Photodynamic Diagnosis-Assisted En Bloc Transurethral Resection of Bladder Tumor for Nonmuscle Invasive Bladder Cancer: Short-Term Oncologic and Functional Outcomes

Current opinions regarding the clinical utility of en bloc resection in the treatment of non-muscle invasive bladder cancer-a review of the literature

Non-muscle invasive bladder cancer (NMIBC) is currently mainly treated with the approach of transurethral resection of bladder tumor (TURBT) followed by pathology investigation of the obtained specimens. However, this approach-TURBT-has a few drawbacks, owing to the inherent technical defect-"piecemeal" resection. With development of medical science and surgical techniques, a new kind of surgical operation-"en bloc" resection of bladder tumor (ERBT)-emerged, hoping to completely remove bladder tumor with surrounding normal tissue. The detrusor muscle layer beneath the tumor is removed, and the surgical quality of bladder tumor is enhanced, with a better pathological outcome, reduced intraoperative complications and lower recurrence rate eventually. This paper reviews current literature concerning a brief history of ERBT developing, surgical steps, its indications, advantages on surgical margin, recurrence during follow-up, pathological performance-presence of detrusor muscle, residual tumor and upstage, as well as such issue as "is reTURBT necessary after ERBT?" and the guiding significance of ERBT in substaging of T1 bladder cancer.

A novel laser resection approach: efficacy of rotatable bi-channel en bloc resection of bladder tumor in a pilot in-vivo study

En bloc resection of bladder tumor (ERBT) involves removing bladder tumors and their base. Laser resection has been used to reduce complications including bleeding and obturator nerve reflex (ONR). We developed a novel approach (rotatable bi-channel en bloc resection of bladder tumor (RBC-ERBT)) and assessed its efficacy in a pilot in-vivo study to enhance laser ERBT's applicability in challenging bladder regions. In the laser RBC-ERBT procedure, lesions were excised by inserting a holmium laser through the rotating external working channel, while forceps were inserted through the internal working channel provided traction on the tissue. Fifteen laser RBC-ERBT procedures were performed in five different bladder areas of three live pigs. The technical success rate (TSR), procedure time, lesion size, occurrence of complications (bleeding, perforation, ONR), and detrusor muscle (DM) presence rate and DM thickness were evaluated. All 15 procedures were performed with a 100% TSR. The resections were successful in all bladder regions (posterior, left, right and anterior walls and dome). Median procedure time was 20 min. The resected specimen size was 10 mm × 7 mm to 17 mm × 13 mm. Mild bleeding occurred in two procedures (13.3%) but was effectively managed. No incidents of ONR or perforation were observed. Histological examination confirmed presence of DM in all specimens with a median DM thickness of 1.26 mm. Our pilot in-vivo study suggested the feasibility and effectiveness of laser RBC-ERBT for bladder tumors in various locations. This technique offers effective traction, improved visualization, and enhanced laser accessibility. Further studies are required to validate its effectiveness in humans.

Recent advancements in the diagnosis and treatment of non-muscle invasive bladder cancer: Evidence update of surgical concept, risk stratification, and BCG-treated disease

In the management of non-muscle invasive bladder cancer (NMIBC), disease progression and long-term control are determined by the intensity of delivered treatment and surveillance and the cancer cells' biological nature. This requires risk stratification-based postoperative management, such as intravesical instillation of chemotherapy drugs, Bacillus Calmette-Guérin (BCG), and radical cystectomy. Advancements in mechanical engineering, molecular biology, and surgical skills have evolved the clinical management of NMIBC. In this review, we describe the updated evidence and perspectives regarding the following aspects: (1) advancements in surgical concepts, techniques, and devices for transurethral resection of the bladder tumor; (2) advancements in risk stratification tools for NMIBC; and (3) advancements in treatment strategies for BCG-treated NMIBC. Repeat transurethral resection, en-bloc transurethral resection, and enhanced tumor visualization, including photodynamic diagnosis and narrow-band imaging, help reduce residual cancer cells, provide accurate diagnosis and staging, and sensitive detection, which are the first essential steps for cancer cure. Risk stratification should always be updated and improved because the treatment strategy changes over time. The BCG-treated disease concept has recently diversified to include BCG failure, resistance, refractory, unresponsiveness, exposure, and intolerance. A BCG-unresponsive disease is an extremely aggressive subset unlikely to respond to a rechallenge with BCG. Numerous ongoing clinical trials aim to develop a future bladder-sparing approach for very high-risk BCG-naïve NMIBC and BCG-unresponsive NMIBC. The key to improving the quality of patient care lies in the continuous efforts to overcome the clinical limitations of bedside management.

