Survival Outcomes Associated With 3 Years vs 1 Year of Adjuvant Imatinib for Patients With High-Risk Gastrointestinal Stromal Tumors

Abstract

IMPORTANCEAdjuvant imatinib is associated with improved recurrence-free survival (RFS) when administered after surgery to patients with operable gastrointestinal stromal tumor (GIST), but its influence on overall survival (OS) has remained uncertain.OBJECTIVE To evaluate the effect of adjuvant imatinib on OS of patients who have a high estimated risk for GIST recurrence after macroscopically complete surgery. DESIGN, SETTING, AND PARTICIPANTSIn this open-label, randomized (1:1), multicenter phase 3 clinical trial conducted in Finland, Germany, Norway, and Sweden, 400 patients who had undergone macroscopically complete surgery for GIST with a high estimated risk for recurrence according to the modified National Institutes of Health Consensus Criteria were enrolled between February 2004 and September 2008. Data for this follow-up analysis were analyzed from September to November, 2019.INTERVENTIONS Imatinib 400 mg/d administered orally for either 12 months or 36 months after surgery. MAIN OUTCOMES AND MEASURESThe primary end point was RFS; the secondary objectives included OS and treatment safety. RESULTSThe intention-to-treat cohort consisted of 397 patients 199; 198; 201 men and 196 women; median [IQR] age, 62 (51-69) years and 60 (51-67) years, during a median follow-up time of 119 months after the date of randomization, 194 RFS events and 96 OS events were recorded in the intention-to-treat population. Five-year and 10-year RFS was 71.4% and 52.5%, respectively, in the 36-month group and 53.0% and 41.8% in the 12-month group (hazard ratio [HR], 0.66; 95% CI, 0.49-0.87; P = .003). In the 36-month group, 5-year OS and 10-year OS rates were 92.0% and 79.0%, respectively, and in the 12-month group 85.5% and 65.3% (HR, 0.55; 95% CI, 0.37-0.83; P = .004). The results were similar in the efficacy population, from which 15 patients who did not have GIST in central pathology review and 24 patients who had intra-abdominal metastases removed at surgery were excluded (36-month group, 10-year OS 81.6%; 12-month group, 66.8%; HR, 0.50; 95% CI, 0.32-0.80; P = .003). No new safety signals were detected.CONCLUSIONS AND RELEVANCE Three years of adjuvant imatinib is superior in efficacy compared with 1 year of imatinib. Approximately 50% of deaths may be avoided during the first 10 years of follow-up after surgery with longer adjuvant imatinib treatment.

Solitary peritoneal metastasis of gastrointestinal stromal tumor: A case report

“…The SSGXVIII/AIO trial, which was an open-label, multicenter, randomized, phase III study, showed that 3 years of adjuvant imatinib improved the recurrence rate and overall survival of GIST patients who were at a high risk of recurrence. Therefore, adjuvant therapy with imatinib for at least 3 years is the standard treatment for patients with high-risk GIST[ 15 ]. Our patient initially had a 4.5 cm GIST located in the stomach, with a mitotic rate of 5 mitoses per HPF, and therefore, the patient was classified into the intermediate-risk group; thus, adjuvant imatinib therapy was not administered.…”

Therapie der Weichgewebssarkome inklusive GIST – Update 2021

“…Auf dem ASCO-Kongress, und direkt anschließend als Vollpublikation, wurden die Daten zum 10-Jahres-Follow-up der SSGXVIII/AIO-Studie publiziert [14]. Die Studie hatte bei Patienten mit hohem Rezidivrisiko eine Therapie mit Imatinib über 1 Jahr mit einer 3-jährigen Therapiedauer verglichen.…”

Herausforderung gastrointestinale Stromatumoren

“…In der deutschen APOLLON-Studie [5] Mit der AIO/SSG XVIII-Studie, in die nur Patienten mit hohem Risiko eingeschlossen wurden, konnte die Überlegenheit einer 3-jährigen Therapie gegenüber der 1-jährigen Gabe sowohl im progressionsfreien als auch im Gesamtüberleben gezeigt werden. 2020 wurden die Daten zum 10-Jahres Follow-up der Studie publiziert [8]. Das Gesamtüberleben in der "intention-to-treat"-Population lag nach 10 Jahren für die Gruppe mit 1-jähriger Therapie bei 65 % und nach 3 Jahren Therapie bei 79 %.…”