Feasibility and accuracy of pathological diagnosis in en-bloc transurethral resection specimens versus conventional transurethral resection specimens of bladder tumour: evaluation with pT1 substaging by 10 pathologists

Prognostic value of micrometric substaging in pT1 bladder cancer patients treated with en-bloc transurethral resection

AIMS

We aimed to assess the oncological impact of micrometric extent of invasion in patients with pT1 bladder cancer (BCa) who underwent en-bloc resection for bladder tumour (ERBT).

METHODS AND RESULTS

We retrospectively analysed the records and specimens of 106 pT1 high-grade BCa patients who underwent ERBT. The extent of invasion, such as depth from basal membrane, number of invasive foci, maximum width of invasive focus, muscularis mucosae invasion and infiltration pattern (pattern A: solid sheet-like, nodular or nested growth, pattern B: trabecular, small cluster or single-cell pattern) were evaluated by a single genitourinary pathologist. The end-points were recurrence-free (RFS) and progression-free survival (PFS). Within a median follow-up of 23 months, overall, 36 patients experienced recurrence and 13 patients experienced disease progression. The 2-year PFS differed significantly depending on depth from basal membrane (< 1.3 mm: 94.8% versus ≧ 1.3 mm: 65.2%, P = 0.005), maximum width of invasive focus (< 4 mm: 91.7% versus ≧ 4 mm: 62.3%, P < 0.001), muscularis mucosae (MM) invasion (above MM = 96.1% versus into or beyond MM = 64.8%, P = 0.002) and infiltration pattern (pattern A: 100% versus pattern B: 83.3%, P = 0.037). In a multivariable analysis, MM invasion [hazard ratio (HR) = 4.54, 95% confidence interval (CI) = 1.25-16.5] and maximum width of invasive focus ≧ 4 mm (HR = 4.79, 95% CI = 1.25-16.5) were independent prognostic factors of progression.

CONCLUSIONS

En-bloc resection facilitates the evaluation of pathologic variables that might be useful in predicting disease recurrence and progression. In particular, not only the MM invasion but also the maximum width of invasion focus, reflecting the invasive volume, appear to be reliable prognosticators for disease progression.

[Should we all switch to en-bloc resection of bladder tumours?]

In En-Bloc Resection of Bladder Tumours (ERBT), tumours are not removed in fragments, but are dissected in one layer and, if possible, extracted in one piece. This method represents a significant shift in the surgical management of non-muscle-invasive bladder tumours, providing multiple benefits over the traditional transurethral resection of the bladder (TUR-B). The histological analysis of ERBT specimens is more accurate, enhancing diagnostic precision. Additionally, the presence of detrusor muscle in ERBT specimens is more frequent, indicating a more complete removal of the tumours. Recent years have seen the consolidation of a robust evidence base emphasizing the advantages of ERBT. Notably, a multicentric, prospective randomized trial has recently revealed a significant reduction in recurrence rates at 12 months follow-up compared with TUR-B. Experienced endourologists should explore this technique, as it may soon become the standard of care. The technique's elegance and effectiveness make it too important to be ignored.

A rare huge bladder inflammatory myofibroblastic tumor treated by en bloc resection with diode laser: a case report and literature review

Background

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm with malignant potential. Bladder IMT is even rarer and mainly treated by surgical resection However, partial or radical cystectomy would affect the quality of life of patients due to major surgical trauma, and classical TURBT is hard to avoid intraoperative complications including obturator nerve reflex and bleeding etc. Therefore, the safe and effective better choice of surgical approaches become critical to bladder IMT.

