What are the 5-year relapse-free survival results for high-risk GIST patients on adjuvant imatinib?

Adjuvant imatinib (a targeted therapy) is given after surgery to lower the risk of the tumor coming back in high-risk gastrointestinal stromal tumors (GIST). The question asks about the 5-year relapse-free survival (RFS) rate — the percentage of patients who remain free of cancer recurrence 5 years after starting treatment. A 2026 study directly compared outcomes for patients who took imatinib for 3 years or less versus more than 3 years. The results show a clear benefit for longer treatment: 84% of patients on imatinib for more than 3 years were relapse-free at 5 years, compared to 74% for those on 3 years or less ³⁶.

What the research says

A 2026 retrospective study from China analyzed 75 high-risk GIST patients who had surgery and then took adjuvant imatinib ³⁶. The 5-year RFS rate was 84% in the group that took imatinib for more than 3 years, versus 74% in the group that took it for 3 years or less — a statistically significant difference ³⁶. However, the study found no significant difference in 5-year overall survival between the two groups ³⁶. This suggests that extending imatinib beyond 3 years helps keep the cancer from returning, but may not yet show a clear impact on how long patients live overall.

For context, older research from 2014 on patients who did not receive imatinib reported a much lower 5-year RFS of only 44.5% for high-risk GIST ⁵. That same study found that intermediate- and high-risk patients who did receive adjuvant imatinib had a 5-year RFS of 82.3% ⁵, which is similar to the 84% seen in the 2026 study for the longer-duration group. This highlights how imatinib has dramatically improved outcomes for high-risk GIST.

The 2026 study also measured imatinib drug levels in the blood (plasma trough concentrations) in some patients, but the results on how drug levels relate to outcomes were not detailed in the abstract ³⁶. The study's authors note that the optimal duration of adjuvant imatinib is still debated, and longer follow-up is needed ³⁶.

What to ask your doctor

• Based on my risk level and tumor characteristics, what is the recommended duration of adjuvant imatinib for me?
• What are the potential benefits and side effects of taking imatinib for more than 3 years?
• Should I have my imatinib blood levels checked to see if my dose is right?
• How often will I need follow-up scans or tests to monitor for recurrence?
• Are there any newer treatments or clinical trials for high-risk GIST that I should consider?