Treatment intensity and survival in patients with relapsed or refractory diffuse large B-cell lymphoma in Denmark: a real-life population-based study

Bente Arboe,1,2 Maja Halgren Olsen,2 Jette Sønderskov Gørløv,1 Anne Katrine Duun-Henriksen,3 Susanne Oksbjerg Dalton,2,4 Christoffer Johansen,2,5 Peter de Nully Brown1 1Department of Hematology, Copenhagen University Hospital, Copenhagen, Denmark; 2Survivorship, The Danish Cancer Society Research Center, Copenhagen, Denmark; 3Statistics and Pharmacoepidemiology, The Danish Cancer Society Research Center, Copenhagen, Denmark; 4Department of Clinical Oncology and Palliative Care Units, Zealand University Hospital, Naestved, Denmark; 5Department of Oncology, Copenhagen University Hospital, Copenhagen, Denmark Purpose: High-dose chemotherapy with autologous stem cell transplantation (ASCT) is considered to be the only curative treatment option for patients with refractory or relapsed diffuse large B-cell lymphoma (DLBCL). Due to toxicity, not all patients are eligible for this treatment leading to different treatment intensities. Here, we aim to analyze the impact of treatment intensity on survival in patients previously treated with rituximab and chemotherapy, and, furthermore, to analyze the association between socioeconomic position and treatment intensity, defined as palliation, non-salvage, and salvage regimens. Materials and methods: We identified patients with refractory or relapsed DLBCL diagnosed in 2000–2015 in the Danish National Lymphoma Registry (n=1,228). We analyzed the impact of treatment intensity on survival in patients previously treated with rituximab (n=277) using a Cox proportional hazards model. Multinomial regression analyses were performed to identify associations between socioeconomic factors and treatment intensity for the entire cohort. Results: In the rituximab era, the 5-year overall survival (OS) was 31% for patients receiving salvage regimens (n=194), and 17% for patients receiving non-salvage regimens (n=83). In the adjusted analysis, HR was 1.88, 95% CI: 0.9–3.9 for patients receiving salvage regimens. Patients living alone were significantly less likely to receive salvage regimens, as were patients with two or more comorbidities.Conclusion: We observed a better OS in patients treated with salvage regimens compared with non-salvage regimens; however, the adjusted analysis contradicts this. Furthermore, our results indicate that there is a chance of remission for patients not eligible for ASCT. Keywords: non-Hodgkin lymphoma, chemotherapy, epidemiology, stem cell transplantation, socioeconomic status, education, incom