Case presentation

A 42-year-old male patient was admitted to the department of urology with persistent painless gross hematuria for more than 10 days without the presentation of hypertension. Preoperative routine urine examination of red blood cells was 7738.9/HPF (normal range ≤ 3/HPF). CTU indicated a space occupying lesion (6.0 cm×5.0 cm) in the left posterior wall of the bladder with heterogeneous enhancement in the excretory phase. MRI also indicated bladder tumor with slightly equal SI on T1WI and mixed high SI on T2WI (6.0 cm×5.1cm×3.5cm) in the left posterior wall of the bladder. En bloc resection of bladder IMT with 1470 nm diode laser in combination of removing the enucleated tumor by the morcellator system was performed. Postoperative pathological examination revealed bladder IMT, with IHC positive for Ki-67 (15-20%), CK AE1/AE3, SMA, and Desmin of bladder IMT and negative for ALK of bladder IMT as well as FISH negative for ALK gene rearrangement. Second TUR with 1470 nm diode laser was performed within 6 weeks to reduce postoperative risk of recurrence due to highly malignant potential for the high expression of Ki-67 (15-20%) and negative ALK in IHC staining. The second postoperative pathology report showed chronic inflammation concomitant with edema of the bladder mucosa without bladder IMT, furthermore no tumor was observed in muscularis propria layer of bladder. No recurrence occurred during the period of 24-month follow-up.

Conclusion

En bloc resection of bladder IMT in combination of the following second transurethral resection with 1470 nm diode laser is a safe and effective surgical approach for the huge bladder IMT with highly malignant potential.

Prospective learning curve analysis of en bloc resection of bladder tumor using an ex vivo porcine model

BACKGROUND

As a relatively new surgical technique, the learning curve of en bloc resection of bladder tumor (ERBT) in ex vivo models remains unaddressed. This study aimed to explore the learning curve of ERBT in an ex vivo porcine model.

METHODS

In this prospective study, eight endoscopists without prior experience in ERBT were divided into two groups: junior endoscopists, with less than 100 transurethral resection of bladder tumor (TURBT) procedure experience, and senior endoscopists, with at least 100 TURBT procedure experience. Each endoscopist performed 30 ERBT procedures on artificial lesions in an ex vivo porcine bladder model. The procedure time, perforation, en bloc resection status, and absence of detrusor muscle (DM) were recorded. The inflection points were identified using cumulative sum (CUSUM) analysis. Procedure results were compared between the two phases and two groups.

RESULTS

In all, 240 artificial lesions were successfully resected using ERBT. The CUSUM regression line indicated the inflection point at the 16th procedure for the junior endoscopists and at the 13th procedure for the senior endoscopists. In both groups, the procedure time, perforation, piecemeal resection, and DM absence rates were significantly lower in the consolidation phase than in the initial phase. The procedure time for the senior endoscopists was lower than for the junior endoscopists in both phases.

CONCLUSIONS

ERBT performance improved significantly after reaching the inflection point of the learning curve in the ex vivo model. We recommend a minimum of 16 ERBT procedures in ex vivo models for urologists with less than 100 TURBT experience and a minimum of 13 procedures for those with at least 100 TURBT experience before advancing to live animal training or supervised clinical practice.

En bloc resection of bladder tumour: the rebirth of past through reminiscence

PURPOSE

To learn about the history and development of en bloc resection of bladder tumour (ERBT), and to discuss its future directions in managing bladder cancer.

METHODS

In this narrative review, we summarised the history and early development of ERBT, previous attempts in overcoming the tumour size limitation, consolidative effort in standardising the ERBT procedure, emerging evidence in ERBT, evolving concepts in treating large bladder tumours, and the future directions of ERBT.

RESULTS

Since the first report on ERBT in 1980, there has been tremendous advancement in terms of its technique, energy modalities and tumour retrieval methods. In 2020, the international consensus statement on ERBT has been developed and it serves as a standard reference for urologists to practise ERBT. Recently, high-quality evidence on ERBT has been emerging. Of note, the EB-StaR study showed that ERBT led to a reduction in 1-year recurrence rate from 38.1 to 28.5%. An individual patient data meta-analysis is currently underway, and it will be instrumental in defining the true value of ERBT in treating non-muscle-invasive bladder cancer. For large bladder tumours, modified approaches of ERBT should be accepted, as the quality of resection is more important than a mere removal of tumour in one piece. The global ERBT registry has been launched to study the value of ERBT in a real-world setting.

CONCLUSION

ERBT is a promising surgical technique in treating bladder cancer and it has gained increasing interest globally. It is about time for us to embrace this technique in our clinical practice.

How do endoscopic bladder tumor resection techniques affect pathology practice? EAU Section of Uro-Technology (ESUT) and Uropathology (ESUP) survey

PURPOSE

We aimed to examine how different endoscopic bladder tumor resection techniques affect pathologists' clinical practice patterns.

