Why mammogram results now include new information for cancer detection

Starting Tuesday, letters to women who have a mammogram will not only contain the findings, but will also tell them about their breast density. That information is important because dense breast tissue makes it harder to spot breast cancer using mammography, while also increasing the risk of developing breast cancer.
And that’s something many women have never been told.
The U.S. Food and Drug Administration issued its final rule on March 10, with notice that it would become effective no later than Sept. 10, 2024.
The tissue will be categorized as “almost entirely fatty,” “scattered areas of fibroglandular density,” “heterogeneously dense which may obscure small masses” or “extremely dense, which lower the sensitivity of mammography.”
Breast cancer is the No. 2 cancer in U.S. women, behind skin cancer. And the American Cancer Society says 1 in 8 women will experience breast cancer at some point. The society’s breast cancer estimates for 2024 are 310,720 new cases of invasive breast cancer in women. About 56,500 new cases of ductal carcinoma in situ, which means it hasn’t spread. And roughly 42,250 women will die from breast cancer.
While routine screening begins in a woman’s 40s, about 10% of all new cases are found in women younger than 45, the Centers for Disease Control and Prevention reports.
Men can also get breast cancer, but it’s less common.
In younger women, it’s more apt to be a hereditary form of breast cancer.
There are two types of breast cancer that are most common and both are invasive, per the CDC. One starts in the ducts and spreads into other parts of the breast. The other starts in the lobules and spreads. Both can spread to other parts of the body.
There are also other, rarer types of breast cancer.
Each letter is required to contain one of two different notes. Both explain that breast tissue is either dense or not dense and that dense tissue makes it harder to detect breast cancer on a mammogram. They both say to discuss density breast cancer risk and individual situations with a health care provider. The notes also say that “your breast tissue is not dense,” or “your breast tissue is dense. In some people with dense tissue, other imaging tests in addition to mammograms may help find cancers.”
About half of women have dense breast tissue, radiologist Dr. Kimberly Feigin, interim chief of Breast Imaging Service and director of Breast Imaging Quality Assurance at Memorial Sloan Kettering Cancer Center, told CNN. “We talk about breast cancer density for two reasons. One is that breast density can make it more difficult to spot a cancer on a mammogram because dense breast tissue — the granular elements and connective tissue supporting elements — look white on a mammogram and cancer also looks white on a mammogram,” she said.
“The second reason is that breast density is important because having dense breast tissue raises a woman’s level of risk of developing breast cancer,” said Feigin.
More detailed information about dense breast tissue is online at densebreast-info.org.