Lymph node metastases in young patients with gastrointestinal stromal tumor: A nationwide analysis.

ABSTRACT

BACKGROUND: Children, adolescents, and young adults (CAYA) (age ≤39 years) with GIST have high rates of LNM, but their clinical relevance is undefined. This study analyzed the impact of LNM on overall survival (OS) for CAYA with GIST. METHODS: The National Cancer Database was queried for patients with resected GIST and pathologic nodal staging data from 2004-2019. Factors associated with LNM were identified. Survival was assessed stratified by presence of LNM. RESULTS: Of 4420 patients with GIST, 238 were CAYA (5.4%). When compared to older adults, CAYA more often had small intestine primaries (51.8% vs. 36.6%, p < 0.0001), T4 tumors (30.7% vs. 24.5%, p = 0.0275) and pN1 disease (11.3% vs. 4.7%, p < 0.0001). Within a multivariable Cox proportional hazards regression model adjusting for age, comorbid disease, mitotic rate, tumor size, and primary site, LNM were associated with increased hazard of death for older adults (hazard ratio [HR] 1.83; confidence interval [CI] 1.35-2.42; p < 0.0001), but not CAYA (HR 3.38; CI 0.50-14.08; p = 0.13). For CAYA, only high mitotic rate predicted mortality (HR 4.68; CI 1.41-18.37 p = 0.02). CONCLUSIONS: LNM are more commonly identified among CAYA with resected GIST who undergo lymph node evaluations, but do not appear to impact OS as observed in older adults. High mitotic rate remains a predictor of poor outcomes for CAYA with GIST.