Table 1.

Demographic Data in Participants with and Those without Multiple Bilateral Circumscribed Benign-appearing Masses at Screening US over Three Annual Examinations

Note.—Unless otherwise specified, data are numbers of participants, with percentages in parentheses. For these data, only participants with two breasts were considered. Multiple bilateral masses = at least three circumscribed benign-appearing masses (excluding simple cysts) were present, two in one breast and one in the other. ADH = atypical ductal hyperplasia, ALH = atypical lobular hyperplasia, LCIS = lobular carcinoma in situ.

^*Data are medians, with ranges in parentheses.

^†Regardless of other risk factors.

^‡Breast density was visually assessed at the time of each annual mammographic examination.

^§Participants with multiple risk factors were considered to have a primary risk factor by using the following hierarchy: mutation in BRCA1 or BRCA2; history of chest, mediastinal, and/or axillary irradiation; personal history of breast cancer; Gail (12) or Claus (13) model lifetime risk ≥ 25%; Gail model 5-year risk ≥ 2.5%; Gail model 5-year risk ≥ 1.7% and extremely dense breasts; and prior biopsy that revealed atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ, or atypical papilloma.