Multiparameter Flow Cytometric Remission Is the Most Relevant Prognostic Factor for Multiple Myeloma Patients Who Undergo Autologous Stem Cell Transplantation
Blood. 2008 Nov 15;112(10):4017-4023, B Paiva, M-B Vidriales, J Cerveró, G Mateo, JJ Pérez, MA Montalbán, A Sureda, L Montejano , NC Gutiérrez, A García de Coca, N de las Heras, MV Mateos, MC López-Berges, R García-Boyero, J Galende, J Hernández, L Palomera, D Carrera, R Martínez, J de la Rubia, A Martín, J Bladé, JJ Lahuerta, A Orfao, JF San Miguel, on behalf of the GEM/PETHEMA cooperative study groups
Minimal residual disease (MRD) assessment is standard in many hematologic malignancies but is considered investigational in multiple myeloma (MM). We report a prospective analysis of the prognostic importance of MRD detection by multiparameter flow cytometry (MFC) in 295 newly diagnosed MM patients uniformly treated in the GEM2000 protocol VBMCP/VBAD induction plus autologous stem cell transplantation (ASCT).
MRD status by MFC was determined at day 100 after ASCT. Progression-free survival (PFS; median 71 vs 37 months, P < .001) and overall survival (OS; median not reached vs 89 months, P = .002) were longer in patients who were MRD negative versus MRD positive at day 100 after ASCT. Similar prognostic differentiation was seen in 147 patients who achieved immunofixation-negative complete response after ASCT. Moreover, MRD− immunofixation-negative (IFx−) patients and MRD− IFx+ patients had significantly longer PFS than MRD− IFx+ patients. Multivariate analysis identified MRD status by MF Cat day 100 after ASCT as the most important independent prognostic factor for PFS (HR = 3.64, P = .002) and OS (HR = 2.02, P = .02). Our findings demonstrate the clinical importance of MRD evaluation by MFC, and illustrate the need for further refinement of MM response criteria.