Study Rationale: an accurate breast cancer staging has a great impact in the management of a breast cancer. MRI is considered as the most sensible exam for this staging. However it has a low specificity and it may result in extra testing and stress for the patient, add to costs, and delay treatment. By contrast, Tomosynthesis is performed during the same time than mammography and has a good specificity. Although this modality is very promising, it has not been assessed in a population of consecutive patients.

Study objectives: To compare the diagnostic performance of preoperative bilateral Combo mode (MG+Tomosynthesis) versus mammography among women with breast cancer for the detection of additional multifocal, multicentric, and contralateral cancers.

Inclusion Criteria:

• Women at least 40 years old
• Subject with a new lesion recommended for biopsy, whatever the modality which detected the lesion (clinical examination, mammography, tomosynthesis, US, or MRI)

Exclusion Criteria:

• Subjects with BRCA mutation or at high genetic risk
• Subjects who have breast implants
• Personal history of breast cancer
• Subjects who are pregnant or who think they may be pregnant
• Subjects who are breast-feeding
• Subjects who are unable or unwilling to tolerate study constraints
• Subjects unable or unwilling to undergo informed consent
• Subject with no rights from the national health insurance programme