Impact of prior cancer on the overall survival of patients with osteosarcoma: A nomogram based on the SEER database

Background: This study aimed to identify the impact of prior cancer on the overall survival (OS) of patients with osteosarcoma and to describe their characteristics and then establish a nomogram. Procedure: Data of patients with osteosarcoma diagnosed between 2010 and 2015 were extracted from the Surveillance, Epidemiology, and End Results database. The difference was balanced by propensity score matching. Kaplan–Meier and Cox analyses were performed to evaluate the influence of prior cancer. Patients were randomly divided into a training cohort and a testing cohort. A nomogram for predicting 3- and 5-year OS was established by multivariate Cox analyses. The discriminative ability and calibration of the nomogram were assessed by C-index values and calibration plots. Results: In total, 615 patients were identified, of which 103 (16.74%) had prior cancer. The most frequently reported type was breast cancer (12.62%). Patients with prior cancer possessed a poorer OS than those without prior cancer (p =0.023). Importantly, patients with prior bone sarcoma, breast, gastrointestinal, and hematological cancers had a non-inferior OS. The nomogram demonstrated favorable discriminatory ability as indicated by the C-index (0.728). Calibration plots indicated optimal agreement between the nomogram-predicted survival and the actual observed survival. Conclusions: This is the first study to report that osteosarcoma patients with prior cancer have a poor OS and provide a novel prognostic nomogram based on prior cancer history. Different prior cancer types had various effects on the OS. The nomogram facilitated individual prognosis prediction and clinical decision-making.