Effect of hormone replacement therapy on serum levels of tumor markers in healthy postmenopausal women.

Objective: The effect of hormone replacement therapy (HRT) on serum levels of tumor markers is barely defined. The aim of this study was to evaluate the effect of HRT on levels of tumor markers CA 125, CA 15-3, CA 19-9, CEA and alpha-FP.

Methods: Retrospective analysis of prospectively collected data in healthy postmenopausal women under oral estrogen replacement therapy (ERT, conjugated equine estrogen (CEE) 0.625 mg (n = 21) or estradiol 2 mg (n = 31)), and continuous combined estrogen and progesterone regimen (HRT, CEE 0.625 mg plus medroxyprogesterone acetate 2.5 mg (n = 34) or estradiol 2 mg plus norethisterone acetate 1 mg (n = 37)). One hundred and twenty-three healthy women among a sampled population of 654 postmenopausal patients with complete records, initial normal tumor marker levels, and at least 1 year of follow-up were included into the study. Tumor markers were measured with 1-year interval.

Results: Fifty-two (41.5%) patients were under ERT and 71 (58.5%) were under combined HRT. The number of months since menopause, age and age at menopause did not influence tumor marker levels at first admission. All of the tumor marker levels were in normal range after 1 year. Pretreatment CA 125 II, CA 15-3 and CEA levels were significantly low (median and range) 5.0 (1.0-11.8) versus 7.45 (1.0-18.1) U/ml for CA 125, 27.05 (7.3-37.5) versus 32.6 (12.5-37.9) U/ml for CA 15-3, 0.88 (0.58-2.8) versus 1.34 (0.53-2.41) ng/ml for CEA in women with hysterectomy when compared to women without hysterectomy. There was no effect of ERT on CA 125 II, CA 19-9, CEA and alpha-FP levels. E2 led to a significant decrease in post-treatment CA 15-3 levels [32.9 (8.1-34.9) vs. 18.1 (6.7-31.4); P < 0.001]. CA 125 levels were only significantly reduced in hysterectomised women using continuously combined HRT [7.9 (2.6-17.7) vs. 5.6 (1.3-19.2) for CEE+MPA, and 7 (1-18.1) vs. 5.8 (1.8-17.4) for E2 + NETA; P < 0.05]. There was a small, but not significant, increase in CA 125 levels in women under ERT.

Conclusion: Although there was a statistically significant decrease in CA 15-3 levels in current E2 and E2 + NETA users, and a decrease in CA 125 levels in combined regimens, this change is clinically not relevant in healthy postmenopausal women. This data will be useful for the caregivers in the management and follow-up of cancer survivors who preferred replacement therapy as the only treatment of their postmenopausal symptoms.