Osteosarcoma is an aggressive bone malignancy often treated with surgery. On diagnosis, the majority of patients present with stage II disease. The objective of this study was to compare differences in survival between three commonly used adjuvant therapies: chemotherapy, radiation, and combined chemoradiation therapy in patients presenting with stage II disease.
The National Cancer Database (NCDB) was used to identify patients diagnosed with osteosarcoma from 2004 to 2018 using the ICD-O-3 histology codes 9180-9187. Patients with stage II disease and who had undergone a surgical procedure at the primary site were identified. Patients were grouped by the receipt of adjuvant chemotherapy, radiation, or chemoradiation. Descriptive statistics and Kaplan-Meier curves were used to measure survival in these patients. One way ANOVA and chi-square analyses were used to evaluate differences among treatment groups. Data were analyzed using SPSS and statistical significance was set at P = .05.
Of 9955 patients in the NCDB diagnosed with osteosarcoma, 4378 (44%) presented with stage II disease. 710 (17.9%) of these surgical patients received additional adjuvant therapy. 66.0% received chemotherapy, 24.4% received radiation, and 9.57% received combined chemoradiation. Adjuvant chemotherapy had the longest median survival time of 91.7 months. Median survival for adjuvant radiotherapy was 48 months and combined chemoradiation was 50.5 months. On log-rank pairwise comparison, the difference in survival between adjuvant chemotherapy and adjuvant chemoradiation was found to be statistically significant. (P < .001). Patients receiving adjuvant chemotherapy were more likely to be younger and have private insurance. (P < .05) Conversely, patients receiving adjuvant radiation were more likely to be older and have Medicare. (P < .05). No significant differences were seen among patient race, sex, income, or Charleson-Deyo comorbidity score.
This study showed that patients with stage II osteosarcoma who receive adjuvant chemotherapy experience improved median survival in comparison to patients who receive adjuvant radiation. This is an important clinical finding, which should guide future treatment. However, further investigation is required to identify patient and treatment specific factors, which are contributing to mortality.