Wednesday, September 26, 2018 9:00 AM – 10:00 AM Best Papers: 3. Epidemiologic and survival trends in primary malignant osseous tumors of the spine: a National Cancer Database study

BACKGROUND CONTEXT Primary malignant osseous spinal tumors (PMOST) are rare and difficult to manage tumors with poor outcomes despite multimodal treatment regimes. The rarity of these neoplasms makes it difficult to perform large studies comparing epidemiologic, survival, and treatment trends.  We investigated the largest registry of primary bone tumors, the National Cancer Database (NCDB), to compare epidemiologic and survival trends between these tumors. PURPOSE To describe epidemiologic, survival, and treatment trends with primary malignant osseous spinal tumors. STUDY DESIGN/SETTING Retrospective. PATIENT SAMPLE N=941. OUTCOME MEASURES Length of survival. METHODS We retrospectively reviewed 941 patients in the NCDB from 2004 through 2015 with histologically confirmed primary osteosarcoma, chondrosarcoma, Ewing's sarcoma, or chordoma of the spine.  Demographic, clinical, and outcomes data were compiled and compared using chi-squared tests and ANOVA.  Long-term survival was compared using the Kaplan-Meier (KM) method with statistical comparisons based on the log-rank test.  Multivariate analysis was performed to determine survival determinants.  Study variables included age, sex, race, Hispanic ethnicity, insurance status, comorbidity score, year of diagnosis, grade of tumor, size of tumor, stage of tumor, surgical resection, chemotherapy, and radiation therapy. RESULTS The cohort included 941 patients; histological diagnosis was chordoma (n=407), chondrosarcoma (n=243), Ewing's sarcoma (n=164), and osteosarcoma (n=127). The average age at diagnosis was younger in Ewing's sarcoma (p CONCLUSIONS This study provides the most comprehensive comparison of epidemiologic, survival, and management trends in PMOST.  Surgical resection is the most common form of treatment for all PMOST. Ewing's sarcoma was treated with adjuvant chemotherapy and radiation therapy more often than other tumor types. Osteosarcoma has the worst 5-year survival prognosis of 32.9%, which did not improve from 2004 to 2015. Radiation therapy did not provide a survival benefit when looking at all PMOST. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.