Authors: E. Arranz, H. Sarmiento Palao, V. Díaz Rodriguez, F. López Castaño, F. García Prieto, O. Alda, P. Piñero, P. Manresa Manresa, B. Villarrubia, C. García Hernandez, M. Jiménez Esteso, S. Sanchez Sanchez, M. Blanes, T. Lopez Cedeño, V. Castaño, C. Fernandez, P. Beneit, K. Javier, C. Amorós, L. Blazquez Izquierdo, S. Martinez Cañabate, F. Tarin Rodrigo
Published: 2019-06-17
DOI: 10.1097/01.hs9.0000566868.23509.f8
Source: Full article
Background:Plasma cell proliferative index (PCPI) is an easily available prognostic parameter as well as a reliable progression indicator in multiple myeloma (MM). Despite this, there are no data regarding the utility of PCPI as a routine indicator to predict the response to second‐line lenalidomide based treatments.Aims:Study of theprognostic value of PCPI in patients with relapsed MM treated with lenalidomide/dexamethasone (len/dex) compared to other available indicators (International Staging System disease stage, high risk cytogenetics, serum albumin, LDH, β2‐microglobulin, depth and duration of the previous response) as well as to immunophenotypic features.MethodsStudy design: Observational retrospective study in a cohort of 108 patients with relapsed MM treated with len/dex (Jun 2014‐Dec 2018). The median age was 69.7 years (range, 44 to 90) with 55 males and 53 females. Study variables: Immunophenotype, PCPI and genetics using fluorescent in situ hibridation were performed in bone marrow specimens before the start of len/dex. Responses to len/dex were evaluated after 6 cycles, also recording time to progression. The primary efficacy endpoint was the progression‐free survival (PFS), and secondary efficacy endpoints included overall response rate (ORR) and rates of very good partial response or better (CR + VGPR). Flow‐cytometry: Flow cytometer FACSCanto II, BD CA was used. Study of PCPI (percentage of plasma cells in S‐phase) was performed using a single propidium iodide/CD138 BV421 double‐staining technique (fig 1‐A). Plasma cell subclones were identified using two specifically designed 8‐color combinations as previously described. Statistical methodology: χ2