Hodgkin's disease (HD) is a common cancer of young adults for which etiology is far from established, and few novel leads have been identified. Scattered reports have linked HD risk with taller height, heavier weight and less physical activity. Body size and physical activity are believed to affect immune function and hormone regulation, both postulated as relevant to HD etiology, but their impact on HD risk has had very little consideration, especially in women. We propose to examine risk for HD in women associated with body size and physical activity over the life-span to test the hypotheses that: 1) Height in adulthood and relative height in childhood are associated with increased HD risk. 2) Birth weight and weight adjusted for height (body mass index) throughout adulthood are associated with HD risk. 3) Frequency of strenuous physical activity in adolescence and through adulthood is associated with HD risk. We will address these topics in data from detailed in-person interviews collected for a completed population-based case-control study of HD in women that had a high response rate, histologically re-reviewed diagnoses, and nearly complete data on 312 cases and 325 random-digit dialing controls frequency-matched to cases on age and race. With logistic regression, we will compute odds ratios to estimate risk associated with: adult height; relative height at ages 8 and 12; birth weight; weight adjusted for height through adulthood; and frequency of leisure-time strenuous physical activity through adolescence and adulthood and physical activity estimated for the longest-held occupation. All analyses will be adjusted for childhood social class, comorbidities, life-time smoking, and other confounders. We will have very good statistical power to detect odds ratios >=2.0, given likely risk factor prevalences. Interactions will be addressed through stratification of analyses by age group, race, histologic type, and EBV in tumor cells, as numbers permit; interactions between variables measuring childhood exposure and body size and physical activity will be considered in regression models. Study strengths include: 1) examination of under-studied risk factors novel for women; 2) a population basis; 3) strong data quality; 4) good to excellent statistical power; 5) re-reviewed diagnoses; 6) life-time body size and physical activity data; 7) detailed data on confounders. Study weaknesses include: 1) self-reported data; 2) limitation to strenuous leisure-time physical activity; 3) poor statistical power to examine associations in some subgroups; 4) potential recall bias and modest selection bias in controls.
| Keegan, Theresa H M; Glaser, Sally L; Clarke, Christina A et al. (2006) Body size, physical activity, and risk of Hodgkin's lymphoma in women. Cancer Epidemiol Biomarkers Prev 15:1095-101 |
