RESUMO
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 (Val560-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.
