A Muscle-Invasive Bladder Cancer Patient With High Tumor Mutational Burden and RB1 Mutation Achieved Bladder Preservation Following Chemotherapy Combined With Immunotherapy: A Case Report

Integrating novel immunotherapeutic approaches in organ-preserving therapies for bladder cancer

Bladder cancer (BC) is a prevalent malignancy with significant morbidity and mortality. Over the years, the landscape of bladder cancer treatment has witnessed notable advancements, particularly in the realm of immunotherapy. Immunotherapy has emerged as a promising adjunct to organ-preserving approaches, harnessing the immune system's potential to target and eliminate cancer cells. Organ preservation strategies offer viable alternatives to radical cystectomy to avoid the morbidities associated with radical surgery, as well as to respond to the needs of patients unfit for or who have refused surgery. However, the challenge lies in achieving durable disease control while minimizing treatment-related toxicities. This review highlights the significance of immune checkpoint inhibitors, such as anti-programmed cell death 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) antibodies, in the treatment of localized bladder cancer. The clinical efficacy of immune checkpoint inhibitors, as both neoadjuvant and adjuvant therapies in combination with radiation or chemotherapy, is discussed. Moreover, the potential of immunotherapies beyond immune checkpoint inhibition, including combinations with bacillus Calmette-Guérin (BCG) instillations and/or investigational gene therapies, is explored. Furthermore, the predictive value of the tumour immune microenvironment for the success of these strategies is examined. Understanding the complex interplay between tumour immunity and therapeutic interventions can aid in identifying predictive biomarkers and tailoring personalized treatment strategies. Further research and clinical trials are warranted to optimize the use of immunotherapy in conjunction with organ-preserving therapies, potentially leading to enhanced patient outcomes and quality of life.

Bladder-sparing treatment for muscle-invasive bladder carcinoma using immune checkpoint inhibitors

Multimodal bladder preservation therapy is already an alternative for patients with muscle-invasive bladder cancer (MIBC) who are unable or unwilling to undergo radical cystectomy. Various bladder-preserving strategies that employ immune checkpoint inhibitors (ICIs) for MIBC have been investigated. There are three common modes of ICI-based bladder preservation therapy, of which the most studied is ICIs combined with chemoradiotherapy. The bladder-preserving strategy of ICIs combined with radiation has been investigated in patients who poorly tolerate chemotherapy. ICIs combined with chemotherapy have also been explored in patients who responded to neoadjuvant therapy with a clinical complete response. All the above-described strategies have shown promising efficacy and manageable safety profiles. However, the value of programmed death-ligand 1 (PD-L1) expression, tumor mutation burden and gene alterations for predicting the efficacy of immune-based bladder preservation therapy is still controversial. There remain some challenges for immune-based bladder preservation therapy, and large-sample randomized trials are needed.

A Systematic Review of Oncological Outcomes Associated with Bladder-sparing Strategies in Patients Achieving Complete Clinical Response to Initial Systemic Treatment for Localized Muscle-invasive Bladder Cancer

CONTEXT

Bladder-sparing strategies (BSSs) have been proposed for the treatment of muscle-invasive bladder cancer (MIBC) patients achieving clinical complete response (cCR) to initial systemic treatment to avoid toxicity related to radical cystectomy.

OBJECTIVE

To systematically review the current literature evaluating oncological outcomes of BSSs in patients achieving cCR to initial systemic treatment for localized MIBC.

EVIDENCE ACQUISITION

A computerized bibliographic search of the Medline, Embase, and Cochrane databases was performed for all studies reporting oncological outcomes of MIBC patients undergoing either surveillance or radiation therapy after achieving cCR to initial systemic treatment. Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, we identified 23 noncomparative prospective or retrospective studies published between 1990 and 2021. The mean bladder and metastatic recurrence rates (range) as well as the mean bladder preservation rate (BPR; range) were calculated, and overall survival (OS) was extracted from included reports.

EVIDENCE SYNTHESIS

Overall, 16 and seven studies evaluated surveillance (n = 610) and radiation therapy (n = 175) in MIBC patients achieving cCR to initial systemic treatment, respectively. With regard to surveillance, the median follow-up ranged from 10 to 120 mo, with a mean bladder recurrence rate of 43% (0-71%), including 65% of non-muscle-invasive bladder cancer (NMIBC) and 35% of MIBC recurrences. The mean BPR was 73% (49-100%). The mean metastatic recurrence rate was 9% (0-27%), while 5-yr OS rates ranged from 64% to 89%. With regard to radiation therapy, the median follow-up ranged from 12 to 60 mo, with a mean bladder recurrence rate of 15% (0-29%), including 24% of NMIBC, 43% of MIBC, and 33% of unspecified recurrences. The mean BPR was 74% (71-100%). The mean metastatic recurrence rate was 17% (0-22%), while the 4-yr OS rate was 79%.

CONCLUSIONS

Our systematic review showed that only low-level evidence supports the effectiveness of BSSs in selected patients achieving cCR to initial systemic treatment for localized MIBC. These preliminary findings highlight the need for further prospective comparative research to demonstrate its efficacy.

PATIENT SUMMARY

We reviewed studies evaluating bladder-sparing strategies in patients achieving complete clinical response to initial systemic treatment for localized muscle-invasive bladder cancer. Based on low-level evidence, we observed that selected patients could benefit from surveillance or radiation therapy in this setting, but prospective comparative research is requested to confirm their efficacy.

