Which of the following facts about ductal carcinoma in situ is incorrect?

a. Ductal carcinoma in situ (DCIS) is a pre-malignant condition. Approximately 40% of DCIS lesions will progress to become invasive breast cancers. As carcinomas in situ they are unable to metastasise. They present in the same way as invasive breast cancers but are more readily picked up on mammography – they account for approximately 25% of all cancers picked up in that way. Management normally involves a wide local excision with possible radiotherapy depending on the clinical decision made at the time of surgery. If the lesion is large axillary node clearance may also be required.