The analysis of the long-term outcomes of sorafenib therapy in routine practice in imatinib and sunitinib resistant gastrointestinal stromal tumors (GIST).

Abstract

Aim of the studywas to analyze the outcome of treatment and factors predicting results of sorafenib therapy in inoperable/metastatic CD117-positive GIST patients after failure on imatinib and sunitinib.Material and methodsWe identified 60 consecutive patients (40 men, 20 women) with advanced inoperable/metastatic GIST after failure on at least imatinib and sunitinib treated in one sarcoma center with sorafenib at initial dose 2 × 400 mg daily in 2007–2015 (in 56 cases it was 3rd line therapy). Median follow-up time was 39 months.ResultsOne year progression-free survival (PFS; calculated from the date of the start of sorafenib to disease progression) rate was 23% and median PFS = 7.7 months. The median overall survival (OS) was 13.5 months calculated from sorafenib start (1-year OS rate = 57%) and 7 years from imatinib start. Three patients (5%) had objective partial responses to therapy, 31 patients (52%) had stabilization of disease > 4 months. Primary tumor mutational status was known in 43 cases (73%), but we have not identified the differences in PFS between tumors carrying different KIT/PDGFRA mutations. The most common adverse events were: diarrhoea, hand and foot syndrome, fatigue, loss of weight and skin reactions; grade 3–5 toxicity occurred in 35% of patients. 23 patients required sorafenib dose reductions due to AEs.ConclusionsWe confirmed that many advanced GIST patients benefit from sorafenib therapy after imatinib/sunitinib failure with OS > 1 year.