Hospital volume, travel burden, and survival disparities in stage IV melanoma: A U.S. national cohort.

Abstract

e21597 Background: Advances in immunotherapy and selective surgical resection have improved outcomes for stage IV melanoma, yet access to high-quality multidisciplinary care might not be possible for all patients. High-volume centers (HVCs) may deliver more guideline-concordant treatment but often require long-distance travel, raising concerns about socioeconomic and racial inequities. We evaluated the association of hospital volume and travel distance with treatment patterns, survival, and equity in stage IV melanoma. Methods: Patients with AJCC stage IV melanoma diagnosed between 2014–2022 were identified from the National Cancer Database. Hospitals were categorized by annual invasive melanoma volume as low (< 35/year), medium (35–91/year), or high ( > 91/year). Patients in the lowest travel-distance quartile treated at low-volume centers (Local-LVC) were compared with those in the highest travel-distance quartile treated at HVCs (Travel-HVC). Overall survival (OS) was analyzed using Kaplan–Meier methods and multivariable Cox regression adjusting for demographics, insurance, comorbidity, metastatic site, facility characteristics, and treatment. Results: Median travel distance ranged from 4.9–9.9 miles for Local-LVC patients versus 25.3–64 miles for Travel-HVC patients, varying by region. Travel-HVC patients were more likely to be White, privately insured, and treated at academic centers, and more frequently received first-line immunotherapy (75.9% vs 63.5%) and immunotherapy followed by surgery (44% vs 32%) (all p < 0.001). On multivariable analysis, treatment at a Travel-HVC was independently associated with improved OS compared with Local-LVC care (HR 0.80, 95% CI 0.67–0.95; p = 0.012). Immunotherapy alone (HR 0.72, 95% CI 0.62–0.82) and immunotherapy plus surgery (HR 0.48, 95% CI 0.42–0.56) were associated with superior OS compared with surgery alone (both p < 0.001). Brain metastases (HR 2.02), lung metastases (HR 1.42), and metastases to > 1 site (HR 2.66) were associated with worse survival (all p ≤0.05), yet the survival benefit of Travel-HVC care persisted across metastatic patterns and treatment strategies. Lack of insurance (HR 1.34) and Medicaid/government insurance (HR 1.37) were independently associated with worse OS, while racial disparities observed on unadjusted analysis were attenuated after adjustment for insurance and care delivery factors. Conclusions: Access to high-volume centers was independently associated with improved survival for patients with stage IV melanoma, even after accounting for treatment modality, disease burden, and socioeconomic factors. These findings suggest that structural access to high-quality multidisciplinary care—rather than race alone—drives much of the observed survival disparity and support regional referral pathways and shared-care models to promote equity in advanced melanoma care.