Long-term Follow-up After En Bloc Transurethral Resection of Non-muscle-invasive Bladder Cancer: Results from a Single-center Experience

Targeting tumour surface collage with hydrogel probe: a new strategy to enhance intraoperative imaging sensitivity and stability of bladder cancer

PURPOSE

The incomplete resection of non-muscle invasive bladder cancer (NMIBC) augments the risk of disease recurrence. Imaging-guided surgery by molecular probes represents a pivotal strategy for mitigating postoperative recurrence. Traditional optical molecular probes, primarily composed of antibodies/peptides targeting tumour cells and fluorescent groups, are challenged by the high heterogeneity of NMIBC cells, leading to inadequate probe sensitivity. We have developed a collagen-adhesive probe (CA-P) to target the collagen within the tumour microenvironment, aiming to address the issue of insufficient imaging sensitivity.

METHODS

The distribution characteristics of collagen in animal bladder cancer models and human bladder cancer tissues were explored. The synthesis and properties of CA-P were validated. In animal models, the imaging performance of CA-P was tested and compared with our previously reported near-infrared probe PLSWT7-DMI. The clinical translational potential of CA-P was assessed using human ex vivo bladder tissues.

RESULTS

The distribution of collagen on the surface of tumour cells is distinct from its expression in normal urothelium. In vitro studies have demonstrated the ability of the CA-P to undergo a "sol-gel" transition upon interaction with collagen. In animal models and human ex vivo bladder specimens, CA-P exhibits superior imaging performance compared to PLSWT7-DMI. The sensitivity of this probe is 94.1%, with a specificity of 81%.

CONCLUSION

CA-P demonstrates the capability to overcome tumour cell heterogeneity and enhance imaging sensitivity, exhibiting favorable imaging outcomes in preclinical models. These findings provide a theoretical basis for the application of CA-P in intraoperative navigation for NMIBC.

International consensus panel for transurethral resection of bladder tumours metrics: assessment of face and content validity

OBJECTIVE

To develop performance metrics that objectively define a reference approach to a transurethral resection of bladder tumours (TURBT) procedure, seek consensus on the performance metrics from a group of international experts.

METHODS

The characterisation of a reference approach to a TURBT procedure was performed by identifying phases and explicitly defined procedure events (i.e., steps, errors, and critical errors). An international panel of experienced urologists (i.e., Delphi panel) was then assembled to scrutinise the metrics using a modified Delphi process. Based on the panel's feedback, the proposed metrics could be edited, supplemented, or deleted. A voting process was conducted to establish the consensus level on the metrics. Consensus was defined as the panel majority (i.e., >80%) agreeing that the metric definitions were accurate and acceptable. The number of metric units before and after the Delphi meeting were presented.

RESULTS

A core metrics group (i.e., characterisation group) deconstructed the TURBT procedure. The reference case was identified as an elective TURBT on a male patient, diagnosed after full diagnostic evaluation with three or fewer bladder tumours of ≤3 cm. The characterisation group identified six procedure phases, 60 procedure steps, 43 errors, and 40 critical errors. The metrics were presented to the Delphi panel which included 15 experts from six countries. After the Delphi, six procedure phases, 63 procedure steps, 47 errors, and 41 critical errors were identified. The Delphi panel achieved a 100% consensus.

CONCLUSION

Performance metrics to characterise a reference approach to TURBT were developed and an international panel of experts reached 100% consensus on them. This consensus supports their face and content validity. The metrics can now be used for a proficiency-based progression training curriculum for TURBT.

Treatment Modalities for Non-Muscle Invasive Bladder Cancer: An Updated Review

The landscape of treatment for non-muscle invasive bladder cancer is rapidly changing. A complete and careful transurethral resection is the mainstay of initial treatment and is followed by intravesical therapy in intermediate or high-risk cases. The standard of care is intravesical BCG. Many alternative or additive approaches to this are being explored. We divided this review into three relevant spaces to consider these novel treatment approaches: (1) low-risk disease, for which intravesical therapy is not usually considered, (2) BCG-naïve disease (i.e., considering alternatives to the standard therapy), and (3) BCG-unresponsive disease. We performed a review of published literature and summarized ongoing trials in the United States. Novel approaches that we explored include surgical techniques for resection, alterations in dwell time for intravesical therapy, delivery method and schedule of intravesical therapies, new intravesical therapy agents, and systemic therapies (especially immunotherapy). These are thoroughly outlined throughout this review article, and the numerous modalities being studied demonstrate significant promise for the future treatment of the expanding space of NMIBC.

