The Risk of Breast Cancer and the Role of Chemoprevention in Women With Atypical Ductal or Lobular Hyperplasia

Women with atypical hyperplasia are about 4 times more likely to develop breast cancer compared with the general population. Atypical hyperplasia has been recommended to be used as a criterion for the inclusion of women in chemoprevention programs. Chemoprevention offers promise as a strategy for reducing the incidence of breast cancer in high-risk population.
A literature search was conducted in PubMed and Scopus databases using the search terms “breast atypia,” “chemoprevention,” and “risk-reducing therapy” for papers published from 1966 to Aug 2017. The search was limited to English-language papers and human studies. It yielded 114 search items. Article selection for possible inclusion was performed using the title and abstract. Finally, 12 studies were identified as eligible for inclusion in the review.
The rates of atypical ductal hyperplasia (ADH) ranged from a low of 2 per 10000 mammograms in 1995 to a high of 6 per 10000 mammograms in 2011. Lobular neoplasia was an incidental finding in 0.5%–3.5% of core biopsies. True incidence of lobular neoplasia is unknown. Women with atypical breast lesions have a 5%–11% risk of developing breast cancer within 5 years and a 17%–26% risk of developing breast cancer within 10 years. The reported risk of breast cancer with atypical hyperplasia (ADH and ALH are often grouped together) is approximately 19% within 15 years. It is believed that the initiation of chemoprevention would be appropriate if the 10-year breast cancer risk is 4% to 8%. Breast cancer risk reduction by chemoprevention is reported to be 32% to 55% in breast atypia.
According to our findings, patients with a diagnosis of ADH, ALH, or severe ADH should be considered for chemoprevention if they are at least 35 years of age and have no contraindications to treatment. Only 4%–20% of high-risk women decide to take chemoprevention, on average.