This trial will compare 6 versus 12 months of trastuzumab in combination with dose dense docetaxel following FE75C as adjuvant chemotherapy in women with axillary lymph node positive breast cancer overexpressing HER2

Anthracycline-containing regimens are recommended as adjuvant treatment for women with node positive breast cancer. In at least three large randomized clinical trials the addition or sequential administration of a taxane (paclitaxel or docetaxel) to an antracycline-based regimen resulted in superior clinical outcome for women with node positive early breast cancer. In two large randomized studies the dose dense administration with G-CSF support of anthracycline-based and paclitaxel combination was superior to the same regimen administered every three weeks without growth factors as adjuvant therapy in women with axillary node positive breast cancer. In one randomized trial, docetaxel was proved superior to paclitaxel in women with metastatic breast cancer. Trastuzumab (anti-HER2 monoclonal antibody) in combination with paclitaxel was superior to paclitaxel alone in women with metastatic breast cancer overexpressing HER2

Inclusion Criteria:

• Women with histologically-confirmed unilateral invasive ductal or lobular breast adenocarcinoma
• HER2/c-neu over expression should be documented by either immunohistochemistry (score 3+) or FISH/CISH positivity. A score of 2+ by immunohistochemistry is acceptable only if FISH/CISH positive
• Within 60 days after the surgical excision of the primary tumor with tumor-free operation margins; at least 10 axillary lymph nodes have to be removed.
• Tumor involvement of at least one axillary lymph node (N0 with HER2/c-neu over expression are also eligible)
• Absence of any clinical or radiological evidence of local or metastatic disease
• Premenopausal or postmenopausal women aged 18-75 years old
• Adequate bone marrow function (absolute neutrophil count >1500/mm3, platelet count >100.000/mm3, hemoglobin >10gr/mm3)
• Adequate liver (bilirubin <1.0 times upper limit of normal and SGOT/SGPT <2.5 times upper limit of normal) and renal function (creatinine <1.5mg/dl)
• Adequate cardiac function (LVEF>50%). Normal electrocardiogram and absence of significant heart disease
• Written informed consent

Exclusion Criteria:

• Positive pregnancy test.
• Psychiatric illness or social situation that would preclude study compliance.
• Other concurrent uncontrolled illness.
• Prior or concurrent antineoplastic therapy e.g. hormonal therapy, radiation therapy, chemotherapy, biological agents.
• Previous history of other invasive malignancy other than non-melanomatous skin cancer.