BackgroundOvarian cancer screening in BRCA1/2 mutation carriers utilizes assessment of carbohydrate antigen 125 (CA125) and transvaginal ultrasound (TVU), despite low sensitivity and specificity. We evaluated the association between CA125 levels, BRCA1/2 mutation status and menopausal status to provide more information on clinical conditions that may influence CA125 levels.MethodsWe retrospectively analyzed repeated measurements of CA125 levels and clinical data of 466 women at high risk for ovarian cancer. CA125 levels were compared between women with and without deleterious mutations in BRCA1/2. Pearson's correlation was used to determine the association between age and CA125 serum level. Differences in CA125 levels were assessed with the Mann–Whitney U test. The effect of BRCA1/2 mutation status and menopausal status on the change in CA125 levels was determined by Two-factor analysis of variance (ANOVA).ResultsThe CA125 serum levels of premenopausal women (median, 13.8 kU/mL; range, 9.4 – 19.5 kU/mL) were significantly higher than in postmenopausal women (median, 10.4 kU/mL; range, 7.7 – 14.0 kU/mL;p< .001). There was no significant difference in the CA125 levels of BRCA mutation carriers and non-mutation carriers across all age groups (p= .612). When investigating the combined effect of BRCA1/2 mutation and menopausal status, variance analysis revealed a significant interaction between BRCA1/2 mutation status and menopausal status on CA125 levels (p< .001). There was a significant difference between the CA125 levels of premenopausal and postmenopausal women, with a large effect in BRCA mutation carriers (p< .001, d = 1.05), whereas in non-mutation carriers there was only a small effect (p< .001, d = 0.32).ConclusionOur findings suggest that hereditary mutations in BRCA1/2 affect the decline of CA125 levels with increasing age. To prove a definite effect of this mutation on the CA125 level, prospective trials need to be conducted to define new cut-off levels of CA 125 in mutation carriers and optimize ovarian cancer screening.