Breast Ultrasound Screening Advice Missing Many Women Who Would Benefit
Informal recommendations on who should have supplemental breast cancer screening with breast ultrasound are aimed at women with dense breasts, but doctors need to take other breast cancer risk factors into account when recommending supplemental screening, according to a study.
The research was published online on June 12, 2023, by the journal Cancer. Read “Breast cancer risk characteristics of women undergoing whole-breast ultrasound screening versus mammography alone.”
Dense breasts and cancer screening
If you have dense breasts, it means you have more fibrous and glandular tissue and less fatty tissue in your breasts than women who don’t have dense breasts.
Dense breasts make it hard for doctors to see cancer on a mammogram. Research suggests that mammograms can miss about half of cancers in women with dense breasts. Besides making it harder to find cancer, dense breast tissue itself is linked to a higher risk of breast cancer. Doctors aren’t sure why this is.
Studies show that 3D mammograms are more accurate than traditional 2D mammograms for dense breasts. Doctors also may recommend supplemental breast cancer screening for women with dense breasts, often with ultrasound or MRI.
There are no overarching expert guidelines on which women should have supplemental breast cancer screening with ultrasound. So most information on ultrasound screening targets women with dense breasts, particularly after a number of states passed laws requiring women to be notified about their breast density with their mammogram results.
In this study, the researchers wanted to analyze the breast cancer risk factors of women having supplemental ultrasound screening to see if women having this type of screening were the ones most likely to benefit from it.
About the study
The researchers looked at information from three regional registries that are part of the Breast Cancer Surveillance Consortium, a database of breast cancer screening records funded by the National Cancer Institute:
Metro Chicago Breast Cancer Registry (data from 2014 to 2018)
San Francisco Mammography Registry (data from 2014 to 2020)
Vermont Breast Cancer Surveillance System (data from 2014 to 2020)
The researchers chose the three registries because they include a number of centers that perform ultrasound. Screening ultrasound is rare within other registries.
The study included:
38,166 ultrasound screening exams among 29,112 women
825,360 mammogram screening exams among 377,140 women
This means that one ultrasound exam was done for every 22 mammogram-only exams.
Among the ultrasounds done:
75% were the woman’s first ultrasound screening
63% were done within nine months after a mammogram
2% were done on women who had a previous MRI screening exam
about 69% were done on women ages 40 to 59
25.7% were done on Black, Asian, or Hispanic women
95.3% were done on women with dense breasts
21.7% were done on women with a family history of breast cancer
24.3% were done on women with a history of benign (non-cancerous) breast disease
43.7% were done on women considered overweight or obese
Women who had ultrasound screening were more likely than women who had mammogram screening alone to:
be younger than 50
be pre-menopausal
have dense breasts
not be overweight or obese
Among women with dense breasts, 35,616 ultrasounds screening exams and 342,343 mammogram-only screening exams were done. This means that one ultrasound was done for every 10 mammogram-only exams.
Among women with dense breasts, ultrasounds were more likely done on women who:
were white
were younger than 50
were pre-menopausal
had extremely dense breasts
had a family history of breast cancer
had a history of benign breast disease
Among women ages 35 to 74:
27.2% of screening ultrasound exams were done on women with an intermediate risk of breast cancer
18.1% of screening ultrasound exams were done on women with a high or very high risk of breast cancer
19.6% of mammogram-only exams were done on women with an intermediate risk of breast cancer
9.5% of mammogram-only exams were done on women with a high or very high risk of breast cancer
Among women ages 35 to 74 with dense breasts:
46.4% of ultrasound exams were done on women with an intermediate or a higher risk of breast cancer
40.7% of mammogram-only exams were done on women with an intermediate or a higher risk of breast cancer
The results show that supplemental ultrasound screening was recommended to women with dense breasts, but only a small percentage of these women were at high risk of having a mammogram miss a cancer. A similar percentage of women who had mammogram screening alone had a high risk of having a mammogram miss a cancer.
“Among women with dense breasts, there was very little targeting of ultrasound screening to women who were at the highest risk of a mammography screening failure,” Brian Sprague, PhD, of the University of Vermont Cancer Center, said in a statement. “Rather, women with dense breasts undergoing ultrasound screening had similar risk profiles to women undergoing mammography screening alone,” Dr. Sprague continued. “In other words, many women at low risk of breast cancer despite having dense breasts underwent ultrasound screening, while many other women at high risk of breast cancer underwent mammography alone with no supplemental screening.”
What this means for you
Although dense breasts increase the risk of breast cancer, not every woman with dense breasts has a high risk of the disease.
To develop a screening plan that’s best for your unique situation, it makes sense to follow the American College of Radiology breast cancer screening guidelines and have a breast cancer risk assessment by age 25.
You and your doctor are likely to discuss the following points:
family history of breast or other related cancers (ovarian, melanoma)
any test results for gene mutations linked to higher breast cancer risk
results of past breast biopsies, even if they were benign
personal history of radiation treatment to the face, chest, or both before age 30
breast density
weight
level of physical activity
any use of post-menopausal combined hormone replacement therapy (HRT)
alcohol consumption, if you regularly drink more than three alcoholic beverages a week
the amount of processed food and trans fats you eat
your smoking history
whether or not you have carried a pregnancy to term or have breastfed
If you decide that you have a higher-than-average risk of developing breast cancer, ask your doctor when you should start annual mammograms and whether you need supplemental screening with ultrasound or MRI.
— Last updated on August 18, 2023 at 3:49 PM