Chromosomal abnormality variation detected by G‐banding is associated with prognosis of diffuse large B‐cell lymphoma treated by R‐CHOP‐based therapy

Diffuse large B-cell lymphoma (DLBCL), which is the most prevalent disease subtype of non-Hodgkin lymphoma, is highly heterogeneous in terms of cytogenetic and molecular features. This study retrospectively investigated the clinical impact of G-banding-defined chromosomal abnormality on treatment outcomes of DLBCL in the era of rituximab-containing immunochemotherapy. Of 181 patients who were diagnosed with DLBCL and treated with R-CHOP or an R-CHOP-like regimen between January 2006 and April 2014, metaphase spreads were evaluable for G-banding in 120. In these 120 patients, 40 were found to harbor a single chromosomal aberration type; 63 showed chromosomal abnormality variations (CAVs), which are defined by the presence of different types of chromosomal abnormalities in G-banding, including 19 with two CAVs and 44 with ≥3 CAVs; and 17 had normal karyotypes. No specific chromosomal break point or numerical abnormality was associated with overall survival (OS) or progression-free survival (PFS), but the presence of ≥3 CAVs was significantly associated with inferior OS rates (hazard ratio (HR): 2.222, 95% confidence interval (CI): 1.056-4.677, P = 0.031) and tended to be associated with shorter PFS (HR: 1.796, 95% CI: 0.965-3.344, P = 0.061). In addition, ≥3 CAVs more frequently accumulated in high-risk patients, as defined by several conventional prognostic indices, such as the revised International Prognostic Index. In conclusion, our results suggest that the emergence of more CAVs, especially ≥3, based on chromosomal instability underlies the development of high-risk disease features and a poor prognosis in DLBCL.