The Effect of Chromosome 1q21 Abnormalities on Outcomes of Autologous Stem Cell Transplantation (ASCT) in Multiple Myeloma Patients

Cytogenetic abnormalities (CA) detected by FISH in multiple myeloma (MM) cells could be highly prognostic of outcome and are incorporated into the Revised International Staging System (R-ISS). Additional copies of chromosome 1q (+1q) is identified in about 40% of newly diagnosed MM (NDMM) patients. Several studies suggested the presence of +1q abnormality negatively affects outcomes in NDMM patients. However, data are conflicting regarding the impact of +1q on ASCT outcomes in these patients. We conducted a retrospective review in our transplant MM patients who had at least 1 year follow up after ASCT. We identified 105 patients during the period Aug 2018 to Sept 2022. We separated patients into 4 groups according to CA including standard risk patients (n=65), any patients with del p53 (n=12), patients with +1q without p53 deletion (n=21), and other high risk patients group that has any or all of the following: t(4;14), t(14;16), t(14;20) (n=7). Patients with high risk CA were put on doublet maintenance usually including an IMiD and a proteasome inhibitor or anti CD38 antibody, otherwise Lenalidomide maintenance for other patients. As expected, patients with del p53 had the highest rate of relapse (RR) (58%) while the other groups had lower rates 12.5-25%. On the other hand, relapse related mortality (RRM) rates were 27% and 12.5% in the del p53 and other high risk group, respectively, while it was 5% in the standard risk group and the +1q group. Further multi variate analysis to include disease stage, absolute lymphocyte count on day +15 and disease status at transplant will be provided. The main conclusion from this study is that, in the current standard of care, MM patients with +1q abnormality, without the presence of del p53, who undergo ASCT, has a RR and RRM similar to that in patients with standard risk MM. Furthermore, patients with del p53 have the highest RR and RRM.