A Retrospective Analysis of the Efficacy and Safety of Imatinib for Advanced Gastrointestinal Stromal Tumor in Elderly Patients.

BACKGROUND

Gastrointestinal stromal tumor (GIST) occurs predominantly in the elderly population. However, clinical data on the outcomes of treatment with imatinib in elderly patients are limited. The aim of this study was to determine the efficacy and safety of imatinib for advanced GIST in the elderly population compared with the non-elderly population.

METHODS

We analyzed the clinical data of patients who received imatinib as first-line treatment for advanced GIST at our hospital between January 2010 and July 2023. Progression-free survival (PFS), overall survival (OS), and adverse events were compared between elderly patients (age ≥ 70 years, E group) and non-elderly patients (age < 70 years, NE group).

RESULT: Data of 91 patients (E group, n = 32; NE group, n = 59) with a median follow-up of 39.8 months were analyzed. A significantly higher proportion of patients in the E group required a reduced starting dose of imatinib (34% vs. 2%, p < 0.001). Median PFS was 29.4 months in the E group and 60.0 months in the NE group (hazard ratio [HR] 2.04, p = 0.04, log-rank test); median OS was 91.5 months in the E group and not reached in the NE group (HR 2.72, p = 0.03, log-rank test). Multivariable analysis identified age as an independent prognostic factor for PFS (HR 2.26, p = 0.03) and a trend towards worse OS with increasing age (HR 2.93, p = 0.06). Grade 2 or higher non-hematological adverse events were more prevalent in the E group (78% vs. 32%, p < 0.001).

CONCLUSION

Imatinib is an effective treatment for advanced GIST in elderly patients. However, elderly patients were associated with poorer efficacy and a Higher incidence of toxicities due to imatinib compared with non-elderly patients.