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Breast cancer is considered a systemic disease requiring medical treatment, as surgery is unable to prevent the occurrence of metastasis. Moreover, biological arguments support early treatment to prevent metastasis . Neoadjuvant cytotoxic chemotherapy was initially proposed for non-operable locally advanced breast cancer, and then for operable breast cancer not suitable for breast-conserving surgery, in order to decrease the number of mastectomies. The concept was validated in the NASBP-B18 trial and confirmed by numerous studies. A complete pathological response was associated with better prognosis, allowing this criterion to be used as a surrogate marker for efficacy. In addition, incomplete responses have enabled those at high risk of relapse to be identified and new options to be proposed. Neoadjuvant treatment is currently included in all guidelines.