'My cancer wasn't in those pictures': How breast density affects mammograms | Well, actually

IIn 2017, 55-year-old Leslie Ferris Yager underwent a routine mammogram and breast ultrasound. They both returned safely. Two months later, she underwent an unrelated Dexa scan to measure bone density. The technician noticed an abnormality in her hip joint. After additional tests, Yarger was diagnosed with stage 4 breast cancer. This is an advanced stage where the cancer has spread beyond the breast.

A mammogram and ultrasound did not detect cancer, as Yarger would learn that her breast tissue was dense.

“My cancer simply wasn't in those photos,” she says. “I also learned that this is not an uncommon story.”

According to National Cancer Instituteapproximately 50% of women over the age of 40 are found to have dense breasts. This is a term that refers to the ratio of fatty tissue to denser fibrous and glandular tissue in a person's breasts. In mammography, the dense tissue can make it difficult for the technician to find potentially cancerous masses.

Some states in the U.S. required mammography reports to include information about a patient's breast density and how it could affect the results, but federal regulations did not exist until this year. There wasn't.

In September, the FDA Request a mammography report Include information about breast density and how it affects patient outcomes. “Dense tissue makes it difficult to detect breast cancer on mammograms and increases the risk of developing breast cancer,” the disclosure statement says. The report states that “in some people with dense tissue, other imaging tests in addition to mammography may help detect cancer.”

This ruling marks a turning point in the field of breast cancer detection and treatment. But there is still no consensus on what these results mean for testing in the U.S. or abroad. For example, in the UK the NHS Does not include Information about breast density from the patient's mammogram report.

Experts say more research and testing is needed, as well as patient advocacy. Here's what you need to know:

What is dense breast?

The breast consists of 3 types of organizations: fatty breast tissue, fibrous connective tissue and glandular tissue. These last two are collectively referred to as .fibroglandular tissue” is denser than adipose tissue. The ratio of fibroglandular to fatty tissue determines whether a breast is considered dense. People with dense breasts have more fibroglandular tissue compared to fat. This decision is not based on a specific ratio, but rather on the radiologist's subjective assessment, explains Dr. Habib Rahbar, a professor of radiology at the University of Washington.

There are four categories of breast density. The first two (completely fatty breast tissue and scattered fibroglandular breast tissue) are considered hypodense. The other two are uneven breast tissue (about 40% of women have it) and very dense breast tissue (about 10% of women have it), which is considered dense.

Despite its prevalence, “there's a lot we don't understand about breast density and why some people have denser breasts than others,” says Abramson of the University of Pennsylvania. said Dr. Angela DeMichele, professor of medicine at the Breast Cancer Center and co-leader of the breast cancer program. center.

People from some racial groups, such as Asian Americans and Black Americans, are more likely to have dense breast tissue, said Dr. Arif Kamal, chief patient officer at American Airlines Hospital. Masu. cancer society. You can also do it as a family.

Additionally, an individual's breast density can change from year to year depending on age, hormone levels, menstrual cycles, and medication status. About 50 percent of women in their 40s have dense breasts, but that number drops to about 25 percent for women over 60, said Dr. Mariam Rustberg, chief of breast oncology at Yale Cancer Center.

How do I know if I have dense breasts?

To find out if you have dense breasts, you need to undergo a mammogram. A radiologist will then examine the results and determine the level of breast density. As a result of the new FDA decision, these findings will be noted on the mammography exam report, along with guidance on whether to request additional testing.

Breast density is not something that can be self-diagnosed, says Kamal. “It says, 'When you look at the screen.' [of a mammogram] Your chest is thick. ” Not that you can feel the difference. ”

How does breast density affect cancer screening?

This increased density of fibroglandular tissue can make mammograms more difficult to read. A mammogram is an x-ray, and x-rays more easily pass through soft tissues such as fat, making these areas appear darker in the resulting image. Dense tissue appears whiter, making it harder to see on a mammogram and making it difficult for radiologists to identify suspicious masses that also appear white. Rustberg likens it to trying to see through a “blizzard.”

For people with dense breasts, doctors often strongly recommend other imaging tests in addition to mammography. This may include a whole breast ultrasound, which uses sound waves rather than X-rays to create images of the breasts. “It's a different style, so if there's a lump hidden behind something, [the sound wave] It’s going to move a little bit differently,” Rustberg explains. However, experts are divided on how useful breast ultrasound is. One person described them as “of limited value.”

Some doctors may recommend that patients with dense breasts have an MRI scan. MRI is an effective way to detect cancer even in very dense breasts. However, MRI can cause false positives. Rustberg says the risk may be justified for people at high risk for breast cancer. MRI can also be helpful for people who are concerned about whether their mammogram is accurate. But for people at average risk, MRIs can cause “unnecessary biopsies” and “increased anxiety.”

Kamal says balancing these factors when it comes to additional testing ultimately comes down to “the patient's risk tolerance.”

“It's very confusing,” DeMichele said. “We don't have definitive studies that tell us exactly what tests to do. [people] Possible dense breasts [detect] It can prevent cancer without leading to more cancers or more biopsies. ”

Compounding the problem is uneven access, Rahver said. Such tests are not always covered by insurance, and some patients live in so-called “medical deserts” where advanced or even basic imaging technology is not available.

Is mammography still useful?

Does all this mean that mammograms are useless for people with dense breasts? Experts say that's not the case.

In addition to detecting dense masses, mammograms also detect calcifications within the breast. “This is one of the best ways to find very small cancers, especially cancers that don't usually show up as densities,” DeMichele says. Although these calcifications are a little less visible on mammograms of dense breasts, they are still “very noticeable,” she says.

Does breast density affect cancer risk?

Breast density itself is a risk factor for cancer, although experts don't fully understand why.

People with dense breasts are two to three times more likely to develop breast cancer during their lifetime, Rustberg said. There are several theories as to why, but none have been conclusively proven. “Dense breasts seem to have a slightly different biology than fatty breast tissue,” Rustberg says.

Experts emphasize that a person's breast density is just one potential risk factor. Breast cancer risk assessment toolSome of these are available online and take into account factors such as a person's age, age when they first got their period, age when they had their first child, and family history of cancer.

“I think it's every woman's right to know her own breast cancer risk,” Rustberg says.

How can patients advocate for themselves when it comes to breast density?

Because there are no clear, standardized guidelines for breast density screening, much of the onus is on the patient to obtain the information they need.

“We shouldn't wait for the scientific community to come out with a unified voice and figure out what they want to do. We don't have time for that,” says Kamal. Instead, she says, patients should insist on having a conversation with their doctor to understand their breast cancer risk and advocate for the care and testing they feel comfortable with.

Yarger founded the advocacy group My Density Matters in 2021. These organizations have been raising awareness about breast density for many years. It also provides information about breast density, questions to ask your health care provider, additional testing options, and advice on how to deal with potential pushback from your doctor or insurance agent.

“What we ask is [patients] It’s not an easy thing to do,” says Yarger. “Now that's what we have to do.”