Expression and mutation of c-kit gene in gastrointestinal stromal tumors

AIM: To investigate the expression and mutation of c-kit gene and its correlation with the clinical pathology and prognosis of gastrointestinal stromal tumors (GISTs).METHODS: A total of 94 cases of GISTs, 10 leiomyomas and 2 schwannomas were studied for the expression of KIT by immunohistochemistry. The c-kit gene mutations in exon 11 of these specimens were detected by PCR-SSCP technique.RESULTS: Of the 94 cases of GISTs, 91 (96.8 %) expressed the KIT protein. Leiomyomas and schwannomas were negative for KIT. The c-kit gene mutations of exon 11 were found in 38 out of the 94 cases of GISTs (40.4 %). The mutations involved point mutations (Va1560-Asp, Ile563-Met),del 557-559 and 579ins12. No mutations were detectable in benign GISTs, leiomyomas or schwannomas. The patients with mutation-positive GISTs showed more frequent recurrences, invasion and metastasis in adjacent tissues than those with mutation-negative ones.CONCLUSION: KIT is a useful marker for diagnosis of GISTs.Mutation of the c-kit gene may play a significant role in the pathogenesis of GISTs and may be associated with poor prognosis in patients with GISTs.