Mammography Screening Interval for a 45-Year-Old Woman with Normal Results
A 45-year-old average-risk woman with a normal mammogram should repeat screening in 1 year (Answer B).
Guideline-Based Recommendation
For women aged 45-54 years, annual mammography screening is the standard of care across major professional societies. 1
Key Supporting Guidelines:
American Cancer Society (ACS): Women aged 45-54 years should be screened annually (qualified recommendation). This represents a strong consensus that annual screening in this age group maximizes mortality reduction while maintaining an acceptable benefit-to-harm ratio. 1
American College of Radiology (ACR): Recommends annual screening mammography beginning at age 40 for average-risk women, which continues through the 45-54 age range. 1
National Comprehensive Cancer Network (NCCN): Recommends annual screening mammography for average-risk women aged 40 years and older. 1
Why Annual Screening at Age 45?
The evidence supporting annual screening in this age group is based on several factors:
Peak incidence period: Women aged 45-54 have higher breast cancer incidence rates (224.0 per 100,000) compared to younger women, making annual screening more beneficial. 2
Mortality reduction: Annual mammography screening achieves a 15-20% reduction in breast cancer mortality, with some studies showing up to 40% reduction with regular screening. 2, 3
Earlier stage detection: Annual screening results in more screening-detected tumors, smaller tumor sizes, fewer interval cancers, and better lymph node status compared to longer intervals. 3, 4
Important Clinical Considerations
The transition to biennial (every 2 years) screening occurs at age 55, not at age 45. 1 At age 45, this patient is in the age bracket where annual screening provides the greatest benefit.
Common Pitfall to Avoid:
Do not confuse the age 45 initiation recommendation with screening interval recommendations. While some guidelines suggest women can begin screening between ages 40-44, once a woman reaches 45-54 years, the interval is clearly annual. 1
Alternative Guideline Perspectives
The Canadian Task Force on Preventive Health Care (CTFPHC) recommends screening every 2-3 years for women aged 50-69, but this represents a more conservative approach with lower certainty evidence and is not the standard in U.S. practice. 1
The American College of Physicians recommends screening every 1 or 2 years based on shared decision-making, but acknowledges that annual screening is a reasonable option, particularly for women under age 55. 1