Difficulty in discerning harmless lesions from potentially invasive ones can lead to overtreatment of this condition in many patients. However, most DCIS lesions remain indolent. Currently, all DCIS lesions are treated, and treatment comprises either mastectomy or breast-conserving surgery supplemented with radiotherapy. Ductal carcinoma in situ (DCIS) now represents 20–25% of all ‘breast cancers’ consequent upon detection by population-based breast cancer screening programmes.
