Abstract
e23512
Background: Osteosarcoma (OSC) is the most common primary bone tumor and typically affects the appendicular skeleton (specifically, the long bones of the upper and lower extremities). However, this cancer can affect other regions of the body as well, such as the skull, mandible, ribs, vertebral column, and other areas involving bone and/or any articular cartilage and, to the author’s knowledge, all possible primary sites have not been investigated. The aim of this study is to see whether or not the primary site of the tumor in OSC patients may have an effect on survival outcomes. Methods: Using the NCDB, patients diagnosed with OSC between 2004-2018 were identified using ICD-O-3 histology codes 9180 through 9193. The cohort was analyzed to investigate survival outcomes in different primary sites. Univariate analysis was then performed assessing patient length of survival for each primary site subtype. Data was analyzed using SPSS and statistical significance was set at α = 0.05. Results: A total of 9826 patients with known primary site that had survival data were included. The site with the best survival was the lower limb which had significantly better survival than all other primary sites. Tumors of the upper limb had highest median survival (153 months) of those with median survival reported (which was all except for lower limb). Patients with primary tumor of ribs, sternum, clavicle had a significantly better survival than both vertebral column and pelvis/sacrum/coccyx (all p < .01). Upper limb patients survived significantly longer than all groups other than the skull, face, and mandible (p < .05). The labeled primary site with the highest mean survival was the lower limb at 123.1 months and the lowest survival was the pelvis, sacrum, and coccyx, with a median survival of 54.6 months. Conclusions: This study found numerous survival differences between patients diagnosed with OSC of different primary sites. Labeled primary sites of the lower limb and upper limb were associated with best survival while the pelvis, sacrum, and coccyx were associated with worst survival. Future studies should be done to investigate variables that may impact the survival of different primary sites, including staging, treatments, time from diagnosis to treatment, socioeconomic factors, and insurance status.[Table: see text]