Prognostic impact of circulating plasma cells in patients with multiple myeloma: implications for plasma cell leukemia definition

Granell, Miquel; Calvo Gonzalo, Xavier; Garcia-Guiñón, Antoni; Escoda, Lourdes; Abella Monreal, Eugenia; Martínez, Clara M.; Teixidó, Montserrat; Gimenez, Mª Teresa; Senín Magan, Maria Alicia; Sanz, Patricia; Campoy, Desirée; Vicent, Ana; Arenillas Rocha, Leonor; Rosiñol, Laura; Sierra, Jorge; Blade, Joan; Fernández de Larrea, Carlos; GEMMAC (Grup per l’estudi del mieloma i l’amiloïdosi de Catalunya)

doi:http://dx.doi.org/10.3324/haematol.2016.158303

Prognostic impact of circulating plasma cells in patients with multiple myeloma: implications for plasma cell leukemia definition

Citation

Granell M, Calvo X, Garcia-Guiñón A, Escoda L, Abella E, Martínez CM. Et al. Prognostic impact of circulating plasma cells in patients with multiple myeloma: implications for plasma cell leukemia definition. Haematologica. 2017 Jun;102(6):1099-1104. DOI: 10.3324/haematol.2016.158303

Abstract

The presence of circulating plasma cells in patients with multiple myeloma is considered a marker for highly proliferative disease. In the study herein, the impact of circulating plasma cells assessed by cytology on survival of patients with multiple myeloma was analyzed. Wright-Giemsa stained peripheral blood smears of 482 patients with newly diagnosed myeloma or plasma cell leukemia were reviewed and patients were classified into 4 categories according to the percentage of circulating plasma cells: 0%, 1-4%, 5-20%, and plasma cell leukemia with the following frequencies: 382 (79.2%), 83 (17.2%), 12 (2.5%) and 5 (1.0%), respectively. Median overall survival according to the circulating plasma cells group was 47, 50, 6 and 14 months, respectively. At multivariate analysis, the presence of 5 to 20% circulating plasma cells was associated with a worse overall survival (relative risk 4.9, 95% CI 2.6-9.3) independently of age, creatinine, the Durie-Salmon system stage and the International Staging System (ISS) stage. Patients with ≥5% circulating plasma cells had lower platelet counts (median 86×109/L vs 214×109/L, P<0.0001) and higher bone marrow plasma cells (median 53% vs 36%, P=0.004). The presence of ≥5% circulating plasma cells in patients with multiple myeloma has a similar adverse prognostic impact as plasma cell leukemia.