The phrase “high-risk breast pathology” has two meanings. Classically, it refers to specific histologic findings in breast biopsy tissue that portend an increased risk of breast cancer for a woman in the years after the breast biopsy. With the shift in recent years from surgical excision of breast lesions to the routine use of percutaneous biopsy for diagnosis, high-risk breast pathology has also taken on a second meaning—breast lesions identified at percutaneous biopsy that may be malignant but are not adequately diagnosed with the percutaneous approach and therefore require surgical excision for definitive exclusion of malignancy. Thus, they are “high-risk” because they indicate a substantial risk that cancer is currently present in the breast at the needle biopsy site. Classic high-risk lesions with proven increase in long-term breast cancer risk include lobular carcinoma in situ (LCIS), atypical lobular hyperplasia (ALH), and atypical ductal hyperplasia (ADH). Other high-risk breast pathology lesions with less long-term risk but with concern for upgrade after needle biopsy include flat epithelial atypia, radial scar, and papillary lesions. This chapter will address both aspects of increased risk for these lesions—long-term increase in breast cancer risk as well as the risk of “upgrade” to cancer with surgical excision of the percutaneous biopsy site.
High-risk breast pathology refers to histologic abnormalities that confer an increased risk of breast cancer. The surgeon’s role in the clinical management of these lesions is twofold and includes (1) ensuring adequate diagnostic sampling of the lesion, and (2) recommending a strategy for long-term breast cancer surveillance and risk reduction that is tailored to the individual’s subsequent breast cancer risk. In the modern era of mammographically detected breast abnormalities and image-guided needle biopsies, some breast lesions are prone to underdiagnosis of cancer with a core needle biopsy approach. Surgeons need to understand which lesions require a surgical excision of the biopsy site in order to obtain adequate diagnosis of any malignancy that exists at that site. Once malignancy at the biopsy site is confidently ruled out, long-term clinical management of the patient depends on the level of breast cancer risk associated with the particular benign pathology identified. In general, patients with high-risk breast pathology are managed with surveillance and prevention strategies, but in some circumstances, surgical risk reduction may be considered. In this chapter, we review issues related to the diagnosis of high-risk lesions and recommendations for clinical management.
HIGH-RISK BREAST PATHOLOGY—HISTORICAL PERSPECTIVE
The “classic” high-risk breast lesions—lobular carcinoma in situ (LCIS), atypical ductal hyperplasia (ADH), and atypical lobular hyperplasia (ALH)—were identified years ago as having an increased future risk of breast cancer. In the 1970s, breast cancer risk after a diagnosis of LCIS was reported as approximately 1% per year, equally distributed across both breasts.1 In 1985 Dupont and Page2 reported on breast cancer risk for women after benign breast biopsies. Risk of breast cancer was compared ...