The persistence of immunophenotypically normal residual bone marrow plasma cells at diagnosis identifies a good prognostic subgroup of symptomatic multiple myeloma patients.
Multiparameter flow cytometry immunophenotyping allows discrimination between normal (N-) and myelomatous (MM-) plasma cells (PCs) within the bone marrow plasma cell compartment (BMPCs). Here we report on the prognostic relevance of detecting more than 5% residual normal plasma cells from all bone marrow plasma cells (N-PCs/BMPCs) by multiparameter flow cytometry in a series of 594 newly diagnosed symptomatic MM patients, uniformly treated according to the Grupo Español de MM 2000 (GEM2000) protocol. Our results show that symptomatic MM patients with more than 5% N-PCs/BMPCs (n = 80 of 594; 14%) have a favorable baseline clinical prospect, together with a significantly lower frequency of high-risk cytogenetic abnormalities and higher response rates. Moreover, this group of patients had a significantly longer progression-free survival (median, 54 vs 42 months, P = .001) and overall survival (median, not reached vs 89 months, P = .04) than patients with less than or equal to 5% N-PCs/BMPCs. Our findings support the clinical value of detecting residual normal PCs in MM patients at diagnosis because this reveals a good prognostic category that could benefit from specific therapeutic approaches. This trial was registered at www.clinicaltrials.gov as NCT00560053.
Paiva
Bruno
B
Hospital Universitario de Salamanca, Salamanca, Spain.
Vidriales
Maria-Belén
MB
Mateo
Gema
G
Pérez
Jose J
JJ
Montalbán
Maria Angeles
MA
Sureda
Anna
A
Montejano
Laura
L
Gutiérrez
Norma C
NC
García de Coca
Alfonso
A
de las Heras
Natalia
N
Mateos
Maria Victoria
MV
López-Berges
Maria Consuelo
MC
García-Boyero
Raimundo
R
Galende
Josefina
J
Hernández
Jose
J
Palomera
Luis
L
Carrera
Dolores
D
Martínez
Rafael
R
de la Rubia
Javier
J
Martín
Alejandro
A
González
Yolanda
Y
Bladé
Joan
J
Lahuerta
Juan José
JJ
Orfao
Alberto
A
San-Miguel
Jesús F
JF
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols; D001854:Bone Marrow Cells / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D005434:Flow Cytometry; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D016130:Immunophenotyping; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D010950:Plasma Cells / Q000473:pathology*; D011379:Prognosis