Near-infrared spectroscopy as a novel method of ex vivo bladder cancer tissue characterisation

OBJECTIVE

To evaluate near-infrared (NIR) spectroscopy in differentiating between benign and malignant bladder pathologies ex vivo immediately after resection, including the grade and stage of malignancy.

PATIENTS AND METHODS

A total of 355 spectra were measured on 71 bladder specimens from patients undergoing transurethral resection of bladder tumour (TURBT) between April and August 2022. Scan time was 5 s, undertaken using a portable NIR spectrometer within 10 min from excision. Specimens were then sent for routine histopathological correlation. Machine learning models were applied to the spectral dataset to construct diagnostic algorithms; these were then tested for their ability to predict the histological diagnosis of each sample using its NIR spectrum.

RESULTS

A two-group algorithm comparing low- vs high-grade urothelial cancer demonstrated 97% sensitivity, 99% specificity, and the area under the receiver operating characteristic curve (AUC) was 0.997. A three-group algorithm predicting stages Ta vs T1 vs T2 achieved 97% sensitivity, 92% specificity, and the AUC was 0.996.

CONCLUSIONS

This first study evaluating the diagnostic potential of NIR spectroscopy in urothelial cancer shows that it can be accurately used to assess tissue in an ex vivo setting immediately after TURBT. This offers point-of-care assessment of bladder pathology, with potential to influence the extent of resection, reducing both the need for re-resection where invasive disease may be suspected, and also the potential for complications where extent of diagnostic resection can be limited. Further studies utilising fibre-optic probes offer the potential for in vivo assessment.

Clinical impact of detrusor muscle in en bloc resection for T1 bladder cancer

PURPOSE

Detrusor muscle (DM) in the resected specimen of patients with pT1 bladder cancer (BCa) is a quality-of-care criteria. We aimed to assess whether obtaining adequate DM is dependent on surgeon's experience, whether is a surrogate for resection quality, and whether the degree of DM thickness is related to postoperative outcomes in en bloc resection for bladder tumors (ERBT).

MATERIALS AND METHODS

We retrospectively analyzed the records of 106 pT1 high-grade BCa patients who underwent ERBT at several institutions. All specimens were reviewed by a single pathologist who assessed the presence or absence of DM and its thickness measured by a micrometer, when present. Early recurrence, defined as pathologically confirmed BCa on repeat resection or tumor recurrence at the first follow-up cystoscopy (within 3 months), was the endpoint reflective of the resection quality.

RESULTS

Of 106 patients, DM was detected in 99 (93%), and the median DM thickness was 1.8 mm. Large tumor size (>30 mm) was associated with adequate DM sampling (>1.8mm) (odds ratio [OR]: 6.10, 95% confidence intervals [CIs]: 2.08-17.9, P = 0.001), while surgeon's experience was not. DM presence and DM thickness were both not associated with early recurrence, while positive surgical margin was an independent prognosticator for early recurrence (OR: 3.38, 95% CI: 1.12-10.2, P = 0.031). Excessive DM sampling (>2.1 mm) was associated with prolonged urethral catheterization (OR: 28.8, 95% CI: 3.36-248, P = 0.002).

CONCLUSIONS

In ERBT, surgeon's experience seems irrelevant to obtain DM. Resection quality relies on surgical margin status, not the degree of DM. Obtaining excessive DM incurs adverse events/unnecessary medical care.

Efficacy and safety of a novel 450 nm blue diode laser versus plasmakinetic electrocautery for the transurethral resection of non-muscle invasive bladder cancer: The protocol and result of a multicenter randomized controlled trial

Objectives

To be the first to apply a novel 450 nm blue diode laser in transurethral resection of bladder tumor (TURBt) to treat patients with non-muscle invasive bladder cancer (NMIBC) and evaluate its efficacy and safety during the preoperative period compared to the conventional plasmakinetic electrocautery.

Materials and Methods

Randomized controlled trial (RCT) in five medical centers was designed as a non-inferiority study and conducted from October 2018 to December 2019. Patients with NMIBC were randomized to the blue laser or plasmakinetic electrocautery group for TURBt. As the first study to evaluate this novel blue laser device, the primary outcome was the effective resection rate of bladder tumors, including effective dissection and hemostasis. The secondary outcomes were the perioperative records, including surgical time, postoperative indwelling catheter time, hospital stay length, blood loss, reoperation rate, wound healing and adverse events.

