Inclusion Criteria:

- Histologically confirmed and surgically treated invasive breast carcinoma (T1/2/3
N0/1/2 M0), irrespective of hormonal (estrogen/progestogen) receptor status.

- Last menstrual bleeding at least 12 months before the start of the study or
ovariectomized or hysterectomized or currently being treated with gonadotropin
releasing hormone analogs.

- Vasomotor symptoms whether related to natural menopause, ovariectomy, or to breast
cancer therapy (chemotherapy, tamoxifen, aromatase inhibitors or other anticancer
therapy).

- In subjects with an intact uterus, a 'normal' endometrium, defined as:

1. in tamoxifen users: absence of endometrial polyps

2. in non-tamoxifen users: double layer endometrial thickness <=4 mm as assessed by
TVUS or double layer endometrial thickness >4 mm and <=8 mm as assessed by TVUS
plus an endometrial biopsy result of inactive/atrophic.

- Voluntary written informed consent and willing and able to make reasonable efforts to
meet all clinical trial requirements.

Exclusion Criteria:

- Age >75 years at baseline.

- Ductal carcinoma in situ (DCIS) of the breast without the existence of invasive
breast carcinoma.

- Invasive breast carcinoma having a tumor of any size with direct extension to chest
wall or skin (T4) and/or having metastasis to ipsilateral mammary lymph node(s) (N3)
and/or having presence of distant metastasis (M1).

- Surgical treatment of the primary breast cancer >5 years ago.

- History or presence of residual or recurrent breast cancer.

- History or presence of endometrial cancer.

- History or presence of any other malignancy (besides breast cancer and endometrial
cancer) within the past 5 years, except for adequately treated basal cell carcinoma
of the skin.

- Diagnostic findings suspicious for any malignancy.

- Double layer endometrial thickness >8 mm as assessed by TVUS in subjects not being
treated with tamoxifen.

- Final diagnosis of endometrial biopsy different from inactive/atrophic

- Existence of endometrial polyps as demonstrated by TVUS.

- Undiagnosed vaginal bleeding.

- Abnormal cervical smear (corresponding to PAP IIb or higher)

- Any previous or current unopposed estrogen administration in women with an intact
uterus (occasional use of estrogen-containing vaginal cream was allowed after an
appropriate washout period - see below).

- Use of systemic estrogens and/or progestogens (including intra-uterine progestogen
therapy) and/or tibolone and/or phytoestrogens within 8 weeks prior to baseline; use
of transdermal hormone therapy and/or local estrogen applications and/or non-hormonal
medication for vasomotor symptoms within 4 weeks prior to baseline.

- Use of progestogen implants or injections and/or estrogen/progestogen injectable
therapy within the past 6 months.

- Use of estrogen implants or injections within the past 5 years.

- Use of raloxifene hydrochloride and/or any non-registered investigational drug within
the last 8 weeks.

- Active deep vein thrombosis, thromboembolic disorders, or a documented history of
these conditions.

- Severe liver disorders.

- Abnormal laboratory values considered to be clinically relevant by the investigator.

- Any disease or condition that is clinically relevant and which, in the opinion of the
investigator, would jeopardize the subject's well-being during the course of the
trial.

- Known hypersensitivity to tibolone or any of its components

- Known or suspected pregnancy

- Age <40 years at baseline and planned breast cancer therapy <2 years after baseline