Due to rare patient population, planned number of patients could not be recruited in a reasonable timeframe. Recruitment was stopped prematurely.

Breast cancer and osteoporosis are two of the most frequent diseases in women. Estrogen may be associated with bone loss and the risk of breast cancer because of its potent effects on the mitotic activity of breast epithelium and on bone turnover.

This study is will assess the safety and efficacy of Zoledronic acid 4 mg, given every 3 months over 24 months, in improving bone mineral density in premenopausal women with hormone receptor negative breast cancer and adjuvant chemotherapeutic treatment compared to placebo.

This study is not recruiting patients in the United States.

Inclusion Criteria:

• Female patients with histologically confirmed incident invasive breast cancer (T1-4) with no evidence of regional lymph node metastasis (N0) or distant metastasis (M0) and after complete primary tumor resection and axillary lymph node dissection less than 90 days before start of study drug treatment.
• Hormone receptor status is negative
• Patient is premenopausal (spontaneous and regular menses with premenopausal estradiol levels (>10ng/dL)
• Patient receives adjuvant standard chemotherapy with approved cytotoxic chemotherapeutic drugs (e.g. AC 4-6 cycles) (prior neoadjuvant CT is allowed)
• Bone density at study entry > -2.5 T-Score

Exclusion Criteria:

• Prior treatment with bisphosphonates and estrogens or treatments for osteoporosis in addition to calcium and vitamin D
• Severe physical or psychological concomitant diseases and other known concurrent, severe medical disorder jeopardizing the life of the patient in the immediate future (e.g., myocardial infarction in previous six months, angina pectoris despite treatment, uncontrolled severe arterial hypertension, progressive cardiac or respiratory failure)
• Known hypersensitivity to bisphosphonates
• Abnormal renal function
• Current active dental problems including infection of the teeth or jawbone (maxilla or mandibular); dental or fixture trauma, or a current or prior diagnosis of osteonecrosis of the jaw (ONJ), of exposed bone in the mouth, or of slow healing after dental procedures and recent (within 6 weeks) or planned dental or jaw surgery (e.g. extraction, implants)