The prognostic impact of 1q21 gain/amplification in newly diagnosed multiple myeloma: a retrospective study based on a single center in China.

1q21gain/amp is the most common in patients with multiple myeloma. However, there is limited research on the prognostic heterogeneity of 1q21+, and the prognostic of the 1q21 copy remains controversial. In this study, we primarily conducted a retrospective analysis of the prognostic significance of 1q21 gain/amp in 375 newly diagnosed multiple myeloma patients. 1q21 + was detected in 164 (43.7%) patients, including 103 (27.5%) with 3 copies and 61 (16.3%) with ≥ 4 copies. Patients with 1q21 + were more likely to be accompanied by anemia, hypercalcemia, t(4;14), and t(14;16). Compared with 1q21-, the progression-free survival (PFS) and overall survival (OS) of 1q21 + are shorter(p <0.0001; p = 0.036). The PFS of 1q21 amp was shorter than 1q21 gain (p = 0.0072). When accompanied by other high-risk abnormalities, 1q21 + was associated with earlier disease progression (all p<0.05). There were no significant differences in survival outcomes among patients with 1q21 gain alone, 1q21 amp alone, and FISH-. Autologous stem cell transplantation can prolong the survival of 1q21 + patients (p = 0.00062). A predictive scoring system based on 1q21 gain, 1q21 amp, del(17p), t(14;16), ISS II/III, and high LDH categorizes patients into three groups: low-risk (44.8%), intermediate-risk (38.9%), and high-risk (16.3%) (p < 0.0001; p < 0.0001). 1q21 + showed a relatively poor prognosis when coexisted with other high-risk cytogenetic abnormalities, especially 1q21 amp. The risk scoring system based on 1q21 copies is a potential risk stratification tool for multiple myeloma.