Abstract
Composite lymphoma (CL) is rare. We conducted an analysis of 53 329 cases of diffuse large B-cell lymphoma (DLBCL), 17,916 cases of Hodgkin lymphoma (HL), and 869 cases of composite HL and DLBCL from the SEER database diagnosed between 2000 and 2019. Incidence rates showed increasing trends with age for CL and DLBCL, while HL exhibited 2 peak incidence rates: 42.05 (95% CI: 40.88-43.25) per million for the age group 20-24 and 43.20 (95% CI: 41.13-45.35) per million for 75-79. Higher incidence rates were observed in males (CL, 0.68, 95% CI: 0.62-0.74; HL, 29.65, 95% CI: 29.27-30.03; DLBCL, 86.18, 95% CI: 85.51-86.86) compared to females (CL, 0.40, 95% CI: 0.36-0.45; HL, 23.15, 95% CI: 22.83-23.49; DLBCL, 57.56, 95% CI: 57.06-58.06; P < .001). We first identified independent prognostic factors for composite HL and DLBCL, which were used for development of a scoring nomogram. Factors such as primary tumor site, marital status, chemotherapy, and sex predominantly influence short-term survival, while Ann Arbor stage plays a significant role in long-term survival. Furthermore, there were notable differences in demographic characteristics, survival outcomes, and death cause among CL, HL, and DLBCL. This study provides the first comprehensive report of composite HL and DLBCL.