Screening

Early detection is highly effective in reducing mortality associated with breast cancer. However, screening can lead to overdiagnosis and overtreatment of breast disease, and women should be informed of both the benefits and harms.[166]

Screening mammography is not routinely performed in men, but may be considered for men at higher risk, especially those with a BRCA2 pathogenic or likely pathogenic variant.[17]

Initial breast cancer risk assessment

Breast cancer risk assessment should be used to identify women at higher risk and guide screening, risk reduction strategies, and genetic evaluation. A validated assessment tool may be used:​[53][101]​​

US guidelines recommend clinical assessment by age 25 years for all women.​[101][102][103]​​​[104] The American College of Obstetricians and Gynecologists (ACOG) and National Comprehensive Cancer Network (NCCN) guidelines recommend offering clinical assessment to women ages 25-39 years every 1-3 years, and annually for women ages 40 years and older.[101][103]

Clinical assessment should include risk assessment, counseling on breast awareness and healthy lifestyle, and may include a breast exam. The National Breast and Cervical Cancer Early Detection Program in the US found that adding clinical breast exam to mammography led to an increase in breast cancer detection rate, such that 5% of cancers were detected by clinical breast exam alone initially (i.e., where screening mammogram had been negative, benign, or probably benign).[167]

Woman at average risk: mammography screening recommendations

US guidelines typically recommend that average-risk women:[101][103][134][168]​​​​

  • Start regular (annual or biennial) bilateral mammography screening at age 40 years.

  • Continue regular breast screening, irrespective of age, unless they have severe comorbidities and/or limited life expectancy (<10 years), or make an informed shared decision to stop.

Reduction in breast cancer mortality varies by screening regimen; mortality reduction is greater when screening starts at 40 years compared with 45 or 50 years, and when done annually rather than biennially.[104][169]​​​ However earlier, more frequent screening may increase over diagnosis.​[101][104][134]​​​​

The American Cancer Society (ACS) and the ACOG recommend shared decision-making about when to start regular screening mammography, starting at age 40 years if they wish, and with all women starting screening by 45 years or no later than 50 years.[103][170]

Most US guidelines do not give an upper age limit for screening; the evidence for or against screening in women ages 75 and over is limited.[168] A shared decision should be made about when to stop screening after age 75 years.[103]

NCCN guidelines recommend screening mammography with digital breast tomosynthesis (DBT; three-dimensional mammography) for women at average risk.[101][168]​ The American College of Radiology (ACR) suggests that DBT may be used as an alternative to conventional mammography or for supplemental screening.[104][171]​ DBT has been found to improve cancer detection and decrease false-positive call back rates compared with two-dimensional mammography alone.[101][172]​​[173][174][175]​​​​​​​​​

Women with dense breasts: supplemental screening

​Dense breast tissue is a risk factor for developing breast cancer, and mammographic sensitivity is lower in women with dense breasts; therefore, supplemental imaging may be warranted.[101]​​[134][135][171]​​​ The addition of MRI, DBT, or ultrasound to conventional mammography increases the sensitivity and rate of cancer detection in women with dense breasts.[171][172][176]​​​[177]​​​​​

Although supplemental imaging may improve detection of breast cancer, the risk of false-positive results and overdiagnosis is increased.[178][176]​​​​​​

​Guidelines do not recommend routine use of supplemental MRI or ultrasound in screening average-risk women with dense breasts, due to a lack of evidence showing a benefit in these women.[101]​​[168][178][179]​​​​​​

However, ​NCCN guidelines recommend that supplemental screening with ultrasound or MRI (in addition to screening mammography with DBT) may be considered for average-risk women ages ≥40 years with heterogeneous or extremely dense breasts, taking into account risk and patient preference.[101] The ACR suggests that DBT is usually appropriate for supplemental screening in average-risk women with dense breasts, and that ultrasound may be appropriate in some cases.[171]​​

For higher-risk women with dense breasts, the US guidelines recommend supplemental screening with annual MRI (without and with contrast) in combination with mammography and DBT.[101][171] Abbreviated MRI (without and with contrast) or ultrasound may be considered as alternative options to MRI, although they have lower sensitivity.[171]​​​

In the US, the Food and Drug Administration (FDA) requires that all mammography reports sent to the clinician and patient should include an assessment of a patient’s breast density to inform decision-making regarding supplemental screening.[179][180][181]

