Object: Radical resection is recommended as the first-line treatment for pediatric intramedullary spinal cord tumors (IMSCTs), but it is associated with morbidity, including risk of neurological decline and development of postoperative spinal deformity. The authors report long-term data on clinical and treatment determinants affecting disease survival and neurological outcomes.
Methods: Case records for pediatric patients (< 21 years of age at presentation) who underwent surgery for IMSCTs at the authors' institution between January 1975 and January 2010 were analyzed. The patients' demographic and clinical characteristics (including baseline neurological condition), the treatment they received, and their disease course were reviewed. Long-term disease survival and functional outcome measures were analyzed.
Results: A total of 55 patients (30 male and 25 female) were identified. The mean duration of follow-up (± SEM) was 11.4 ± 1.3 years (median 9.3 years, range 0.2-37.2 years). Astrocytomas were the most common tumor subtype (29 tumors [53%]). Gross-total resection (GTR) was achieved in 21 (38%) of the 55 patients. At the most recent follow-up, 30 patients (55%) showed neurological improvement, 17 (31%) showed neurological decline, and 8 (15%) remained neurologically stable. Patients presenting with McCormick Grade I were more likely to show functional improvement by final follow-up (p = 0.01) than patients who presented with Grades II-V. Kaplan-Meier actuarial tumor progression-free survival rates at 5, 10, and 20 years were 61%, 54%, and 44%, respectively; the overall survival rates were 85% at 5 years, 74% at 10 years, and 64% at 20 years. On multivariate analysis, GTR (p = 0.04) and tumor histological grade (p = 0.02) were predictive of long-term survival; GTR was also associated with improved 5-year progression-free survival (p = 0.01).
Conclusions: The prognosis for pediatric IMSCTs is favorable with sustained functional improvement expected in a significant proportion of patients on long-term follow-up. Long-term survival at 10 years (75%) and 20 years (64%) is associated with aggressive resection. Gross-total resection was also associated with improved 5-year progression-free survival (86%). Hence, the treatment benefits of GTR are sustained on extended follow-up.
Keywords: GTR = gross-total resection; HR = hazard ratio; IMSCT = intramedullary spinal cord tumor; OS = overall (disease) survival; PFS = progression-free survival; STR = subtotal resection; disease-free survival; functional improvement; gross-total resection; intramedullary tumors; oncology; spinal cord; spine.