Abstract
OBJECTIVES: In women with ovarian cancer, tumor features largely determine serum HE4 and CA125 levels, but non-tumor factors may also influence levels and be better understood by studying determinants in a well-characterized sample of women without cancer. METHODS: Serum HE4 and CA125 were measured in 2302 women from the 2001-2002 cohort of the National Heath and Nutritional Survey (NHANES). Publicly-available data on this cohort included demographic/reproductive variables, blood counts, and measurements of C-reactive protein (CRP), total homocysteine (tHcy), cotinine, and creatinine which were examined as predictors of HE4 and CA125 using multivariate models and correlational analyses. RESULTS: HE4 increased non-linearly by age and current smokers had higher HE4. CA125 was lower in postmenopausal women and non-whites and trended downward with increasing BMI. Current-users of oral contraceptives (OCs) had lower HE4 and CA125; and a downward trend for CA125 was seen with increasing OC use. Pregnant women had higher CA125 and nursing women higher HE4. HE4 and CA125 were positively correlated with neutrophils, monocytes, and the neutrophil-to-lymphocyte ratio and inversely correlated with lymphocytes and the lymphocyte-to-monocyte ratio. CRP was positively correlated with both HE4 and CA125 in postmenopausal women. Strong positive correlations existed for HE4 with both tHcy and creatinine. CONCLUSIONS: Serum levels of HE4 and CA125 are influenced by several hormonal or environmental stimuli which affect non-cancerous tissues normally expressing HE4 or CA125. Cytokine co-expression in those tissues may, in turn, affect white cell counts and account for their correlation with HE4 or CA125 levels.