Adjuvant therapy for older women with early-stage breast cancer: treatment selection in a complex population.

Breast cancer is a disease of aging. However, older women with breast cancer are less likely to participate in clinical trials or to receive recommended treatment. This undertreatment has contributed to a lag in breast cancer survival outcomes for older women compared with that for their younger counterparts. The principles that govern recommendations for adjuvant treatment of breast cancer are the same for younger and older women. Systemic adjuvant treatment recommendations should be offered on the basis of tumor characteristics that divide patients into three distinct subgroups. These include (1) older women with hormone receptor (HR)-positive and human epidermal growth factor 2 (HER2)-negative breast cancer who should be offered endocrine therapy; (2) older women with HR-negative and HER2-negative breast cancer who should be offered adjuvant chemotherapy; and (3) older women with HER2-positive disease who should be offered chemotherapy with trastuzumab. Exceptions to these guidelines may be made for older women with small node-negative tumors or frail older women with limited life expectancy, where close surveillance may be a reasonable alternative. Addressing the current age-related disparities in breast cancer survival will require that older women are offered the same state-of-the-art-treatment as their younger counterparts, with a careful weighing of the risks and benefits of each treatment in the context of the individual's preferences. In addition, older women should be encouraged to participate in breast cancer clinical trials to generate additional chemotherapy efficacy, toxicity, and quality of life data.