Description: The purpose of this guidance statement is to provide advice to clinicians on breast cancer screening in average-risk women based on a review of existing guidelines and the evidence they include.

Methods: This guidance statement is derived from an appraisal of selected guidelines from around the world that address breast cancer screening, as well as their included evidence. All national guidelines published in English between 1 January 2013 and 15 November 2017 in the National Guideline Clearinghouse or Guidelines International Network library were included. In addition, the authors selected other guidelines commonly used in clinical practice. Web sites associated with all selected guidelines were checked for updates on 10 December 2018. The AGREE II (Appraisal of Guidelines for Research and Evaluation II) instrument was used to evaluate the quality of guidelines.

Target audience and patient population: The target audience is all clinicians, and the target patient population is all asymptomatic women with average risk for breast cancer.

Guidance statement 1: In average-risk women aged 40 to 49 years, clinicians should discuss whether to screen for breast cancer with mammography before age 50 years. Discussion should include the potential benefits and harms and a woman's preferences. The potential harms outweigh the benefits in most women aged 40 to 49 years.

Guidance statement 2: In average-risk women aged 50 to 74 years, clinicians should offer screening for breast cancer with biennial mammography.

Guidance statement 3: In average-risk women aged 75 years or older or in women with a life expectancy of 10 years or less, clinicians should discontinue screening for breast cancer.

Guidance statement 4: In average-risk women of all ages, clinicians should not use clinical breast examination to screen for breast cancer.