The Agency for Healthcare Research and Quality (AHRQ) announces the availability of an evidence report summary on the management of specific breast abnormalities. The evidence report topic was nominated for review by Kaiser Permanente Northern California and was developed under contract with AHRQ's Evidence-based Practice Center (EPC), MetaWorks Inc., located in Medford, MA.

The report found strong evidence for performing an excisional biopsy following a stereotactic core needle biopsy diagnosis of atypical ductal hyperplasia (ADH), as the excisional biopsy results often lead to a change in diagnosis. ADH, a condition where the cells lining the milk ducts of the breast grow abnormally, can only be diagnosed by examining a sample of breast tissue under a microscope. While ADH is a non-cancerous condition, cancer tissue can also be found with ADH. Stereotactic core needle biopsy removes only small fragments of breast tissue through a hollow needle and may fail to capture cancerous tissue in its sampling. An excisional biopsy removes breast tissue through a surgical procedure and allows for a larger volume of tissue to be tested.

Both ADH and lobular carcinoma in situ (LCIS), a non-cancerous abnormality of the cells contained in the milk-producing lobules of the breast, place women at greater risk for developing breast cancer in the future. Although data are limited, the evidence suggests that Tamoxifen therapy markedly decreases the incidence of breast cancer following a diagnosis of ADH or LCIS, but is associated with increased risk of endometrial cancer, thromboembolic disease and other complications.

MetaWorks Inc. also found that while studies to date suggest sentinel lymph node biopsy is successful in determining whether breast cancer has spread throughout the regional lymph nodes in most patients, long-term cancer outcomes and survival data are required before sentinel lymph node biopsy can be considered standard of care. The authors suggest future research should examine breast disease risk factors, breast symptoms, and how they relate to cancer diagnoses. New research should also be done to identify new and additional risk factors.