ES6-3: Breast Cancer in the Older Adult.

Breast cancer is a disease associated with aging. In the US, the median age of breast cancer diagnosis and death is 61 years and 68 years, respectively. The number of older adults in the US is rising, and the number of individuals age 65 and older is expected to double by the year 2030. This demographic shift will lead to an increase in the number of individuals diagnosed with breast cancer. It is estimated that from 2010 to 2030 there will be a 57% growth in the number of new cases of breast cancer in patients age 65 and older.1 A challenge in caring for older adults with breast cancer is that they have been historically underrepresented in clinical trials that set the standard for breast cancer care.2 However, a growing body of evidence-based literature can be utilized to inform and optimize the care of the older adults with breast cancer. This presentation will focus on the treatment of early stage breast cancer in older adults, including the risks and benefits of local and systemic therapies, as well as survivorship issues. Recently reported phase III studies have led to advances in the treatment of older adults with breast cancer. A phase III randomized study evaluated the role of radiation therapy following lumpectomy in patients age 70 and older with stage I hormone receptor (HR) positive breast cancer who received treatment with tamoxifen. Receipt of radiation therapy was associated with a decrease in the risk of locoregional recurrence; however, there was no difference in overall survival. The study results underscore the importance of competing comorbidity as a cause of death in older adults with early stage breast cancer.3 The role of axillary lymph node dissection was evaluated in a randomized study of women over age 60 with node-negative, HR positive breast cancer who received treatment with tamoxifen. Patients were randomized to breast surgery and axillary dissection, or breast surgery alone. There was no difference between disease-free and overall survival in the 2 study arms.4 A phase III randomized study evaluated the efficacy of standard adjuvant IV chemotherapy (doxorubicin and cyclophosphamide [AC] or cyclophosphamide, methotrexate, and 5-fluorouracil [CMF]) versus oral chemotherapy (capecitabine) in patients age 65 and older with stage I-III breast cancer. Those patients who received standard chemotherapy showed improvement in progression-free and overall survival compared with patients who received capecitabine. This study demonstrates that IV polychemotherapy regimens remain the standard of care for older adults who are prescribed adjuvant chemotherapy.5 These phase III studies advance our understanding in the care of older adults with breast cancer. Furthermore, they demonstrate the feasibility and importance of accruing older adults to phase III trials, which will improve our evidence-based care of this growing population. References 1. Smith BD, Smith GL, Hurria A, Hortobagyi GN, Buchholz TA. Future of Cancer Incidence in the United States: Burdens Upon an Aging, Changing Nation. J Clin Oncol 2009. 2. Hutchins LF, Unger JM, Crowley JJ, Coltman CA, Jr., Albain KS. Underrepresentation of patients 65 years of age or older in cancer- treatment trials. The New England journal of medicine 1999;341:2061–7. 3. Hughes KS, Schnaper LA, Berry D, et al. Lumpectomy plus tamoxifen with or without irradiation in women 70 years of age or older with early breast cancer. The New England journal of medicine 2004;351:971–7. 4. International Breast Cancer Study Group, Rudenstam CM, Zahrieh D, et al. Randomized trial comparing axillary clearance versus no axillary clearance in older patients with breast cancer: first results of International Breast Cancer Study Group Trial 10–93. J Clin Oncol 2006;24:337–44. 5. Muss HB, Berry DA, Cirrincione CT, et al. Adjuvant chemotherapy in older women with early-stage breast cancer. The New England journal of medicine 2009;360:2055–65. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr ES6-3.