Information is lacking regarding the interaction of established breast cancer risk factors and patient age. We attempted to study this interaction in high-risk women at the extremes of age in our population. The Women-At-Risk Registry was queried for women who were ≤35 and ≥70 years of age. Enrollment criteria included: strong family history of breast cancer (FHBC), and/or biopsy-proven history of atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), or lobular carcinoma in situ (LCIS). Descriptive analyses and Fisher's exact tests were used to analyze these factors and to assess their influence on breast cancer development. Our population included 1,412 high-risk women with median follow-up of 4 years. Of 195 women ≤35 years, 3 (1.5%) developed breast cancer. All three had strong FHBC and none had a prior high-risk lesion. Of 82 women ≥70 years, 6 (7.3%) developed breast cancer. Mean Gail score for women ≥70 years was 4.3, as compared with 4.7 in the subset of older women diagnosed with cancer. Fisher's tests demonstrated that ADH (p = 0.15), ALH (p = 1.0), LCIS (p = 1.0), and FHBC (p = 1.0) were not associated with breast cancer development in older women. We conclude that, for women ≤35 years, a significant FHBC may be a stronger predictor for breast cancer development than high-risk lesions. For women ≥70 years, FHBC and history of ADH, ALH, and LCIS were not predictors of breast cancer. This study emphasizes the importance of defining age-appropriate recommendations for breast cancer risk management, including surveillance and chemoprevention.