Diagnosis and treatment of gastrointestinal stromal tumors of the stomach: report of 28 cases.

We retrospectively analyzed 28 patients with gastric gastrointestinal stromal tumors (GISTs) at our hospital to investigate their clinical features, diagnosis, and treatment. All patients underwent surgical resection. There were 18 cases with subtotal gastrectomy, 8 cases with partial gastrectomy, 1 case with total gastrectomy, and 1 case with subtotal gastrectomy combined with right hemihepatectomy. Based on pathological findings, the tumors were benign in 16 cases (57%), borderline in 2 cases (7%), and malignant in 10 cases (36%). The tumor diameter was significantly correlated with the malignancy of gastric GISTs (3.5+/-1.6 cm in benign tumors, vs 7.5+/-1.3 cm in malignant tumors, p<0.05). Immunohistochemical staining for CD117 and CD34 was positive in 26 (93%) and 17 (61%), respectively. The mean follow-up period ranged from 6 to 60 mo in 23 of the patients, and the other 5 patients (all with benign tumors) were lost to follow-up. No recurrence or metastasis was found in patients with benign gastric GISTs. Four cases of malignant GISTs (17%, 4/23) had liver metastasis or intra-abdominal dissemination, and 2 of them received a second resection for liver metastasis. Four cases of malignant gastric GISTs died with tumors more than 10 cm in maximum diameter, 3 of them died of liver metastasis and multiple organ failure, and 1 died of myocardial infarction. Excluding 2 patients with benign tumors that were followed for <3 yr, the 3-yr survival rate was 81% (17/21) in this group, and 60% (6/10) in the patients with malignant gastric GISTs. In conclusion, the prognosis is related to the tumor size and the number of mitoses seen on histological examination. Positive detection of CD117, combined with other markers and pathological features, is of great importance in the differential diagnosis of gastric GISTs. Complete resection with negative margins remains the fundamental objective in the surgical management of gastric GISTs.