P76. An analysis of prognostic factors for patients with primary osseous malignancies of the mobile spine in the California Cancer Registry, 1988-2016

Abstract

<h3>BACKGROUND CONTEXT</h3> Malignant neoplasms of the mobile spine are associated with high morbidity and mortality. While treatment paradigms have evolved, factors associated with receipt of appropriate treatment and survival are not well defined. <h3>PURPOSE</h3> The goal of this study is to examine factors predictive of survival or receipt of the standard treatment paradigm for primary tumors of the mobile spine from 1988-2016 in the California Cancer Registry (CCR). <h3>STUDY DESIGN/SETTING</h3> The CCR was reviewed from the years 1988 to 2016 for patients who received treatment for a primary tumor of the mobile spine. <h3>PATIENT SAMPLE</h3> Patients of all ages with Ewing sarcoma, osteosarcoma, chondrosarcoma, or chordoma primarily located in the vertebral column and at least one year of registry follow-up were included. Sacrum/pelvis tumors were excluded. <h3>OUTCOME MEASURES</h3> Survival at the end of the study was the primary outcome of interest. A secondary outcome was receipt of the standard treatment paradigm by histology. <h3>METHODS</h3> Collected data included age, sex, race (white vs non-white), neighborhood socioeconomic status (nSES, low vs high), insurance status, Charlson Comorbidity Index (CCI), histologic diagnosis, tumor stage at presentation, and treatment at a National Cancer Institute designated Cancer Center (NCICC). Univariate and multivariate analyses were performed to identify predictors of survival and receipt of standard treatment for each histologic type. <h3>RESULTS</h3> Four hundred eighty-four patients met inclusion criteria. The cohort was mixed: >20 years old (80%), "white" (64%); "low nSES" (56%); private insurance (36%), Medicaid/public insurance (16%), Medicare (15%), uninsured/self-pay (6.4%). Chordoma (37%) was most common, while osteosarcoma was least common (16%). Ewing sarcoma and chondrosarcoma each accounted for 24% of the cohort. Locally advanced disease (40%) and localized disease (34%) were most common. Metastatic disease was uncommon (16%). The minority (29%) received treatment at a NCICC. Mortality was 58%. There were significant differences in receipt of "standard" treatment based on histology: chondrosarcoma (47%), chordoma (28%), Ewing's sarcoma (24%), osteosarcoma (21%) (p<0.0001). Patients with private insurance were most likely to receive "standard" treatment. Race and nSES were not associated with receipt of "standard" treatment for each histology, but being seen at an NCICC was (p = 0.0006). In regard to survival, age>20, higher CCI, Medicare/Medicaid insurance, more extensive stage of disease, and receiving no known treatment (compared to the "standard" treatment) were associated with lower odds of survival (all p<0.05). <h3>CONCLUSIONS</h3> Over a 28-year timeframe, the majority of patients with a primary osseous sarcoma of the mobile spine in the California Cancer Registry neither received "standard" treatment nor were cared for at an NCI cancer center. Mortality within 1 year was 58%. That survival was jeopardized by having public insurance and more extensive stage of disease and that survival was improved by receipt of "standard" treatment suggest that efforts should aim to improve access to designated cancer institutes and "standard" treatment paradigms to improve outcomes and survival for patients with malignant tumors of the mobile spine. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.