Tissue Nuclear Matrix Protein Expression 22 in Various Grades and Stages of Bladder Cancer.

Objective: To study the tissue nuclear matrix protein 22 (NMP22) expression in bladder carcinoma biopsy and correlate it with prognostic factors like stage and grade of bladder cancer.

Study Design: Descriptive cross-sectional study.

Place And Duration Of Study: Pathology and Urology Departments, King Edward Medical University/Mayo Hospital, Lahore, Pakistan from January to October 2019.

Methodology: Data of all bladder cancer patients' biopsy blocks, presenting to histopathology section, was collected. NMP22 protein expression levels were analysed by immunohistochemical staining using a quantitative scoring method defined by staining intensity (I), and percentage of positive-stained cells (P). Data was analysed by SPSS version 22. Chi-square test and crosstabs were used to correlate grade and stage of urothelial tumors with gender and NMP22 expression. p ≤0.05 was taken as significant.

Results: A total of 95 paraffin blocks of bladder carcinoma biopsies with data were retrieved for the study. NMP22 was expressed immunohistochemically in 87/95(91.6%) of cases and was negative in 8/95(8.4%) of cancers. Correlation of intensity of NMP22 staining with histologic grade showed that 58.3% of high grade BC expressed NMP22 strongly, 23.6% moderately and 11.1% weakly. In low grade tumors, no biopsy (0/23) expressed strong expression. Moderate intensity in 8.69% and weak in 78.26% of tumors (p<0.001). Intensity of staining with stage of tumor association revealed that 40.8% of stage I tumor showed strong staining, 16.9% moderate, and 32.3% weak staining pattern. In stage II tumors 54.1% showed strong, 29.1% moderate, and 12.5% weak NMP 22 expression. (p=0.148).  Conclusion: NMP 22 is highly expressed in urinary bladder carcinoma and in male patients. It has strong association with grade and weak association with stage of tumor. Immunohistochemical expression of this protein can help in better detection and prognostic prediction of bladder carcinoma. Key Words: Bladder carcinoma, Grade, Immunohistochemistry, NMP22, Stage.