Expression of DOG1, CD117 and PDGFRA in Gastrointestinal Stromal Tumors and Correlations with Clinicopathology

Objective: To discuss the significance of DOG1, CD117 and PDGFRA in the diagnosis of gastrointestinalstromal tumors (GISTs), and analyze their correlations with clinicopathological features and risk ranking.
Method: DOG1, CD117 and PDGFRA were detected with IHC Envision ldpe-g-nvp in 63 GISTs and 43 cases ofnon-GISTs, and analyzed for relations with clinicopathological factors (gender, age, location, tumor size, mitoticphase, histology) and risk degree.
Results: The positive expression rate of DOG1, CD117 and PDGFRA in GISTswas 84.1% (53/63), 90.5% (57/63), 53.2% (33/63), respectively. Among the 6 CD117 negative cases, all were DOG1positive and 5 were PDGFRA positive. Rates in patients with non-GISTs was 11.6%, 16.3%, 6.98%, respectively.Expression of DOG1 and PDGFRA demonstrated no significant variation with gender, age, position, tumor size,mitotic phase, histology, and risk rank. However, CD117 was related with position and histology (P=0.008 andP=0.045), those in the mesentery having a higher positive rate than those derived from stomach, small intestine,colon and rectum (50.0% vs 94.7%, P=0.008). Furthermore CD117 was also highly expressed in spindle andepithele types.
Conclusions: DOG1 had a good sensitivity and specificity as a kind of newly discovered marker,especially for KIT negative GISTs. However, DOG1, CD117 and PDGFRA cannot be used for assessing the rishof patients.