Določanje mutacij v genih c-KIT in PDGFRA pri bolnikih z gastrointestinalnimi stromalnimi tumorji Identification of c-KIT and PDGFRA gene mutations in patients with gastrointestinal stromal tumours

Abstract

Na Oddelku za molekularno diagnostiko Onkološkega inštituta Ljubljana smo uvedli testiranje mutacij v protoonkogenih c-KIT in PDGFRA z metodo neposrednega sekvenciranja. Uporaba zaviralcev tirozin kinaz za zdravljenje bolnikov z gastrointestinalnimi stromalnimi tumorji (GIST) je omogočila uspešnejše zdravljenje. Na izbiro najustreznejšega zdravila za bolnike z GIST vplivajo aktivacijske mutacije v genih c-KIT in PDGFRA. Mutacije v navedenih genih najdemo pri približno 90 % bolnikov z GIST. Večina izmed teh mutacij omogoči dober odgovor na zdravljenje z zaviralci tirozin kinaz (npr.imatinibom v prvi liniji zdravljenja), nekatere izmed mutacij pa povzročijo neodzivnost bolnika na zdravljenje. Pogosto se pojavijo tudi sekundarne mutacije, ki kljub prvotnemu dobremu odgovoru na zdravljenje z zaviralci tirozin kinaz povzročijo neodzivnost bolnika na prvotno zdravilo. V tem primeru je treba izbrati drugo vrsto zaviralca tirozin kinaz (npr. sunitinib, sorafenib, nilotinib). Poznavanje mutacijskega statusa genov c-KIT in PDGFRA predstavlja pomemben podatek za zdravnika pri izbiri ustreznega zdravljenja za posameznega bolnika.

Abstract (Eng)

At the Institute of Oncology Ljubljana, the Department of Molecular Diagnostics introduced testing of mutations in the c-KIT and PDGFRA proto-oncogenes using the direct sequencing method. The use of tyrosine kinase inhibitors to treat patients with gastrointestinal stromal tumours (GIST) enables a more successful treatment. Selection of the most appropriate drug for patients with GIST depends on the activation mutations in the c-KIT and PDGFRA genes. Mutations in these genes are found in approximately 90% of patients with GIST. The majority of these mutations show a good response to treatment with tyrosine kinase inhibitors (e.g. imatinib in the first-line treatment), while some mutations cause the patient to become unresponsive to treatment. Secondary mutations are also common, which cause patient’s lack of response to the original drug despite the originally good response to treatment with tyrosine kinase inhibitors. In this case, it is necessary to choose a different type of tyrosine kinase inhibitor (e.g. sunitinib, sorafenib, nilotinib). Identification of the c-KIT and PDGFRA gene mutation status represents important information for the doctor when deciding on the appropriate treatment for individual patients.