New reference levels for CA125 in pre- and postmenopausal women

Abstract

Objective: CA125 is a glycoprotein commonly produced by the endometrium. Serum CA125 is widely useful as a marker for ovarian cancer screening, with 35 U/mL the generally accepted upper limit of normal. Since CA125 is known to fluctuate with vaginal bleeding and menopausal status, the purpose of this study was to develop different reference ranges for normal women of differing physiologic states. Methods: We retrospectively analyzed 1,407 patients with serum CA125 levels taken at Cleveland Clinic Florida between 1992 and 1997. Patients with obvious elevation of CA125 from gynecologic cancers were excluded. Student t test was used to determine statistical significance. Results: Among 1,407 patients studied, 256 were premenopausal, 46 perimenopausal, 957 postmenopausal, and 148 excluded due to known gynecologic cancers. There was a significant difference between the mean CA125 values of premenopausal (19.3 ± 15.6) and postmenopausal women (11.7 ± 9.2) with P .7 × 10 −6. Among premenopausal women, there was a statistically significant difference between CA125 levels during menses (21.4 ± 19.3) and luteal phase (14.0 ± 9.1) with P = .03. Among the subgroup of postmenopausal women with known bleeding history, the mean CA125 values for women with vaginal bleeding was 12.49 ± 11.5 compared to those without bleeding, 9.62 ± 4.6 ( P = .017). Conclusions: For normal premenopausal women, the overall upper limit of CA125 should be 50 U/mL. However, if menstrual status is known, the upper normals should be: 62 during menses, 51 for proliferative phase, and 32 for luteal phase. For postmenopausal women, the CA125 levels should be no more than 35 for those with vaginal bleeding and 20 for those without bleeding. The stratified CA125 values may help provide more specific ovarian cancer screening.