The clinicopathologic features and gene mutation status of gastrointestinal stromal tumor (with the analysis of 660 cases of patients)

Objective To investigate the clinical and pathological features in patients with gastrointestinal stromal tumors (GISTs), focusing on the mutation status of c-kit and PDGFRA. Methods Data and tumor samples of 660 patients diagnosed and treated as GISTs in Peking University Cancer Hospital from January 2002 to October 2011 were collected. Mutation status of c-kit (exons 9, 11, 13 and 17) 、 PDGFRA (exons 12 and 18) were detected by direct sequencing. Statistical tool was used to analyze the relationship between gene mutation types and pathological features. Results 389(58.9%) men and 271(41.4%) women, median age 56 years (15-82 years), were involved. The predominant sites of tumor origin were from stomach (37%) and small intestine (35%) , while liver and peritoneum were the most commons sites of metastasis. 95.0% and 88.1% of GIST patients were positive for the CD117 and DOG1 antigens, respectively. A total number of 360 GIST patients were genotyped, with 241 (66.9%), 43 (11.9%), 6 (1.7%), 4 (1.1%), 1 (0.3%) and 7 (1.9%) having c-kit exons 11, 9, 13, 17, PDGFRA exons 12 and 18 mutations, respectively. The remaining 58(16.2%) patients were wild type. C-kit exon 9 mutations were mainly observed in the small intestine, while PDGFRA exons 12 and 18 mutations were strongly associated with the gastric. C-kit and PDFGRA mutation frequencies were not correlated with either tumor sizes or the nuclear mitotic. Conclusions The stomach and small intestinal were the primary locations of GIST. GISTs were most commonly seen in c-kit exon 11 mutation. The types of c-kit and PDGFRA mutations were associated with the sites of origin in GISTs.