Recent Survival Trends in Diffuse Large B-Cell Lymphoma (DLBCL)-Did We Make Any Progress Beyond Rituximab?

Background While rituximab revolutionized outcomes in DLBCL, little is known regarding survival improvements at population level beyond the introduction of rituximab. The advent of novel agents, improvements in supportive care and expansion of autologous hematopoietic cell transplantation (auto-HCT) to older individuals may have improved survival of DLBCL patients. We hypothesized that outcomes for patients diagnosed with DLBCL in the U.S. has continued to improve in recent years and intended to measure improvements and identify possible disparities by comparing survival of DLBCL between two consecutive post-rituximab eras. Methods We used the population-based SEER-18 registry to calculate the incidence and relative survival rates (RSR) of DLBCL in the U.S. for two consecutive eras since broad availability of rituximab in upfront DLBCL treatment, 2002-2007 (era-1, early years after adoption of rituximab) and 2008-2013 (era-2, availability of novel agents, broader use of auto-HCT and improvement in supportive care). We included adult patients with microscopically confirmed DLBCL as first malignant neoplasm regardless of histologic subtype and survival follow up to the end of 2015. Results There were a total of 56,625 DLBCL patients diagnosed between 2002 and 2013, of which 27,306 patients were diagnosed during era-1 and 29,319 during era-2. Median follow up of survivors was 125 months in era-1 and 53 months in era-2. The median age at diagnosis was 66 years with slight male predominance in both the eras. There were no differences in age, gender, race/ethnicity and stage characteristics. There was a slight decline in incidence of DLBCL (era-1 vs. era-2), 8.11 (95% CI=8.01-8.2) vs. 7.82 (95% CI=7.73-7.91) cases per 100,000 persons (P