Hispanic Ethnicity Differences in Birth Characteristics, Maternal Birthplace, and Risk of Early-Onset Hodgkin Lymphoma: A Population-Based Case-Control Study

Background: Hispanic ethnicity differences in the risk of early -onset Hodgkin lymphoma diagnosed at < 40 years are understudied. We conducted a population-based case-control study to evaluate associations between birth characteristics and early-onset Hodgkin lymphoma with a focus on potential ethnic differences. Methods: This study included 1,651 non-Hispanic White and 1,168 Hispanic cases with Hodgkin lymphoma endorsing a range of races diagnosed at the age of 0 to 37 years during 1988-2015 and 140,950 controls without cancer matched on race/ethnicity and year of birth from the California Linkage Study of Early-Onset Cancers. OR and 95% confidence intervals (CI) were estimated from mul-tivariable logistic regression models. Results: Having a foreign-born mother versus a United States- born mother (i.e., the reference group) was associated with an increased risk of early-onset Hodgkin lymphoma among non -Hispanic Whites (OR = 1.52; 95% CI, 1.31-1.76; P < 0.01) and a decreased risk among Hispanics (OR = 0.78; 95% CI, 0.69-0.88; P < 0.01). Among both race groups, risk of early-onset Hodgkin lymphoma increased with birthweight and maternal age (all Ptrends < 0.01). Among non-Hispanic Whites, each 5-year increase in maternal age (OR = 1.11; 95% CI, 1.04-1.18; Ptrend < 0.01) and paternal age (OR = 1.07; 95% CI, 1.02-1.13; Ptrend < 0.01) was associated with increased risk of early-onset Hodgkin lymphoma. Compared with female Hispanics, male Hispanics had an increased risk of early-onset Hodgkin lymphoma (OR = 1.26; 95% CI, 1.12- 1.42; P < 0.01). Conclusions: Maternal birthplace may play a role in risk of early -onset Hodgkin lymphoma that differs by ethnicity. Impact: The ethnic differences observed between certain birth characteristics, maternal birthplace, and early-onset Hodgkin lym-phoma raise questions about the underlying biological, generational, lifestyle, residential, and genetic contributions to the disease.