Duration of adjuvant treatment following radical resection of metastases from gastrointestinal stromal tumours

Large-scale studies have demonstrated that continuative treatment in advanced and adjuvant settings results in a gain-of-survival. However, the discontinuation, and the duration of treatment in disease-free patients who have undergone radical surgical resection of metastases from gastrointestinal stromal tumours (GISTs) have yet to be evaluated. We retrospectively reviewed 40 patients with advanced and recurrent GIST, included in our GIST database, focusing on patients (5 males and 2 females; median age 56 years) who continued medical treatment following radical surgical resection of metastatic lesions. Seven out of 40 patients underwent surgery and continued medical treatment following radical surgical resection of metastatic lesions. The duration of adjuvant therapy was 3, 12, 16, 24, 35, 37 and 52 months, respectively, with a median of 26 months. No patients discontinued therapy and all were disease-free at the final CT-scan evaluation. Considering that the discontinuation of imatinib in responding patients with advanced GIST (even in complete remission) results in a rapid high risk of progression, and a short adjuvant therapy results in a shorter disease-free and overall survival in high-risk GIST patients, it is also likely that treatment should not be discontinued in this setting. However, large-scale studies are required to better assess the optimal duration of treatment, particularly after 5 years, by focusing on the identification of predictive factors for the selection of patients who may benefit from a prolonged or lifelong imatinib treatment.