Numerous studies have documented that there are significant treatment differences in older patients compared to younger patients. Elderly women with early-stage breast cancer are less likely to undergo breast-conserving surgery than younger women, despite the increase in breast conservation over recent years among all age groups. Older women are also more likely to have radiotherapy or lymph node dissection omitted after breast-conserving surgery. Concerning systemic therapy, older women are more likely to be treated solely with adjuvant tamoxifen and are much less likely to undergo chemotherapy than younger women.

Less aggressive care of elderly breast cancer patients may be associated with a poorer outcome. Studying 390 women ages 45 to 90, Lash et al. found that patients who received a less than definitive prognostic evaluation had an adjusted relative hazard of recurrence of 1.7 [95% confidence interval (CI), 1.0-2.7] and an adjusted relative hazard for breast carcinoma mortality of 2.2 (95% CI, 1.2-3.9).

Patients who received less than definitive therapy had an adjusted relative hazard of recurrence of 1.6 (95% CI, 1.0-2.5) and an adjusted relative hazard of breast carcinoma mortality of 1.7 (95% CI, 1.0-2.8). Women aged 75 to 90 were least likely to receive definitive care and had relative hazards associated with less than definitive care as great or greater than the relative hazards observed in the whole cohort. This finding has implications for older women with localized breast cancer who are not receiving standard evaluations and therapy, as they may be at excess risk for disease recurrence and mortality. Other authors have not found differences in survival between older women who receive standard treatment and those who receive less aggressive care, after controlling for age, stage, and other clinical factors. Because elderly patients have more comorbidity, as well as functional limitations, less aggressive care may represent appropriate clinical judgment. Several studies indicate, however, that comorbidity or functional impairment cannot always explain less aggressive care. Furthermore, there is significant geographic variation in the care received by older breast cancer patients that cannot be explained by differences in functional status or comorbidity. For example, Mandelblatt and colleagues found that, between 1995 and 1997, women with localized breast cancer from five regions in the United States were 3.3 times more likely to have a mastectomy if they lived in Texas than if they lived in Massachusetts.

Other studies have shown that elderly patients with metastatic disease also appear to receive less aggressive care. In a population-based study of the treatment of metastatic breast cancer, Fetting et al. evaluated 132 cases of women who died of metastatic breast cancer in Washington County, Maryland, from 1984 to 1991. Sixty percent of women aged 75 years and older were referred to a medical oncologist, in contrast to 68% of women aged 65 to 74 years and 89% of women under age 65. Seventy-four percent of patients less than 65 years old received chemotherapy, compared to 42% of patients aged 65 to 74 years and 12% of women aged 75 years or older, despite the fact the there is not evidence that metastatic breast cancer responds differently to chemotherapy by age. Adjusting for other medical conditions and whether or not the patient saw a medical oncologist, there was still a significant effect of age on whether patients received chemotherapy. Of note, the different patterns of chemotherapy utilization were not associated with survival differences. Radiation therapy was also utilized significantly less frequently in older patients; however, there was no age effect on the utilization of hormonal therapy in this study. Less frequent utilization of palliative chemotherapy and radiation in older patients may be caused by a combination of patient and physician factors and may result in less effective palliation for older patients.

The specific reasons underlying these variations in care have not been studied extensively. Physician attitudes about appropriateness of therapy, patient comorbidity, and patient preferences, including body image and side effect concerns, have been found to influence the selection of treatment for elderly women with breast cancer. In a recent study of 718 women with early-stage breast cancer aged 67 years and older, Mandelblatt et al. found that women who were concerned with body image were 1.8 times more likely to receive breast-conserving surgery and radiotherapy compared to women without this concern. After controlling for other factors, women who preferred no therapy beyond primary surgery were 3.9 times more likely to undergo mastectomy than other women. In this study, women 80 years and older were 3.4 times less likely to undergo radiation therapy after breast-conserving surgery when compared to women ages 67 to 79 years, independent of comorbid illnesses, performance status, or women’s treatment preferences. Furthermore, older women were 70% less likely to receive chemotherapy than women aged 67 to 79. However, women 80 years and older tended to receive tamoxifen more often than the younger women in this study. The finding that patient preferences were independent predictors of therapy among these women has implications for shared decision making and communication between elderly patients and their physicians.

Silliman et al. surveyed physicians who did not recommend adjuvant therapy as part of a study in which women aged 75 years or older were significantly less likely to receive adjuvant therapy (including radiotherapy following breast-conserving surgery, chemotherapy, and hormonal therapy). Physicians’ attitudes about appropriateness of therapy appeared to be the major determinant of what treatment was received. In the majority of cases, physicians believed that the treatment was not indicated on the basis of patient stage or treatment efficacy. Patient factors, such as age, comorbidity, functional status, ability to tolerate treatment, and patient preferences, were cited infrequently.

Goodwin and Samet studied a population-based cohort of women 65 years or older with early-stage breast cancer in New Mexico. In this study, specific characteristics other than age that were associated with nonstandard treatment included impairments in activities of daily living, low physical activity, impaired mental status, poor access to transportation, and low social support. There was only a small, statistically nonsignificant relationship between comorbidity, based on patient self-report, and not receiving definitive treatment. It is likely that patient factors and preferences, as well as physician attitudes and beliefs, play an important role in explaining age-related variations in breast cancer care.

Elderly breast cancer patients (and elderly cancer patients in general) are substantially underrepresented in treatment protocols. Some of the same physician and patient factors that contribute to less aggressive treatment of elderly patients probably contribute to this underrepresentation in clinical trials. Studies are necessary to better understand physician attitudes, patient preferences, and other barriers to standard care and protocol therapy for older women. Kemeny and colleagues studied barriers to participation in clinical trials among breast cancer patients. After controlling for other conditions including comorbidity, older age was associated with whether a patient was offered participation in a clinical trial even when a patient met eligibility criteria. Reasons that physicians did not offer patients trial participation were similar for older and younger patients except for two factors: (1) the presence of comorbid conditions that was not excluded by the protocol but that the physician believed would have affected the patient’s response was a factor in 17% of older patients and none of the younger patients; and (2) the opinion that the regimen was too toxic was a factor in 27% of the older patients and none of the younger patients. Patient difficulty in understanding, costs, transportation, and short life expectancy did not appear to influence physicians’ decisions. Importantly, there was no evidence that age was associated with whether or not a patient accepted clinical trial participation when offered.