Breast cancer events in women with atypical ductal hyperplasia who do not undergo surgical excision.

Abstract

1562 Background: Atypical ductal hyperplasia (ADH) found on core needle biopsy is associated with an upgrade to carcinoma in 10-30% of women, thus surgical excision remains the standard of care. We sought to review the incidence of breast cancer in women with ADH managed by either observation or surgical excision over a 15 year period. Methods: Our prospectively maintained registry was reviewed to identify patients with ADH diagnosed by core needle biopsy between 1/2004 and 10/2018. Observed patients were deemed low risk for upgrade after multidisciplinary review confirmed adequate sampling, limited atypia and concordance between imaging and histology. Surgical patients were excluded if upstaged to carcinoma following excision. Patients with < 1 year follow-up were excluded. Subsequent breast cancer was classified as ipsilateral or contralateral to the previous ADH and was further classified as index site if the new cancer was identified in the same quadrant as prior ADH. Multivariate logistic regression models were used to assess potential predictors of subsequent breast cancer events. Results: Four hundred and seventy-eight women with 483 ADH lesions met criteria; 305 were observed and 173 underwent excision. Median follow-up was 5.2 years, range 1.1-15.3. At the time of ADH diagnosis, 91 women had a personal history of breast cancer. Age < 50 was the only statistically significant difference between the groups (24.6% vs. 33.3%, p = 0.04). Race, receipt of chemoprevention, prior breast cancer history and median follow-up were not significant between the groups. Prior history of breast cancer was associated with subsequent breast cancer risk in multivariate analysis (OR 2.25, 95% CI 1.04-4.87, p = 0.04). After excluding patients with a history of breast cancer, multivariate analysis demonstrated no association of age, race, use of chemoprevention or surgical excision with future cancer risk. Among the 387 patients without a prior breast cancer history, 21 patients developed a subsequent cancer; 10 in the surgical group and 11 in the observed group (7.3% vs. 4.4% respectively, p = 0.2). Two cancers were identified at the index site in the surgery group (2/137, 1.5%) and three in those observed (3/250, 1.2%). Conclusions: Observation, rather than surgical excision, is safe in selected women that have a core biopsy diagnosis of ADH. Index site failures are rare and are superseded by cancer risk elsewhere in the breast. National screening and diagnosis recommendations should consider recommending observation for this select group of patients with ADH.