This study aimed to investigate the prevalence, clinical characteristics, and prognostic impact of 1p32.3 deletion in patients with newly diagnosed multiple myeloma (MM). A retrospective analysis was conducted on 411 patients with newly diagnosed MM; among which, 270 received bortezomib-based therapies, and 141 received thalidomide-based therapies. Fluorescence in situ hybridization (FISH) was performed to detect six cytogenetic abnormalities, namely, del(1p32.3), gain(1q21), del(17p13), del(13q14), t(4;14), and t(11;14). Results showed that 8.3% of patients with MM were detected with del(1p32.3) and had significantly more bone marrow plasma cells (P = 0.025), higher β2-microglobulin levels (P = 0.036), and higher lactate dehydrogenase levels (P = 0.042) than those without del(1p32.3). Univariate analysis showed that patients with del(1p32.3) under thalidomide-based therapies (median PFS 11.6 vs. 31.2 months, P = 0.002; median OS 16.8 vs. 45.9 months, P < 0.001) were strongly associated with short progression-free survival (PFS) (P = 0.002) and overall survival (OS) (P < 0.001). Multivariate analysis revealed that del(1p32.3) remained a powerful independent factor with worse PFS (P = 0.006) and OS (P = 0.016) for patients under thalidomide-based treatments. Patients with del(1p32.3) under bortezomib-based treatments tended to have short PFS and OS. In conclusion, del(1p32.3) is associated with short PFS and OS in patients with MM who received thalidomide- or bortezomib-based treatments.
Keywords: 1p32.3 deletion; 1q21 gain; FISH; bortezomib; multiple myeloma; prognosis; thalidomide.