Factors influencing serum CA125II levels in healthy postmenopausal women

Our objective was to identify factors that correlate with CA125 concentrati ons in healthy postmenopausal women and to introduce recommendations for re porting and interpreting individual CA125 assay results. We analyzed repeat ed serum CA125 levels, as measured by the CA125II assay, in 18,748 postmeno pausal women who participated in the St. Bartholomew's/Royal London Hospita l Ovarian Cancer screening trial from 1986 to 1994 and were not diagnosed w ith ovarian cancer during the l2-year follow-up period. We found that race is a substantial predictor of normal levels of CA125, with average CA125II concentration from African (median, 9.0; 95% range, 4.0-26.0 units/ml) and Asian women (median, 13.0; range, 5.9-33.3 units/ml) lower than that in Cau casian women (median, 14.2; range, 6.0-41.0 units/ml; P < 0.001). Women wit h a hysterectomy have lower CA125II values (median, 13.6; range 5.5-39.0 un its/ml; P < 0.001), and women with a prior cancer diagnosis other than ovar ian cancer have higher levels of CA125 II (median, 16.0; range, 6.0-49.0 un its/ml; P < 0.003), Regular smoking and caffeine consumption decrease CA125 levels (P < 0.001). A woman's age, age at menarche, age at menopause, and history of a previous ovarian cyst (P < 0.05) are also predictive of baseli ne CA125 levels. Parity, history of hormone replacement therapy or unilater al oopherectomy, and previous use of oral contraceptives or talcum powder a re not significant predictors of CA125 concentrations (P > 0,05). We conclu ded that clinically significant differences in individual patient character istics need to be reflected in the screening algorithms that use CA125II so that designed performance characteristics (sensitivity and specificity) ar e maintained in practice.