Open AccessThe clinical significance of stringent complete response in multiple myeloma is surpassed by minimal residual disease measurements
Author(s) -
María-Teresa Cedena,
Estela Martín-Clavero,
Sandy W. Wong,
Nina Shah,
Natasha Bahri,
Rafael Alonso,
Carmen Bárcenas,
Antonio Valeri,
Johny Salazar Tabares,
José María Sánchez-Pina,
Clara Cuéllar,
Thomas Martin,
Jeffrey L. Wolf,
Juan José Lahuerta,
Joaquín MartínezLópez
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0237155
Subject(s) - minimal residual disease , multiple myeloma , bone marrow , medicine , flow cytometry , oncology , immunoglobulin light chain , pathology , immunology , antibody
Background Stringent complete response (sCR) is used as a deeper response category than complete response (CR) in multiple myeloma (MM) but may be of limited value in the era of minimal residual disease (MRD) testing. Methods Here, we used 4-colour multiparametric flow cytometry (MFC) or next-generation sequencing (NGS) of immunoglobulin genes to analyse and compare the prognostic impact of sCR and MRD monitoring. We included 193 treated patients in two institutions achieving CR, for which both bone marrow aspirates and biopsies were available. Results We found that neither the serum free light chain ratio, clonality by immunohistochemistry (IHC) nor plasma cell bone marrow infiltration identified CR patients at distinct risk. Patients with sCR had slightly longer progression-free survival. Nevertheless, persistent clonal bone marrow disease was detectable using MFC or NGS and was associated with significantly inferior outcomes compared with MRD-negative cases. Conclusion Our results confirm that sCR does not predict a different outcome and indicate that more sensitive techniques are able to identify patients with differing prognoses. We suggest that MRD categories should be implemented over sCR for the future classification of MM responses.