[Effects of tamoxifen and estrogen replacement therapy on lipid metabolism and some other cardiovascular risk factors. A prospective study in hysterectomised women]

Abstract

Background: The aim of this clinical study was to evaluate the relationship of tamoxifen and the risk factors of cardiovascular disease in hysterectomised women.

Methods: Between 1992 and 1998, 93 women were recruited for a prospective study with follow-up at 0, 12 and 24 months. All women had an increased risk of breast cancer and they were hysterectomised and ovariectomised for a benign pathology. They were divided according to the following categories: Group A was constituted of 26 (28%) symptomatic patients (hot flushes, depression) who had received tamoxifen and oral conjugated estrogens. Group B was constituted of 27 (29%) symptomatic patients who had received tamoxifen and transdermal 17B-estradiol. Group C was constitued of 19 (21%) asymptomatic patients who had received only tamoxifen. Group D (control) was constitued of 21 (22%) asymptomatic patients who had not received any therapy. A venous blood sample for total cholesterol levels (T-C), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), triglycerides (TRG), fibrinogen (FBR), platelets (PLT) and antithrombin III (AT III) was taken during follow-up. ANOVA (repeated measures) was used to assess statistical significance: p<0.05 was considered significant (95% CI).

Results: The patients who received tamoxifen with or without estrogen replacement therapy showed after 24 months, a reduction of T-C, LDL-C and FBR (p<0.01); the HDL-C levels did not vary significantly compared to the control group (p=NS); the 26 patients of group A showed an increase of HDL-C (p<0.02). We reported an increase of TRG in the patients of group A and C (p<0.05); on the contrary, we obtained a significant reduction of TRG (p<0.01) in the patients who received tamoxifen and transdermal 17B-estradiol (group B). There was no interaction on plateled count (p=NS).

Conclusions: These results suggest the administration of tamoxifen in hysterectomised women with a high risk of breast cancer and without climateric symptoms. In these patients, tamoxifen could reduce coronary heart disease and incidence of breast cancer. The symptomatic patients are suggested to receive tamoxifen and transdermal 17B-estradiol because of the better effects on lipid metabolism.