PB1805 SURVIVAL OF EXTRANODAL LARGE B CELL LYMPHOMA. THE EXPERIENCE OF ONE CENTER IN MEXICO CITY
Authors: Rojas Zaldivar E. , Aguirre Reyes O. , Altamirano Solórzano G.A. , Rivas Vera S. , Ramírez Ibarguen A.F. 
Published: June 2019

Background:Diffuse large B cell lymphoma (LDCGB) is the most frequent subtype of non‐Hodgkin lymphomas, accounting for approximately 30‐40% of cases. Extranodal disease (END) is associated with a poor prognosis, however the epidemiology, impact on treatment response and survival is not described in our population.Aims:Describe the frequency of END, impact on treatment response, overall survival (OS) and event‐free survival (EFS).Methods:Retrospective and longitudinal cohort. It was included patients diagnosed with LDCGB between 2011‐2016. We review the clinical characteristics of the population. Data was analyzed by Chi‐square test (X2) and we used univariate and multivariable Cox regression analysis of overall survival and Kaplan‐Meier survival plotsResults:We analyzed 449 patients with LDCGB. Their clinical characteristics described in table 1 according with the type of involvement as nodal disease (ND), nodal disease plus extranodal (ND+END) and primary extranodal disease (PEND). Of the total population 94% received chemotherapy based on anthracycline (R‐CHOP/R‐EPOCH). The overall response for the entire cohort was 79% (CR 72%, PR 7%). The extranodal involvement was presented as a factor risk for treatment failure (p = 0.03). At 5 years the OS was 66% for the whole cohort. In the univariate analysis ECOG≥2 (p = 0.001), high IPI (p = 0.002), bulky disease (p = 0.01), HIV‐associated infection (p = 0.03), advanced clinical stage (p = 0.01), albumin <4 g/L (p = 0.01) and hemoglobin <10 g/dl (p = 0.02) had a worse prognostic impact. In the multivariate analysis only the bulky disease (p = 0.012, 95% CI 1.08‐1.94) and the ECOG≥2 (p = 0.007, 95% CI 1.1‐2.3) were significant. According to the location, the gut was associated with a shorter survival (median 35 months) compared with the rest of the sites (p = 0.05). The number of extranodal involvement sites had not a prognostic impact. There were no differences observed according to the location in the PEND. At 5 years the OS in ND group was 68%, ND+END 63% and PEND 73% (p = 0.180). The event‐free survival was 57% at 5 years in the all cohort, 69% in ND, 72% in ND+END and 69% in PEND (p = 0.031). In the univariate analysis the elevated LDH (p = 0.026), bulky disease (p = 0.0001), bone marrow infiltration (p = 0.009), ECOG≥2 (p = 0.0001), albumin<4 g/L (p = 0.032), hemoglobin<10 g/dl (p = 0.014), high IPI (p = 0.001) and advance clinical stage (p = 0.0001) had a worse prognostic impact. In the multivariate analysis (Cox regression) bulky disease (p = 0.016, 95% CI 1.0‐1.95), bone marrow infiltration (p = 0.014, 95% CI 1.1‐3.5), ECOG≥2 (p = 0.0001, 95% CI 1.2‐2.4) and advanced clinical stage (p = 0.039, 95% CI 1.01‐2.05) were significant. According to the location, only the genitourinary tract was associated with better EFS (p = 0.026).Summary/Conclusion:In our population, most patients present END at diagnosis and therefore advanced stages, reflecting a late diagnosis. The END was not related with an adverse prognostic. About the location of extranodal involvement, the gut infiltration it was the only location related with a poor overall survival. Related factors with a high tumoral burden as bulky disease, bone marrow infiltration, ECOG≥2 and advance stage were independent factors for OS and EFS.image