Donaldson AR et al. -In the current study, the cumulative breast cancer incidence after a core biopsy diagnosis of atypical hyperplasia (ductal or lobular) or lobular carcinoma in situ was determined. It was shown that the 7-year cumulative breast cancer incidence approached 10% in such patients.

Methods

• Core biopsy diagnoses of atypical hyperplasia and lobular carcinoma in situ were reviewed for 393 patients.
• Follow-up was available for 255 of 264 patients (97%) at a median of 87 months (range, 3-236 months).

Results

• There were 212 patients (54%) who were not upgraded on excision and had no history of breast cancer.
• 21 of 212 (9.9%) developed breast cancer, including 15 invasive carcinomas, 4 ductal carcinomas in situ, 1 pleomorphic lobular carcinoma in situ, and 1 unknown type.
• The prior core biopsy diagnoses were atypical ductal hyperplasia for 11 patients (52%) and atypical lobular hyperplasia/lobular carcinoma in situ in the remaining 10 patients (48%).
• The number of atypical foci in the core biopsy was not significantly associated with the subsequent development of breast cancer.
• Of the 15 invasive carcinomas, 11 (73%) were ipsilateral, 11 (73%) were pathologic T1 tumors, 5 (33%) were pathologic N1 tumors, 13 (87%) were estrogen receptor-positive, and 1 (7%) was amplified for human epidermal growth factor receptor 2.