Clinicopathologic features and outcome of extra-nodal diffuse large B-cell lymphoma: An institutional experience from North India.

Abstract

e20079 Background: Primary extranodal diffuse large B cell lymphoma (DLBCL) forms upto 40-50% of all cases of DLBCL . Clinicopathological features and outcome of extranodal DLBCL patients especially in the rituximab era are scarce from developing countries. Methods: We carried out an ambispective analysis of newly diagnosed DLBCL patients (n = 417) over a period of 5 years (2014-2018).Of this total cohort 224 (53.7%) were found to have primary or predominant extranodal involvement. Prognostic factors were identified using Cox-regression analyses. Results: Median age was 50 years (18-86) with male female ratio of 2:1. B symptoms were seen in 48% patients and bulky disease in 39%. ECOG performance status of 0 or 1 was present in 50% and 63% presented with advanced disease. Bone was the most common site of extranodal involvement (32%) in our study followed by gastrointestinal tract ( 30%).Cell of origin (based on Hans algorithm) was available in 80% patients with Germinal center subtype (GCB) forming 44% and non-GCB forming 36% of all patients. Bone marrow involvement was present in 13 % patients. Low risk International Prognostic Index (IPI) was seen in 32 % and 41% were having intermediate risk IPI, the remaining being high risk. CHOP based treatment was used in 80 % of cases and rituximab was used in 76% of all cases. The overall response rate was 76% with a complete response rate (CR) of 65.5%. Presence of B-symptoms, central nervous system (CNS) involvement, non R-CHOP regimen and non-radiotherapy treatment protocols were associated with inferior CR rate. After a median follow up of 26 months, the 3-year event free survival and overall survival were 65 % and 82.7 % respectively. Involvement of specific extranodal sites (kidney, adrenals and CNS), high IPI score and use of non R-CHOP regimens were associated with poor EFS and OS on multivariate analysis Conclusions: This is one of the largest studies from India on extranodal DLBCL in the rituximab era. Involvement of specific extranodal sites, high IPI score and use of non R-CHOP regimens were associated with inferior survival.