Reassessing Adjuvant Treatment of Early-Stage Breast Cancer in Elderly Women: Focus on Findings from 2007 ASCO Meeting

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Introduction

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).¹ If these incidence rates remain stable, by 2030, two-thirds of patients with breast cancer will be 65 years of age or older, and by 2050, the total number of breast cancer cases will double due to the aging of the population.²

Less aggressive management of breast cancer in older women has been widely reported.^3-5  Older women may be more likely to have nonstandard initial therapy than younger women⁴ and appear to be less likely to be represented in clinical trials.^6,7

Although not unique to older individuals, chronic disease is more common with advancing age. Almost 80% of people older than age 65 have at least one chronic disease, and approximately one-third have three or more chronic diseases.⁸ This finding is important for two reasons:  First, the choice of therapy is influenced by the presence of coexisting diseases that may increase complications; and, second, in clinical trials, the best measure of success of cancer treatment is overall survival, which may be limited by coexisting illness, making the benefit of therapy difficult to evaluate. 

The guiding principles of breast cancer management are early detection, aggressive local therapy to prevent recurrence of breast cancer at the primary site, and systemic therapy to prolong survival by preventing the development or slowing the progression of metastatic disease. These principles apply to treatment of older women but are more complicated because of the presence of other illnesses that may also limit survival. In some cases, the focus of treatment is then redirected to improving the remaining years, either by maintaining breast cancer recurrence-free survival and/or quality of life.

The results of studies focusing on older women with breast cancer are heterogeneous because of the varying definitions of “elderly.” Some studies define “elderly” as any postmenopausal woman, whereas others use the cutoff age of 65. However, with improved life expectancy in the United States, age 65 should be considered a younger-old person. In this article, we initiate the discussion of adjuvant radiotherapy and hormonal therapy by looking at two abstracts from the 2007 American Society of Clinical Oncology (ASCO) meeting and use their findings as a springboard to evaluate the published literature, specifically focusing on women aged 75 or older with early-stage breast cancer.