Perioperative immunotherapy for muscle-invasive bladder cancer

Plasma-Derived Cell-Free DNA as a Biomarker for Early Detection, Prognostication, and Personalized Treatment of Urothelial Carcinoma

Bladder cancer (BC) is one of the most common malignancies in the United States, with over 80,000 new cases and 16,000 deaths each year. Urothelial carcinoma (UC) is the most common histology and accounts for 90% of cases. BC management is complicated by recurrence rates of over 50% in both muscle-invasive and non-muscle-invasive bladder cancer. As such, the American Urological Association (AUA) recommends that patients undergo close surveillance during and after treatment. This surveillance is in the form of cystoscopy or imaging tests, which can be invasive and costly tests. Considering this, there have been recent pushes to find complements to bladder cancer surveillance. Cell-free DNA (CfDNA), or DNA released from dying cells, and circulating tumor DNA (ctDNA), or mutated DNA released from tumor cells, can be analyzed to detect and characterize the molecular characteristics of tumors. Research has shown promising results for ctDNA use in the BC care realm. A PubMed literature review was performed finding studies discussing cfDNA and ctDNA in BC detection, prognostication, and monitoring for recurrence. Keywords used included bladder cancer, cell-free DNA, circulating tumor DNA, urothelial carcinoma, and liquid biopsy. Studies show that ctDNA can serve as prognostic indicators of both early- and late-stage BC, aid in risk stratification prior to major surgery, assist in detection of disease progression and metastatic relapse, and can assess patients who may respond to immunotherapy. The benefit of ctDNA is not confined to BC, as studies have also suggested its promise as a biomarker for neoadjuvant chemotherapy in upper-tract UC. However, there are some limitations to ctDNA that require improvements in ctDNA-specific detection methods and BC-specific mutations before widespread utilization can be achieved. Further prospective, randomized trials are needed to elucidate the true potential ctDNA has in advancements in BC care.

Perioperative Immune Checkpoint Blockade for Muscle-Invasive and Metastatic Bladder Cancer

Checkpoint inhibitors offer promise in treating muscle-invasive and metastatic bladder cancer, but the optimal timing of their administration-neoadjuvant or adjuvant-remains unclear. To determine the efficacy of combining checkpoint inhibition with standard cisplatin-based chemotherapy, we conducted a phase II trial of neoadjuvant anti-PD-1 (αPD-1) and anti-CTLA-4 (αCTLA-4), in combination with cisplatin-gemcitabine, for patients with muscle-invasive bladder cancer prior to radical cystectomy. In addition, a novel murine model of spontaneous metastatic bladder cancer was used to compare the efficacy of neoadjuvant versus adjuvant anti-PD-L1 (αPD-L1) treatment. The clinical trial was closed prematurely due to the industry's withdrawal of drug provision. Adverse events were observed in all patients; however, serious adverse events were not observed in any patient. A complete pathologic response was observed in 50% of the 4 patients enrolled. Response to treatment was significantly associated with elevated urinary T cells including CD8+ and IFNγ+ CD4+ T cells, suggesting potential reinforcement of immune responses by neoadjuvant αPD-1 and αCTLA-4 against bladder tumor cells. These findings suggest that combining chemotherapy and immunotherapy in the neoadjuvant setting could be safe. However, the complete response rate of this four-drug regimen was modest and emphasizes the need for randomized controlled trials to properly assess immunotherapy efficacy in the neoadjuvant setting. In corresponding murine studies, the MB49-met model consistently displayed widespread metastasis, including tumor growth in the lungs, liver, and bowel mesentery, within 20 days of subcutaneous transplantation. Mice receiving surgery plus neoadjuvant αPD-L1 or adjuvant αPD-L1 exhibited improved survival compared to those receiving only αPD-L1. However, no significant difference in survival was observed between the neoadjuvant and adjuvant αPD-L1 cohorts. Furthermore, the timing of neoadjuvant therapy administration (early vs. late) did not significantly impact survival. This study highlights the potential of perioperative immunotherapy in the treatment of locally advanced and metastatic bladder cancer.

