Imatinib is currently the standard therapy for first line treatment of metastatic GIST. Although this treatment has demonstrated durable responses with PFS and OS benefit, most patients develop resistance and experience subsequent disease progression. Current treatment available in second line are Imatinib high-dose (800 mg/day) or Sunitinib. The presence of two options in this setting, in the absence of direct comparisons, raises many questions on the choice.
A total of 128 patients with metastatic GIST were collected in our analysis in this large database. We analyzed the validity of several parameters as possible predictors of response to treatment with Imatinib high-dose vs Sunitinib in patients progressing at the standard dose of Imatinib 400 mg/day. The parameters analyzed were: anatomic site of primary GIST, site of metastasis, KIT and PDGFRa mutational status, and FDG-PET status at progressing disease. Every factor has been correlated with Progression Free Survival (PFS) for Imatinib 800 mg/day and Sunitinib treatment, measured in months. Datas collected have been analyzed with software “Medcalc”, performed by using the Kaplan-Meier method.
Univariate analysis showed Sunitinib more active then Imatinib in gastric GISTs (median PFS: Sun 12 months vs Ima 800 6 months; p
with the limitations of a retrospective analysis, this study identifies the gastric site of primary tumor as a predictive factor to efficacy of Sunitinib treatment in second line. The mutational status (GIST WT), the site of metastasis (peritoneum) and the FDG-PET status (negative), although not statistically significantly, seem to be elements of increased activity for Sunitinib treatment in second line.
Clinical trial identification
Legal entity responsible for the study
University of Palermo
All authors have declared no conflicts of interest.