[Breast cancer]

Many studies have suggested that older women with breast cancer have tumors with less aggressive biological features such as small tumor size, higher expression of steroid hormone receptor, and absence of expression of HER2. The 3 major treatments for breast cancer are surgery, drug therapy, and radiotherapy. The treatment of choice is determined by many factors, particularly the biological characteristics of the tumor and the risk of recurrence; the same factors are used to determine the treatment of choice in elderly patients. Surgery, endocrine therapy, and radiotherapy are relatively less invasive treatments. However, chemotherapy is a highly invasive treatment especially given its side effects. Because few women older than 70 years have been enrolled in randomized controlled trials, evidence-based treatment guidelines, particularly with regard to adjuvant chemotherapy, are lacking. A few older patients with breast cancers have high-risk features such as positive lymph nodes, absence of hormone receptors, and presence of HER2 expression. Chemotherapy is recommended for those older women for whom the risk of recurrence is higher. The important factors influencing the choice of treatment for breast cancer are the risk of recurrence and efficacy of treatment. Life expectancy, comorbidities, and organ function are also features that have to be considered when treating the elderly.