To study the clinicopathological features and the expression significance of immune markers CD34, smooth muscle actin (SMA) and DOG-1 in gastrointestinal stromal tumor (GIST).

Total of 98 GIST patients from May 2015 to November 2019 in Wuxi Huishan District People's Hospital were selected. The expressions of CD34, SMA and DOG-1 protein in tumor specimens of GIST patients were detected by immunohistochemistry. The clinicopathological data, histological classification and risk degree of GIST were analyzed retrospectively.

Among the 98 GIST patients, there were 38 cases (38.78%) with tumors at small intestine, 56 cases (57.14%) with the adventitia invasion and 39 cases (39.80%) with tumor metastasis. The results of histological classifications showed that there were 60 cases (61.22%) with spindle cytoma, 23 cases (23.47%) with epithelioid cytoma and 15 cases (15.31%) with mixed cytoma. In terms of risk grading, there were 45 cases (45.92%) at low grade, 20 cases (20.41%) at moderate grade, 17 cases (17.34%) at high grade and 16 cases (16.33%) at extremely low grade. The results of immunohistochemistry showed that positive expression rates of CD34, SMA and DOG-1 were 90.82%, 45.92% and 87.76% respectively. The co-positive expression rates of CD34 with SMA, and CD34 with DOG-1 were 42.86% and 89.80% respectively. The number of CD34 positive cases in GIST patients with different tumor diameters, adventitia invasion and histological classifications were significantly different(χ² values were 8.144, 4.935 and 7.119 respectively, all P values<0.05). The positive cases of DOG-1 in GIST patients with different tumor metastases, histological classifications and risk grading were also significantly different (χ² values were 5.650, 11.439 and 9.317 respectively, all P values<0.05). There was no significant difference in SMA positive cases among GIST patients with different clinicopathological features (P>0.05).

The main histological classification of GIST patients was spindle cell tumor. CD34 and DOG-1 are effective indicators for the diagnosis of GIST, and the combined diagnosis of CD34 and DOG-1 can improve the detection accuracy.

Gastrointestinal stromal tumor; CD34; Smooth muscle actin; DOG-1; Pathological diagnosis