Development of a Clinical Prognostic Model for Primary Plasma Cell Leukemia Patients Treated with Novel Agents: a Multicenter Retrospective Cohort Study

The prognosis of primary plasma cell leukemia (pPCL) is poor, and the relevant prognostic factors are incompletely understood. We aimed to explore the prognostic factors and develop a validated prognostic prediction model for pPCL patients in the new era. This multicenter retrospective study was conducted across 16 hospitals in China. Cox proportional hazards regression analysis was used to develop a prediction model. The predictive performance of the model was assessed using multiple metrics. Internal validation was conducted using bootstrap resampling. A total of 102 pPCL patients were included in this study, and 57 (55.9%) were male. The 12-month, 24-month, and 36-month OS rates for pPCL patients were 75.4%, 58.3%, and 47.6%, respectively. An overall survival prognostic nomogram for pPCL patients was established by integrating independent prognostic factors, including age, B2MG, and del17p. The nomogram exhibited good performance, with a C-index of 0.720 (95% CI 0.642-0.797) and an AUC of 0.653. Bootstrap validation yielded a C-index of 0.721 (95% CI 0.629-0.787) and an AUC of 0.653 (95% CI 0.546-0.759), indicating a relatively good fit of the calibration curve. A nomogram incorporating age, B2MG grade, and del17p were developed and validated to accurately and consistently predict the prognosis of pPCL patients.