Breast cancer risk associated with atypical hyperplasia and lobular carcinoma in situ initially diagnosed on core-needle biopsy.

Background: Breast cancer risk estimates for atypical lesions are based primarily on case-control studies of patients with open biopsies. The authors report the cumulative breast cancer incidence after a core biopsy diagnosis of atypical hyperplasia (ductal or lobular) or lobular carcinoma in situ.

Methods: A cohort study with central pathology review was conducted on 393 patients who had core biopsy diagnoses of atypical hyperplasia and lobular carcinoma in situ from 1995 through 2010.