METHODS

An online survey including 28 questions clustered in four main sections was prepared by the ESUT ERBT Working Group and released to the pathologists working in the institutions of experts of the ESUT Board and the working groups and experts in the uropathology working group. A descriptive analysis was performed using the collected data.

RESULTS

Sixty-eight pathologists from 23 countries responded to the survey. 37.3% of the participants stated that they always report the T1 sub-staging. Of those who gave sub-staging, 61.3% used T1a, b. 85.2% think that en bloc samples provide spatial orientation faster than piecemeal samples, and 60% think en bloc samples are timesaving during an inspection. 55.7% stated that whether the tissue sample is en bloc or piecemeal is essential. 57.4% think en bloc sample reduces turnaround time and is cost-effective for 44.1%. A large number of pathologists find that the pathology examination of piecemeal samples has a longer learning curve.

CONCLUSION

The survey shows that pathologists think that they can diagnose faster, accurately, and cost-effectively with ERBT samples, but they do not often encounter them in practice. Moreover, en bloc samples may be a better choice in pathology resident training. Evidence from real-life observational pathology practice and clinical research can reveal the current situation more clearly and increase awareness on proper treatment in endoscopic management of bladder tumors.

A 10-year renaissance of en bloc resection of bladder tumors (ERBT): Are we approaching the peak or is it back to the trough?

BACKGROUND

The number of studies suggesting that en bloc resection of bladder tumor (ERBT) is superior to transurethral resection of bladder tumor (TURBT) for non-muscle-invasive bladder cancer (NMIBC) management is growing. The aim of this review is to discuss the features of these procedures and to determine the prospects of en bloc in NMIBC management.

MATERIALS AND METHODS

We conducted a literature search using two databases (Medline and Scopus) and included any research which reported ERBT outcomes.

RESULTS

The lasers with minimal tissue penetration depth are becoming the main tool for ERBT. Unfortunately, most of the systematic reviews continue to be characterized by high heterogeneity. However, recent studies indicate that ERBT may have the edge when it comes to the detrusor muscle rate and the quality of the histological specimen. ERBT may favor in terms of in-field relapse, but its rate in the studies varies greatly. As for out-field relapse-free survival, the data are still lacking. The strongest evidence supports that ERBT is superior to TURBT in complications rate (bladder perforation). ERBT is feasible irrespective to tumor size and location.

CONCLUSIONS

ERBT has gained in momentum with the increasingly widespread use of this kind of laser surgery. The introduction of novel sources (TFL and Thulium:YAG pulsed laser) will definitely affect how the field develops and will result in further improvements in safety and precision. The latest trials make us more certain in our belief that ERBT will be beneficial in terms of histological specimen quality, relapse rate and complications rate.

Rotatable Bi-Channel En Bloc Resection of Bladder Tumor for Non-Muscle-Invasive Bladder Cancer in an Ex Vivo Porcine Model

En bloc resection of bladder tumor (ERBT) is a promising alternative for non-muscle-invasive bladder cancer management. However, the tumor characteristics and surgeon's experience influence its application. Therefore, in this pilot study, we developed a technique called "rotatable bi-channel en bloc resection of bladder tumor (RBC-ERBT)" and assessed its feasibility, efficacy, and safety compared with those of conventional ERBT. In an ex vivo porcine bladder model, 160 bladder lesions of varying morphologies (exophytic and flat) and sizes (1 and 2 cm) were created and evenly distributed across different locations. A total of 160 procedures were performed, with the ERBT and RBC-ERBT group each exhibiting 80 lesions. RBC-ERBT had a significantly higher technical success rate than ERBT (98.8% vs. 77.5%) for exophytic and flat lesions of both sizes and dome lesions. The procedure time was significantly shorter in the RBC-ERBT group, particularly for flat lesions, lesions with a 2 cm diameter, and lesions located at the dome. RBC-ERBT had a significantly lower piecemeal resection rate than ERBT (0% vs. 18.8%). The incidence of perforation or detrusor muscle sampling did not differ between the groups. Compared with conventional ERBT, RBC-ERBT offered improved success rates, reduced resection times, and effective management of challenging lesions.

