Progression free survival of myeloma patients who become IFE-negative correlates with the detection of residual monoclonal free light chain (FLC) by mass spectrometry.
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All Authors
Giles, HV.
Drayson, MT.
Kishore, B.
Pawlyn, C.
Kaiser, M.
Cook, G.
de Tute, R.
Owen, RG.
Cairns, D.
Menzies, T.
LTHT Author
de Tute, Ruth
Owen, Roger
Owen, Roger
LTHT Department
Haematological Malignancy Diagnostic Service
Leeds Cancer Centre
Haematology
Leeds Cancer Centre
Haematology
Non Medic
Clinical Scientist
Publication Date
2024
Item Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, Non-U.S. Gov't
Language
Subject
Subject Headings
Abstract
Deeper responses are associated with improved survival in patients being treated for myeloma. However, the sensitivity of the current blood-based assays is limited. Historical studies suggested that normalisation of the serum free light chain (FLC) ratio in patients who were negative by immunofixation electrophoresis (IFE) was associated with improved outcomes. However, recently this has been called into question. Mass spectrometry (MS)-based FLC assessments may offer a superior methodology for the detection of monoclonal FLC due to greater sensitivity. To test this hypothesis, all available samples from patients who were IFE negative after treatment with carfilzomib and lenalidomide-based induction and autologous stem cell transplantation (ASCT) in the Myeloma XI trial underwent FLC-MS testing. FLC-MS response assessments from post-induction, day+100 post-ASCT and six months post-maintenance randomisation were compared to serum FLC assay results. Almost 40% of patients had discordant results and 28.7% of patients with a normal FLC ratio had residual monoclonal FLC detectable by FLC-MS. FLC-MS positivity was associated with reduced progression-free survival (PFS) but an abnormal FLC ratio was not. This study demonstrates that FLC-MS provides a superior methodology for the detection of residual monoclonal FLC with FLC-MS positivity identifying IFE-negative patients who are at higher risk of early progression.
Journal
Blood Cancer Journal