ductal carcinoma in situ (DCIS)

A 45-year-old woman with a suspicious breast mass on mammography undergoes a biopsy, which confirms invasive ductal carcinoma. She is referred to an oncologist for further management. What is the next step in her management?

A 50-year-old woman with a breast lump undergoes a mammogram, which shows microcalcifications. A core biopsy confirms ductal carcinoma in situ (DCIS). What is the most appropriate next step?

Mrs. Eleanor Vance, a 62-year-old retired teacher, presents for her routine biennial screening mammogram through the BreastScreen Australia program. She has no personal history of breast disease, and her family history is negative for breast or ovarian cancer in first-degree relatives. She is otherwise healthy, with a history of diet-controlled type 2 diabetes and osteoarthritis managed with paracetamol. She denies any breast pain, lumps, nipple discharge, or skin changes. Her last mammogram two years ago was reported as normal (BIRADS 1). Physical examination of both breasts and axillae is unremarkable. The current screening mammogram is performed. The image provided is a magnified view from the craniocaudal projection of the left breast, specifically highlighting an area that has been flagged for further assessment by the reporting radiologist due to a change from the previous study. Assuming that subsequent investigation of the area highlighted in the image confirms a diagnosis of ductal carcinoma in situ (DCIS) and the patient undergoes breast-conserving surgery, which of the following factors is most important in determining the need for adjuvant radiotherapy?