VEGF Expression in Gastrointestinal Stromal Tumor

초록

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. They are c-kit receptor-positive mesenchymal spindle cell or epithelioid neoplasms primary in the GI tract, omentum and mesentery. The significance of various prognostic factors, such as tumor size and mitotic index (MI), has been well established for GIST, but definite criteria for its biologic behavior is still uncertain. Vascular endothelial growth factor (VEGF)-C is a specific ligand which induces lymphangiogenesis. We examined the expression of VEGF-C protein to evaluate its prognostic significance in GISTs. We retrospectively reviewed all surgically treated GIST specimens which are confirmed by CD117. Main prognostic factors including tumor size, mucosal invasiveness, necrosis, nuclear/cytoplasmic ratio, nuclear pleomorphism, mitotic count, and metastasis were evaluated. Immunohistochemical analysis revealed that VEGF-C was overexpressed in 18 out of 34 GIST specimens (52.9%). The expression of VEGF-C did not show any significant correlation with prognostic factors. However, it is noteworthy that benign GISTs were positive for VEGF-C in only one among 4 cases (25%) but malignant GISTs and those of uncertain malignant potential were positive in 17 among 29 cases (58.6%).