Energy source comparison in en-bloc resection of bladder tumors: subanalysis of a single-center prospective randomized study

PURPOSE

Different energy sources are employed to perform en-bloc transurethral resection of bladder tumor (ERBT). No study compared different energy sources in ERBT. The aim is to compare the different ERBT sources in terms of pathological, surgical and postoperative outcomes.

METHODS

This is a sub-analysis of a prospective randomized trial enrolling patients submitted to ERBT vs conventional TURBT from 03/2018 to 06/2021 (NCT04712201). 180 patients enrolled in ERBT group were randomized 1:1:1 to receive monopolar (m-ERBT), bipolar (b-ERBT) or thulium laser (l-ERBT). Endpoints were the comparison between energies in term of pathological analysis, intra, and post-operative outcomes.

RESULTS

49 (35%) m-ERBT, 45 (32.1%) b-ERBT, and 46 (32.9%) l-ERBT were included in final analysis. The rate of detrusor muscle (DM) presence was comparable between the energies used (p = 0.796) or the location of the lesion (p = 0.662). Five (10.2%), 10 (22.2%) and 0 cases of obturator nerve reflex (ONR) were recorded in m-ERBT, b-ERBT and I-ERBT groups, respectively (p = 0.001). Conversion to conventional TURBT was higher for lesions located in the anterior wall/dome/neck (p < 0.001), irrespective from the energy used. The presence of artifact in the pathological specimen was higher for lesions at the posterior wall (p = 0.03) and trigone (p = 0.03).

CONCLUSIONS

In our study, no difference in staging feasibility among energies was found. Laser energy might be beneficial in lateral wall lesions to avoid ONR. Since there is an increased risk of ERBT conversion to conventional TURBT for lesions of the anterior wall, electrocautery might be preferred over laser to avoid waste of material.

En bloc resection of bladder tumors: challenges and unmet needs in 2021

Non-muscle invasive bladder cancer accounts for the majority of new bladder cancer diagnoses, and endoscopic transurethral resection of bladder tumor (TURBT) represents the standard-of-care. Although a relatively safe and common procedure, TURBT is often hampered by the questionable quality of resection. The evolution of surgical techniques has brought en bloc resection of bladder tumor (ERBT) to the forefront. ERBT has emerged as an alternative to conventional TURBT, incorporating a more delicate en bloc sculpting and tumor excision, in contrast to 'piecemeal' resection by conventional TURBT. ERBT appears safe, feasible and effective with demonstrably higher rates of detrusor muscle in the pathologic specimen, all while providing better staging and obviating the need for a re-TURBT in selected patients. However, the method's adoption in the field is still limited. This review summarizes the recent evidence relevant to ERBT while further highlighting the technique's limitations and unmet needs.

Comparison of Clinicopathologic and Oncological Outcomes Between Transurethral En Bloc Resection and Conventional Transurethral Resection of Bladder Tumor: A Systematic Review, Meta-Analysis and Network Meta-Analysis with Focus on Different Energy Sources

Introduction: It has been hypothesized that transurethral en bloc (TUEB) of bladder tumor offers benefits over conventional transurethral resection of bladder tumor (cTURBT). This study aimed to compare disease outcomes of TUEB and cTURBT with focus on the different energy sources. Methods: A systematic search was performed using PubMed and Web of Science databases in June 2021. Studies that compared the pathological (detrusor muscle presence), oncological (recurrence rates) efficacy, and safety (serious adverse events [SAEs]) of TUEB and cTURBT were included. Random- and fixed-effects meta-analytic models and Bayesian approach in the network meta-analysis was used. Results: Seven randomized clinical trials (RCTs) and seven non-RCTs (NRCT), with a total of 2092 patients. The pooled 3- and 12-month recurrence risk ratios (RR) of five and four NRCTs were 0.46 (95% CI 0.29-0.73) and 0.56 (95% CI 0.33-0.96), respectively. The pooled 3- and 12-month recurrence RRs of four and seven RCTs were 0.57 (95% CI 0.25-1.27) and 0.89 (95% CI 0.69-1.15), respectively. The pooled RR for SAEs such as prolonged hematuria and bladder perforation of seven RCTs was 0.16 (95% CI 0.06-0.41) in benefit of TUEB. Seven RCTs (n = 1077) met our eligibility criteria for network meta-analysis. There was no difference in 12-month recurrence rates between hybridknife, laser, and bipolar TUEB compared with cTURBT. Contrary, laser TUEB was significantly associated with lower SAEs compared with cTURBT. Surface under the cumulative ranking curve ranking analyses showed with high certainty that laser TUEB was the best treatment option to access all endpoints. Conclusion: While NRCTs suggested a recurrence-free benefit to TUEB compared with cTURBT, RCTs failed to confirm this. Conversely, SAEs were consistently and clinically significantly better for TUEB. Network meta-analyses suggested laser TUEB has the best performance compared with other energy sources. These early findings need to be confirmed and expanded upon.