Feasibility of Novel Technique of Flexible Cystoscopic En Bloc Snare Resection of Bladder Tumor: f-ESRBT

Background: En bloc resection of bladder tumors (ERBT) has been used as a treatment option to improve pathologic diagnostic accuracy in non-muscle invasive bladder cancer. We report on the feasibility of a novel ERBT technique using an electrosurgical snare with flexible cystoscope: flexible cystoscopic En bloc Snare Resection of Bladder Tumor (f-ESRBT). Methods: We used the electrosurgical snare to resect a superficial bladder tumor after injection of 50% glucose in the submucosa at the tumor base. We collected each resected tumor with a basket catheter and coagulated the resected area with a coagulation electrode. A flexible cystoscope was used for all procedures. Results/Discussion: We performed 10 operations. Mean tumor size was 10.2 ± 7.3 mm and mean surgery time was 13.8 ± 6.8 minutes. All procedures were performed without complications. Results showed f-ESRBT to be simple and minimally invasive and to enable accurate pathologic diagnoses. Conclusion: f-ESRBT is a feasible treatment option for small and non-muscle invasive bladder cancer.

En Bloc Resection Versus Conventional TURBT for T1HG Bladder Cancer: A Propensity Score-Matched Analysis

BACKGROUND

We aimed to assess the clinical, oncological, and pathological impact of en bloc resection of bladder tumors (ERBT) compared with conventional transurethral resection of bladder tumors (cTURBT) for pT1 high-grade (HG) bladder cancer.

PATIENTS AND METHODS

We retrospectively analyzed the record of 326 patients (cTURBT: n = 216, ERBT: n = 110) diagnosed with pT1 HG bladder cancer at multiple institutions. The cohorts were matched by one-to-one propensity scores based on patient and tumor demographics. Recurrence-free survival (RFS), progression-free survival (PFS), cancer-specific survival (CSS), and perioperative and pathologic outcomes were compared. The prognosticators of RFS and PFS were analyzed using the Cox proportional hazard model.

RESULTS

After matching, 202 patients (cTURBT: n = 101, ERBT: n = 101) were retained. There were no differences in perioperative outcomes between the two procedures. The 3-year RFS, PFS, and CSS were not different between the two procedures (p = 0.7, 1, and 0.7, respectively). Among patients who underwent repeat transurethral resection (reTUR), the rate of any residue on reTUR was significantly lower in the ERBT group (cTURBT: 36% versus ERBT: 15%, p = 0.029). Adequate sampling of muscularis propria (83% versus 93%, p = 0.029) and diagnostic rates of pT1a/b substaging (90% versus 100%, p < 0.001) were significantly better in ERBT specimen compared with cTURBT specimen. On multivariable analyses, pT1a/b substaging was a prognosticator of disease progression.

CONCLUSIONS

In patients with pT1HG bladder cancer, ERBT had similar perioperative and mid-term oncologic outcomes compared with cTURBT. However, ERBT improves the quality of resection and specimen, yielding less residue on reTUR and yielding superior histopathologic information such as substaging.

Development of a New Two-Arm Transurethral Surgical System for En Bloc Resection of Bladder Tumor: A Preclinical Study

Backgrounds and Objectives: To overcome the piecemeal nature of bladder tumor resection, en bloc resection of bladder tumor (ERBT) has been introduced. ERBT is difficult for surgeons to perform using the currently available system because it has only one arm. Herein, we aimed to develop a new transurethral surgical system to facilitate two-arm ERBT and to report the results of preclinical experiments using tumor phantoms. Methods: Initially, we aimed to develop a brand-new surgical system for ERBT but, after trial and error, we redirected our development to the creation of three elements: the left arm to grasp the tumor; the right arm to cut the tumor; and the system to operate the arms that can be attached to the existing surgical system (UES-40 SurgMaster^® [Olympus Co. Ltd., Tokyo, Japan]). The current system was evaluated by performing simulated ERBTs using tumor phantoms made from konjac jelly. Results: Following the assembly of developed arms into the UES-40 SurgMaster, we conducted preliminary ERBTs. After performing several resections, we adopted a basket-shaped forceps as the left arm instead of grasping forceps and an arched electrode as the right arm. The two arms and single endoscope were placed in an equilateral triangle. We performed ERBT for the tumor phantoms that ranged from 0.5 to 2.0 cm without major redo. Conclusion: Herein, we introduced our development for two-arm ERBT. The current concept of "two-hand transurethral surgery" has the potential to be developed in future in vivo and clinical trials.

