Pb2095: relapsed and refractory diffuse large b cell lymphoma: experience of a low-income center in time of new drugs

Background: Refractory/relapsed (RR) disease is the main cause of morbidity and mortality in Diffuse Large B cell Lymphoma (DLBCL). Unfortunately, one-third of patients with diffuse large B-cell lymphoma continue on to relapsed or refractory disease despite the improvement of its management. Aims: The aim of this study is to evaluate our management of RR disease in our low-income center in the era of immunotherapy and monoclonal antibodies. Methods: This is a single-center retrospective study. We included all the cases of DLBCL diagnosed in University Hospital of Sfax between 2008-2019 that were refractory and/or relapsed. Clinical and biological characteristics at diagnosis were reported. A second biopsy was indicated in all cases when feasible. Refractory disease was defined as the absence of criteria of remission (complete or partial). Relapse was defined as the appearance of new lesions or the increase of at least 50% from nadir in the SPD from any previously involved site after a complete remission. Early relapse was defined as a relapse happening 12 months after end of treatment. The patients were treated with a second-line platinum based chemotherapy if fit. Autologous stem cell transplantation (ASCT) was indicated for patients who respond to second line treatment (partial or complete remission) and are fit for ASCT. Kaplan Meier system was used to estimate survival. Results: Among the 150 DLBCL diagnosed and treated during the study, 46 (31%) were relapsed/refractory: 13 (9%) were refractory to first line chemotherapy and 33 experienced relapse (22%). At the diagnosis, RR-patients are aged of 60 and less in 69% of the cases. A poor performans status≥2 was found in 30% of the cases. We found raised LDH levels in 53%. The disease was localized in 31%. aaIPI was at a minimum of 1 in 87% of the cases (1: 42%, 2: 24%, 3: 21%). We identified 3 predictive factors of refractory disease: Performans status (p=0,007), aaIPI (p=0,036) and raised LDH (p=0,019). For patients who relapsed, an early relapse was noted in 51,5% of the cases. Five patients relapsed after ASCT. Mean time from diagnosis was 20 months (2-72). Twenty-six patients were eligible for chemotherapy: 20 were treated with DHAP and 6 with ICE regimen. Five patients were in complete remission after salvage chemotherapy and 3 were in partial remission. Only 1 patient underwent ASCT after relapse and 3 patients after refractory disease. 1-year and 5-years Post-RR survival were respectively 24% and 14%. Summary/Conclusion: Even in the Rituximab era, patients continue to experience relapse and refractory disease. Our results are comparable to the literature where one third of DLBCL are either refractory (10-15%) or relapse (20-30%) and most relapses happen within the first 2 years after treatment. Predictive factors of RR identified in our study are the same than the factors reported in the literature in addition to age, B symptoms, advanced stage of the disease and bulk. Post-RR survival was poor in our study as well as in reports from the literature. The poor survival post-RR could be improved with new drugs regrettably not available in our country.