Uncovering the Uncommon: Institutional Insights Into the Clinical and Epidemiological Characteristics of Rarer Forms of Bladder Cancer Beyond Transitional Cell Carcinoma.

Introduction Non-transitional cell carcinomas of the bladder (NTCCB) represent a significant clinical challenge due to their rarity, heterogeneity, and poor prognosis. Despite their poor prognosis, the treatment of NTCCB has historically been based on the same principles used for transitional cell carcinomas (TCCs). Our study focuses on the management of non-transitional cell carcinomas and aims to identify areas where treatment outcomes can be improved based on our institutional experience. Materials and methods A retrospective analysis of patients with NTCCB who presented at Kasturba Hospital Manipal was conducted between 2012 to 2021. Patient data were collected, and demographic characteristics, presenting symptoms, history of other primary malignancies, comorbidities, location of the tumour, stage at presentation, histopathological subtype, site of systemic metastasis, and primary treatment given were analyzed descriptively. Median overall survival was determined by calculating the time from the initial diagnosis to the date of death. Results Among 31 patients with NTCCB, 15 (48%) presented with metastatic disease, five (16%) with locally advanced disease, and 11 (36%) with localized disease. The most common histopathological subtypes were squamous cell carcinoma and adenocarcinoma, as noted in 14 (45.2%) and 13 (41.9%) patients, respectively, followed by neuroendocrine tumours in two (6.5%), extra-adrenal phaeochromocytoma in one (3.3%), and sarcomatoid carcinoma in one (3.3%) patient, respectively. The lung was the most frequent site of systemic metastasis as noted in six (40%) patients, followed by the liver and skeletal system in three (20%) patients each, peritoneum in two (13.3%), cerebral cortex in one (6.7%), and non-regional lymph nodes in one (6.7%) patient. The primary treatment given included palliative chemotherapy in 14 (45.2%) patients, radical cystectomy with ileal conduit in 10 (32.3%), neoadjuvant chemotherapy only in four (12.9%), partial cystectomy in one (3.2%), pelvic exenteration with ileal conduit in one (3.2%), and peritoneal debulking with palliative chemotherapy in one (3.2%) patient. The overall median survival was 15 months, with a one-year survival rate of 67.4%. Conclusion NTCCB exhibits aggressive clinical behaviour and presents with nonspecific clinical features in the early stages, often leading to late diagnosis and an advanced tumour stage at presentation. Multi-institutional studies with larger patient cohorts are needed to recommend best clinical practices for early detection and optimal treatment strategies to improve patient survival.