Neoadjuvant Chemotherapy or Immunotherapy for Clinical T2N0 Muscle-invasive Bladder Cancer: Time to Change the Paradigm?

Recent Advances of Neoadjuvant Immunotherapy for Urothelial Bladder Cancer

Urothelial bladder cancer is one of the most common malignant tumors of the urinary system, which accounts for 90~95% of urothelial carcinoma. Despite the current standard neoadjuvant management for localized urothelial MIBC (T2-4cN0M0) is cisplatin-based chemotherapy before radical cystectomy, there still had poor performances and less overall survival benefits in patients with localized urothelial MIBC. Moreover, nearly half of MIBC patients were ineligible for receiving cisplatin because of chronic kidney disease and performance status. Although immunotherapy, immune checkpoint inhibitors (ICIs) has been identified as first or second-line treatments for localized and metastasis bladder cancer based on less adverse reactions and favorable outcomes, neoadjuvant immunotherapy had rarely used for the treatment of these patients because of less large-scale clinical randomized studies and limited outcomes. Therefore, we reviewed the advances of efficacy and safety with neoadjuvant immunotherapy for urothelial bladder cancer depended on published articles and clinical studies, which could provide more theoretical evidences and promising strategy for clinical therapeutic development.

Detailed bladder cancer immunoprofiling reveals new clues for immunotherapeutic strategies

Objectives

Bladder cancer (BlCa) is the tenth most frequent malignancy worldwide and the costliest to treat and monitor. Muscle-invasive BlCa (MIBC) has a dismal prognosis, entailing the need for alternative therapies for the standard radical cystectomy. Checkpoint blockade immunotherapy has been approved for high-grade non-muscle-invasive BlCa (HG NMIBC) and metastatic disease, but its effectiveness in localised MIBC remains under scrutiny. Herein, we sought to characterise and compare the immune infiltrate of HG NMIBC and MIBC samples, including ICOS expression, a targetable immune checkpoint associated with regulatory T cell(T_regs)-mediated immunosuppression.

Methods

Immunohistochemistry for CD83, CD20, CD68, CD163, CD3, CD8, CD4, FoxP3/ICOS and PD-L1 was performed in HG NMIBC and MIBC samples (n = 206), and positive staining was quantified in the peritumoral and/or intratumoral tissue compartments with QuPath imaging software.

Results

CD20⁺ B cells, CD68⁺ and CD163⁺ tumor-associated macrophages were significantly increased in MIBCs and associated with poor prognosis. In turn, higher infiltration of T cells was associated with prolonged survival, with exception of the CD4⁺ helper subset. Intratumoral expression of CD3 and CD8 was independent prognostic factors for increased disease-free survival (DFS) in multivariable analysis. Remarkably, T_regs (FoxP3⁺/FoxP3⁺ICOS⁺) were found differentially distributed between tissue compartments. PD-L1 immunoexpression independently predicted a shorter DFS and associated with higher infiltration of FoxP3⁺ICOS⁺ T_regs.

Conclusions

Immune infiltrates of HG NMIBC and MIBC display significant differences that may help selecting patients for immunotherapies. Considering ICOS immunoexpression results, it might constitute a relevant therapeutic target, eventually in combination with anti-PD-1/PD-L1 therapies, for certain BlCa patient subsets.

Advances in Diagnosis and Therapy for Bladder Cancer

Bladder cancer (BCa) is one of the most common and expensive urinary system malignancies for its high recurrence and progression rate. In recent years, immense amounts of studies have been carried out to bring a more comprehensive cognition and numerous promising clinic approaches for BCa therapy. The development of innovative enhanced cystoscopy techniques (optical techniques, imaging systems) and tumor biomarkers-based non-invasive urine screening (DNA methylation-based urine test) would dramatically improve the accuracy of tumor detection, reducing the risk of recurrence and progression of BCa. Moreover, intravesical instillation and systemic therapeutic strategies (cocktail therapy, immunotherapy, vaccine therapy, targeted therapy) also provide plentiful measures to break the predicament of BCa. Several exploratory clinical studies, including novel surgical approaches, pharmaceutical compositions, and bladder preservation techniques, emerged continually, which are supposed to be promising candidates for BCa clinical treatment. Here, recent advances and prospects of diagnosis, intravesical or systemic treatment, and novel drug delivery systems for BCa therapy are reviewed in this paper.

Bladder-sparing combination treatments for muscle-invasive bladder cancer: A plea for standardized assessment and definition of clinical trials endpoints

Radical cystectomy is the standard of care for muscle invasive bladder cancer, although it represents a surgical procedure with high complication and mortality burden. Thus, more and more emphasis has been placed in favor of alternative treatments especially for patients who are unfit for or aim to avoid radical cystectomy. In this context, preclinical studies highlighted that chemoradiation therapy (CRT) may have immunomodulatory properties on tumor microenvironment with a consequent increase in immune biomarkers. Thus, following the encouraging results reached by immune checkpoint inhibitors (ICIs) in both metastatic and localized disease, CRT and ICIs combination treatment gained momentum as bladder-sparing option and several clinical trials were recently launched both as concurrent and sequential treatments. A narrative review of the literature was performed to summarize the rationale and clinical outcomes of trials testing CRT and ICIs combination. Promising results were recently released mainly from phase II trials reporting clinal complete response rates from 48% to 83%. Moreover, combination treatment, both as concurrent and sequential schedules, appeared to be quite tolerable. However, interpretation of preliminary findings is made difficult due to the heterogeneity of clinical endpoints among trials, patient population included and different measurement of response to treatment. Novel bladder-sparing strategies are finally gaining momentum in bladder cancer treatment. Despite preliminary findings are encouraging, harmonization of terminology and definition of clinical endpoints among trials will be mandatory to correctly assess the potential role of CRT and immunotherapy combination as bladder-sparing solution in routine clinical practice.

