CD56 negativity is associated with worse survival outcomes in patients with multiple myeloma: a meta-analysis

The prognostic value of cluster of differentiation 56 (CD56) in patients with multiple myeloma (MM) is controversial. This meta-analysis aimed to investigate the association of CD56 with overall survival (OS) and progression-free survival (PFS) in patients with MM. Studies reporting the association of CD56 with survival outcomes in patients with MM were included. Hazard ratio (HR) values with 95% confidence intervals (CIs) were gathered for pooled analysis. Twenty-two studies with 2791 patients were included. CD56 negativity was associated with worse OS [HR (95% CI): 2.04 (1.57, 2.65), p < 0.001] and PFS [HR (95% CI): 1.43 (1.23, 1.65), p < 0.001] in patients with MM. Subgroup analyses stratified by regions and CD56 cutoff values were performed. CD56 negativity was associated with shorter OS in studies conducted in Asian countries, studies using ≤ 20% for the cutoff value, and studies using other cutoff values (all p < 0.01). In studies conducted in regions other than Asia, CD56 was not associated with OS. Additionally, CD56 negativity was associated with worse PFS, regardless of region and CD56 cutoff value (all p < 0.05). No publication bias was found, and the pooled analysis was robust. CD56 negativity serves as a potential biomarker for predicting worse survival outcomes in patients with MM, especially in Asians, which could improve personalized treatment for these patients.