This is an open randomized phase III study. The primary objective of this study is to compare FEC adjuvant chemotherapy in operable breast cancer given either as fixed doses calculated according to the patients surface area or with doses adjusted according to leukopenia after course one in order to achieve hematological equitoxicity. The main aim of the study is to test whether chemotherapy dosage aimed at hematological equitoxicity will improve the effect of adjuvant chemotherapy.

Group A, FECStandard(standard FEC) is given 7 courses of 5-fluorouracil-epirubicin (Farmorubicin)-cyclophosphamide with doses based on the patient's surface area. Leukocyte nadir values at day 10, 12 or 13 and 15 are measured. Dose-reductions of one step according to table 8.2.1 are performed in case of leukopenic fever or grade 4 leukopenia.

Group B FECTailored(Tailored FEC) receives course one at identical doses to group A. Leukocyte nadir values at day 10,12 or 13 and 15 are measured. Doses of subsequent courses are adjusted to achieve grade 3 leukopenia (leukocyte nadir 1.0 to 2.0) in patients experiencing only grade 0 to 2 leukopenia after course one.

Dose-reductions of one step according to table 8.2.1 are performed in case of leukopenic fever or grade 4 leukopenia .

Patients achieving only grade 0-2 leukopenia at the first course will be randomized into continued treatment at standard doses (Group A) or to doses tailored to achieve grade 3 leukopenia (Group B). The primary comparisons will be made between these two groups of patients.

Patients with grade 3-4 leukopenia after the first course not be randomized but followed according to the protocol and received treatment as group A, FECStandard.

Inclusion Criteria:

• Node positive or 2) High-risk node negative#
• no major cardiovascular morbidity
• female age 18-60
• ECOG/WHO performance status <1
• histologically proven invasive breast cancer
• written or oral witnessed informed consent according to the local Ethics Committee requirements
• start of adjuvant chemotherapy within 8 weeks after surgery

Exclusion Criteria:

• distant metastases (M1)
• locally advanced cancer
• nonradically operated (positive resection margins)
• pregnancy or lactation
• leukocyte count < 3.5 x109 /l
• platelets < 100 x109 /l
• other serious medical condition
• previous or concurrent malignancies at other sites, except basal cell carcinoma and carcinoma cervicis uteri in situ

Sharing with EBCTCG (Early Breast Cancer Trialists' Collaborative Group).

After 5 years.