When is good enough really good enough? Defining the role of radiation in low-risk ductal carcinoma in situ

A 67-year-old woman undergoing screening mammography was found to have a new focus of clustered microcalcifications at 9 o'clock in the left breast. Magnification views confirmed this focus, which measured 5 mm (Fig 1). Stereotactic core biopsy revealed ductal carcinoma in situ (DCIS), low nuclear grade, and cribriform pattern without necrosis (Fig 2). Subsequent needle-localized segmental mastectomy revealed a 5-mm focus of low-grade DCIS, cribriform type without necrosis, positive for both estrogen receptor and progesterone receptor. Surgical margins were negative at aminimumof 3mm.The patient is healthy without major medical problems but has an elevated body mass index. She is now referred for consideration of adjuvant radiation therapy. Examination shows an excellent cosmetic outcome, D-cup breasts, and a wellhealed curvilinear scar in the medial left breast with minimal underlying postoperative induration.