Atypical Ductal Hyperplasia (ADH)

ADH and atypical lobular hyperplasia are now frequently diagnosed with use of core-needle biopsy.

Although atypia can be difficult to distinguish from carcinoma in situ, pathologic criteria exist to distinguish the two entities.

This distinction is important because, while in situ carcinoma is malignant and may progress to invasive disease, ADH is a non-obligate cancer precursor and often represents a marker of an elevated future breast cancer risk.

ADH is most frequently found by mammography.

Atypia alone, with no other risk factors, confers an approximate four-fold to five-fold risk of the development of breast cancer.

Although breast MRI is more sensitive to detect intermediate- and high-grade ductal carcinoma in situ (DCIS) as well as invasive cancers, breast MRI lacks sufficient diagnostic ability to differentiate ADH versus DCIS or invasive cancers.

Excision is indicated for ADH found on core needle biopsy, as concomitant in situ or invasive cancer will be found in approximately 15% of cases.

The 10-year risk of developing a breast cancer after a diagnosis of ADH is approximately 17%.

Risk is bilateral yet breast cancers developing within 5 years of a biopsy of ADH more likely to occur in the ipsilateral breast than those developing more than 5 years (82% ipsilateral in the first 5 years vs 58% ipsilateral after 5 years).

The National Surgical Adjuvant Breast and Bowel Project (NSABP) P-1 trial showed that when atypia is found on a sample obtained with needle biopsy and excision rules out cancer, tamoxifen reduces the risk of developing breast cancer by about 86%; these patients should therefore be referred for discussion about this endocrine prophylaxis.

Similarly, the Study of Tamoxifen and Raloxifene (STAR, NSABP P-2) trial, which randomized post-menopausal women to tamoxifen or raloxifene, found that raloxifene provided equivalent risk reduction to tamoxifen with less toxicity (e.g., endometrial cancer).

References:

Coopey SB, Mazzola E, Buckley JM, et al. The role of chemoprevention in modifying the risk of breast cancer in women with atypical breast lesions. Breast Cancer Res Treat. 2012;136:627-633.

Heller SL, Moy L. Imaging features and management of high-risk lesions on contrast-enhanced dynamic breast MRI. AJR Am J Roentgenol. 2012;198:249-255.

Krishnamurthy S, Bevers T, Kuerer H, Yang WT. Multidisciplinary considerations in the management of high-risk breast lesions. AJR Am J Roentgenol. 2012;198:W132-140.

Hartmann LC, Radisky DC, Frost MH, et al. Understanding the premalignant potential of atypical hyperplasia through its natural history: a longitudinal cohort study. Cancer Prev Res (Phila). 2014;7:211-217.

Vogel VG, Costantino JP, Wickerham DL, et al; National Surgical Adjuvant Breast and Bowel Project. Update of the National Surgical Adjuvant Breast and Bowel Project Study of Tamoxifen and Raloxifene (STAR) P-2 Trial: Preventing breast cancer. Cancer Prev Res (Phila). 2010;3:696-706.