Abstract B94: A10-year retrospective analysis of African American and white patients with diffuse large B cell lymphoma treated at the University of Alabama at Birmingham

Abstract

Abstract Introduction: Diffuse large B cell lymphoma (DLBCL) is the commonest type of NHL and has variable clinical behavior because of distinct molecular signatures that have recently been identified. The treatment of this lymphoma has improved dramatically after the addition of rituximab to the commonly used first line chemotherapy CHOP but there is still a wide variation in response to treatment. Our study aim was to see if race as well as socioeconomic status played a role in diagnosis as well as treatment of this disease. Methods: We performed a retrospective analysis of all patients from 1997-2007 with a biopsy confirmed diagnosis of DLBCL that were treated at the University of Alabama at Birmingham (UAB) and analyzed various factors like age, sex, marital status, insurance status, Stage, B symptoms, extranodal sites, ECOG performance status (PS), type of treatment and survival after stratifying them by reported race as either white or African American(AA). We excluded patients that had evidence of transformation or mixed histology or incomplete information about demographics or treatment. Results: A total of 292 patients met the inclusion criteria.10 patients with race reported as ‘Other’ were further excluded. A total of 282 patients were analyzed out of which 240(85%) of patients were white and 15% of patients were AA. Of note, Jefferson County where UAB is located has an approximately 33% of AA residents. The mean age of diagnosis for AA patients was lower at 48 yrs as compared to 52 yrs for white patients (p=0.01). AA patients were more likely to be uninsured (5%) as opposed to white patients (3%)(p=0.02). AA patients seemed to have an inferior performance status (PS) at presentation with only 57% presenting at with an ECOG PS of 0-1 as compared to 73% of white patients.(p<0.001). They also seemed presented at a later stage of the disease.31% presented at Stage I/II vs 34% of white patients (p<0.012) with correspondingly higher LDH values (50% with values greater than upper limit of normal compared to 37% of White patients, p=0.024). There was no significant difference in the type of first chemotherapy regimen that both groups received with approximately similar proportions receiving CHOP (42% of white patients vs 35% of AA patients) or R-CHOP(35% of white patients vs 44% of AA patients). The median survival for AA patients was 2 years as compared to 3 years in the white patients but this was not statistically significant (p=0.2). In conclusion, DLBCL is a heterogeneous disease with distinct molecular subtypes that have been recently identified. Our single institution 10-year analysis shows that a significantly greater proportion of AA patients appear to present at a younger age, with more advanced disease but do not seem to have a significant difference in overall survival. We hypothesize that these findings may be due to socioeconomic status as well as inherent differences in the biology of the tumor. There is a well documented decreased incidence of various B cell NHL in the African American population and this is confirmed in our analysis with only a 15% incidence of DLBCL even in a county with a higher percentage of AA residents. These observations can help guide further research into identifying the different molecular subtypes of DLBCL in various ethnic populations and help us develop more targeted therapy for this disease. Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):B94.