Key questions 1a. Does screening with mammography (film and digital) or MRI decrease breast cancer mortality and all-cause mortality among women aged 40 to 49 y and ≥ 70 y? 1b. Does CBE screening decrease breast cancer mortality for women of all ages? Alone or with mammography? 1c. Does BSE practice decrease breast cancer mortality for women of all ages? 2a. What are the harms associated with screening with mammography (film and digital) and MRI? 2b. What are the harms associated with CBE? 2c. What are the harms associated with BSE? Contextual questions What are the patient values and preferences related to screening for breast cancer? Are there subgroups of the Canadian population who have a higher burden of breast cancer or for whom it would be difficult to implement screening programs? Subgroup analysis that explores issues of burden of disease, screening rates, and special implementation issues includes the following: aboriginal women, women living in rural or remote areas, and consideration of ethnicity What is the optimal mammography screening frequency? What is the cost-effectiveness of screening for breast cancer?

BSE—breast self-examination, CBE—clinical breast examination, MRI—magnetic resonance imaging.