From the Guidelines
Breast cancer screening guidelines recommend biennial mammograms for women aged 50-74 years, with individualized decisions for those aged 40-49 and 75 years or older. Women at average risk should discuss their personal risk factors with healthcare providers to determine the most appropriate screening schedule for their situation 1. The decision to start screening should be an individual one for women aged 40-49 years, with a consideration of the benefits and harms of screening 1.
Key Recommendations
- Women aged 50-74 years should screen every 2 years with conventional digital mammography, which has essentially replaced film mammography as the primary method for breast cancer screening in the United States 1.
- For women aged 40-49 years, the decision to start screening should be an individual one, with a consideration of the benefits and harms of screening, including the risk of false-positive results and unnecessary biopsies 1.
- Women at high risk, such as those with a family history or genetic mutations like BRCA1/2, should begin screening earlier, typically at age 30, and may benefit from additional imaging like breast MRI 1.
- Clinical breast exams by healthcare providers are not recommended for breast cancer screening among average-risk women at any age, and breast self-awareness is encouraged, though formal self-examination is optional 1.
Rationale
The recommendations are based on the balance of benefits and harms of screening, including the reduction in breast cancer mortality and the risk of over-diagnosis and over-treatment 1. The evidence for effectiveness of mammography screening in women aged 40-49 years is limited, and there is no consensus about the exact effect of mammography screening on breast cancer mortality reduction 1. However, mammography screening and population-based awareness programmes, together with improved treatment, may contribute to mortality reduction in breast cancer 1.
Individualized Approach
Women should discuss their personal risk factors with healthcare providers to determine the most appropriate screening schedule for their situation, taking into account their age, family history, genetic mutations, and other risk factors 1. This individualized approach will help to maximize the benefits of screening while minimizing the harms.
From the Research
Breast Cancer Screening Guidelines
- The American College of Radiology (ACR) recommends annual screening beginning at age 40 for women of average risk and earlier and/or more intensive screening for women at higher-than-average risk 2.
- For most women at higher-than-average risk, the supplemental screening method of choice is breast MRI 2.
- Women with genetics-based increased risk, those with a calculated lifetime risk of 20% or more, and those exposed to chest radiation at young ages are recommended to undergo MRI surveillance starting at ages 25 to 30 and annual mammography (with a variable starting age between 25 and 40, depending on the type of risk) 2.
- Mutation carriers can delay mammographic screening until age 40 if annual screening breast MRI is performed as recommended 2.
- Women diagnosed with breast cancer before age 50 or with personal histories of breast cancer and dense breasts should undergo annual supplemental breast MRI 2.
- Others with personal histories, and those with atypia at biopsy, should strongly consider MRI screening, especially if other risk factors are present 2.
- For women with dense breasts who desire supplemental screening, breast MRI is recommended 2.
- For those who qualify for but cannot undergo breast MRI, contrast-enhanced mammography or ultrasound could be considered 2.
Screening Intervals
- The balance between the benefits and harms of different screening intervals is still a matter of debate 3.
- Annual compared to biennial screening may have small additional benefits but an important increase in false positive results 3.
- Triennial compared to biennial screening may have smaller benefits while avoiding some harms 3.
- In women 50-69, biennial screening may be the most favorable option 3.
- In younger women (aged 45-49), annual screening may have a less favorable balance, while in women aged 70-74 years longer screening intervals may be more favorable 3.
Effectiveness of Screening Methods
- Mammography screening has consistently been shown to significantly reduce breast cancer mortality over a variety of study designs 4.
- MRI has been shown to detect cancers that were not identified on mammography 6 months earlier in women at genetically high risk of developing breast cancer 5, 6.
- Screening MRI in high-risk women was capable of detecting mammographically and clinically occult breast cancer 6.