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An international collaborative consensus statement on en bloc resection of bladder tumour incorporating two systematic reviews, a two-round delphi survey, and a consensus meeting

  • Jeremy Yuen-Chun Teoh,
  • Steven MacLennan,
  • Vinson Wai-Shun Chan,
  • Jun Miki,
  • Hsiang-Ying Lee,
  • Edmund Chiong,
  • Lui-Shiong Lee,
  • Yong Wei,
  • Yuhong Yuan,
  • Chun-Pong Yu,
  • Wing-Kie Chow,
  • Darren Ming-Chun Poon,
  • Ronald Chan,
  • Fernand Lai,
  • Chi-Fai Ng,
  • Alberto Breda,
  • Mario Wolfgang Kramer,
  • Bernard Malavaud,
  • Hugh Mostafid,
  • Thomas Herrmann,
  • Marek Babjuk

Publication: European Urology, October 2020

Background 

There has been increasing interest in en bloc resection of bladder tumour (ERBT) as an oncologically noninferior alternative to transurethral resection of bladder tumour (TURBT) with fewer complications and better histology specimens. However, there is a lack of robust randomised controlled trial (RCT) data for making recommendations.

Objective 

We aimed to develop a consensus statement to standardise various aspects of ERBT for clinical practice and to guide future research.

Design, setting, and participants 

We developed the consensus statement on ERBT using a modified Delphi method. First, two systematic reviews were performed to investigate the clinical effectiveness of ERBT versus TURBT (effectiveness review) and to identify areas of uncertainty in ERBT (uncertainties review). Next, 200 health care professionals (urologists, oncologists, and pathologists) with experience in ERBT were invited to complete a two-round Delphi survey. Finally, a 16-member consensus panel meeting was held to review, discuss, and re-vote on the statements as appropriate.

Outcome measurements and statistical analysis 

Meta-analyses were performed for RCT data in the effectiveness review. Consensus statements were developed from the uncertainties review. Consensus was defined as follows: (1) ≥70% scoring a statement 7-9 and ≤15% scoring the statement 1-3 (consensus agree), or (2) ≥70% scoring a statement 1-3 and ≤15% scoring the statement 7-9 (consensus disagree).

Results and limitations 

A total of 10 RCTs were identified upon systematic review. ERBT had a shorter irrigation time (mean difference -7.24 h, 95% confidence interval [CI] -9.29 to -5.20, I2 = 85%, p < 0.001) and a lower rate of bladder perforation (risk ratio 0.30, 95% CI 0.11-0.83, I2 = 1%, p = 0.02) than TURBT, both with moderate certainty of evidence. There were no significant differences in recurrences at 0-12, 13-24, or 25-36 mo (all very low certainty of evidence). A total of 103 statements were developed, of which 99 reached a consensus. A summary of statements is as follows: ERBT should always be considered for treating non-muscle-invasive bladder cancer; ERBT should be considered feasible even for bladder tumours larger than 3 cm; number and location of bladder tumours are not major limitations in performing ERBT; the planned circumferential margin should be at least 5 mm from any visible bladder tumour; after ERBT, additional biopsy of the tumour edge or tumour base should not be performed routinely; for the ERBT specimen, T1 substage, and circumferential and deep resection margins must be assessed; it is safe to give a single dose of immediate intravesical chemotherapy, perform second-look transurethral resection, and give intravesical bacillus Calmette-Guérin (BCG) therapy after ERBT; and in studies of ERBT, both per-patient and -tumour analysis should be performed for different outcomes as appropriate. Important outcomes for future ERBT studies were also identified. A limitation is that as consensus statements are brief, concise and binary in nature, areas of uncertainty that are complex in nature may not be addressed adequately.

Conclusions 

We have provided the most comprehensive review of the evidence base to date using a meta-analysis where appropriate and applying the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, and mobilised the international urology community to develop a consensus statement on ERBT using transparent and robust methods. The consensus statement will provide interim guidance for health care professionals who practice ERBT and inform researchers regarding ERBT-related studies in the future.

Commentary by Dr. Xylinas

En-bloc resection of bladder tumor (ERBT) has gained interest in the last years. ERBT has three potential benefits in treating non–muscle-invasive bladder cancer (NMIBC) when compared with the standard of care (ie.; conventional trans-urethral resection of bladder tumor (TURBT). First, bladder tumor is resected in one piece and the tumor specimen remains intact for a proper histological assessment. Second, the resection process is more precise and controlled; thus, the complication profile, in particular the risk of bladder perforation, may be reduced. Third, ERBT can avoid tumor fragmentation as in the case of conventional piecemeal resection. It can potentially decrease the risk of recurrence by avoiding floating tumor cells and therefore reimplantation.

Despite these potential benefits, there is a lack of standardization leading to heterogeneity in the clinical and technical aspects of ERBT. Therefore, Teoh and colleagues developed a consensus statement on ERBT that can serve as a standard reference for health care professionals in the future. They performed two systematic reviews, a two-round Delphi survey, and a face-to-face consensus meeting. The systematic reviews were performed to investigate the clinical effectiveness of ERBT versus TURBT (effectiveness review) and to identify areas of uncertainty in ERBT (uncertainties review). Afterwards, 200 health care professionals (urologists, oncologists, and pathologists) with experience in ERBT were invited to complete a two-round Delphi survey. Finally, a 16-member consensus panel meeting was held to review, discuss, and re-vote on the statements as appropriate.

A total of 10 RCTs were identified upon systematic review. En-bloc resection was associated with a shorter irrigation time (mean difference –7.24 h, 95% confidence interval [CI] –9.29 to –5.20, I2 = 85%, p < 0.001) and a lower rate of bladder perforation (risk ratio 0.30, 95%CI 0.11–0.83, I2 = 1%, p = 0.02) than TURBT. With regards to oncological outcomes, there were no differences in terms of disease recurrence among the two techniques. With regards to the Delphi survey, a total of 103 statements were developed, of which 99 reached a consensus. The most important statements are as follows:  ERBT should always be considered for treating NMIBC; ERBT should be considered feasible even for bladder tumors larger than 3 cm; number and location of bladder tumors are not major limitations in performing ERBT; the planned circumferential margin should be at least 5 mm from any visible bladder tumor; after ERBT, additional biopsy of the tumor edge or tumor base should not be performed routinely; for the ERBT specimen, T1 substage, and circumferential and deep resection margins must be assessed; it is safe to give a single dose of immediate intravesical chemotherapy, perform second-look transurethral resection, and give intravesical bacillus Calmette-Guérin (BCG) therapy after ERBT; and in studies of ERBT, both per-patient and -tumor analysis should be performed for different outcomes as appropriate. 

Watch also our interview with Ass. Prof. Teoh on this consensus statement.