Atypical ductal hyperplasia (ADH) is a non-invasive breast condition characterized by abnormal cell growth within the milk ducts. While not cancerous itself, ADH indicates an increased predisposition for developing breast cancer in the future.
Understanding Atypical Ductal Hyperplasia
Atypical ductal hyperplasia involves an abnormal accumulation of cells inside the breast’s milk ducts. Under a microscope, these cells appear disorganized and differ from normal breast cells, but they do not invade surrounding tissues, distinguishing ADH from cancerous cells.
ADH is considered a “high-risk” lesion because its presence signals a significantly increased chance of developing breast cancer later on. The increased risk of breast cancer can occur anywhere in the breasts, not just in the area where ADH was found.
ADH is discovered incidentally during a breast biopsy. This procedure is performed after an abnormality is detected through imaging, such as a mammogram, or during a clinical breast examination. The prevalence of ADH in breast biopsies ranges from 3.5% to 20%.
Recurrence Rates and Influencing Factors
For individuals diagnosed with atypical ductal hyperplasia, “recurrence” refers to the development of new breast cancer, which can be either invasive or non-invasive like ductal carcinoma in situ (DCIS), in either breast. It does not mean the ADH itself returns in the exact same location. The risk of developing breast cancer increases over time following an ADH diagnosis.
7% of women with ADH may develop breast cancer within five years of diagnosis, and this figure rises to 13% after ten years. Over a longer period, 30% of women diagnosed with ADH may develop breast cancer within 25 years. Overall, women with atypical hyperplasia have a fourfold increased relative risk of developing breast cancer compared to the general population.
Several factors can influence an individual’s specific risk. A family history of breast cancer or the presence of genetic mutations, such as BRCA1 or BRCA2, can elevate this risk. The extent of the ADH, specifically the number of atypical foci found in the pathology specimen, also correlates with a higher risk. Lifestyle factors, including obesity, alcohol consumption, and smoking, are also associated with an increased risk of breast cancer and can influence risk for those with ADH.
Post-Diagnosis Management and Monitoring
Following an ADH diagnosis, ongoing management and monitoring are recommended to address the increased risk of breast cancer. Surveillance strategies are an important part of this approach. These include regular clinical breast examinations every six to twelve months, and annual diagnostic mammograms with tomosynthesis.
For some individuals, especially those with additional risk factors or dense breast tissue, supplemental imaging like breast MRI may be considered annually. These screenings help to detect any new breast cancers as early as possible. Medical risk reduction strategies may also be discussed.
Risk-reducing medications, such as selective estrogen receptor modulators (SERMs) like tamoxifen or raloxifene, may be offered to certain individuals. These medications can reduce the risk of developing invasive breast cancer, with studies showing reductions of up to 70% in women with atypical hyperplasia. Lifestyle modifications, including maintaining a healthy weight, engaging in regular physical activity, and limiting alcohol consumption, are encouraged to promote overall breast health and manage risk. The management plan is individualized and should be determined in consultation with a healthcare provider.