Successful Management of Immune-Related Cardiac Adverse Events and Long-term Survival in a Patient with Metastatic Urothelial Carcinoma Treated with Tislelizumab: A Case Report

Abstract Background Urothelial carcinoma is the most common pathological type of bladder tumor, accounting for approximately 90% of all primary bladder malignancies. Locally advanced or metastatic urothelial carcinoma is generally difficult to cure, and treatment options remain limited. PD-1/PD-L1 immune checkpoint inhibitors (ICIs) have led to revolutionary advances in the treatment of various cancers, including urothelial carcinoma. The introduction of these new therapies may prolong overall survival in patients with metastatic urothelial carcinoma. At the same time, the possible adverse cardiac events that may be triggered during the treatment of urothelial carcinoma will also be discussed. Purpose This case report aims to explore the feasibility of using systemic myocardial enzyme monitoring and cardiac function assessment to achieve long-term survival while preventing severe immune-related cardiac toxicity in patients with metastatic urothelial carcinoma who receive tislelizumab treatment. Methods The patient, a 64-year-old male, was admitted to the Weihei Medical District of PLA 970 Hospital on August 9, 2020 due to “intermittent gross hematuria for 4 months, worsening for 1 day.” Imaging and cystoscopy confirmed “bladder cancer,” with elevated CEA. On August 31, 2020, the patient underwent “transurethral resection of bladder tumor (TURBT)” under general anesthesia. Postoperative pathology and staging revealed: T1N0M0 (right bladder wall) invasive high-grade urothelial carcinoma. The patient subsequently received standardized intravesical chemotherapy. During follow-up, CEA remained normal. In October 2021, cystoscopy and chest CT indicated recurrent bladder cancer and multiple bilateral pulmonary metastases, with elevated tumor markers CEA and CYFRA21-1. Tislelizumab 200 mg IV every 21 days was initiated on November 27, 2021. And during the entire treatment process, comprehensive monitoring plans for thyroid function, myocardial enzyme spectrum, liver and kidney functions, etc. were implemented simultaneously. Results After 3 cycles of tislelizumab, chest CT showed significant shrinkage of lung lesions, and tumor markers returned to normal. In November 2022, follow-up chest CT indicated disappearance of bilateral pulmonary lesions. The patient discontinued treatment on December 25, 2023. Subsequent follow-ups showed stable disease. The most recent chest CT on April 27, 2025 indicated no signs of recurrence, with both CEA and CYFRA21-1 within normal ranges. The patient has survived with tumor burden for 49 months since the diagnosis of pulmonary metastases from urothelial carcinoma. During the patient's medication period, multiple examinations of thyroid function, myocardial enzyme spectrum, liver and kidney functions, etc. did not reveal any serious immune-related myocarditis, thyroid function changes, or immune-related liver and kidney damage. Conclusion In this case, a patient with bilateral pulmonary metastases from urothelial carcinoma achieved 49 months of long-term survival with tislelizumab treatment, and no serious adverse immune reactions such as those affecting the heart, liver or kidneys occurred. This highlights that by optimizing the tumor immune microenvironment and utilizing immune checkpoint inhibitors with unique design mechanisms, long-term “survival with tumor burden” is entirely achievable for patients with advanced malignancies.