Treatment for breast cancer in patients with Alzheimer's disease.

OBJECTIVES

To report use of breast cancer treatment (surgery, radiation, and chemotherapy) by patients with Alzheimer's disease (AD).

DESIGN

Retrospective cohort study.

SETTING

Surveillance, Epidemiology, and End Results (SEER) is a population-based cancer registry covering 14% of the U.S. population.

PARTICIPANTS

Fifty thousand four hundred sixty breast cancer patients aged 65 and older, of whom 1,935 (3.8%) had a diagnosis of AD before or up to 6 months after cancer diagnosis.

MEASUREMENTS

Diagnosis of AD was taken from International Classification of Diseases, Ninth Revision, diagnostic codes accompanying Medicare billing claims between 1992 and 1999. The SEER program reported surgery and radiation. Chemotherapy was taken from Medicare billing records.

RESULTS

Subjects with AD were diagnosed with breast cancer at later stages, when tumors were larger and the likelihood of lymph node involvement had increased. Patients with AD had a lower likelihood of surgery (odds ratio (OR)=0.60, 95% confidence interval (CI)=0.46-0.81), radiation (OR=0.31, 95% CI=0.23-0.41), and chemotherapy (OR=0.44, 95% CI=0.34-0.58) than those without AD.

CONCLUSION

Overall, AD patients receive less treatment for breast cancer than do comparable female Medicare beneficiaries. Chemotherapy and radiation are administered less frequently to women with AD than to other comparable patients. It is unclear whether suboptimal medical care has an effect on their survival. Further research on the effect of screening and treatment decision-making for these patients is warranted.