Recent developments in perioperative combination therapy in muscle-invasive bladder cancer.

PURPOSE OF REVIEW: A summary of recent literature to provide a comprehensive overview of the current state of systemic perioperative treatment combinations for muscle-invasive bladder cancer (MIBC). RECENT FINDINGS: We discuss recent developments in standard and experimental treatment modalities. The VESPER trial has shown that six cycles of neoadjuvant dose-dense MVAC are superior to four cycles of gemcitabine/cisplatin (GC), though it is unclear whether the superiority is derived from the specific regimen or number of cycles. Adjuvant cisplatin-based chemotherapy, a subject of longstanding debate, was shown to have comparable overall survival-benefit to neoadjuvant chemotherapy in an updated meta-analysis. Neoadjuvant chemotherapy and anti-PD-(L)1 show encouraging results, but with no comparative studies to standard care, context is lacking. Immunotherapeutic neoadjuvant anti-CTLA-4/PD-(L)1 combinations or combinations of checkpoint inhibitors with antibody-drug-conjugates are in early stages of development and show promising preliminary results. SUMMARY: Six cycles of neoadjuvant dose-dense MVAC are superior to four cycles of gemcitabine/cisplatin. Adjuvant cisplatin-based chemotherapy is a viable option for patients with high-risk tumours who did not receive prior neoadjuvant treatment. The added value of anti-PD-(L)1 to chemotherapy still needs to be established. Novel developments in immunotherapy combinations, while promising, are still in an early stage and randomized studies are ongoing.

Platinum-Based Chemotherapy Induces Opposing Effects on Immunotherapy Response-Related Spatial and Stromal Biomarkers in the Bladder Cancer Microenvironment.

PURPOSE: Platinum-based chemotherapy and immune checkpoint inhibitors are key components of systemic treatment for muscle-invasive and advanced urothelial cancer. The ideal integration of these two treatment modalities remains unclear as clinical trials have led to inconsistent results. Modulation of the tumor-immune microenvironment by chemotherapy is poorly characterized. We aimed to investigate this modulation, focusing on potential clinical implications for immune checkpoint inhibitor response. EXPERIMENTAL DESIGN: We assessed immune cell densities, spatial relations, and tumor/stromal components from 116 patients with urothelial bladder cancer (paired data for 95 patients) before and after platinum-based chemotherapy. RESULTS: Several published biomarkers for immunotherapy response changed upon chemotherapy treatment. The intratumoral CD8+ T-cell percentage increased after treatment and was associated with increased TNFα-via-NF-κB signaling. The percentage of PDL1+ immune cells was higher after chemotherapy. An increase in chemo-induced changes that potentially inhibit an antitumor immune response was also observed, including increased fibroblast-based TGFß signaling and distances from immune cells to the nearest cancer cell. The latter two parameters correlated significantly in posttreatment samples, suggesting that TGFß signaling in fibroblasts may play a role in spatially separating immune cells from cancer cells. We examined specific chemotherapy regimens and found that treatment with methotrexate, vinblastine, doxorubicin, and cisplatin was associated with an increase in the macrophage cell percentage. Gemcitabine-containing chemotherapy was associated with upregulation of fibroblast TGFß signaling. CONCLUSIONS: The opposing effects of platinum-based chemotherapy on the immune cell composition and stromal context of the tumor-immune microenvironment may explain the inconsistent results of clinical trials investigating chemotherapy and immune checkpoint inhibitor combinations in bladder cancer.