Inclusion Criteria:

- Adult Females (≥ 18 years), with effective contraception. The contraceptive should
not use estrogen to a derivative. It must be continued during treatment with
tamoxifen for at least two months after his arrest.

- histologically confirmed diagnosis of invasive breast cancer, previously untreated.
Patients have been supported for a breast cancer may be included if a period of at
least 2 years between the last systemic treatment of inclusion in the study.

- Primary tumor hormonopositive: ER and / or PR ≥ 50% by immunostaining with an HR for
Allred score> or = 3

- lack of HER2 overexpression

- palpable primary tumor or greater than or equal to 20 mm in diameter, measured by
ultrasound

- readily operable tumor

- No metastases

- Clinical Stage M0

- performance index ≤ 1 (OMS)

- Polynuclear > or = 1500 / mm3, Hb Platelets > or = 100 000/mm3 Hb ≥10 g/dL

- normal liver function: bilirubin ≤ 1.5 x ULN, aspartate aminotransferase (AST) and
alanine aminotransferase (ALT) ≤ 2.5 x ULN (≤ 5 x ULN if liver metastases).

- Normal renal function (creatinine ≤ 1.5 mg / dL or creatinine clearance ≥ 60 mL /
min)

- cardiac function (MUGA scan or ultrasound February> 55%) and lung function, 5.2.2
Criteria related to participation in the study:

- Patient affiliated to social security, Patient has signed and dated consent

Exclusion Criteria:

- Alcohol Consumption

- Pregnancy, Breastfeeding

- Smoking

- Use of St. John's Wort (herbal tea ...) within 5 days before starting treatment

- Consumption of grapefruit juice in the last 5 days of starting treatment

- congenital galactosemia

- malabsorption glucose and galactose

- lactase deficiency

- Co-medications that may interfere with cytochrome P450:

- enzyme inducers in progress:

- Antiepileptic drugs: carbamazepine, phenobarbital, phenytoin

- Antinfectieux: rifampin, rifabutin, névrirapine, griséofilvine, efavirenz

- Enzyme Inhibitors in progress:

- Inhibitors of serotonin reuptake: fluoxetine, paroxetine

- Thioridazine. Quinidine

- Amiodarone

- Ca antagonists: diltiazem, verapamil

- azole antifungals ketoconazole, fluconazole, miconazole. No protease inhibitors:
ritonavir, nelfinavir, amprenavir, indinavir.

- Macrolides: erythromycin, clarithromycin, josamycin