P5-11-13: Rates of Upgrade to Malignancy for 271 Cases of Atypical Columnar Cell Hyperplasia Diagnosed by Breast Core Biopsy.

Purpose : Atypical columnar cell hyperplasia (ACCH) is a borderline lesion that might represent an early stage in the development of certain low-grade carcinomas in situ (CIS) and invasive cancers. There are no guidelines on its management. Our objectives were to determine the upgrade to malignancy rate and identify a subpopulation of patients that might undergo just mammographic surveillance. Methods : We retrospectively reviewed the data for 271 ACCH cases among 5555 breast core biopsies obtained over a 7-year period (Jan. 2003 — Jan. 2010). We collated clinical data (age, history of cancer, menopausal status), radiological data (lesion type, size, Bi-Rads category), technical data (number of biopsies, needle gauge, excision quality) and histological data and sought correlations between these factors and upgrade rate. Results : The 271 ACCH comprised 128 cases of pure ACCH, 135 cases of ACCH + atypical ductal hyperplasia, and 8 cases of ACCH + atypical lobular hyperplasia. Overall, 184 patients underwent surgery and 46 mammographic surveillance. Surgery detected 34 cases of malignancy (23 CIS, 7 invasive cancers, and 4 mixed cases) giving a 15% upgrade rate. Quality of excision was the only factor associated with under-diagnosis. Conclusion : The presence of ACCH at biopsy warrants surgery. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-11-13.