OBJECTIVETo investigate the expression of DOG-1 in gastrointestinal stromal tumors (GIST) and its diagnostic application.

METHODSImmunohistochemical EnVision technique was used to assess the expression of DOG-1 in 84 cases of GIST in comparison with CD117 and CD34.

RESULTSAll 84 cases of GIST consisted of variable proportions of spindle and epithelioid tumor cells or just one type of the tumor cell. The expression rates of DOG-1, CD117 and CD34 were 91.3% (42/46), 95.7% (44/46) and 82.6% (38/46), in the group of very low and low risk GIST, and were 100% (38/38), 100% (38/38) and 78.9% (30/38), respectively, in the group of moderate and high risk GIST. True leiomyomas, schwannomas, fibromatosis and normal gastrointestinal mucoca did not express these markers. Moreover, the sensitivity and specificity of DOG-1 in the detection of GIST were similar to those of CD117, without statistical difference (P > 0.05) between the two markers. However, the sensitivity and specificity of DOG-1 detection of moderate and high risk GIST were significantly higher than those of CD34 (P < 0.01).

CONCLUSIONSDOG-1 is a novel marker of gastrointestinal stromal tumors. It has the sensitivity and specificity higher than CD34, especially in the detection of moderate and high risk GIST. Combined DOG-1 and CD117 immunohistochemistry will likely improve the diagnostic accuracy of GIST.