Non-IgM monoclonal gammopathy (MG) was associated with shorter progression-free survival (PFS) and worse overall survival (OS) in patients with diffuse large B-cell lymphoma (DLBCL), according to results of a retrospective study. The findings from this study were published in Hematological Oncology.
Although the presence of MG, an abnormally high level of a serum monoclonal antibody resulting from proliferation of a clone of an antibody-producing cell, is common in some indolent B-cell lymphomas, such as Waldenstrom macroglobulinemia, the incidence and prognostic implications of MG in the setting of DLBCL are less well understood.
This study included 138 patients with DLBCL treated during the rituximab era for whom immunofixation electrophoresis was performed at disease diagnosis.
Monoclonal gammopathy was present in 19 (13.8%) of these patients.
Within the group of patients with MG, MG characterized by IgM was observed in 11 patients (57.9%), whereas IgG MG, a mixture of IgG and IgA MG, and monoclonal free light chains were seen in 4 (21.1%), 2 (10.5%) and 2 (10.5%) patients, respectively.
A comparison of patients with and without MG showed a significant association between the presence of MG and more advanced disease, higher-risk disease, and worse performance status.
At a mean follow-up of 41.1 months, the PFS of patients with MG was significantly shorter compared with those without MG (P =.003). However, when the specific type of MG was considered in the analysis, this association remained significant only for patients with IgG/IgA MG (P <.001), and not for those with IgG MG (P =.159).
Similarly, the presence of MG was also significantly associated with worse OS compared with the absence of MG (P =.004), with subgroup analyses showing that the finding of inferior survival was driven by those patients with IgG/IgA MG (P <.001), and not those with IgM MG (P =.435).
Multivariate analyses showed the presence of IgG/IgA MG to be an independent predictor of worse PFS and OS.
The study authors noted that “further prospective studies with gel electrophoresis and elaborate immunohistochemical data are needed to validate the prognostic significance of MG in DLBCL and elucidate the underlying mechanisms implicated in the worse prognosis of these patients.”
Papageorgiou SG, Thomopoulos TP, Spathis A, et al. Prognostic significance of monoclonal gammopathy in diffuse large B-cell lymphoma [published online October 28, 2019]. Hematol Oncol. doi: 10.1002/hon.2685