As reported in the Journal of Clinical Oncology by Heikki Joensuu, MD, PhD, of the Comprehensive Cancer Center Helsinki, Finland, and colleagues, the second planned analysis in the Scandinavian Sarcoma Group XVIII/AIO trial showed a recurrence-free survival benefit and a continued overall survival benefit with 3 years vs 1 year of adjuvant imatinib in patients with gastrointestinal stromal tumors with high-risk features.1 Other data have indicated improved recurrence-free survival with adjuvant imatinib but no overall survival benefit in this setting.
In the open-label trial, 400 patients with macroscopically completely excised, KIT-positive gastrointestinal stromal tumor with a high risk of recurrence (based on the modified National Institutes of Health criteria) were randomized between February 2004 and September 2008 to receive imatinib at 400 mg once daily for 1 (n = 200) or 3 years (n = 200) after surgery. The primary endpoint was recurrence-free survival.
After a median follow-up of 90 months, 5-year recurrence-free survival was 71.1% in the 3-year group vs 52.3% in the 1-year group (hazard ratio [HR] = 0.60, P < .001), and 5-year overall survival was 91.9% vs 85.3% (HR = 0.60, P = .036). Among patients in the 3-year group, 5-year overall survival was improved among those with centrally confirmed gastrointestinal stromal tumor and no macroscopic metastases (93.4% vs 86.8%, HR = 0.53, P = .024).
During follow-up, cardiac events occurred in 3.0% of patients in the 3-year group and 5.2% of patients in the 1-year group; cardiac failure occurred in one patient in the 1-year group, and myocardial infarction occurred in one patient in each group. A second cancer was identified in 11.1% and 9.8% of patients, with the most common being prostate cancer (2.5% and 3.6%).
The investigators concluded: “Three years of adjuvant imatinib therapy results in longer survival than 1 year of imatinib. High 5-year survival rates are achievable in patient populations with high-risk GIST.” ■
Disclosure: The study was supported by Novartis Oncology, the Academy of Finland, the Cancer Society of Finland, Sigrid Juselius Foundation, and Helsinki University. For full disclosures of the study authors, visit jco.ascopubs.org.
1. Joensuu H, Eriksson M, Sundby Hall K, et al: Adjuvant imatinib for high-risk GI stromal tumor: Analysis of a randomized trial. J Clin Oncol 34:244-250, 2016.