This is a proposal to continue the study of health and functioning in middle-aged and elderly women with breast cancer, compared to women of the same age without the disease. Preliminary research suggests that the functional status of cases aged 55 to 64 is significantly poorer 3 months after diagnosis than the functional status of women of the same age without the disease. In contrast, there is little difference between cases and controls aged 75 to 84. Research is proposed to both confirm and more closely analyze these case-control differences by increasing the number of cases and controls aged 75 to 84, and introducing a younger group of women aged 40 to 54. Case-control differences will be examined in greater detail by age, with a primary focus on differences will be examined in greater detail by age, with a primary focus on differences in occupational functioning among cases and controls aged 40 to 54. A total of 276 women aged 40 to 54 and 134 aged 75 to 84, newly diagnosed with invasive breast cancer in the Detroit Metropolitan area, will be identified and interviewed at 3 and 12 months after diagnosis. A total of 410 population-based controls of the same age also will be enrolled and interviewed twice over the same period. Biomedical and treatment data for breast cancer cases will obtained from the population-based Metropolitan Detroit Cancer Surveillance System (MDCSS) operated by the Division of Epidemiology, Michigan Cancer Foundation. Interview, biomedical, and treatment data will be combined with those data already collected in the initial study of cases and controls aged 55 to 84. Multivariate techniques will be employed to assess differences in physical and social functioning, occupational status and performance, and economic resources. This research is designed to provide an assessment of functional needs, occupational performance, and economic resources, which may suggest, in turn, rehabilitation and home-care programs for those middle-aged and elderly women with breast cancer in greatest need.