Abstract
e23502 Background: Well-differentiated intraosseous osteosarcoma (WDIO) is a rare cancer that primarily affects the medullary cavity of the femur and tibia. While WDIO accounts for only 2% of osteosarcomas, 10% of patients do not survive past 5 years. Due to its rare nature, there is difficulty diagnosing WDIO, and as such, patients present in later stages of the disease with more secondary complications. There is no standard of treatment for WDIO. The socioeconomic factors of WDIO have yet to be addressed in literature using data from the NCDB. The purpose of this study is to analyze the demographic and socioeconomic factors of patients diagnosed with WDIO, using the National Cancer Database (NCDB) to better understand its epidemiology. Methods: The National Cancer Database (NCDB) was used to create a retrospective cohort analysis of histologically-confirmed WDIO patients (N = 30) from 2004 – 2020. Regression analysis was performed to interpret incidence trends and descriptive statistics on specific demographic factors (sex, race, age, insurance status, income, type of treatment, facility type, and Charleson-Deyco score) on patients with WDIO. Results: There were a total of 30 patients in the NCDB database identified with a diagnosis of WDIO. From 2004 – 2020, there has been an increasing incidence rate (R2 = 0.3). The mean age of WDIO diagnosis is 37.9 (SD = 18.6 range = 8 – 80 years). The long bones of the upper and lower limbs accounted for 63.4% of the primary sites of the cancer. More women (63.3%) than men were diagnosed. The majority (83.3%) of the patients had Charlson-Deyo comorbidity scores of 0. The upper income quartile contained the highest percentage of patients (42.3%) compared to each of the other lower quartiles. There were more privately insured patients (63.3%) than patients on Medicaid/Medicare. Over half of the patients (51.9%) came from metropolitan areas with a population greater than 1 million. More than half of the patients were treated at research/academic facilities (51.3%). The main form of treatment in patients with WDIO was radical excision with limb salvage (60%). Local and partial resection occurred in 30% of the cases. Conclusions: This study addresses a significant gap in knowledge on the diagnosis of WDIO and its relation to socio-demographic factors. The majority of the patients present with WDIO in the long bones of the upper and lower body, which is concurrent with previous reports of WDIO. From our analysis, patients with WDIO tend to be in the upper income quartile, live in densely-populated urban areas, and receive radical excision surgery in academic programs. This preliminary research on the impacts of demographic and socioeconomic factors on WDIO could bring more awareness to its diagnosis. Further research on the impacts of these demographics on treatment options and overall prognosis would significantly enhance our knowledge regarding the social inequality surrounding WDIO.