SURG-31. Impact of facility caseload on outcomes in patients with primary malignant spinal intramedullary neoplasms

BACKGROUND The impact of facility volume on patient outcomes for primary malignant intramedullary tumors remains unclear. This study aimed to evaluate survival differences based on facility volume, analyze variations in treatment approaches, and assess the association between facility caseload and both survival and perioperative outcomes. METHODS This retrospective cohort study utilized data from the National Cancer Database from 2004 to 2022. Patients diagnosed with primary malignant intramedullary tumors were categorized based on facility volume: high-volume facilities (>32 cases over the study period) and low-volume facilities (≤32 cases). The primary outcome was overall survival (OS), while secondary outcomes included treatment utilization and perioperative outcomes in surgically treated patients. RESULTS A total of 3,667 patients were included, with 502 treated at high-volume facilities and 3,165 at low-volume facilities. Treatment at high-volume facilities was associated with significantly improved OS (P<0.001), with a 10-year survival rate of 81.4% compared to 69.8% at low-volume facilities. While surgical procedures, radiation therapy, and systemic therapy utilization remained stable at high-volume facilities, low-volume facilities exhibited a significant increase in surgical procedures (RR 1.021, 95%CI 1.011–1.032; P<0.001) and a significant decline in radiation therapy use (RR 0.971, 95%CI 0.955–0.987; P<0.001). After adjusting for confounding variables, treatment at high-volume facilities remained independently associated with lower mortality risk (HR 0.737, 95%CI 0.578–0.94; P=0.014), a reduced likelihood of receiving radiation therapy (OR 0.539, 95%CI 0.413–0.697; P<0.001), and significantly lower 30-day readmission rates following surgical resection (OR 0.313, 95%CI 0.147–0.586; P=0.001). CONCLUSIONS Despite the rarity of primary malignant intramedullary tumors, treatment at high-volume facilities was associated with significantly improved survival and lower 30-day readmission rates following surgical resection, even after adjusting for potential confounders. These findings underscore the importance of specialized centers in optimizing patient outcomes and can inform referral patterns and treatment strategies for these complex tumors.