Increased β-catenin and c-myc expression predict aggressive growth of non-functioning pituitary adenomas: An assessment using a tissue microarray-based approach

Non-functional pituitary adenomas (NFPAs) account for 80% of pituitary adenomas with the majority of these exhibiting recurrences post-surgery. Overexpression of β-catenin and c-myc is common in numerous invasive tumors. The present study sought to investigate the correlation of β-catenin and c-myc expression levels with aggressive growth and recurrence of NFPAs, using immunohistochemical examination of tissue microarrays. Tissue microarrays comprised 212 NFPAs specimens and 10 healthy specimens as controls. NFPAs were categorized as non-aggressive or aggressive. Immunohistochemical examination was performed to determine the expression of β-catenin and c-myc. Correlation of the expression levels of β-catenin and c-myc with clinicopathological parameters, including aggressiveness and recurrence, were assessed by univariate, multivariate and logistic regression analysis. Increased expression of β-catenin and c-myc was detected in the majority of aggressive NFPAs specimens (71.1 and 88.7%, respectively). There was a significant positive correlation between β-catenin and c-myc expression and aggressiveness [P=0.001, Odds Ratio (OR)=4.011; P