Analysis of clinical and immunophenotypic features along with treatment outcomes of diffuse large B cell lymphoma patients, based on the involvement of nodal or extranodal primary sites

Abstract

Aims: The aim of the present study was to elucidate the clinical features, immunophenotype and treatment outcomes of diffuse large B cell lymphoma (DLBCL) patients based on the involvement of the primary site i.e. lymph node or specific extranodal sites.

Methods: We analyzed the clinical characteristics, immunophenotype and treatment outcomes of 207 DLBCL patients diagnosed in China between 2007 and 2014 based on the primary site of location.

Results: Based on the involvement of primary site of occurrence, DLBCL cases, were classified into different groups like, lymph node (60 cases, 28.98%), gastrointestinal tract (GI) (53 cases, 25.60%), Waldeyer's ring (WR) (31 cases, 14.97%), gland (25 cases, 12.08%), and other extranodal sites (38 cases, 18.36%). Patients with WR involvement were more frequently associated with early stage disease, favorable performance status, absence of bulky disease, normal LDH and ESR levels, and low- or low/intermediate-risk IPI than the other groups. The proportion of DLBCL patients with germinal center B cell (GCB) phenotype was 56.0% for WR, 46.5% for GI, 34.5% for lymph node, 27.8% for other extranodal sites, and 18.2% for gland (P=0.035). The 5-year overall survival (OS) of the entire patient population was 71.1%, and WR group showed a better outcome than nodal group (84.9% vs. 55.9%, P=0.015). In multivariate analysis, bulky disease, bone marrow infiltration, non-GCB phenotype, intermediate/high- or high-risk IPI and SD/PD/Death after first therapy were identified as independent factors for poor OS, while regular application of rituximab and remission after first therapy were identified as favorable prognostic factors for PFS.

Conclusions: In this study, WR involvement was associated with more favorable clinical & pathological features along with better outcome than nodal lymphoma. The OS and PFS were largely dependent on other prognostic variables such as IPI or immunophenotype instead of the sites of involvement.

Keywords: Diffuse large B cell lymphoma; Extranodal involvement; GCB phenotype; Rituximab; Waldeyer's ring.