Purpose: To examine the relationship between guideline-concordant care (GCC) on the basis of national clinical practice guidelines and survival in children (0-14 years), adolescents and young adults (AYAs, 15-39 years), and adults (40 years and older) with osteosarcoma, and to identify sociodemographic and clinical factors associated with receipt of GCC and survival.
Methods: We used data from the California Cancer Registry (CCR) on patients diagnosed with osteosarcoma during 2004-2019, with detailed treatment information extracted from the CCR text fields, including chemotherapy regimens. Multivariable logistic and Cox proportional hazard regression were used for statistical analyses.
Results: Of 1,716 patients, only 47% received GCC, with variation by age at diagnosis: 67% of children, 43% of AYAs, and 30% of adults. In multivariable models, patients who received part or all care (v none) at specialized cancer centers were more likely to receive GCC. AYAs and adults were less likely to receive GCC than children (odds ratio [OR], 0.38 [95% CI, 0.30 to 0.50] and OR, 0.40 [95% CI, 0.28 to 0.56], respectively). In a model excluding adults, patients treated by pediatric (v medical) oncologists were more likely to receive GCC (OR, 3.44 [95% CI, 2.40 to 4.94]). Patients with metastatic osteosarcoma at diagnosis who did not receive GCC had a greater hazard of death (hazard ratio [HR], 2.02 [95% CI, 1.55 to 2.63]) but no statistical differences were found in those diagnosed at earlier stages (HR, 1.15 [95% CI, 0.92 to 1.43]).
Conclusion: GCC was associated with improved survival in patients with metastatic osteosarcoma in California. However, we found disparities in the delivery of GCC, highlighting the need for target interventions to improve delivery of GCC in this patient population.