At what age should a woman get her first mammogram (mammography)?

Age Recommendations for First Mammogram Screening

Women should begin annual mammographic screening at age 40 for average risk individuals, with earlier screening recommended for those at higher-than-average risk. 1

Screening Recommendations by Risk Category

Average Risk Women

• Begin annual mammography at age 40 1
• Continue screening as long as the woman remains in good health and is willing to undergo additional testing if abnormalities are found 1
• No upper age limit for screening; decisions should be based on life expectancy and comorbidities rather than age alone 1

Higher-Than-Average Risk Women

Early screening is recommended for women with:

1. Family history of breast cancer:

   • Begin screening 10 years before the age of youngest affected first-degree relative (but generally not before age 30) 1, 2
   • Example: If mother diagnosed at 42, daughter should begin at age 32

2. Genetic predisposition:

   • BRCA1/BRCA2 mutation carriers: Begin MRI at age 25-30, with mammography starting between ages 25-40 3
   • May delay mammography until age 40 if annual MRI screening is performed 3

3. History of high-risk lesions:

   • Lobular neoplasia or atypical hyperplasia: Begin annual mammography at time of diagnosis (not before age 30) 1

4. History of chest radiation at young age:

   • Begin screening 8-10 years after radiation exposure or at age 25, whichever comes later 1

Benefits and Limitations of Mammography

Benefits

• Reduces breast cancer mortality by at least 22% in randomized controlled trials 1
• Observational studies show up to 40% mortality reduction in women who actually get screened 1
• Annual screening provides greater mortality reduction than biennial screening (40% vs 32%) 1
• Detects cancers at earlier stages, allowing for less aggressive treatment 1

Limitations

• False positive results (approximately 10% of screening mammograms result in recall) 1
• Lower sensitivity in women with dense breasts 1
• Potential for overdiagnosis of cancers that might never become clinically significant 1

Supplemental Screening Considerations

For women with dense breasts or other risk factors:

• MRI is the preferred supplemental screening method for high-risk women 3
• Ultrasound can be considered for those who qualify for but cannot undergo MRI 1
• Digital breast tomosynthesis (DBT) shows increased cancer detection rates and decreased recall rates compared to standard mammography 1

Common Pitfalls to Avoid

1. Delaying screening until age 50: This approach misses the opportunity for mortality reduction that begins at age 40 1

2. Risk-based screening only: Restricting screening to only women with family history or dense breasts would miss 66% of potentially screen-detected cancers in women under 50 1

3. Stopping screening at arbitrary age cutoffs: Screening decisions for older women should be based on overall health status and life expectancy, not age alone 1

4. Ignoring risk assessment: All women should undergo risk assessment by age 30 to identify those who would benefit from earlier or supplemental screening 1, 3

5. Inappropriate early screening: About 14.3% of women aged 18-39 years report having had a mammogram, often without clear clinical indications 4

The evidence clearly supports beginning mammography at age 40 for average-risk women, with earlier screening for those with risk factors. This approach maximizes the mortality benefit while maintaining a reasonable balance with potential harms.