The aim of the study was to stratify high-grade T1 (HGT1) bladder urothelial carcinoma into risk categories based on the presence of variant histology when compared to conventional urothelial carcinoma. The clinicopathological features of 104 HGT1 cases of urothelial carcinoma of the bladder with variant histology present in 34 (37%) were assessed. The endpoint of the study was disease-free survival and cancer-specific survival. Overall, variant histology was identified as a significant predictor of disease-free survival (P = 0.035). The presence of any specific variant histology (squamous, glandular, micropapillary, nested, microcystic, inverted growth, villous-like, basaloid, and lymphoepithelioma-like) was identified as a significant predictor of disease-free survival (P = 0.008) and cancer-specific survival (P = 0.0001) in HGT1 bladder cancer. Therefore, our results support including micropapillary HGT1 urothelial carcinoma within the aggressive high-risk category, as suggested by some recent clinical guidelines, but also favor nested, glandular, and basaloid to be placed in the high-risk category due to their potential of aggressive, life-threatening behavior and their limited response to bacillus Calmette-Guerin therapy. Conversely, the low-risk category would include urothelial carcinomas with squamous, inverted growth, or microcystic morphology, all with limited life-threatening potential and good response to current therapy. A very low-risk category would finally include patients whose tumors present villous-like or lymphoepithelioma-like morphology. In conclusion, our findings support the value of reporting the variant histology as a feature of variable aggressiveness in HGT1 urothelial carcinoma of the bladder.
Virchows Archiv : an international journal of pathology. 2022 Feb 04 [Epub ahead of print]
Antonio Lopez-Beltran, Ana Blanca, Alessia Cimadamore, Rodolfo Montironi, Rafael J Luque, Metka Volavšek, Liang Cheng
Department of Morphological Sciences, University of Cordoba Medical School, Cordoba, Spain. ., Maimonides Biomedical Research Institute of Cordoba, E-14004, Cordoba, Spain., Institute of Pathological Anatomy and Histopathology, School of Medicine, Polytechnic University of the Marche Region, United Hospitals, Ancona, Italy., UGC Anatomía Patológica, Hospital Universitario de Jaén, Jaén, Spain., Institute of Pathology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia., Departments of Pathology and Laboratory Medicine and Urology, School of Medicine, Indiana University, Indianapolis, IN, USA.