Impact of Bone Marrow Evaluation Using Bone Marrow Biopsy, Flow Cytometry, and PET/CT in B-Cell Non-Hodgkin Lymphomas

• Published in: Blood 2024-11, Vol.144 (Supplement 1), p.4401-4401
• Main Authors: Sánchez Salas, José Antonio, Ruiz Ruiz, Estela, Cascales Hernandez, Almudena, Gomez Espuch, Joaquin, Poveda Garcia, Andrea, Heredia Cano, Angela, Blanquer Blanquer, Miguel, Garay, Maria Carmen GARCIA, Martinez Mellado, Antonio Jose, Minguela Puras, Alfredo, Bas Bernal, Agueda, Roldan Schilling, Vanessa, Salar Silvestre, Antonio
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2024-208744

Introduction The initial evaluation and staging of non-Hodgkin lymphomas (NHL) are currently conducted according to the Lugano classification (2014). The incorporation of PET/CT and other techniques such as flow cytometry (FCM) and molecular studies into routine clinical practice has recently questioned the utility of bone marrow biopsy (BMB) in the initial work-up of NHL. Our study aimed to evaluate bone marrow (BM) involvement through BMB and FCM, and also by PET/CT in patients with B-cell NHL. We assessed the impact of each method on lymphoma staging and their ability to discriminate progression-free survival (PFS) and overall survival (OS). Material and Methods This observational retrospective study consecutively included all patients with B-cell NHL of any histological type who underwent BM evaluation between 2019 and 2023 at a single tertiary hospital. Inclusion criteria were: > 18 years, B-cell NHL and BM evaluation through aspiration/trephine biopsy at diagnosis at our center. Diagnoses were grouped into indolent NHL (follicular lymphoma (FL), marginal zone lymphoma (MZL), or other indolent lymphomas) or aggressive NHL (diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), or other aggressive lymphomas). The Ann Arbor (AA) stage was initially defined based on clinical and imaging findings by PET/CT without considering BM (AA-baseline), and subsequently incorporating BMB (AA-BMB), FCM (AA-FCM), and PET/CT considering BM findings (AA-PET). FCM was performed in BM aspirate according to EuroFlow based methods (at least eight colors) resulting in a general sensitivity between 10-3 and 10-4. Concordance Index (C-Index), Akaike Information Criterion (AIC), and estimated concordance probability (CPE) were used to evaluate discrimination for PFS and OS. Results A total of 224 patients were identified, of whom 134 (59%) met the inclusion criteria. The median age was 64 years (range 19-91) with 65.1% being male. Of the total number of patients, 219 (97.8%) were caucasian, 4 (1.8%) were arab, and 1 (0.4%) was black. Histologies were as follows: FL 25.4%, MZL 19.4%, other indolent NHL 2.2%, DLBCL 41.8% and MCL 11.2%. BMB was performed in 85.2%, CFM in 95.5% and PET/CT in 83.9%. A total of 123 patients (91.8%) received treatment: 21 (15.7%) rituximab monotherapy, 77 (57.5%) rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), 15 (11.2%) R plus other chemotherapy combinations, 2 (1.5%) radiotherapy (RT), and 8 (5.9%) other