Objective: Gain or amplification 1q21 (1q21+) is one of the most common recurrent cytogenetic abnormalities in multiple myeloma (MM). Our aim was to explore the presentation and outcomes of patients with MM harboring 1q21 + .
Methods: We retrospectively analyzed the clinical features and survival outcomes in 474 consecutive patients with MM receiving immunomodulatory drugs or proteasome inhibitor-based regimens as first-line therapies.
Results: 1q21 + was detected in 249 (52.5%) patients. Patients with 1q21 + had a higher proportion of subtypes of IgA, IgD, and λ-light chain than non-1q21 + . 1q21 + was associated with more advanced ISS stage and was more frequently accompanied by del(13q), elevated lactate dehydrogenase and lower levels of hemoglobin and platelets. Patients with 1q21 + had shorter PFS (21 months vs. 31 months, P = 0.001) and OS (43 months vs. 72 months, P < 0.001) than those without 1q21 + . Multivariate Cox regression analysis confirmed that 1q21 + was an independent prognostic factor for both PFS (HR 1.277, P = 0.031) and OS (HR 1.547, P = 0.003). Patients with 1q21 + del(13q) double-abnormality had shorter PFS (P < 0.001) and OS (P = 0.001) than those with no FISH abnormalities, and they also had shorter PFS (P = 0.018) and OS (P = 0.026) than those with del(13q) single abnormality. No significant difference in PFS (P = 0.525) or OS (P = 0.245) was found between patients with 1q21 + del(13q) double-abnormality and 1q21 + del(13q) multiple-abnormality.
Conclusions: Patients with 1q21 + were more likely to have coexisting negative clinical features and del(13q). 1q21 + was an independent prognostic factor associated with poor outcomes. Concurrence with such unfavorable features may account for poor outcomes given 1q21 + .
Keywords: Multiple myeloma; OS; PFS; del(13q); gain/amplification 1q21.