Gretchen G. Kimmick, MD, MS

Approximately 212,920 new cases of invasive breast cancer were estimated to occur in the United States in 2006.1 The incidence rate has continued to rise slowly over the past 20 years due to the continued increase of breast cancer in women aged 50 and older (375 cases per 100,000 women), peaking at 75 to 79 years of age (525 per 100,000 women).

As half of all breast cancers occur in patients beyond the age of 65 and a quarter beyond the age of 75, a significant number of patients with metastatic breast cancer are elderly. New hormonal therapies, such as aromatase inhibitors, appear to have favorably improved the survival of these patients. Side effects such as osteoporosis or cognitive issues appear manageable. Information specific to elderly patients has recently emerged in the field of chemotherapy for metastatic breast cancer. This article reviews data on anthracyclines, taxanes, capecitabine (Xeloda), gemcitabine (Gemzar), trastuzumab (Herceptin), and bevacizumab (Avastin). For most patients in this setting, sequential single-agent chemotherapy appears at this time to be the preferred course of treatment.

As the aging population in the United States continues to grow, the incidence of diseases of the elderly, such as breast cancer, are increasing. Many more elderly women are expected to be diagnosed with new breast cancers, most of them in an early stage. Appropriate treatment of these women is important, as they have poorer outcomes when undertreated. In this review, we will discuss the biology and treatment of early breast cancer in elderly women. We will focus on the role of comorbidity and its effect on life expectancy, treatment decisions, current recommendations for primary treatment with surgery, radiation and neoadjuvant strategies, and adjuvant treatment including local radiation therapy and systemic treatment with endocrine therapy, chemotherapy, and newer agents. Finally we will discuss the importance of clinical trials in the elderly.

Breast cancer is a common problem in older women. As the number of medical illnesses increases with age and the life expectancy decreases, the benefits of systemic therapy for women with breast cancer become questionable. All women over age 65 years are at high enough risk of breast cancer to consider the risk/benefit ratio of preventive therapy with tamoxifen (Nolvadex) or participation in the Study of Tamoxifen and Raloxifene (STAR) trial. Adjuvant chemotherapy and hormonal therapies for early breast cancer significantly improve disease-free and overall survival; recommendations for their use are based on risk of tumor recurrence. Use of tamoxifen in the adjuvant setting in women with receptor-positive tumors is a relatively simple decision in light of its favorable toxicity profile. The delivery of adjuvant chemotherapy is a more complicated decision, and the patient’s wishes, estimated life expectancy, presence of comorbid conditions, and estimated benefit from treatment should be considered. The primary goal of the treatment of metastatic breast cancer is palliation. We discuss trials specific to older women and make appropriate treatment recommendations. Unfortunately, there is a paucity of data from clinical trials in women over age 70 years. However, because the clinical trial is the primary scientific mechanism for testing the efficacy of a treatment, every effort should be made to enter older women into treatment protocols. [ONCOLOGY 15(3):280-299, 2001]

Hormonal manipulation is currently the mainstay of palliative care for metastatic breast cancer because it is well tolerated and produces significant responses in approximately one-third of unselected patients. Tamoxifen, a nonsteroidal antiestrogen, is currently considered first-line therapy. Second-line agents include progestins and aromatase inhibitors.

Tamoxifen (Nolvadex) is widely used in the treatment of breast cancer. It is effective in the management of both early stage and advanced disease. The recent comprehensive meta-analysis of systemic treatment in early breast cancer reported that tamoxifen reduced the annual odds of breast cancer recurrence by 25%, and the risk of death by 16%, compared with patients not treated with tamoxifen [1]. The benefits are even more pronounced in postmenopausal patients, with 29% decreases in recurrence and 20% reduction in the risk of death. The risk of contralateral primary breast cancer is also decreased by approximately 28% in women receiving adjuvant tamoxifen [2]. This has prompted its use in prevention trials; the National Surgical Adjuvant Breast and Bowel Project Prevention trial (NSABP P1) is an ongoing trial randomizing women at high risk for breast cancer to receive tamoxifen or placebo. Tamoxifen's use in otherwise healthy women has brought attention to the few potential toxicities of the drug.