Correlation of CTNNB1 Mutation Status with Progression Arrest Rate in RECIST Progressive Desmoid-Type Fibromatosis Treated with Imatinib: Translational Research Results from a Phase 2 Study of the German Interdisciplinary Sarcoma Group (GISG-01).

Summary

CTNNB1 gene mutations are the molecular key events in the majority of sporadic desmoid-type fibromatosis (DF). The specific S45F mutation has been reported to be associated with a more aggressive clinical course in DF. For the current study, the CTNNB1 mutation status was analyzed in DF samples from the prospective German Interdisciplinary Sarcoma Group (GISG) phase 2 study evaluating imatinib to induce progression arrest in DF Response Evaluation Criteria In Solid Tumors (RECIST) progressive patients. Mutations at position S45 were overrepresented in the GISG-01 trial recruiting RECIST progressive patients only. The positive correlation of CTNNB1 mutation status with the progression arrest rate after imatinib therapy supports the idea of a potential predictive impact of the mutation status on DF treatment decision making.