The Expression of p21 Marker in Bladder Urethral Tumor and its Association with Histopathologic Characteristicslogic charactristics

Background: In addition to clinical and histologic factors that are able to differentiate between low and high grades of bladder's urethral tumor from each other, there are a number of biomarkers that may be helpful in evaluating the degree, outcome, and prognosis of the tumor. The aim of this study was to investigate the relationship between overexpression of p21 marker and histologic status, prognosis, and recurrence of urethral carcinoma of the bladder. Methods: In this cross-sectional study, the paraffin wax blocks of 356 patients were gathered. Tumor points of the tissue were selected from the main block and mounted on the tissue microarray (TMA) of receptor block. Immunohistochemical staining was performed for the p21 marker. The intensity and extent of staining for this marker were determined by two pathologists using the combined and semi-quantitative method [Histochemical Score (H-Score)]. Results: The expression of p21 marker was significantly different in the high- and low-grade tumors. On the basis of H-Score, and in the high-grade tumor group, this expression was significantly higher than the low-grade (153.85 ± 91.06 versus 130.01 ± 82.20). Using the receiver operating characteristic (ROC) curve analysis, the p21 marker (based on the H-Score) had a high degree of precision in distinguishing high-grade items from the low-grade (ROC = 0.596, P = 0.002). Accordingly, the best cut-off value for the marker in differentiation of two grades was 92.5%, at which, the sensitivity and specificity were 67.7% and 44.7%, respectively. Regarding the results of multivariate logistic regression analysis, in the evaluation of factors related to tumor recurrence, the presence of non-papillary pattern predicted the recurrence (likelihood ratio: 6.363, P = 0.001). Conclusion: By determining the H-Score of p21 marker, the high- and low-grade tumors can be discriminated with an acceptable sensitivity and specificity. The presence of non-papillary pattern has a high predictive value for tumor recurrence