The effect of aging on the utilization of chemotherapy for metastatic breast cancer: A population-based study

Older women (i. e., greater than or equal to 65 years of age), receive less adjuvant chemotherapy than younger women, in part because chemotherapy has been less effective in postmenopausal than premenopausal women in clinical trials. Metastatic breast cancer, however; does not respond differently to chemotherapy by age. Therefore, to evaluate further the effect of age on chemotherapy utilization, we conducted a population-based study of the treatment of metastatic breast cancer. Patients (n = 132) were identified by cross-tabulating death certificates front 1984 to 1991 with breast cancer cases in the Washington County Cancer Registry. Treatment information was obtained from the Tumor Registry of the Washington County Hospital and Hospital medical records. Forty patients (74%) <65 years old received chemotherapy compared to 11 (42%) 65-74 and 6 (12%) greater than or equal to 75 (p < 0.0001). Adjusting for other medical conditions and whether or not the patient saw a medical oncologist, there was still a significant effect of age in patients greater than or equal to 75 (p < 0.001) and a trend (p = 0.17) for patients 65-74. The different patterns of chemotherapy utilization were not associated with survival differences. Radiation therapy was also utilized significantly less frequently in older than younger patients, but the age effect was not as pronounced as with chemotherapy. There was no age effect on the utilization of hormonal therapy. Less frequent utilization of chemotherapy in older patients is probably caused by a combination of patient and physician factors and may result in less effective palliation for older patients.