Study of Neoadjuvant Chemotherapy and Trimodal Therapy for Muscle Invasive Bladder Cancer with Variant Histology

What this Trial Is About

Researchers are evaluating treatment options for patients with muscle invasive bladder cancer MIBC that have variant histology, a rare tumor type with different cell characteristics mixed with conventional urothelial carcinoma. This Phase II, single group study aims to assess outcomes for patients receiving neoadjuvant chemotherapy NAC with or without immunotherapy IO followed by trimodal therapy TMT, which is an alternative to radical cystectomy. The study tests if TMT can be started within 45 days after NAC - IO in these patients at risk of systemic disease spread. Participants will receive at least three cycles of NAC with or without IO as chosen by their oncologist. After this, they will undergo a four- or six-week course of concurrent standard chemotherapy combined with radiation therapy as part of the TMT approach. This treatment sequence is compared to historical data from patients with pure urothelial carcinoma treated with TMT. The therapy involves tumor resection TURBT followed by the combined chemotherapy and radiation. Throughout the study, patients are monitored to determine if TMT can be initiated within 45 days after NAC - IO. The researchers will also measure bladder intact event-free survival at three years. Participants provide informed consent and undergo imaging tests such as CT or PET scans to confirm diagnosis. The study will continue through treatment and follow-up until December 2030, with assessments focused on treatment feasibility and long-term bladder preservation outcomes.

Bladder Preservation for Patients With Muscle Invasive Bladder Cancer (MIBC) With Variant Histology