1q21+ is associated with poor prognosis in newly diagnosed multiple myeloma patients with extramedullary disease: a retrospective study

1q21+ is a common cytogenetic abnormality in multiple myeloma (MM) and is considered an independent predictor of poor prognosis; however, its impact on extramedullary disease (EMD) remains unknown. Our study reviewed the clinical relevance and prognostic value of 1q21+ status in 92 patients with NDMM and EMD. 1q21+ was detected in 23.9% (22/92) of patients. Patients with 1q21+ presented with advanced International Staging System stages (P = 0.006), lower level of hemoglobin (P = 0.004), higher percentage of plasma cells in the bone marrow (P < 0.001), higher level of serum β2-microglobulin (7.24 g/L vs. 3.85 g/L, P = 0.003), and higher levels of lactic dehydrogenase (LDH) (206.5 U/L vs. 177 U/L, P = 0.019). The prevalence of soft tissue-related EMD (EMD-S) (54.5% vs. 18.6%, P < 0.001), renal dysfunction (50.5% vs. 17.7%, P = 0.002), and hypercalcemia (27.3% vs. 7.1%, P = 0.011) was also higher. 1q21+ was strongly associated with other high-risk cytogenetic abnormalities, including IgH/FGFR3 (22.7% vs. 4.3%, P = 0.007) and IgH/MAF translocations (22.7% vs. 1.4%, P < 0.001). 1q21+ patients had significantly shorter overall survival (OS) and progression-free survival (PFS) (OS: 24 months vs. 47 months, P = 0.002; PFS: 14 months vs. 38 months, P < 0.001); the poor survival outcomes could not be reversed by autologous hematopoietic stem cell transplantation. Multivariate analysis suggested that 1q21+ , EMD-S, elevated lactate dehydrogenase (LDH) levels, and P53 deletion were independent risk factors for poor prognosis in patients with EMD. In patients with 1q21+ EMD, hypercalcemia, elevated LDH levels, and P53 deletion were independent adverse risk prognostic factors.