Development and validation of a nomogram for specific survival in osteosarcoma patients less than 60 years old: a population-based study.

Purpose: The present study aimed to develop a nomogram to predict the overall survival of patients with osteosarcoma, especially those less than 60 years old.

Methods: 903 osteosarcoma patients less than 60 years old were collected from the Surveillance, Epidemiology, and End Results (SEER) database.Univariate and multivariate analyses identified the independent prognostic factors of osteosarcoma. Nomogram was used to predict 3- and 5-year overall survival (OS) of osteosarcoma.The accuracy of the model was determined using the concordance index (C‑index), calibration curves, the area under the receiver operating characteristic curves (ROC),as well as decision curve analysis (DCA).

Results: Osteosarcoma patients less than 60 years old were randomly assigned into a training cohort (n=635) or validation cohort (n=268). Age, tumor site, tumor grade, tumor size, and tumor stage were identified as independent prognostic factors via univariate and multivariate Cox analyses (all p<0.05) and then included in the prognostic nomogram. The concordance indices(C-index) for OS prediction in the training cohort was 0.788 (95% CI 0.751-0.852) and in the external validation cohort was 0.779 (95% CI 0.712-0.846). Calibration plots and the area under the ROC revealed excellent consistency between actual survival and nomogram prediction. Finally, DCA demonstrated that the prognostic nomogram was clinically meaningful.

Conclusion: A nomogram could accurately predict the OS of osteosarcoma patients less than 60 years old and contribute to making better clinical treatment decisions for the treating doctors.