The Immunohistochemical Expression of SOX-10 in Urothelial Carcinoma and the Non Neoplastic Urothelium; and a Correlation with the Tumor Features

OBJECTIVE: Evaluation of SOX-10 expression in malignant urothelial cells, comparing it with the phenotypically non neoplastic urothelium, and correlating it with the various clinicopathological variables, with a focus on the invasive pattern. METHODS: Eighty paraffin blocks of urothelial carcinoma were stained by H&E. Histopathological features were evaluated and then immunostained with SOX-10 to evaluate its expression. RESULTS: The evaluation of SOX-10 expression in urothelial carcinoma, revealed a high grade of SOX-10 expression in the malignant urothelium (43\80 cases; 53.7%), while the adjacent the non neoplastic urothelium expressed high SOX-10 in (12\42 case; 28.6%). Correlation of SOX-10 score with the various variables revealed a statistically significant correlation with the gross shape (P value=0.002), the tumor grade ((P value=0.009), the muscle invasion by the tumor ((P value=0.004), the tumor T stage, (P-value <0.001), N stage (P value=0.003), associated Schistoma hematobium infestation (P-value =0.016), and the presence of vascular tumor emboli (P-value =0.009). It was statistically insignificant with the gender, the anatomical site, and the perineural tumor invasion. Correlating the mean of SOX-10 score with some tumor features revealed a statistically significant correlation with the muscle invasion by the tumor, Tumor grade, T stage, and non neoplastic urothelium; P-value <0.001 each and N stage P value=0.006. CONCLUSION: SOX-10 is overexpressed in urothelial carcinoma and it was also detected in a significant part of the surrounding non neoplastic urothelium, which may contribute to understanding its role in multistep urothelial carcinogenesis as transcription or tumor-promoting factor, thus it could be used in future trials for specific targeted therapy.