Precise diagnosis and treatment of non-muscle invasive bladder cancer - A clinical perspective

According to the guidelines, transurethral resection of bladder tumor (TURBT) followed by intravesical therapy remains the standard strategy for the management of non-muscle invasive bladder cancer (NMIBC). However, even if patients receive standard strategy, the risk of postoperative recurrence and progression is high. From the clinical perspective, the standard strategy needs to be optimized and improved. Compared to conventional TURBT, the technique of en bloc resection of bladder tumor (ERBT) removes the tumor tissue in one piece, thus following the principles of cancer surgery. Meanwhile, the integrity and spatial orientation of tumor tissue is protected during the operation, which is helpful for pathologists to make accurate histopathological analysis. Then, urologists can make a postoperative individualized treatment plan based on the patient's clinical characteristics and histopathological results. To date, there is no strong evidence that NMIBC patients treated with ERBT achieve better oncological prognosis, which indicates that ERBT alone does not yet improve patient outcomes. With the development of enhanced imaging technology and proteogenomics technology, en bloc resection combined with these technologies will make it possible to achieve precise diagnosis and treatment of bladder cancer. In this review, the authors analyze the current existing shortcomings of en bloc resection and points out its future direction, in order to promote continuous optimization of the management strategy of bladder cancer.

French AFU Cancer Committee Guidelines - Update 2022-2024: Non-muscle-invasive bladder cancer (NMIBC)

OBJECTIVE

To update the ccAFU recommendations for the management of bladder tumours that do not infiltrate the bladder muscle (NBMIC).

METHODS

A systematic review (Medline) of the literature from 2020 to 2022 was performed, taking account of the diagnosis, treatment options and surveillance of NMIBC, while evaluating the references with their levels of evidence.

RESULTS

The diagnosis of NMIBC (Ta, T1, CIS) is made after complete full-thickness tumour resection. The use of bladder fluorescence and the indication of a second look (4-6 weeks) help to improve the initial diagnosis. The EORTC score is used to assess the risk of recurrence and/or tumour progression. Through the stratification of patients in low, intermediate and high-risk categories, adjuvant treatment can be proposed: intravesical chemotherapy (immediate postoperative, initiation regimen) or BCG (initiation and maintenance regimen) instillations, or even the indication of cystectomy for BCG-resistant patients.

CONCLUSION

Updating the ccAFU recommendations should contribute to improving patient management, as well as the diagnosis and treatment of NMIBC.

En bloc resection, is this the future of non-muscle invasive bladder cancer management? Presentation of our technique and brief review of the literature

INTRODUCTION

The quality of the initial transurethral resection of bladder tumors (TURBT) plays a key role in accurate local staging thus affecting treatment decision-making and disease prognosis. TURBT is still the gold standard for non-muscle invasive bladder cancer (NMIBC). However, en bloc resection of bladder tumors (ERBT) gradually expanded as a promising alternative to TURBT, aiming to overcome certain inherent limitations of conventional resection. We hereby describe a step-by-step bipolar ERBT technique and briefly review the current trends surrounding the role of various en bloc techniques in the field.

CASE PRESENTATION

We present the case of a 65-year old patient undergoing bipolar ERBT for a single, approximately 2 cm, papillary bladder mass. An experienced urologist completed the procedure within 17 min and without any intra- or postoperative complications. No conversion to TURBT was needed, and an adequate specimen for histological assessment was obtained. The patient made an uneventful recovery, and no recurrence was noted at 12-months.

CONCLUSION

Our initial experience demonstrates that ERBT via bipolar current is relatively quick, safe, and reliable. Prospective comparative clinical trials will examine its efficacy, and long-term oncological superiority in managing NMIBC.

Diagnostic accuracy of vesical imaging-reporting and data system (VI-RADS) in suspected muscle invasive bladder cancer: A systematic review and diagnostic meta-analysis

OBJECTIVE

To investigate the accuracy of Vesical Imaging-Reporting and Data System (VI-RADS) in detection of muscle-invasive bladder cancer (MIBC) we performed a systematic review and meta-analysis of the available literature.