Causal contributors to tissue stiffness and clinical relevance in urology

Mechanomedicine is an emerging field focused on characterizing mechanical changes in cells and tissues coupled with a specific disease. Understanding the mechanical cues that drive disease progression, and whether tissue stiffening can precede disease development, is crucial in order to define new mechanical biomarkers to improve and develop diagnostic and prognostic tools. Classically known stromal regulators, such as fibroblasts, and more recently acknowledged factors such as the microbiome and extracellular vesicles, play a crucial role in modifications to the stroma and extracellular matrix (ECM). These modifications ultimately lead to an alteration of the mechanical properties (stiffness) of the tissue, contributing to disease onset and progression. We describe here classic and emerging mediators of ECM remodeling, and discuss state-of-the-art studies characterizing mechanical fingerprints of urological diseases, showing a general trend between increased tissue stiffness and severity of disease. Finally, we point to the clinical potential of tissue stiffness as a diagnostic and prognostic factor in the urological field, as well as a possible target for new innovative drugs.

Three vs. Four Cycles of Neoadjuvant Chemotherapy for Localized Muscle Invasive Bladder Cancer Undergoing Radical Cystectomy: A Retrospective Multi-Institutional Analysis

BACKGROUND

Three or four cycles of cisplatin-based chemotherapy is the standard neoadjuvant treatment prior to cystectomy in patients with muscle-invasive bladder cancer. Although NCCN guidelines recommend 4 cycles of cisplatin-gemcitabine, three cycles are also commonly administered in clinical practice. In this multicenter retrospective study, we assessed a large and homogenous cohort of patients with urothelial bladder cancer (UBC) treated with three or four cycles of neoadjuvant cisplatin-gemcitabine followed by radical cystectomy, in order to explore whether three vs. four cycles were associated with different outcomes.

METHODS

Patients with histologically confirmed muscle-invasive UBC included in this retrospective study had to be treated with either 3 (cohort A) or 4 (cohort B) cycles of cisplatin-gemcitabine as neoadjuvant therapy before undergoing radical cystectomy with lymphadenectomy. Outcomes including pathologic downstaging to non-muscle invasive disease, pathologic complete response (defined as absence of disease -ypT0), overall- and cancer-specific- survival as well as time to recurrence were compared between cohorts A vs. B.

RESULTS

A total of 219 patients treated at 14 different high-volume Institutions were included in this retrospective study. Patients who received 3 (cohort A) vs. 4 (cohort B) cycles of neoadjuvant cisplatin-gemcitabine were 160 (73,1%) vs. 59 (26,9%).At univariate analysis, the number of neoadjuvant cycles was not associated with either pathologic complete response, pathologic downstaging, time to recurrence, cancer specific, and overall survival. Of note, patients in cohort B vs. A showed a worse non-cancer specific overall survival at univariate analysis (HR= 2.53; 95 CI= 1.05 - 6.10; p=0.046), although this finding was not confirmed at multivariate analysis.

CONCLUSIONS

Our findings suggest that 3 cycles of cisplatin-gemcitabine may be equally effective, with less long-term toxicity, compared to 4 cycles in the neoadjuvant setting.

Intermediate- and high-risk nonmuscle invasive bladder cancer: Where do we stand?

INTRODUCTION

The standard of care for intermediate- and high-risk non-muscle invasive bladder cancer (NMIBC) patients is transurethral resection of bladder tumor followed by intravesical adjuvant immunotherapy with Bacillus Calmette-Guerin (BCG). However, a non-negligible portion of patients is doomed to fail BCG-therapy and, consequently, undergo radical cystectomy as only treatment option available. In this context, effective options to improve tumor response, thus delaying or even avoiding radical cystectomy, are urgently needed. A narrative review of the literature was performed to summarize the rationale and the clinical outcomes regarding the use of immunotherapy and novel therapeutic perspectives both for BCG-treated and BCG-naïve NMIBC patients.

RESULTS

Several clinical trials are currently investigating immune checkpoint inhibitors and novel targeted approaches, including cancer vaccines, for NMIBC patients with BCG-naïve and BCG-unresponsive disease. Despite the lack of long-term safety data, novel therapeutic options, both by systemic and intravesical delivery, demonstrated a good tolerability, antitumor efficacy, and low rates of recurrence and/or progression to muscle-invasive disease.

CONCLUSIONS

Although clinical data available are mostly limited to phase I/II trials, novel targeted therapies have raised as an effective and reliable approach for patients failing BCG and for those who are therapy naïve. Phase III trials will be crucial in order to change the current clinical practice, after many years in which BCG was the only therapy available for intermediate- and high-risk NMIBC patients.