The American College of Radiology (ACR) is at the forefront of radiology, representing almost 40,000 imaging physicians. In March 2018 the ACR published the following article to educate both radiologists and primary care providers: “Cancer Screening in Women at Higher-Than-Average Risk: Recommendations from the ACR.” The following is a summary of these recommendations for breast cancer screening in high-risk women.
The ACR breast cancer screening recommendations incorporate screening by both mammography and breast MRI. The article provides a brief description of these imaging techniques and how they compare to each other in terms of detecting cancer.
2D mammogram vs. 3D mammogram:
- 3D mammography is done in addition to 2D mammography, not as a replacement for 2D mammography.
- 3D mammography detects more cancers than 2D mammography alone.
- 3D mammography results in fewer women having to return for additional imaging following a screening mammogram compared with 2D mammography alone.
Breast MRI
- Detects more cancers than both 2D and 3D mammography
- In high-risk women a recent study showed that 90% of breast cancers were found with MRI compared with 37.5% of cancers found by mammography.
- Because some cancers are only seen on mammography and not breast MRI, breast MRI alone is not recommended for comprehensive breast cancer screening, even in high-risk patients.
Two things should be established to determine which breast cancer screening protocol is most appropriate:
Determine if you meet the criteria to be considered high risk for developing breast cancer. High-risk patients include the following:
- Lifetime risk of developing breast cancer >20%
- Multiple lifetime breast cancer risk determination models are available. Each model has its strengths and weaknesses. The most appropriate model should be chosen by your primary care provider to determine your lifetime breast cancer risk.
- Some radiology institutions will include the lifetime breast cancer risk percentage in the screening mammogram report.
- Genetic mutations determined through genetic testing (see your primary care provider to determine if testing for possible mutations is warranted)
- History of treatment with chest or mantle radiation therapy (e.g. treatment for Hodgkin lymphoma) before the age of 30
- Personal history of breast cancer diagnosed at or before age 50 and treated with breast-conserving therapy (lumpectomy)
- Previous breast biopsy with pathology results of a high-risk marker (consultation with your primary care provider is recommended to discuss any prior biopsy results)
Do you have dense breast tissue?
Identifying a cancer on a screening mammogram can be more difficult in women with dense breast tissue. Breast density is determined on a screening mammogram and this information is included in the screening mammogram report. Federal law requires a letter to be mailed to all women who have dense breast tissue informing them of their dense breast tissue status. Younger women tend to have denser breast tissue while 40-50% of women over age 40 have dense breast tissue. There is also an increased risk of developing breast cancer in women with dense breast tissue, however, in the absence of other risk factors this risk is not enough to classify a patient as high risk.
The ACR Breast Cancer Screening recommendations are as follows:
- By age 30:
- All women should be evaluated for breast cancer risk by their primary care provider.
- Early breast cancer risk determination is particularly important for women of Ashkenazi Jewish descent and African American descent, as these women are at higher risk for genetic mutations which can lead to more aggressive young-onset breast cancers.
- Average Risk Women (<10% lifetime risk of breast cancer as per a risk determination model):
- Age 40: Begin annual screening mammography
- High-risk women AND their first-degree relatives (e.g. mom, sister, and daughter) due to:
- specific genetic mutations determined through genetic testing
- OR >20% lifetime risk:
- Age 30: Begin annual screening mammography
- Age 25-30: Breast MRI annually
- History of chest radiation therapy before the age of 30:
- Age 25 or 8 years after radiation therapy, whichever is later: Begin annual screening mammography
- Age 25-30: Breast MRI annually
- If EITHER of the following applies:
- Personal history of breast cancer AND dense breast tissue
- Personal history of breast cancer diagnosed before age 50
- Continue annual screening mammography
- Breast MRI annually
- If EITHER of the following applies:
- Personal history of breast cancer diagnosed AFTER age 50 without dense breast tissue
- Women with a history of a high-risk marker found at time of breast biopsy but <20% lifetime risk as per the risk assessment model:
- Continue annual screening mammography
- Consider adding an annual screening breast MRI
To gain the most from these recommendations, early breast cancer risk assessment is paramount. Once breast cancer risk assessment is complete, this article can help facilitate an informed conversation with your primary care provider to determine your individualized breast cancer screening protocol.