Divergent squamous differentiation in upper urothelial carcinoma-comparative clinicopathological and molecular study.

Upper urothelial carcinoma (UUC) has a plasticity to demonstrate divergent differentiation with squamous metaplastic elements. There was no previous study exploring profiling of molecular markers in metaplastic squamous upper urothelial carcinoma (SUUC) and conventional upper urothelial carcinoma (CUUC). The aims of this study was to compare expression of the phenotypic characteristics of tumors and molecular markers (p53, p16, cyclin D1, E-cadherin, HER-2, Ki-67, Bcl-2, Bax) in SUUC and CUUC. SUUC was detected in 20% of 44 patients. There was significant difference between SUUC and CUUC in the pathological stage, grade, growth and presence of lymphovasular invasion (p < 0.05; 0.05; 0.05; 0.01 respectively). The mean Ki-67 and p53 labeling index was significantly higher in SUUC than in CUUC (p < 0.05; 0.05). There was no significant difference in the expression of p16, cyclin D1, E-cadherin, HER-2, Bcl-2 and Bax between SUUC and CUUC. Univariant model showed that SUUC was significantly associated with lymphovascular invasion (p = 0.007), Ki-67 activity (p = 0.016) and growth (p = 0.026). Exploration of UUC with squamous divergent differentiation showed changes in phenotypic characteristics and Ki-67, as well as similar molecular profile with CUUC.