Construction and Validation of a Novel Web-Based Nomogram for Solitary Plasmacytoma of Bone of the Spine: A Real-World Analysis Based on the Surveillance, Epidemiology, and End Results Database.

Objective: Solitary plasmacytoma of bone of the spine (SPBS) was rarely detected in the past. However, its incidence has gradually increased with improvements in the diagnosis and understanding of the disease. We aimed to conduct a population-based cohort study to characterize the prevalence and factors associated with SPBS and develop a prognostic nomogram for predicting the overall survival of SPBS patients with a real-world analysis based on the surveillance, epidemiology, and end results database.

Methods: Patients with SPBS at diagnosis were identified using the SEER database from 2000-2018. Multivariable and univariate logistic regression analyses were used to identify factors for developing a novel nomogram. Nomogram performance was evaluated using the calibration curve, area under the curve (AUC), and decision curve analyses. Kaplan-Meier analysis was used to estimate survival durations.

Results: A total of 1,147 patients were selected for survival analysis. Multivariate analysis demonstrated that independent predictors for SPBS were as follows: ages: 61-74 and 75-94, marital status: unmarried, treatment: radiation alone and radiation with surgery. The 1-, 3-, and 5-year AUCs for OS were 0.733, 0.735, and 0.735 in the training cohort and 0.754, 0.777, and 0.791 in the validation cohort, respectively. The C-index values in the 2 cohorts were 0.704 and 0.729. The results indicated that nomograms could satisfactorily identify patients with SPBS.

Conclusions: Our model effectively demonstrated the clinicopathological features of SPBS patients. The results indicated that the nomogram had a favorable discriminatory ability, good consistency, and yielded clinical benefits for SPBS patients.