Beta-catenin and surviving expression in keratocystic odontogenic tumor (KCOT). A comparative immunohistochemical study in primary, recurrent and nevoid basal cell carcinoma syndrome (NBCCS)-associated lesions

Aim: To determine the epithelial expression of ß-catenin and survivin in sporadic (primary, and recurrent) and nevoid basal cell carcinoma syndrome (NBCCS) keratocystic odontogenic tumour (KCOT) in order to assess activation of the ß-catenin pathway and evidence of apoptotic inhibition, processes that may contribute to the known differences in their biological behaviour. Materials and Methods: Sections from 40 cases of KCOT (19 sporadic/primary; 9 sporadic/recurrent and 12 NBCCS-associated) were immunohistochemically stained for ß-catenin and survivin. The extent and intensity of immunoreactivity within the lining epithelium was assessed, using semi-quantitative scales, independently by two pathologists who were blinded to the clinical-pathological data. Data were analysed using Kruskal-Wallis test and, for pair-wise comparisons, Mann-Whitney test with Bonferroni correction. Results: All cystic epithelial linings stained for ß- catenin and survivin but there were differences in the pattern and intensity of staining among KCOT types. Sporadic primary KCOT showed weaker staining for ß- catenin (P=0.0003) and survivin (P