En-bloc resection of bladder tumour as primary treatment for patients with non-muscle-invasive bladder cancer: routine implementation in a multi-centre setting

[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.

Transurethral En Bloc Resection Versus Standard Resection of Bladder Tumour: A Randomised, Multicentre, Phase 3 Trial

BACKGROUND

Conventionally, standard resection (SR) is performed by resecting the bladder tumour in a piecemeal manner. En bloc resection of the bladder tumour (ERBT) has been proposed as an alternative technique in treating non-muscle-invasive bladder cancer (NMIBC).

OBJECTIVE

To investigate whether ERBT could improve the 1-yr recurrence rate of NMIBC, as compared with SR.

DESIGN, SETTING, AND PARTICIPANTS

A multicentre, randomised, phase 3 trial was conducted in Hong Kong. Adults with bladder tumour(s) of ≤3 cm were enrolled from April 2017 to December 2020, and followed up until 1 yr after surgery.

INTERVENTION

Patients were randomly assigned to receive either ERBT or SR in a 1:1 ratio.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was 1-yr recurrence rate. A modified intention-to-treat analysis on patients with histologically confirmed NMIBC was performed. The main secondary outcomes included detrusor muscle sampling rate, operative time, hospital stay, 30-d complications, any residual or upstaging of disease upon second-look transurethral resection, and 1-yr progression rate.

RESULTS AND LIMITATIONS

A total of 350 patients underwent randomisation, and 276 patients were histologically confirmed to have NMIBC. At 1 yr, 31 patients in the ERBT group and 46 in the SR group developed recurrence; the Kaplan-Meier estimate of 1-yr recurrence rates were 29% (95% confidence interval, 18-37) in the ERBT group and 38% (95% confidence interval, 28-46) in the SR group (p = 0.007). Upon a subgroup analysis, patients with 1-3 cm tumour, single tumour, Ta disease, or intermediate-risk NMIBC had a significant benefit from ERBT. None of the patients in the ERBT group and three patients in the SR group developed progression to muscle-invasive bladder cancer; the Kaplan-Meier estimates of 1-yr progression rates were 0% in the ERBT group and 2.6% (95% confidence interval, 0-5.5) in the SR group (p = 0.065). The median operative time was 28 min (interquartile range, 20-45) in the ERBT group and 22 min (interquartile range, 15-30) in the SR group (p < 0.001). All other secondary outcomes were similar in the two groups.

CONCLUSIONS

In patients with NMIBC of ≤3 cm, ERBT resulted in a significant reduction in the 1-yr recurrence rate when compared with SR (funded by GRF/ECS, RGC, reference no.: 24116518; ClinicalTrials.gov number, NCT02993211).

PATIENT SUMMARY

Conventionally, non-muscle-invasive bladder cancer is treated by resecting the bladder tumour in a piecemeal manner. In this study, we found that en bloc resection, that is, removal of the bladder tumour in one piece, could reduce the 1-yr recurrence rate of non-muscle-invasive bladder cancer.

Bladder cancer

Bladder cancer is a global health issue with sex differences in incidence and prognosis. Bladder cancer has distinct molecular subtypes with multiple pathogenic pathways depending on whether the disease is non-muscle invasive or muscle invasive. The mutational burden is higher in muscle-invasive than in non-muscle-invasive disease. Commonly mutated genes include TERT, FGFR3, TP53, PIK3CA, STAG2 and genes involved in chromatin modification. Subtyping of both forms of bladder cancer is likely to change considerably with the advent of single-cell analysis methods. Early detection signifies a better disease prognosis; thus, minimally invasive diagnostic options are needed to improve patient outcomes. Urine-based tests are available for disease diagnosis and surveillance, and analysis of blood-based cell-free DNA is a promising tool for the detection of minimal residual disease and metastatic relapse. Transurethral resection is the cornerstone treatment for non-muscle-invasive bladder cancer and intravesical therapy can further improve oncological outcomes. For muscle-invasive bladder cancer, radical cystectomy with neoadjuvant chemotherapy is the standard of care with evidence supporting trimodality therapy. Immune-checkpoint inhibitors have demonstrated benefit in non-muscle-invasive, muscle-invasive and metastatic bladder cancer. Effective management requires a multidisciplinary approach that considers patient characteristics and molecular disease characteristics.

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.

Development of a dynamic risk system for predicting the risk of recurrence and progression in patients with non-muscle-invasive bladder cancer after thulium laser resection of bladder tumor or transurethral resection of bladder tumor followed by intravesical BCG instillation

Background

The high recurrence rate of non-muscle-invasive bladder cancer (NMIBC) after tumor resection brings huge physical and financial burdens for patients. Several predictive models that predict the recurrence of patients with NMIBC have drawbacks in clinical practice. With the rapid development of therapeutic methods, more factors should be taken into consideration when constructing predictive model.

Methods

We retrospectively enrolled 90 patients who were diagnosed as intermediate- or high-risk NMIBC and received a Thulium laser resection of bladder tumor (TmLRBT) or transurethral resection of bladder tumor (TURBT) followed by BCG instillation. Univariate Cox regression analysis and multivariate Cox regression analysis were performed to screen out the independent prognostic factors of recurrence free survival (RFS). A nomogram and risk index were constructed using these prognostic factors.

