Unexpected Heterogeneity of Newly Diagnosed Multiple Myeloma Patients with Plasmacytomas

Abstract

In multiple myeloma (MM), malignant plasma cells infiltrate the bone marrow. In some cases, plasma cells migrate out of the bone marrow creating either para-skeletal plasmacytomas (PS) or infiltrating soft tissues as extramedullary plasmacytomas (EMD). The aim of this study was to define risk groups in newly diagnosed MM (NDMM) patients with PS and EMD plasmacytomas. In total, 523 NDMM patients with PS plasmacytomas and 196 NDMM patients with EMD plasmacytomas were diagnosed in the Czech Republic between 2004 and 2021 using modern imaging methods. Patients’ data were analyzed from the Registry of Monoclonal Gammopathies of the Czech Myeloma Group. In NDMM patients with PS plasmacytomas, we found a subgroup with <5% of bone-marrow plasma cells to have the best prognosis (mPFS: 58.3 months (95% CI: 33.0–NA); mOS: not reached). The subgroup with >5% of bone-marrow plasma cells and ≥3 plasmacytomas had the worst prognosis (mPFS: 19.3 months (95% CI: 13.4–28.8), p < 0.001; mOS: 27.9 months (95% CI: 19.3–67.8), p < 0.001). Our results show association between tumor burden and prognosis of NDMM patients with plasmacytomas. In the case of PS plasmacytomas, NDMM patients with low BM PC infiltration have an excellent prognosis.

Daratumumab with lenalidomide and dexamethasone in relapsed or refractory multiple myeloma patients – real world evidence analysis

“…In our analysis, patients with plasmacytoma found at the time of NDMM had somehow better Dara-Rd treatment results than patients, who developed plasmacytoma in disease relapse or progression (RRMM). This interesting finding demonstrates different clinical course of these two entities, even in relapsed setting [45][46][47]. Our results were, however, influenced by relatively low number of patients with this form of MM.…”

Daratumumab Post Maintenance after Relapse in Multiple Myeloma

“…Indeed, deep responses and prolonged progression-free survival can be achieved in relapsed refractory MM patients when CD38 antibodies are combined with immunomodulatory agents or proteosome inhibitors. In this report we have observed with surprise the benefit of daratumumab with durable and sustained responses in patients with various lines of treatment [2,3].…”