This study is to evaluate the effects of continuously combined 17b-estradiol/dydrogesterone in comparison with tibolone on the breast metabolic markers, in particular the total insulin-like growth factor-1 (IGF-1), in postmenopausal women.

Inclusion Criteria:

• Natural or surgical postmenopausal amenorrhea since ≥ 12 months,
• non hysterectomized women, complaining of at least 14 hot flushes per week

Exclusion Criteria:

• Known, suspected or history of breast cancer or hormone-dependent neoplasia,
• undiagnosed genital bleeding,
• venous or arterial history or presence of thromboembolism,
• cerebrovascular disease