Chemotherapy for Invasive Bladder Cancer: Five Simple Rules Learned Over 30 Years

A validated mathematical model of FGFR3-mediated tumor growth reveals pathways to harness the benefits of combination targeted therapy and immunotherapy in bladder cancer

Bladder cancer is a common malignancy with over 80,000 estimated new cases and nearly 18,000 deaths per year in the United States alone. Therapeutic options for metastatic bladder cancer had not evolved much for nearly four decades, until recently, when five immune checkpoint inhibitors were approved by the U.S. Food and Drug Administration (FDA). Despite the activity of these drugs in some patients, the objective response rate for each is less than 25%. At the same time, fibroblast growth factor receptors (FGFRs) have been attractive drug targets for a variety of cancers, and in 2019 the FDA approved the first therapy targeted against FGFR3 for bladder cancer. Given the excitement around these new receptor tyrosine kinase and immune checkpoint targeted strategies, and the challenges they each may face on their own, emerging data suggest that combining these treatment options could lead to improved therapeutic outcomes. In this paper, we develop a mathematical model for FGFR3-mediated tumor growth and use it to investigate the impact of the combined administration of a small molecule inhibitor of FGFR3 and a monoclonal antibody against the PD-1/PD-L1 immune checkpoint. The model is carefully calibrated and validated with experimental data before survival benefits, and dosing schedules are explored. Predictions of the model suggest that FGFR3 mutation reduces the effectiveness of anti-PD-L1 therapy, that there are regions of parameter space where each monotherapy can outperform the other, and that pretreatment with anti-PD-L1 therapy always results in greater tumor reduction even when anti-FGFR3 therapy is the more effective monotherapy.

Role of Pentacyclic Triterpenoid Acids in the Treatment of Bladder Cancer

Bladder cancer carries a poor prognosis and has proven resistance to chemotherapy. Pentacyclic Triterpenoid Acids (PTAs) are natural bioactive compounds that have a well-known impact on cancer research because of their cytotoxic and chemopreventive activities. This review focuses on bladder cancer which can no longer be successfully treated by DNA damaging drugs. Unlike most of the existing drugs against bladder cancer, PTAs are non-toxic to normal cells. Collecting findings from both in vitro and in vivo studies, it has been concluded that PTAs may serve as promising agents in future bladder cancer therapy. In this review, the roles of various PTAs in bladder cancer have been explored, and their mechanisms of action in the treatment of bladder cancer have been described. Specific PTAs have been shortlisted from each of the chief skeletons of pentacyclic triterpenoids, which could be effective against bladder cancer because of their mode of action. This review thereby throws light on the multi targets and mechanisms of PTAs, which are responsible for their selective anticancer effects and provides guidelines for further research and development of new natural antitumor compounds.

Tumor cell invasiveness in the initial stages of bladder cancer development - A computational study

Bladder cancer is one of the most common types of cancer, being the sixth more frequent in men, and one with higher recurrence rates and overall treatment costs. We introduce an agent-based computational model of the urothelium, adopting a Cellular Potts Model (CPM) approach to describe both a healthy urothelium and the development of bladder cancer. We focus on the identification of the conditions in which cancer cells cross, by mechanical means, the basement membrane and invade the bladder lamina propria. When within the urothelium the tumor grows in a very constrained environment. These tight conditions imply that the urothelium layer where the tumor initiates greatly determines tumor growth and invasiveness. Moreover, we demonstrate how specific mechanical properties of the cancer cells, as their stiffness or the adhesion to neighboring cells, heavily modulate the critical initial moments of tumor development. We propose that these characteristics should be considered as therapeutic targets to control tumor growth.

Targeting the Immune system and Epigenetic Landscape of Urological Tumors

In the last years, we have witnessed remarkable advances in targeted therapies for cancer patients. There is a growing effort to either replace or reduce the dose of unspecific, systemic (chemo)therapies, given the associated short- and long-term side effects, by introducing more specific targeted therapies as single or combination agents. Due to the well-known implications of the immune system and epigenetic landscape in modulating cancer development, both have been explored as potential targets in several malignancies, including those affecting the genitourinary tract. As the immune system function is also epigenetically regulated, there is rationale for combining both strategies. However, this is still rather underexplored, namely in urological tumors. We aim to briefly review the use of immune therapies in prostate, kidney, bladder, and testicular cancer, and further describe studies providing supporting evidence on their combination with epigenetic-based therapies.

Systemic Therapy for Invasive Bladder Cancer: The Value Proposition

Neoadjuvant methotrexate, vinblastine, doxorubicin, and cisplatin chemotherapy followed by definitive local treatment should be the treatment of choice for otherwise healthy and robust patients with T2b–T4 invasive bladder cancer.

A Nonselective Cyclooxygenase Inhibitor Enhances the Activity of Vinblastine in a Naturally-Occurring Canine Model of Invasive Urothelial Carcinoma

Background: Chemotherapy is expected to remain an important part of invasive urothelial carcinoma (UC) treatment. Strategies to enhance chemotherapy efficacy are needed.

Objective: To determine the chemotherapy-enhancing effects of a nonselective cyclooxygenase (COX) inhibitor on vinblastine in a naturally-occurring canine model of invasive UC.

Methods: With IACUC approval, privately-owned dogs with naturally-occurring histologically-diagnosed invasive UC, expected survival ≥6 weeks, and informed owner consent were randomly allocated to receive vinblastine (2.5 mg/m² intravenously every 2 weeks) plus piroxicam (0.3 mg/kg daily per os) or vinblastine alone (same dose) with the option to receive piroxicam alone when vinblastine failed. Scheduled evaluations included physical exam, standard laboratory analyses, thoracic radiography, abdominal ultrasonography, and standardized measurement of urinary tract tumors.

Results: Dogs receiving vinblastine alone (n = 27) and vinblastine-piroxicam (n = 24) were similar in age, sex, breed, tumor stage, and grade. Remission occurred more frequently (P <  0.02) with vinblastine-piroxicam (58.3%) than with vinblastine alone (22.2%). The median progression free interval was 143 days with vinblastine alone and 199 days with the combination. Interestingly, the overall median survival time was significantly longer (P <  0.03) in dogs receiving vinblastine alone followed by piroxicam alone (n = 20, 531 days) than in dogs receiving the combination (299 days). Treatment was well tolerated in both arms.

Conclusions: Piroxicam significantly enhanced the activity of vinblastine in dogs with UC where the cancer closely mimics the human condition, clearly justifying further study. The study suggest the potential importance of tracking COX inhibitor use in patients in clinical trials as COX inhibitors could affect treatment response.