Results

In this study, 22 patients suffered recurrence; 37 patients (41%) received TmLRBT, and over 90% patients completed intravesical BCG instillation for one year. The univariate Cox regression showed that surgery (TURBT vs TmLRBT), previous bladder tumor, tumor number, pathological stage, post-operative catheterization and number of BCG therapy were associated with RFS. The multivariate Cox regression revealed that surgery (TURBT vs TmLRBT) (HR = 3.16, 95%CI [1.02 - 9.83]); previous bladder tumor (HR = 4.03, 95%CI [1.41 - 11.54]); number of BCG therapy (HR = 0.89, 95%CI [0.84 - 0.95]) were independent prognostic factors. A nomogram was constructed and exhibited excellent capability in predicting the RFS with an AUC of 0.789, 0.848, 0.806 at 6-, 12- and 24-months respectively and a c-index of 0.822. Also, the calibration curve and decision curve analysis were performed to verify the predictive efficacy. The risk index was derived from the nomogram and also exhibited favorable capability in predicting the progression free survival (PFS) of patients.

Conclusions

Patients who received TmLRBT, without previous bladder tumor history and had more intravesical BCG instillations are likely to have better RFS. The nomogram and the risk index which were constructed to predict the RFS and PFS of patients may help urologists to make clinical decisions and aid in precision medicine.

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.

Health-related quality of life after curative treatment for muscle-invasive bladder cancer

Muscle-invasive bladder cancer (MIBC) is an aggressive disease for which the gold-standard treatment is radical cystectomy (RC) in combination with cisplatin-based neoadjuvant chemotherapy. Bladder-sparing strategies such as trimodal therapy (TMT) have also emerged to improve health-related quality of life (HRQoL) of patients. However, an improved understanding of the effect of all these treatment modalities on HRQoL is essential to provide personalized patient care. Different combinations of generic, cancer-specific and bladder cancer-specific questionnaires can be used as instruments for HRQoL evaluation in patients with MIBC before and after curative treatments, which can largely affect multiple domains of HRQoL including general health as well as physical, functional, social and emotional well-being. However, diagnosis of MIBC per se is also likely to affect HRQoL, and the perspective of cure after RC or TMT could induce a return to baseline HRQoL values for most of these domains. A considerable amount of data on HRQoL after RC is available, but conflicting results have been reported regarding the effect of urinary diversion (ileal conduit or orthotopic neobladder) and surgical approach (open or robotic surgery) on patient quality of life. Data on HRQoL after TMT are scarce, and additional comparative studies including patients receiving RC (especially using ileal orthotopic neobladder) are needed.

In vitro cytotoxicity of human urine and its potential toxic parameters towards bladder cancer cells

Background

Bladder cancer (CaB) has a high recurrence rate despite surgery. As bladder is constantly filled with urine, it is worthwhile to investigate whether it could have any detrimental effects on bladder cancer cells.

Methods

We investigated the cytotoxicity of urine samples from CaB patients and normal controls on four CaB cell lines and tested the percentage of cell death, proliferation, adhesion, invasion and colonies formation ability. In order to identify the potential components involving in urine cytotoxicity, we evaluated some basic physiochemical parameters of urines, such as pH, osmolarity, creatinine (Cr), sodium (Na), potassium (K), chloride (Cl), calcium (Ca) and phosphate (PO₄). We further compared the pH values of urine samples between CaB who developed recurrence versus those who did not. A more in-depth analysis on inflammatory markers was performed for two representative urine samples which demonstrated opposite cytoxic effects.

Results

23 CaB patients and 20 normal controls were recruited into this study. According to in vitro experiments, both CaB and non-CaB urines had comparable effect on cell toxicity, proliferation, adhesion, invasion and colonies formation ability in four cell lines, HTB9, RT4, T24 and UMUC3, while RT4 was the most sensitive to urine toxicity. After evaluating the relationship between basic physiochemical parameters and cytotoxicity, we found out that there were strong negative correlations between pH value and 24 hours death rate for the 4 CaB cell lines (HTB9 r = -0.6651, p<0.001; RT4 r = -0.8335, p<0.001; T24 r = -0.4924, p<0.001; UMUC3 r = -0.7066, p<0.001). Osmolarity, urine Cr and PO₄ all had weakly or moderately positive correlations with CaB cells on 24 hours death rate. CaB patients who developed recurrence had more alkaline urine than those who did not develop recurrence. In the urine sample with the highest cytoxicity, high concentrations of IL-6 and IFN-gamma were found.

Conclusions

Our study confirmed that there was not statistically significant difference in cytotoxicity between CaB and non-CaB urines. However, we identified some parameters that could have an impact on cytotoxicity towards CaB cells. Modifying certain urine characteristics peri-operatively may induce cytotoxicity, avoid tumour re-implantation, and reduce the chance of cancer recurrence.

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.

Recurrence mechanisms of non-muscle-invasive bladder cancer - a clinical perspective

Non-muscle-invasive bladder cancer (NMIBC) is an early-stage cancer without invasion into the detrusor muscle layer. Transurethral resection of bladder tumour (TURBT) is a diagnostic and potentially curative procedure for NMIBC, but has some limitations, including difficulties in ascertaining complete tumour removal upon piecemeal resection and the possibility of tumour re-implantation after the procedure. The oncological control of NMIBC is far from satisfactory, with a 1-year recurrence rate of 15-61%, and a 5-year recurrence rate of 31-78%. Various recurrence mechanisms have been described for NMIBC, such as undetected tumours upon cystoscopy, incomplete resection during TURBT, tumour re-implantation after TURBT, drop metastasis from upper tract urothelial carcinoma and field change cancerization. Understanding the recurrence mechanisms from a clinical perspective has strong implications for the optimization of NMIBC oncological outcomes, as a cure for patients with NMIBC can only be achieved by tackling all possible recurrence mechanisms in a comprehensive manner.

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.