Immunohistochemical staining with non-phospho beta catenin as a diagnostic and prognostic tool of COX-2 inhibitor therapy for patients with extra-peritoneal desmoid-type fibromatosis

Summary

This study aimed to evaluate the diagnostic and prognostic value of immunohistochemical staining with anti-non-phospho beta- catenin antibody, which might more accurately reflect the aggressiveness of desmoid-type fibromatosis, in comparison to the conventional anti-beta-catenin antibody. Between 2003 and 2015, 40 patients with extra-peritoneal sporadic DF were prospectively treated with meloxicam or celecoxib, a COX-2 inhibitor, therapy. The positive nuclear expression of non-phospho beta-catenin showed a significant correlation with positive CTNNB1 mutation status detected by Sanger method (p = 0.025), and poor outcome in COX-2 inhibitor therapy (p = 0.022). In contrast, nuclear expression of beta-catenin did not show a significant correlation with either CTNNB1 mutation status (p = 0.43) or outcome of COX-2 inhibitor therapy (p = 0.38). Nuclear expression of non-phospho beta-catenin might more appropriately reflect the biological behavior of DF, and immunohistochemical staining with non-phospho beta-catenin could serve as a more useful diagnostic and prognostic tool of COX-2 inhibitor therapy for patients with DF.