What are the guidelines for breast cancer screening?

From the Guidelines

Breast cancer screening should begin at age 45 for women at average risk, with annual mammograms recommended for women aged 45-54 years, and biennial screening for women aged 55 and older, as long as their overall health is good and they have a life expectancy of 10 years or more. The American Cancer Society recommends that women with an average risk of breast cancer should undergo regular screening mammography starting at age 45 years 1. The guidelines also suggest that women who are ages 45 to 54 years should be screened annually, while women who are age 55 years and older should transition to biennial screening or have the opportunity to continue screening annually 1. Additionally, women should have the opportunity to begin annual screening between the ages of 40 and 44 years, and should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or more 1. It is also recommended that clinical breast examination is not used to screen for breast cancer among average-risk women at any age 1. Some studies suggest that mammography screening in women aged 50-69 years has shown the greatest mortality reduction benefit, and is recommended by the European Union and numerous individual countries 2. However, 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 2. In women with familial breast cancer, with or without proven BRCA mutations, annual screening with magnetic resonance imaging (MRI) of the breast, in combination with mammography, can detect the disease at a more favourable stage compared with mammography screening alone 2. Key points to consider when developing a breast cancer screening plan include:

• Starting age: 45 years for average-risk women
• Screening interval: annual for women aged 45-54 years, biennial for women aged 55 and older
• Screening method: mammography, with consideration of MRI for high-risk women
• Continuation of screening: as long as overall health is good and life expectancy is 10 years or more
• Clinical breast examination: not recommended for average-risk women at any age. It is essential to weigh the benefits and harms of screening, including the risk of over-diagnosis and over-treatment, as well as false-positive screening, when balancing the benefits and harms of screening 2. Women should discuss their personal risk factors with healthcare providers to determine the most appropriate screening schedule for their individual circumstances.

From the Research

Guidelines for Breast Cancer Screening

• The American College of Radiology (ACR) recommends annual screening beginning at age 40 for women of average risk 3, 4, 5.
• For women at higher-than-average risk, the ACR recommends earlier and/or more intensive screening, with breast MRI as the supplemental screening method of choice 3.
• 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 3.
• The American Society of Breast Surgeons also recommends that average-risk women undergo breast cancer screening every year starting at age 40 6.
• Screening should continue past age 74 years, without an upper age limit unless severe comorbidities limit life expectancy 4.

Special Considerations

• Women diagnosed with breast cancer before age 50 or with personal histories of breast cancer and dense breasts should undergo annual supplemental breast MRI 3.
• Others with personal histories, and those with atypia at biopsy, should strongly consider MRI screening, especially if other risk factors are present 3.
• For women with dense breasts who desire supplemental screening, breast MRI is recommended 3.
• For those who qualify for but cannot undergo breast MRI, contrast-enhanced mammography or ultrasound could be considered 3.

Benefits and Risks

• Mammography screening has been proven effective in reducing breast cancer deaths in women age 40 years and older, with a mortality reduction of 40% possible with regular screening 4.
• The benefits of screening should be considered along with the possibilities of recall for additional imaging and benign biopsy and the less tangible risks of anxiety and overdiagnosis 4.
• The risks associated with mammography screening, including false-positive recalls and over-diagnosis, should also be considered 7.