A nomogram for predicting recurrence-free survival in patients with high-risk GIST receiving adjuvant imatinib: A...

Despite adjuvant imatinib therapy, a substantial proportion of patients with high-risk gastrointestinal stromal tumor (GIST) experience disease recurrence. This study aimed to identify prognostic factors associated with poor recurrence-free survival (RFS) and develop a predictive nomogram for personalized clinical decision-making. In the present study, a retrospective analysis was conducted of 269 patients with modified Armed Forces Institute of Pathology-classified high-risk GIST who underwent macroscopically complete resection and received adjuvant imatinib therapy at 11 Taiwanese centers between 2013 and 2023. All patients were intended to receive 3 years of adjuvant imatinib and were categorized into disease-free (n=204) and recurrence (n=65) cohorts. Independent predictors of poor RFS were identified through multivariate Cox regression analysis and incorporated into a nomogram. Model performance was assessed using concordance index (C-index) and calibration plots. The cohort comprised 149 males and 120 females with a median age of 60.9 years (range, 29-88 years). At a median follow-up of 62.6 months, the 1-, 3- and 5-year disease-free survival rates were 97.0, 91.7 and 76.4%, respectively. Multivariate analysis identified male sex [hazard ratio (HR): 1.76, P=0.039], non-gastric tumor origin with duodenum showing highest risk (HR: 6.15, P<0.0001) and shorter imatinib duration with <1 year treatment showing HR: 3.91 (P=0.002) as independent predictors of poor RFS. The resulting nomogram demonstrated robust predictive performance with good calibration and C-index of 0.72. Nomogram-based prognostic stratification identified three distinct groups with 5-year survival rates of 99.2% (favorable prognosis), 68.1% (moderate prognosis) and 16.7% (poor prognosis). In the present study, a clinically applicable nomogram was developed that accurately predicts poor RFS in patients with high-risk GIST following surgery and adjuvant imatinib therapy. While external validation is needed before clinical implementation, this prognostic tool may facilitate individualized treatment strategies and patient counseling.