Identification and validation of RB1 as an immune-related prognostic signature based on tumor mutation burdens in bladder cancer

Bladder cancer (BCa) is one of the most common malignant tumors in the urinary system. Developing effective prognostic gene and exploring the immune cells that affect the prognosis of tumor are required. Full transcriptome data ( n = 433), clinical information ( n = 581) and mutation sequencing ( n = 412) were obtained from The Cancer Genome Atlas and independent mutation sequencing data of 101 samples were acquired from International Cancer Genome Consortium. Statistical processing was conducted using R packages. Gene biologically functional research was performed with gene set enrichment analysis based on Kyoto Encyclopedia of Genes and Genomes database. Twenty-two types of immune cell infiltration were assessed and calculated in 398 samples of BCa. Furthermore, the expression of immune-related prognostic signature was verified. The relationship between prognostic gene and immune cells was explored preliminarily. Tumor mutation burdens of mutant-type groups were higher than wild-type groups of 19 genes, except for FGFR3 and CREBBP. Kaplan-Meier analysis showed that high frequency of retinoblastomal 1 (RB1) mutation led to poor prognosis of BCa patients and was an independent prognostic factor ( P = 0.004; HR = 1.776). Proportions and correlation of 22 types of immune cells in 433 samples were determined. We found that RB1 expression decreased in BCa validated through quantitative PCR and immunohistochemistry. In addition, regulatory T cells (Tregs) were detected as a negatively correlated type of immune cell to mutation of RB1, whereas fluorescence costaining showed that Foxp3 expression of Tregs infiltration was negatively related to the expression of RB1. Mutation of RB1 can be identified as an independent prognostic predictor of BCa, and it may suppress the infiltration of Tregs in BCa tissues, increasing the incidence of tumor immune escape.

Expression and prognostic value of carbonic anhydrase IX (CA-IX) in bladder urothelial carcinoma

Objective

To investigate the expression intensity of carbonic anhydrase IX (CA-IX) in bladder urothelial carcinoma and its predictive value for the recurrence after transurethral resection of bladder tumor.

Methods

A retrospective analysis was made of 194 specimens who underwent transurethral resection of bladder tumors in our hospital from January 2014 to January 2016 and completed follow-up. The expression intensity of CA-IX and the clinical data of the patients were analyzed, and the subjects were divided into positive group and negative group according to the expression intensity of CA-IX. The age, gender, T stage, degree of differentiation, tumor number, tumor diameter, recurrence of each group was analyzed. Logistic univariate and multivariate analysis was used successively to find independent influencing factors for predicting the recurrence of bladder urothelial carcinoma after resection. The Kaplan–Meier survival curve was drawn according to the relationship between CA-IX expression intensity and postoperative recurrence.

Results

The positive expression rates of CA-IX in bladder urothelial carcinomas were 68.1% (132/194). The positive expression of CA-IX had no statistical significance with age, gender and tumor diameter (P > 0.05), while the positive expression of CA-IX had statistical significance with tumor T stage, tumor differentiation, tumor number and recurrence (P < 0.05); Logistic regression analysis showed that clinical T stage, tumor differentiation, tumor number, and CA-IX expression intensities were independent risk factors for predicting recurrence of bladder urothelial carcinoma after resection (P < 0.05); There were 59 cases of recurrence in the positive expression of CA-IX group, with a recurrence rate of 44.69% (59/132), and 17 cases of recurrence in the negative expression group, with a recurrence rate of 27.41% (17/62). The mean recurrence time of CA-IX positive group was 29.93 ± 9.86 (months), and the mean recurrence time of CA-IX negative group was 34.02 ± 12.44 (months). The Kaplan–Meier survival curve showed that the recurrence rate and recurrence time of patients with positive expression of CA-IX in bladder urothelial carcinomas were significantly higher than those of patients with negative expression of CA-IX.

Conclusion

CA-IX is highly expressed in bladder urothelial carcinoma, is a good tumor marker, and can be used as a good indicator for predicting the recurrence of bladder urothelial carcinoma after transurethral resection of bladder tumor.

Case report: Bladder preserving after maximal transurethral resection of the bladder tumor combined with chemotherapy and immunotherapy in recurrent muscle-invasive bladder cancer patients: A report of two cases

Background

Cisplatin-based neoadjuvant chemotherapy combined with radical cystectomy (RC) plus pelvic lymph node dissection (PLND) is the preferred treatment option for muscle-invasive bladder cancer (MIBC). However, some patients are unable to tolerate RC or may have postoperative complications after RC. And most patients have a strong desire for bladder-preserving treatment. There are no reports on the efficacy of maximal transurethral resection of the bladder tumor (TURBT) in combination with chemotherapy plus tislelizumab for bladder-preserving in recurrent MIBC patients.

Case presentation

We report two cases diagnosed with recurrent MIBC who achieved pathological complete response (pCR) and bladder-preserving after maximal TURBT combined with chemotherapy plus tislelizumab.

Conclusion

Postoperative immunotherapy should be considered for all patients with recurrent MIBC who are eligible for immunotherapy. In addition, high programmed death ligand-1 (PD-L1) expression, high tumor mutation burden (TMB), and TP53 mutation level can be combined to predict tislelizumab efficacy.