The impact of high-risk cytogenetic abnormalities in extramedullary multiple myeloma in the era of novel agents: insights from a multicenter study

Purpose: This study aimed to examine the impact of high-risk cytogenetic abnormalities (HRA) on the survival outcomes of multiple myeloma patients with extramedullary disease (EMD) in the era of novel agents, utilizing the largest dataset of extramedullary multiple myeloma patients in China.

Methods: This study included a total of 371 patients with EMD, comprising 113 patients with de novo EME and 258 patients with EMB.

Results: Patients with one HRA and those with ≥ 2 HRA demonstrated significantly worse overall survival (OS) (P < 0.01) and progression-free survival (PFS) (P < 0.01) compared to patients without HRA. Additionally, 1q21 gain/amplification (1q21 +) remained a predictor of poor prognosis in EMD. CD38 monoclonal antibody-based therapy and single transplantation were less effective in improving survival outcomes for EMD with ≥ 2 HRA. Multivariable analysis identified LDH levels > 250 U/L, creatinine levels > 177 μmol/L, extramedullary extraosseous (EME), 1 HRA, and ≥ 2 HRA as independent adverse prognostic factors in patients with EMD.

Conclusion: Patients with EMD who had ≥ 2 HRA experienced an extremely poor prognosis, which could not be improved by single transplantation or CD38 monoclonal antibody-based treatment. The number of HRA could serve as an important factor in guiding treatment choices and predicting prognosis in patients with EMD. Furthermore, 1q21 + remained a significant factor associated with worse survival outcomes in EMD.