Survival of patients with transformed follicular lymphoma in the United States: a multiple cohort study

Population-based data comparing the outcomes of patients with transformed follicular lymphoma (t-FL) and de novo diffuse large B-cell lymphoma (DLBCL) are lacking. The objective of this study was to compare the survival of patients with t-FL and de novo DLBCL diagnosed in the United States between 2010–2018. We hypothesized that patients with t-FL would have an inferior survival compared to patients with de novo DLBCL. The study outcomes were relative survival (RS), overall survival (OS), and lymphoma-specific survival (LSS) compared between t-FL and de novo DLBCL. Flexible parametric survival models were used to estimate the study outcomes. There were 569 cases of t-FL and 44,706 cases of de novo DLBCL. Patients with t-FL had an estimated 5-year RS of 54% [95% confidence interval (CI), 49–59%) compared to 67% (95% CI, 66–67%) for those with de novo DLBCL (adjusted hazard ratio, 1.29; 95% CI, 1.11–1.50; P = 0.001). The corresponding 5-year OS estimates were 49% (95% CI, 44–53%) and 57% (95% CI, 57–58%), respectively (adjusted hazard ratio, 1.23; 95% CI, 1.07–1.42; P = 0.004). The corresponding 5-year LSS estimates were 54% (95% CI, 50–59%) and 66% (95% CI, 65–66%), respectively (adjusted hazard ratio, 1.34; 95% CI, 1.15–1.56; P < 0.001). This population-based registry analysis shows that patients with t-FL continue to have an inferior survival in the modern era and should be prioritized for enrollment in clinical trials. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40364-023-00525-1.