Effects of hormone replacement therapy on postmenopausal uterine myoma

Abstract

Objectives: To evaluate the effects of sequential continuous hormone replacement therapy (HRT) on myoma size and on pulsatility index (PI) of uterine arteries and to verify the correlation between uterine artery flow impedance and the growth rate of myoma in women receiving HRT. Methods: In a prospective 1-year study 60 postmenopausal women were enrolled into three study-groups to receive continuous transdermal 17β-oestradiol 0.05 mg/day plus nomegestrolo acetate 5 mg/day sequentially added: 20 patients (group A) unaffected by uterine myomas, 20 patients (group B) with single asymptomatic myoma <3 cm/14 cm 3, 20 patients (group C) with single asymptomatic myoma >3 cm/14 cm 3. The changes in myoma volume and in PI were assessed by means of transvaginal ultrasonographic scan every 3 months. The patients with myoma were divided into two subgroups: quiescent myoma (B1, C1) and growing myoma (B2, C2). Results: No significant increase of uterine fibroids volume was found after 1-year HRT (24.14±20.02→28.81±30.02 cm 3). Six out of eight myomas growing during HRT belonged to group C. The uterine artery basal PI value of group A was significantly higher ( P<0.01) than the corresponding PI in group B and C. At 3 months follow-up, uterine artery PI was significantly higher ( P<0.01) than the basal value in both group B (1.70±0.22→1.88±0.16) and C (1.59±0.28→1.92±0.21). The baseline PI values in group B1 and C1 were significantly higher than the baseline values observed in group B2 and C2 (1.76±0.17 vs. 1.32±0.02, 1.76±0.16 vs. 1.24±0.08) and significantly lower than those observed in group A (2.39±0.47). After 3 months of HRT, the PI values were not significantly higher than the baseline values in groups B1 and C2 (1.76±0.17→1.90±0.17; 1.24±0.08→1.74±0.16), while they were significantly higher in group C1 (1.76±0.16→2.01±0.17). Conclusions: Sequential continuous HRT does not increase the volume of the uterine myoma. The findings of very low resistance index in the uterine arteries of women with growing myoma may indicate the risk of growth of the neoplasia during HRT. The assessment of PI in the uterine arteries could be helpful in predicting the growth rate of the myomas before starting HRT.