Three arm randomized parallel phase II/III study evaluating the efficacy and safety of the combinations Epirubicin and Taxotere (ET), Taxotere and Navelbine (TN) and Navelbine and Epirubicin (EN) as first line therapy in pat. with metastatic breast cancer.

1. Histologically proven breast cancer at first diagnosis. At study entry histological or cytological proof of metastasis is required in case of a single metastatic target lesion.
Female metastatic breast cancer patients
Measurable disease or evaluable disease (bone metastases only allowed).

2. Previous chemotherapy:

Adjuvant: Patients may have had adjuvant and/or neoadjuvant chemotherapy but no more than 240 mg/m² cumulative dose of prior doxorubicin or no more than 450 mg/m² of Epirubicin. Taxanes in adjuvant setting are allowed. However, there must be at least 12 months interval between the end of (neo-)adjuvant chemotherapy and protocol entry. This interval is not required for patients who received non-anthracycline/non-taxane adjuvant and/or neoadjuvant chemotherapy. No previous chemotherapy for metastatic breast cancer is allowed.

3. Previous hormonal treatment:

Previous hormonal treatment is allowed provided discontinuation >4 weeks before start of study treatment.

4. Previous radiation:

Previous radiation therapy may have been given provided it is not the only site to assess response.

5. Age > 18 and < 70 years.

6. WHO performance status 0, 1 or 2.

7. Laboratory requirements:

a. Hematology : White blood cell count > 3.0 x109/l (if WBC < 3.0 x 109/l, Neutrophils should be > 1.5 x 109/l)Platelets > 100 x 109/lHemoglobin > 10 g/dl (> 6.2 mmol/L).

b. Hepatic functionTotal bilirubin < 1.00 times the upper-normal limits of the institutional normal values.ASAT (SGOT) and/or ALAT (SGPT) < 2.5 UNL, alkaline phosphatase < 5 UNL (unless bone metastasis are present in the absence of any liver disorders). NB: Patients with ASAT and/or ALAT > 1,5 UNL associated with alkaline phosphatase > 2.5 UNL are not eligible for study.

c. Renal function : Serum creatinine < 80 µmol/lIf serum creatinine > 80 µmol/l, calculated creatinine clearance (Cockroft Gould) should be > 60 ml/min.

8. Normal left ventricular ejection fraction (LVEF) or superior to the lower limits of the institution (determined by either MUGA scan or ultrasound methods).

9. Patients must be accessible for treatment and follow-up.

10. Measurability of the disease and evaluation of response according to RECIST criteria.

11. Complete initial work-up within 3 weeks prior to first infusion.

12. Written informed consent.

1. Prior chemotherapy for metastatic disease.

2. Locally advanced inoperable breast cancer (Stage III B) as only manifestation of the disease.

3. Non-measurable disease.

4. Pregnant or lactating women or women of childbearing potential not using adequate contraception.

5. History of prior malignancies (other than non melanoma skin cancer or excised cervical carcinoma in situ).

6. Clinical evidence of cerebral metastasis.

7. Symptomatic peripheral neuropathy > grade 2 according to the NCI Common Toxicity Criteria.

8. WHO PS>2.

9. Concurrent treatment with other experimental drugs. Participation in another clinical trial with any investigational drug within 30 days prior to study screening.

10. Concurrent treatment with any other anti-cancer therapy except for concomitant treatment with bisphosphonates, provided that bone metastases are not the only evaluable lesions for response to therapy (see measurability of disease and evaluation of response).