cancer-specific survival (CSS) compared with radical cystectomy alone. However, the optimal anatomic extent of LND is still unclear.

RECENT FINDINGS

Retrospective studies were consistent in reporting oncological benefits of extended LND over nonextended LND. A recent RCT (the LEA trial) failed to demonstrate any benefit in terms of RFS, CSS and OS of super-extended LND over standard LND. Several confounding factors hindered the interpretation of the results, leaving the question of the right extent for LND still open. Results of a similar study, the SWOG S1011 are, therefore, highly anticipated. This study differed from the LEA study in several aspects but might also turn out to be a negative study.

SUMMARY

There are still no firm data on the oncological benefit brought by more extended LND in patients with MIBC. Survival benefits seem limited, at least in the general population. Other factors could influence the impact of LND on survival, including the administration of adjuvant and neoadjuvant chemotherapies.