Results

A total of 174 patients were randomized to either the blue laser group (85 patients) or plasmakinetic electrocautery group (89 patients). There was no statistical significance in the clinical features of bladder tumors, including tumor site, number and maximum lesion size. Both the blue laser and plasmakinetic electrocautery could effectively dissect all visible bladder tumors. The surgical time for patients in the blue laser group was longer (p=0.001), but their blood loss was less than that of patients in the control group (p=0.003). There were no differences in the postoperative indwelling catheter time, hospital stay length, reoperation rate or other adverse events. However, the patients undergoing TURBt with the blue laser showed a faster wound healing at 3 months after operation.

Conclusion

The novel blue laser could be effectively and safely used for TURBt in patients with NMIBC, and this method was not inferior to plasmakinetic electrocautery during the perioperative period. However, TURBt with the blue laser may provide the benefit to reduce preoperative blood loss and accelerate postoperative wound healing. Moreover, longer follow-up to confirm recurrence-free survival benefit was required.

The Safety and Efficacy of Vela Laser En-Bloc Endoscopic Resection versus Conventional Transurethral Resection of Bladder Tumor-A Single Center Experience

(1) Background: The current gold standard treatment of bladder cancer is conventional transurethral resection of the bladder tumor (CTURBT) using monopolar or bipolar resectoscopes. Laser en-bloc resection of the bladder tumor (LERBT) could achieve a higher quality of the specimen, reduce perioperative complications, and decrease the recurrence rate. Here, we compare the efficacy and safety of en-bloc Vela laser resection versus the conventional monopolar/bipolar resection; (2) Methods: A total of 100 clinically cT1-2 patients with bladder cancer were retrospectively reviewed in this study. Among these patients, 50 patients received LERBT, and 50 patients received CTURBT. The baseline characteristics, operation variables, and clinical outcomes were collected. The primary performance was the presence of muscle layer in the specimen. Perioperative complications and recurrence-free survival (RFS) were also compared. Independent t-test, Chi-square test, Kaplan–Meier curves, and the Cox-regression model were used in the analysis; (3) Results: The median age of the patients in the laser and resectoscope groups was 69.2 and 68.0 years old, respectively. The statistical difference in the presence of the detrusor muscle was 92.0% in the laser group and 70.0% in the CTURBT group (p = 0.005). A lower incidence of bladder perforation (p = 0.041) and major surgical complications (p = 0.046) in the LEBRT group was observed. We found no differences in operation duration, catheterization time, and hospitalization time after adjustment. Additionally, there was no statistical difference in RFS after a median follow-up time of 25 months; (4) Conclusions: Endoscopic laser en-bloc resection of bladder tumor with Vela laser is an effective method with higher muscle inclusion rate and fewer complications.

Intratumoral Switch of Molecular Phenotype and Overall Survival in Muscle Invasive Bladder Cancer

In recent years, immunohistochemical protein expression was studied as a surrogate to the molecular classification of bladder cancer, although no tissue biomarkers are available for clinical use to predict survival or the response to neoadjuvant chemotherapy (CT) in UC, as the literature produced conflicting results. This retrospective study included TURB specimens harboring foci of HG pT2 muscle-invasive bladder carcinoma (MIBC) from 251 patients who subsequently underwent radical cystectomy. We performed immunohistochemical analysis on tumor samples, for relevant gene-expression-based markers for basal type (CD44, CK5/6) and luminal type (CK20 and pPARγ). Piescore, investigated in both non-muscle-invasive (NMI) and muscle-invasive (MI) components of the tumor, divided basal and luminal UC-types when at least three of the four markers were consistent with a specific phenotype, mixed types if one/two luminal and basal markers were present simultaneously, and neu-like types when all four markers investigated were negative. Eighteen selected cases were also investigated with RT-PCR to validate, and to increase the specificity of, the immunohistochemical results. We observe an immunophenotypical difference in the NMI and MI components in 96/251 UC patients (38.25%): half of tumors (44/96 cases) have a transition to basal, 36.46% (35/96 cases) to neu-like, 12.5% (12/96 cases) to mixed, and 5.2% (5/96 cases) to luminal phenotypes. Mixed tumors in the NMI component are more likely to change phenotype than other groups, particularly compared with basal tumors, which demonstrate greater stability (only 8/96 cases, p < 0.00001). The transition of luminal tumors to basal display a better OS compared with the transition toward neu-like tumors (p = 0.027). Overall, the phenotypical switch does not affect lymphovascular invasion, pT, DFS, or OS compared with non-switched cases. In the MI component, the presence of CD44 expression, irrespective of score-related phenotype, shows a protective effect in papillary-type UC (OS p = 0.008, HR 0.453, PFS p = 0.07, HR 0.599), and in UC naïve for CT (p = 0.0479). Piescore immunophenotyping reveals an intratumoral phenotypical transition between the NMI and MI components of the same tumor. The molecular change is a common event in the mixed and luminal categories, but not in basal tumors, which show better phenotypical stability. This phenomenon could partially explain the sensitivity of a subset of luminal UC to chemotherapy: good responders could be “non-real” luminal UC, which acquire nasal markers, such as CD44.

