IMATINIB U LIJEČENJU GASTROINTESTINALNIH STROMALNIH TUMORA – ISKUSTVA KBC-a ZAGREB

Damir Vrbanec, Branka Petričević, Mate Majerović, Ranka Štern-Padovan, Borislav Belev, Mate Škegro, Davorin Herceg, Stjepko Pleština, Natalija Dedić-Plavetić, Jasna Jakić-Razumović

Gastrointestinalni stromalni tumori (GIST)  intraabdominalni su mezenhimalni tumori koji izražavaju KIT protein ili imaju aktivirajuću mutaciju gena  za tirozinkinaze receptor (KIT ili PDGFRα). Kod većine GIST-a postoji odgovor na  imatinib mesilat, koji selektivno inhibira  KIT i PDGFRα, te se smatra standardnom terapijom za uznapredovali  i/ili metastatski GIST. U zavodu za internističku onkologiju liječeno je 14 bolesnika s uznapredovalim GIST-om od 2002. do kraja 2004. godine. Imatinib mesilat je primjenjivan u dozi od 400 mg na dan. Samo kod dva bolesnika doza je povišena na 800 mg na dan zbog progresije. Svi tumori imali su ekspresiju KIT-proteina potvrđenu imunohistokemijski. Srednja dob pacijenata bila je 56 godina. Liječeno je 12 muškaraca i 2 žene. Kod 6 pacijenata primarno sijelo tumora bilo je tanko crijevo, u 4 mezenterij te u 4 želudac. Srednje trajanje liječenja bilo je 14 mjeseci (2 do 32 mjeseca). U 6 bolesnika postignuta je parcijalna remisija, također u 6 održano je stabilno stanje, dva bolesnika imala su progresiju. Kompletna remisija bolesti nije postignuta ni u jednog bolesnika. Nuspojave liječenja bile su prihvatljive i ni u jednog pacijenta nisu zathtijevale snjiženje doze niti prekid liječenja.  Naši rezultati pokazuju učinkovitost ciljane antitumorske terapije imatinib mesilatom kod uznapredovalog i/ili metastatskog GIST-a i odgovaraju onima iz literature.

Summary. Gastrointestinal stromal tumours (GIST) may be defined as intraabdominal mesenchymal tumours that express KIT protein or have an activating mutation in class III receptor tyrosine kinase gene (KIT or PDGFRa). Most GISTs respond to imatinib mesylate, which selectively inhibits both KIT and PDGFRa, and is now considered standard systemic therapy for advanced GIST. We assessed the antitumour response of patients treated with imatinib mesylate who had advanced and/or metastatic (GIST). In the Department of Medical Oncology fourteen (14) patients with advanced GIST were treated in the period from year 2002 to 2004. Imatinib mesylate was applied at the dose of 400 mg daily. Only two patients required dose enlargement up to 800 mg. All tumours had positive immunohystochemical expression of KIT. Median age of patients was 56 years. 12 male patients and 2 female patient was treated. Considering primary site of tumour we had 6 small intestine, 4 mesenterium and 4 gastric tumours. Mean duration of the treatment was 14 months (5 to 30 months). Six patients had partial remission, six had stable disease and two progression. Complete remission has not been achieved in any patient. Side-effects were mild and no patient required dose reduction or treatment discontinuation. Our results show the effectivness of targeted antitumour therapy with imatinib mesylate in advanced and/or metastatic GIST, and correspond to those in literature.