Hodgkin lymphoma incidence in California Hispanics: influence of nativity and tumor Epstein-Barr virus.

PURPOSE

For classical Hodgkin lymphoma (HL), migrant studies could elucidate contributions of environmental factors (including Epstein-Barr virus (EBV)) to the lower rates in non-whites. Given the well-described etiologic complexity of HL, this research requires a large, immigrant population, such as California Hispanics.

METHODS

With 1988-2004 California Cancer Registry data (2,595 Hispanic, 8,637 white HL cases) and tumor cell EBV status on a subset (218 Hispanics, 656 whites), we calculated ethnicity- and nativity-specific HL incidence rates simultaneously by age, sex, and histologic subtype, and tumor cell EBV prevalence.

RESULTS

Compared with white rates, Hispanic HL rates were lower overall (70 %) and for nodular sclerosis HL, particularly among young adults (60-65 % for females). However, they were higher among children (200 %) and older adults, and for mixed cellularity HL. Compared with rates in foreign-born Hispanics, rates in US-born Hispanics were higher among young adults (>threefold in females), lower for children and adults over age 70, and consistently intermediate compared with rates in whites. EBV tumor prevalence was 67, 32, and 23 % among foreign-born Hispanics, US-born Hispanics, and whites, respectively, although with variation by age, sex, and histology.

CONCLUSIONS

Findings strongly implicate environmental influences, such as nativity-related sociodemographic differences, on HL occurrence. In addition, lower young adult rates and higher EBV prevalence in US-born Hispanics than in whites raise questions about the duration/extent of environmental change for affecting HL rates and also point to ethnic differences in genetic susceptibility. Lesser variation in mixed cellularity HL rates and greater variation in rates for females across groups suggest less modifiable factors interacting with environmental influences.