Fluorescent cystoscopy-assisted en bloc transurethral resection versus conventional transurethral resection in patients with non-muscle invasive bladder cancer: study protocol of a prospective, open-label, randomized control trial (the FLEBER study)

Background

Transurethral resection of bladder tumor (TURBT) is an essential procedure both for the treatment and staging of bladder cancer, particularly non-muscle invasive bladder cancer (NMIBC). The dissemination of cancer cells during resection and the consequent seeding into the bladder mucosa is the main cause of post-TURBT intravesical recurrence. Although the tumor dissemination is inevitable during conventional TURBT (cTURBT), this drawback can be overcome by tumor resection in one piece with intact surrounding normal tissues, referred to as en bloc resection. We previously described the photodynamic diagnosis (PDD)-assisted en bloc TURBT (EBTUR) technique and its favorable outcomes. Based on our preliminary studies, this randomized controlled trial was designed to evaluate the superiority of PDD-EBTUR to PDD-cTURBT.

Methods

The FLEBER study is a single-center randomized controlled trial in NMIBC patients who require TURBT. The longest diameter of the tumor must be between 6 and 30 mm. A total of 160 eligible patients will be enrolled after screening and randomly allocated to the PDD-EBTUR (experimental) and PDD-cTURBT (control) groups in a 1:1 ratio (80 cases to 80 cases). All patients will be treated using a single, immediate postoperative intravesical chemotherapy with epirubicin. The primary endpoint of this trial is the 2-year recurrence-free survival after surgery in pathologically proven low- or intermediate-risk NMIBC. All patients will be monitored by cystoscopy and urine cytology every 3 months for 2 years. Patient data including adverse events and complications, and data from frequency volume charts, pain scales, and health-related QOL questionnaires will be collected before and after the TURBT at indicated visits.

Discussion

The goal of this trial is to determine the potential benefits of PDD-cTURBT and PDD-EBTUR followed by a single immediate postoperative intravesical chemotherapy in patients with low- or intermediate-risk NMIBC who undergo TURBT. Ultimately, our findings will lead to the development of better interventions and potentially change the standard of care.

Trial registration

This clinical trial was prospectively registered with the UMIN Clinical Trials Registry on 1 August 2020. The reference number is UMIN000041273, and the Ethics Committee of Nara Medical University Approval ID is 2702.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05094-y.

Photodynamic Diagnosis-Assisted Transurethral Resection Using Oral 5-Aminolevulinic Acid Decreases the Risk of Repeated Recurrence in Non-Muscle-Invasive Bladder Cancer: A Cumulative Incidence Analysis by the Person-Time Method

Clinical evidence regarding risk reduction of repeated bladder recurrence after initial photodynamic diagnosis (PDD)-assisted transurethral resection of bladder tumor (TURBT) is still limited in patients with non-muscle-invasive bladder cancer (NMIBC). We analyzed patients with primary NMIBC undergoing TURBT without any adjuvant treatment to compare the risk of cumulative recurrence between the conventional white-light (WL)-TURBT and PDD-TURBT. Out of 430 patients diagnosed with primary NMIBC from 2010 to 2019, 40 undergoing WL-TURBT and 60 undergoing PDD-TURBT were eligible. Multivariate Cox regression analysis for time to the first recurrence demonstrated that PDD assistance was an independent prognostic factor with better outcome (p = 0.038, hazard ratio = 0.39, and 95% confidence interval 0.16–0.95). While no patient experienced more than one recurrence within 1000 postoperative days in the PDD-TURBT group, five out of 40 patients treated by WL-TURBT experienced repeated recurrence. The comparison of cumulative incidence per 10,000 person-days between the two groups revealed that PDD assistance decreased by 6.6 recurrences per 10,000 person-days (exact p = 0.011; incidence rate ratio 0.37, Clopper–Pearson confidence interval 0.15–0.82). This is the first study addressing PDD assistance-induced risk reduction of repeated bladder recurrence using the person-time method. Our findings could support clinical decision making, especially on adjuvant therapy after TURBT.