Women at higher risk

US guidelines recommend more intensive screening for higher-risk women, with mammography, DBT, and MRI (without and with contrast).[17][101]​​​​​​​​​​​[102][104][178]​​​​​​ Contrast-enhanced mammography or molecular breast imaging are also options for higher-risk breast cancer screening; they may be considered if MRI is not suitable. Whole breast ultrasound is an option if these are not available.[101]

Recommendations for screening women at higher-risk:[17][101]

  • ≥20% lifetime risk of breast cancer (calculated using a validated risk assessment tool that is primarily based on family history: for example, BRCAPro, Tyrer-Cuzick, BOADICEA/CanRisk): annual screening with mammography, DBT, and MRI (without and with contrast) should start at age 40 years, or when identified at risk assessment, or 10 years before the earliest known breast cancer in the family (but not before age 25 years).

  • History of radiation therapy with exposure to breast tissue between the ages of 10 and 30 years: annual screening with mammography, DBT, and MRI (without and with contrast) should start 8 years after radiation therapy (but not before age 25 years).

  • Personal history of lobular carcinoma in situ, or atypical ductal or lobular hyperplasia: annual screening with mammography and DBT, and consideration of supplemental MRI (without and with contrast) may be considered if they have a ≥20% lifetime risk of breast cancer, starting at age of diagnosis (but not before age 25 years).

  • Known or likely high-risk genetic mutation (e.g., BRCA1, BRCA2) or a first-degree relative with a BRCA mutation: annual MRI (without and with contrast) from ages 25 to 29 years, with mammography added from age 30 to 75 years, and individualized screening >75 years. Annual mammography may be considered for men with a known or likely BRCA mutation, starting at age 50 years or 10 years before the earliest known male breast cancer in the family.

  • Diagnosis of Li-Fraumeni syndrome (TP53 mutation), Cowden syndrome/PTEN hamartoma tumor syndrome, or a first degree relative with one of these syndromes: for Li-Fraumeni syndrome, annual MRI (without and with contrast) from ages 20 to 29 years, with mammogram added from ages 30 to 75 years, and individualized screening >75 years; for Cowden/PTEN hamartoma tumor syndrome, annual mammogram and MRI (without and with contrast) from ages 30 to 75 years, and individualized screening >75 years.

  • 5-year breast cancer risk ≥1.7% using Gail model; or 10-year risk of ≥5% using IBIS/Tyrer-Cuzick model: annual screening mammography with DBT, starting when identified at risk assessment.

Genetic evaluation

The NCCN recommends genetic counseling and testing for high-penetrance breast cancer susceptibility genes (e.g., BRCA1, BRCA2, CDH1, PALB2, PTEN, STK11, and TP53) in the following women at high-risk for hereditary breast cancer:[17]

  • With any blood relative with a known pathogenic/likely pathogenic variant in a cancer susceptibility gene.

  • With a personal history of breast cancer and any of the following specific features:

    • Diagnosed ages ≤50 years

    • Ashkenazi Jewish ancestry

    • Triple-negative breast cancer, or multiple primary (synchronous or metachronous) breast cancers, or lobular breast cancer (with a personal or family history of diffuse gastric cancer).

  • With a personal history of breast cancer and a strong family history, including:

    • ≥1 close blood relative diagnosed with breast cancer at ages ≤50 years, or with male breast cancer, ovarian or pancreatic cancer, or prostate cancer (with metastatic, or high- or very high-risk group) at any age; or

    • ≥3 diagnoses of breast and/or prostate cancer on the same side of the family (including the patient being assessed).

  • With a strong family history of breast cancer (first- or second-degree relative with specific features as above).

  • Who meet the testing criteria for Li-Fraumeni syndrome, or Cowden syndrome/PTEN hamartoma tumor syndrome.

  • With >5% probability of a BRCA1 or BRCA2 pathogenic/likely pathogenic variant based on prior probability models (e.g., Tyrer-Cuzick, BRCAPro, CanRisk).

All male patients with breast cancer at any age should have genetic testing.[17][116]

The American Society of Breast Surgeons and the USPSTF have published recommendations for genetic testing for breast cancer.​[115][182]

The results of genetic testing should be used to guide screening and risk reduction strategies, and inform cascade screening (genetic counseling and testing in blood relatives of individuals who have been identified with specific genetic mutations). Hereditary breast cancer has been identified by the Centers for Disease Control and Prevention as a high-priority syndrome for cascade screening.[183][184]

Use of this content is subject to our disclaimer