"The incidence of breast cancer increases with increasing age, and almost half of all new breast cancers in the United States occur in women 65 years of age or older," the authors note in background information in the article. "Systemic adjuvant (secondary treatment) chemotherapy in women with early-stage breast cancer significantly improves both relapse-free and overall survival in women aged 50 to 69 years old, but data are lacking for women aged 70 years or older." The authors add that available data suggest that adjuvant chemotherapy may be significantly underused in older patients or that inappropriate dose reductions are made that decrease its effectiveness.
Hyman B. Muss, M.D., from the Vermont Cancer Center, Burlington, Vt., and investigators from the Cancer and Leukemia Group B (CALGB) analyzed data from four randomized clinical trials of treatments for lymph node-positive breast cancer cases between 1975 and 1999. These trials compared more aggressive with less aggressive chemotherapy regimens. A total of 6, 487 women with lymph node-positive breast cancer were included in the trials; 542 (8 percent) of the patients were 65 years or older and 159 (2 percent) were 70 years or older.
"... smaller tumor size, fewer positive lymph nodes, more chemotherapy, and tamoxifen (drug used to treat breast cancer) use were all significantly related to longer disease-free and overall survival," the authors found in their analyses of the studies. "There was no association between age and disease-free survival. Overall survival was significantly worse or patients aged 65 or older because of death from causes other than breast cancer. Thirty-three deaths (0.5 percent of all patients) were attributed to treatment, and older women had higher treatment-related mortality. Older women and younger women derived similar reductions in breast cancer mortality and recurrence from regimens containing more chemotherapy."
"Our study adds to the increasing number of trials that suggest that older patients in fair to good health tolerate standard chemotherapy regimens, and even more intensive regimens, almost as well as younger patients," the researchers write. "A sobering finding from this analysis is the observation that only 8 percent of patients entered in the trials analyzed in this study were aged 65 years or older; about 50 percent of new breast cancer diagnoses occur in women in the older age group." In conclusion the authors write, "the data from this study should help to encourage clinicians to offer healthy older patients participation in newer trials, because healthy older patients are likely to derive similar treatment benefits as younger patients."
(JAMA.2005;293:1073 - 1081. Available post-embargo at JAMA.com).
Editor's Note: This CALGB research was supported in part by a grant from the National Cancer Institute. Please see JAMA study for complete list of investigators and funding. Co-author Dr. William C. Wood has received financial support from Aventis and Genomic Health. All other authors reported no disclosures.
Editorial: Adjuvant Therapy of Breast Cancer in the Elderly
In an accompanying editorial, Dr. William J. Gradishar, M.D., and Virginia G. Kaklamani, M.D., D.Sc., from Feinberg School of Medicine, Northwestern University, Chicago, write, "the impact of adjuvant therapy for treatment of early stage breast cancer has clearly reduced the risk of disease recurrence and breast cancer mortality."
"A limitation of the data ... [from breast cancer studies] ... is that very few patients in the oldest age groups (over 65 years) have been included in clinical trials to date. This paucity of data is the result of exclusion criteria for age in some clinical trials and physician bias based on the notion that older patients will not benefit from adjuvant chemotherapy, will not tolerate it as well as younger patients, or both."
"Ultimately, it will be incumbent on the physician, in consultation with the patient and family, to carefully articulate the potential benefits and adverse effects of adjuvant therapy in a patient population for whom both the length and quality of life can be threatened by a variety of other issues," the editorial authors conclude.
(JAMA. 2005;293:1118 - 1119. Available post-embargo at JAMA.com)