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.

Could We Safely Avoid a Second Resection in Selected Patients With T1 Non-Muscle-Invasive Bladder Cancer? Preliminary Results of Cost-Effectiveness Study From HUmanitas New Indications for ReTUR (HuNIRe) Multicenter Prospective Trial

Objectives

The aim of this study is to assess whether restaging transurethral resection (ReTUR) could be safely replaced with urine cytology (UC) and in-office fiexible cystoscopy in selected T1 non-muscle-invasive bladder cancer (NMIBC).

Materials and Methods

This is an ongoing prospective multicenter trial enrolling patients diagnosed with T1 BC from 5 Italian centers. Patients with a macroscopically incomplete initial resection or absence of detrusor muscle were subjected to ReTUR according to European Association of Urology (EAU) guidelines. Conversely, those with a complete tumor resection at initial TUR underwent UC at 3-4 weeks and in-office fiexible white-light and narrow-band cystoscopy at 4-6 weeks. In case of positive UC, or evidence of recurrence at cystoscopy, ReTUR was performed within 2 weeks. Otherwise, patients started Bacillus Calmette-Guérin (BCG) induction course without ReTUR. The primary endpoint was to determine the feasibility and the clinical utility of not performing ReTUR in selected T1 NMIBC patients. The secondary endpoint was to perform a cost-benefit analysis of this alternative approach.

Results

Since May 2020, among 87 patients presenting with T1, 76 patients were enrolled. Nineteen (25%) patients underwent standard ReTUR after initial resection, 10 (13.2%) due to the absence of the detrusor muscle and 9 (11.8%) due to a macroscopically incomplete initial TUR. Overall, 57 (75%) patients initially avoided immediate ReTUR and underwent UC plus in-office flexible cystoscopy. Among them, 38 (66.7%) had no evidence of residual disease and immediately started the BCG induction course. Nineteen patients (33.3%) underwent "salvage" ReTUR due to either positive UC (7; 12.3%) or suspicious cystoscopy (12; 21%). Considering only the patients who initially avoided the ReTUR, disease recurrence was observed in 10/57. The saving of resource for each safely avoided ReTUR was estimated to be 1,759 €. Considering the entire sample, we estimated a saving of 855 € per patient if compared with the EAU guideline approach.

Conclusion

The preliminary results of our trial suggested that ReTUR might be safely avoided in highly selected T1 BC patients with a complete resection at first TUR. Longer follow-up and larger sample size are needed to investigate the long-term oncological outcomes of this alternative approach.

Clinical outcomes of reresection in patients with high-risk nonmuscle-invasive bladder cancer treated with en bloc transurethral resection: a retrospective study with a 1-year follow-up

Purpose To evaluate the impact of reresection on the clinical outcome in patients with primary high-risk nonmuscle-invasive bladder cancer (NMIBC) who initially received en bloc transurethral resection. Methods A retrospective analysis of data on eligible high-risk NMIBC with en bloc resection from June 2015 to June 2019 was performed. Patients were divided into two groups based on the presence or absence of reresection after the initial en bloc resection. The primary study endpoint was recurrence-free survival. The secondary outcomes were the residual rate of the tumor after initial en bloc resection, tumor upstaging rate and progression-free survival. Results We identified 115 eligible patients, including 51 (44.3%) who underwent reresection within 6 weeks of the initial en bloc resection and 64 (55.7%) who did not undergo en bloc reresection after the initial en bloc resection. The clinicopathological features were similar in patients with or without reresection. On finding tumor residues after the first en bloc resection, there were 3 cases (5.9%) in the reresection group compared to 2 cases (3.1%) in the non-reresection group (P=0.473). Two patients (3.9%) in the reresection group had tumor progression to muscle-invasive bladder cancer, whereas one patient (1.6%) in the non-reresection group exhibited tumor progression (P=0.430). The 1-year recurrence-free survival rate was 94.1% in the reresection group and 90.6% in the non-reresection group (P=0.269). In multivariate analysis, multifocality and T1 staging were independent prognostic factors for recurrence in patients with high-risk NMIBC who underwent en bloc resection. Conclusion In patients with high-risk NMIBC not exceeding 4 cm in diameter with no more than 4 lesions and not in the anterior bladder wall, reresection after en bloc resection seems to have failed to improve the patient's prognosis. However, a randomized controlled clinical study is required to confirm this hypothesis.