Hodgkin lymphoma (HL) demonstrates heterogenous histologic findings, clinical presentation, and outcomes. Using the United States Surveillance, Epidemiology, and End Results (SEER) data we examined relationships between patient characteristics, clinical features at diagnosis, and survival in HL patients. From 2000 to 2007, 16,710 cases were recorded in 17 SEER registries. Blacks and Asians had low incidence (black/white incidence rate ratio (IRR) 0.86, P < .01; Asian/white IRR 0.43, P < .01). The bimodal pattern of incidence was less prominent for black males. Asians and Blacks presented at a mean age of 38 years compared to 42 years for Whites (P < .001). Race was a predictor for survival with HR of 1.19 (95% CI 1.11–1.28) for Blacks. Age was the most important predictor of survival (HR for patients ≥45 years 5.08, 95% CI 4.86–5.31). These current patterns for presentation and outcomes of HL help to delineate key populations in order to explore risk factors for HL and strategies to improve treatment outcomes.

Epidemiological studies suggest unique occurrence patterns of Hodgkin lymphoma (HL) worldwide. In most Western countries there is a clear bimodal age distribution with an early peak in young adults followed by a second peak in older adults, particularly among males. In the Middle East and Asia, HL is more common in early childhood. There also are marked racial differences in the presentations of HL and HL subtypes, and particular single nucleotide polymorphisms (SNPs) have been identified as etiological factors suggesting that gene-gene and gene-environment interactions are involved. Personal health choices such as exercise and smoking may modify an individual's chances of developing HL. Numerous studies highlight the impact that exposure to Epstein-Barr virus and other environmental factors have on HL risk. Understanding the relative importance of each of these findings and their links to HL development and survival will help clinical researchers expand curative therapies and create preventative strategies for HL.

Follicular lymphoma (FL) is an indolent malignancy of germinal center B cells with varied incidence across racial groups and geographic regions. Improvements in the classification of non-Hodgkin lymphoma subtypes provide an opportunity to explore associations between environmental exposures and FL incidence. Our paper found that aspects of Western lifestyle including sedentary lifestyle, obesity, and diets high in meat and milk are associated with an increased risk of FL. Diets rich in fruits and vegetables, polyunsaturated fatty acids, vitamin D, and certain antioxidants are inversely associated with FL risk. A medical history of Sjogren's syndrome, influenza vaccination, and heart disease may be associated with FL incidence. Associations between FL and exposure to pesticides, industrial solvents, hair dyes, and alcohol/tobacco were inconsistent. Genetic risk factors include variants at the 6p21.32 region of the MHC II locus, polymorphisms of the DNA repair gene XRCC3, and UV exposure in individuals with certain polymorphisms of the vitamin D receptor. Increasing our understanding of risk factors for FL must involve integrating epidemiological studies of genetics and exposures to allow for the examination of risk factors and interactions between genes and environment.