Inclusion Criteria:

1. - Patient aged 18 years and above,

2. - Patient with invasive breast cancer histologically proven or cytologically proven
by fine needle biopsy,

3. - Patient with a unifocal tumor T0 - T1 - T2 up to 5 cm (clinical or in imagery),
without previous therapy (neoadjuvant chemotherapy or hormone therapy),

4. - Patient with clinical N0 status,

5. - Absence of clinically detectable metastases known,

6- Patients for whom conservative surgery with sentinel lymph node (SLN) technique is
feasible from the start in terms of carcinologic,

7 -All patients with lymph node involvement (GS+), whatever the size of the metastasis
(macro-metastasis, micro-metastasis, cellular cluster or isolated tumor cells),

8 - Patient affiliated to a social security system or benefiting from such a system,

9 - Signed consent to participate.

Exclusion Criteria:

1. - Tumor of more than 5 cm

2. - Indication of neoadjuvant therapy by chemotherapy or hormone therapy

3. - History of breast cancer (ipsilateral, ie recurrence, or contralateral breast)

4. - History of any other invasive cancer other than a past cutaneous cancer correctly
treated

5. - Initial metastatic disease known

6. - Presence of clinical axillary adenopathy

7. - Contra-indication to surgical excision

8. - Contra-indication to the SLN technique

9. - Pregnant women, of child-bearing potential, or lactating women

10- Patient deprived of liberty or under supervision of a guardian

11- Impossibility to undergo medical examinations of the study for geographical, social or
psychological reasons.