Ductal carcinomas in situ (DCIS) of the breast account for 85% to 90% of breast cancer in situ. Current recommendations for the management of DCIS in France are based on surgical excision of the lesions, lumpectomy in healthy margins (margins of excision ≥ 2 mm) or mastectomy in case of extensive lesions. Radiation therapy is recommended after conservative surgical treatment. However, it seems relevant for some patients to discuss the benefit of a therapeutic de-escalation.