MATERIALS AND METHODS

Scopus, Web of Science, PubMed, and EMBASE were searched up to 8 March 2021 for the studies evaluating the diagnostic performance of VI-RADS for the detection of MIBC. Inclusion criteria were patients with bladder cancer; index test of VI-RADS based on multiparametric MRI; reference test of histopathological findings from TURBT, re-TURBT, or cystectomy and study design of cohort. Case reports, review articles, and editorials were eliminated, as well as studies with insufficient knowledge to acquire TP, FP, FN, and TN values of VI-RADS. The MIDAS module of STATA was for statistical analysis. The heterogeneity was explored using subgroup analysis and meta-regression analysis.

RESULTS

Overall, 22 eligible studies, consisting of 2,576 participants and 5,414 MRI reports, were included in this meta-analysis. The area under curve (AUC) of VI-RADS at cut-point values of 3 and 4 were 0.93 (95%CI: 0.91, 0.95), 0.93 (95%CI: 0.90, 0.95), respectively. Based on Youden's J statistic, the optimal VI-RADS cutoff value for predicting MIBC was determined as 3 which granted a pooled sensitivity of 89% (95%CI: 87%, 91%; I²=48%) and a specificity of 84% (95%CI: 80%, 87%; I²=90%). Based on meta-regression, the sources of inter-study heterogeneity for VI-RADS ≥ 3 were the sample size > 70, study design, single-center vs multi-center, patient population characteristics (i.e., gender, age), reference standard, histology, magnetic strength, T2WI slice thickness, and the number of radiologists reporting the MRI results (P value ≤ 0.01).

CONCLUSION

The VI-RADS demonstrates consistently high diagnostic accuracy to predict MIBC. This scoring system could be applied in standard staging MRI reports of bladder cancer and can be incorporated into future MIBC work up guidelines.

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.

En Bloc Resection of Bladder Tumor-Is It the Way Forward?

Transurethral resection of bladder tumors (TURBT) represents the cornerstone in diagnosis and treatment of bladder cancer but recurrence is observed in up to 80% and over- or understaging with TURBT is common. A more recent development to overcome these limitations represents en-bloc resection of bladder tumors (ERBT) which offers several advantages over TURBT. In this report, we briefly review studies assessing outcomes of bladder cancer patients undergoing ERBT. Most randomized and non-randomized trial demonstrate improvement in clinical outcomes for ERBT over TURBT, however more pathological and translational studies are warranted.

En Bloc Tumor Resection, Optical Molecular Imaging, and the Potential Synergy of the Combination of the Two Techniques in Bladder Cancer

Although transurethral resection of bladder tumor is the golden standard for the treatment of non-muscle invasive bladder cancer, this surgical procedure still has some serious drawbacks. For example, piecemeal resection of tumor tissue results in exfoliated tumor cells dissemination and implantation, and fragmented tumor specimens make it difficult for pathologists to accurately assess the pathological stage and histologic grade. En bloc tumor resection follows the basic principle of oncological surgery and provides an intact tumor specimen containing detrusor muscle for pathologists to make accurate histopathological assessment. However, there is no robust clinical evidence that en bloc tumor resection is superior to conventional resection in terms of oncological outcomes. Considering the high recurrence rate, small or occult tumor lesions may be overlooked and incomplete tumor resection may occur during white light cystoscopy-assisted transurethral resection. Molecular fluorescent tracers have the ability to bind tumor cells with high sensitivity and specificity. Optical molecular imaging mediated by it can detect small or occult malignant lesions while minimizing the occurrence of false-positive results. Meanwhile, optical molecular imaging can provide dynamic and real-time image guidance in the surgical procedure, which helps urologists to accurately determine the boundary and depth of tumor invasion, so as to perform complete and high-quality transurethral tumor resection. Integrating the advantages of these two technologies, optical molecular imaging-assisted en bloc tumor resection shows the potential to improve the positive detection rate of small or occult tumor lesions and the quality of transurethral resection, resulting in high recurrence-free and progression-free survival rates.