Disease status, comorbidity, life expectancy, patient preferences, and goals of therapy should guide treatment of an older patient with breast cancer. These decisions should be made with an understanding of the treatment regimens that have been shown to improve survival or quality of life. Numerous advances have been made over the past 30 years in the treatment of breast cancer. Both local and systemic therapy have changed substantially during this time, guided by the results of large randomized clinical trials, often performed through large cooperative groups. Because most randomized clinical trials in breast cancer have not included patients over the age of 70, cautious extrapolation of the results to older women is often necessary.

A woman’s likelihood of dying of breast cancer versus other causes can be assessed with competing risks analysis. When devising rational treatment plans for an older woman with breast cancer, one must consider not only her risk of disease recurrence as influenced by disease stage, tumor grade, and hormone receptor status, but also her life expectancy as determined by age and comorbidity.

Life expectancy for women in Western societies is approximately 15.5 years at age 70 and 9.2 years at age 80 (

Table 33.5). As one might expect, comorbidity is a significant risk factor for shortened life expectancy in women with breast cancer. Satariano and colleagues revealed that among breast cancer patients identified through the Metropolitan Detroit Cancer Surveillance System, 3-year mortality was four times higher in women with three or more comorbid conditions when compared to women with no comorbid illness. In women aged 55 to 84 years, those who died within 2 years after assessment of comorbidity were more likely to have reported one or more comorbid conditions than were survivors (62% versus 38%). Furthermore, the greater the number of comorbid illnesses, the higher the risk of death from all causes, including breast cancer, independent of age and stage of disease. Because the number of comorbid conditions tends to increase with age, older women with breast cancer are at increased risk of dying of nonbreast cancer-related causes. Fish et al. analyzed 678 patients diagnosed between 1971 and 1990. Among women who died, 20% of women over age 65 died of causes other than breast cancer compared to 3% of women under age 65.

In the following sections, we review current breast cancer treatment recommendations, focusing on the data available regarding older patients and relevance of existing studies to breast cancer in the elderly.