Current and Future Landscape of Perioperative Treatment for Muscle-Invasive Bladder Cancer

Cisplatin-based neoadjuvant chemotherapy followed by radical cystectomy is the current standard of care for muscle-invasive bladder cancer (MIBC). However, less than half of patients are candidates for this treatment, and 50% will develop metastatic disease. Adjuvant chemotherapy could be offered if neoadjuvant treatment has not been administered for suitable patients. It is important to reduce the risk of systemic recurrence and improve the prognosis of localized MIBC. Systemic therapy for metastatic urothelial carcinoma has evolved in recent years. Immune checkpoint inhibitors and targeted agents, such as antibody-drug conjugates or FGFR inhibitors, are new therapeutic alternatives and have shown their benefit in advanced disease. Currently, several clinical trials are investigating the role of these drugs, as monotherapy and in combination with chemotherapy, in the neoadjuvant and adjuvant settings with promising outcomes. In addition, the development of predictive biomarkers could predict responses to neoadjuvant therapies.

Transurethral resection of bladder tumor-based bladder preservation therapy for refractory high risk non-muscle invasive bladder cancer: Current landscape and future directions

Bladder cancer is the most common malignant tumor of urinary system worldwide. Approximately 75% of patients with bladder cancer present with non-muscle-invasive bladder cancer (NMIBC), which is effectively managed with transurethral resection of bladder tumor (TURBT). For refractory high risk NMIBC, patients are typically treated by radical cystectomy (RC). TURBT deserves further evaluation. Growing evidence suggests that repeated TURBT-based bladder-sparing approaches may improve oncological outcomes and quality of life in highly selected patients. Novel imaging techniques and biomarkers may aid in patients selection and postoperative surveillance. With growing interest in adding immunotherapy to refractory bladder cancer, TURBT based approaches enable the bladder preservation therapy for high risk NMIBC. Here we summarize the current landscape, biomarkers for surveillance, and future directions for applying TURBT-based bladder preservation therapy.

B7-H4 correlates with clinical outcome and immunotherapeutic benefit in muscle-invasive bladder cancer

AIM

B7-H4, a sibling to PD-L1 in B7 family, has been reported to be a novel immune checkpoint that is prevalent among non-inflamed tumors. Herein, we attempt to explore the potential of B7-H4 in survival prediction and therapeutic guidance in muscle-invasive bladder cancer (MIBC) patients.

METHODS

This study included 391 patients from The Cancer Genome Atlas (TCGA) database and 122 patients from Zhongshan (ZS) Hospital. The evaluation of response to PD-L1 inhibitors was based on 270 patients in IMvigor210 cohort. Kaplan-Meier survival and multivariate analyses were performed to assess clinical outcomes in three cohorts. The correlation of B7-H4 expression with immune contexture and genomic alterations was analyzed based on immunohistochemistry, Microenvironment Cell Populations-counter (MCP-counter) tool, and whole-exome sequencing.

RESULTS

MIBC patients with the high level of B7-H4 expression (B7-H4^high) were found to possess an inferior overall and recurrence-free survival. Nonetheless, substantial clinical benefits of cisplatin-based chemotherapy and anti-PD-L1 immunotherapy were observed in these patients. After identifying a positive correlation between B7-H4 and tumor mutation burden (TMB), clinical benefits in B7-H4^high TMB^high subgroup were found to be the most upon PD-L1 blockade. Further studies revealed that B7-H4^high subgroup was featured by non-inflamed immune contexture and cell cycle-related gene alterations.

CONCLUSIONS

Despite adverse clinical outcomes, B7-H4^high patients possessed superior responsiveness to chemotherapy and immunotherapy. B7-H4 stratification could also synergize with TMB to pinpoint the patients who benefited most from immunotherapy. The clinical exploration of B7-H4 as a companion predictor could allow clinicians to direct proper therapeutic agents to patients.

Perioperative Systemic Treatment for Muscle-Invasive Bladder Cancer: Current Evidence and Future Perspectives

Radical cystectomy is the primary treatment for muscle-invasive bladder cancer; however, approximately 50% of patients develop metastatic disease within 2 years of diagnosis, which results in dismal prognosis. Therefore, systemic treatment is important to improve the prognosis of muscle-invasive bladder cancer. Currently, several guidelines recommend cisplatin-based neoadjuvant chemotherapy before radical cystectomy, and adjuvant chemotherapy is recommended in patients who have not received neoadjuvant chemotherapy. Immune checkpoint inhibitors have recently become the standard treatment option for metastatic urothelial carcinoma. Owing to their clinical benefits, several immune checkpoint inhibitors, with or without other agents (including other immunotherapy, cytotoxic chemotherapy, and emerging agents such as antibody drug conjugates), are being extensively investigated in perioperative settings. Several studies for perioperative immunotherapy have shown that immune checkpoint inhibitors have promising efficacy with relatively low toxicity, and have explored the predictive molecular biomarkers. Herein, we review the current evidence and discuss the future perspectives of perioperative systemic treatment for muscle-invasive bladder cancer.