RESUMO
OBJECTIVE: To analyze the value for grading of a previously developed quantitative morphometric/cytometric multivariate grading model (consisting of the mean nuclear area of the 10 largest nuclei (MNA-10, mitotic activity index = MAI and Ki-67 area% = Ki-67) in two new independent test sets of urothelial carcinomas (UCs) of the urinary bladder and to evaluate the additional value of p53 area% (p53) in this model. STUDY DESIGN: Ki-67 immunoquantitation, morphometric MAI and MNA-10 assessments using a previously described, strict protocol and matching of the resulting morphometric grade with subjective grade in two test sets of 154 T(A,1) UCs of the bladder (consensus grade between two independent observers). Further testing of this morphometric grading model was performed in 57 cases that lacked initial interobserver agreement on grade. Single and multivariate analysis of all features (including p53) was performed. RESULTS: With the previously developed morphometric/cytometric grading model, 93% (grade 1 vs. 2) and 91% (grade 2 vs. 3) of the consensus cases were correctly classified. These percentages were very similar to previous results, suggesting that the model is robust. Of the 57 cases that lacked initial interobserver agreement on grade, 53/57 (93%) were classified unambiguously as grade 1, 2 or 3 with the quantitative morphometric/ cytometric grading model. In the exploratory analysis, p53 was significant but with more overlap than the other features had. In multivariate analysis p53 did not improve the overall classification result of the original morphometric/cytometric model. CONCLUSION: The value of MNA-10, MAI and Ki-67 for grading in T(A,1) urothelial carcinomas of the urinary bladder was confirmed. p53 Did not improve overall grading classification of this combination.
