The purpose of this study is to identify patients with persisting tumor cells after standard epirubicin-containing treatment to test a non-cross resistant chemotherapy regimen (docetaxel) for these patients, and to explore the analysis of disseminated tumor cells in bone marrow as a surrogate marker for clinical outcome.

The presence of disseminating (or isolated) tumor cells (DTC/ITC) in bone marrow (BM) after completion of adjuvant chemotherapy for breast cancer is associated with poor prognosis. Methods for detection of DTC have potential as a tool for monitoring occult residual disease during follow up. Also, there exists potent chemotherapy proven to be effective when anthracycline-based chemotherapy fails (f.ex. docetaxel). Consequently, a study has been started to test DTC detection as a surrogate marker for clinical outcome in localized breast cancer patients, selected by the presence of DTC in BM after standard adjuvant chemotherapy, receiving secondary treatment with docetaxel. In brief, patients having received anthracycline-containing chemotherapy for localized breast cancer are candidates. After informed consent and no radiologic signs of distant metastasis, the first BM aspiration is performed at the end of radiotherapy or 8-12 weeks after the last chemotherapy cycle. The next BM aspiration is performed 6 months later. At that time point the BMs are analyzed for the presence of DTC. If DTC are present in the 6 months BM test (the first BM sample is for exploratory research purposes), 6 cycles of docetaxel are administered (3qw), followed by a third and forth BM analysis 1 month and 13 months after the end of chemotherapy. The patients receiving docetaxel with eradication of the DTC will be clinically compared to those with persistence of DTC after docetaxel treatment.

Inclusion Criteria:

1. Breast cancer with node positive disease or high risk node negative disease (pT1c/T2GII-IIIN0, pT3N0, cT3N0). Patients < 35 years with pT1a-bN0G2-3.

2. Primary surgery for breast cancer completed

3. Completed 6 cycles of adjuvant (or neoadjuvant) chemotherapy containing anthracycline

4. Age ≥ 18 and < 70 years

5. Eastern Cooperative Oncology Group or WHO performance status < 2

6. Written informed consent prior to beginning protocol specific procedures

7. Laboratory requirements (within 5 weeks prior to end of radiation treatment or within 5 weeks prior to completion of baseline examinations):

   Neutrophils ≥ 1.1 10^9/l, Platelets ≥ 100 10^9/l, Hemoglobin ≥ 10 g/dl, ASAT and ALAT ≤ x 2.5 UNL (If ALP > 2.5 ≤ x 5 UNL, then ASAT and ALAT ≤ x 1.5 UNL), ALP ≤ x 5 UNL (If ASAT and ALAT > 1.5 ≤ x 2.5 UNL, then ALP ≤ 2.5 x UNL), Creatinine ≤ 175 umol/l

8. Completed staging analysis including chest X-ray, bone scintigraphy or MRI, liver ultrasound or liver CT scan

Exclusion Criteria:

1. Other (than breast carcinoma) earlier or concomitant carcinoma, except for skin and in situ cervix cancer
2. M1 breast cancer or locoregional recurrence of previously diagnosed breast cancer.
3. Earlier treatment with paclitaxel or docetaxel.
4. Pre-existing motor or sensory neurotoxicity of a severity ≥ grade 2 by NCI criteria (see appendix II)
5. Cardiac disease with symptoms classified as NYHA ≥ 2
6. Definite contraindications for the use of corticosteroids
7. Concurrent treatment with other experimental drugs
8. Concurrent treatment with any other anti-cancer therapy (except for endocrine therapy and trastuzumab)
9. Pregnancy