Extradural Primary Malignant Spinal Tumors in a Population Younger than 25 Years: An Ambispective International Multicenter Study on Onco-Surgical Outcomes

SIMPLE SUMMARY: Extradural primary malignant spinal tumors in the younger population are a rarity. Their diagnosis can cause an ordeal for the patients as well as their families. Specialist multidisciplinary sarcoma management is mandatory. Only limited outcome information on interdisciplinary treatment is available. The aim of this study is to report on the clinical outcomes of young patients who received surgery for an extradural primary malignant spinal tumor. This is the first and largest multicenter cohort of surgically treated extradural malignant spinal tumors in young patients. The results underline the value of surgery in a multidisciplinary concept with the intent to cure using EA resections to achieve better overall survival and low local recurrence rates. Due to the necessary experience for pediatric oncology care and specialist spinal oncology surgery, primary malignant spinal tumor treatment in young patients must be centralized. ABSTRACT: Extradural malignant primary spinal tumors are rare and outcome data, especially for younger patients, is limited. In a worldwide (11 centers) study (Predictors of Mortality and Morbidity in the Surgical Management of Primary Tumors of the Spine study; ClinicalTrials.gov Identifier NCT01643174) by the AO Spine Knowledge Forum Tumor, patients surgically treated for primary tumors of the spine between 1992 and 2012, were retrospectively analyzed from a prospective database of their medical history. Medical history, tumor characteristics, diagnostics, treatments, cross-sectional survival, and local recurrences were analyzed. Sixty-eight cases (32 f; 36 m), at an average age of 18.6 ± 4.7 years at the time of diagnosis, were identified (median follow-up 2.9 years). The most common entities were Ewing’s sarcoma (42.6%). Of the patients, 28% had undergone previous spine tumor surgery in another center (84% with intralesional margins). Resection was considered “Enneking appropriate” (EA) in 47.8% of the cases. Of the patients, 77.9% underwent chemotherapy and 50% radiotherapy. A local recurrence occurred in 36.4%. Over a third of patients died within a 10-year follow-up period. Kaplan-Meier-analysis demonstrated statistically significant overall survival (p = 0.007) and local recurrence rates (p = 0.042) for tumors treated with EA surgery versus Enneking inappropriate surgery. Aggressive resection of extradural primary malignant spinal tumors combined with adjuvant therapy reveals low local recurrence rates and better outcomes overall in younger patients.