ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of DOG-1 in gastrointestinal stromal tumors (GIST) and its diagnostic application.</p><p><b>METHODS</b>Immunohistochemical EnVision technique was used to assess the expression of DOG-1 in 84 cases of GIST in comparison with CD117 and CD34.</p><p><b>RESULTS</b>All 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).</p><p><b>CONCLUSIONS</b>DOG-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.</p>