Routine Mammography Screening Frequency
For women over 40 with no personal or family history of breast cancer, annual mammography starting at age 40 provides the greatest mortality reduction (40%) and should be performed yearly through at least age 74. 1
Screening Schedule by Age
Ages 40-54
- Annual mammography is recommended starting at age 40, which provides superior outcomes compared to biennial screening 1
- Annual screening results in more screening-detected tumors, smaller tumor sizes, and fewer interval cancers than longer screening intervals 1
- Women screened in their 40s are more likely to have early-stage disease, negative lymph nodes, and smaller tumors compared to unscreened women 1
- Delaying screening until age 45 or 50 results in unnecessary loss of life to breast cancer 1
Ages 55-74
- Annual mammography remains the preferred approach, though biennial screening is acceptable for some women after age 55 2
- The evidence supporting mortality benefit is strongest in this age group 2
- Annual screening provides 40% mortality reduction versus 32% with biennial screening 3
Age 75 and Beyond
- Screening should continue past age 74 without an upper age limit unless severe comorbidities limit life expectancy to less than 10 years 1, 2
- The decision should be based on health status rather than chronological age alone 1
Key Supporting Evidence
The American College of Radiology and Society of Breast Imaging strongly recommend annual screening beginning at age 40 1. This recommendation is based on evidence that:
- Treatment advances cannot overcome the disadvantage of being diagnosed with advanced-stage tumors 1
- Regular annual screening provides the greatest mortality reduction, earlier stage diagnosis, better surgical options, and more effective chemotherapy 1
- The benefits of mammography continue to increase with age while risks of harm decrease between ages 40 and 70 3
Important Considerations
Screening intervals matter: While some organizations suggest biennial screening is acceptable (particularly the U.S. Preventive Services Task Force for ages 50-74), annual screening detects more cancers at earlier stages and prevents more deaths 1, 2
Potential harms to discuss: Approximately 10% of screening mammograms result in recall for additional imaging, though less than 2% require biopsy 3. False-positive results may lead to additional testing and anxiety 2. However, women who wish to maximize benefit will choose annual screening starting at age 40 and will not stop screening prematurely 1
Quality assurance: Screening should be performed at accredited centers with appropriate quality assurance standards to ensure accurate imaging and radiographic interpretation 3
Digital Breast Tomosynthesis (DBT): This may be used instead of standard mammography, as it decreases recall rates and improves cancer detection rates, particularly beneficial in women under age 50 3