Few women pay attention to this breast cancer risk factor

Dense breast tissue has been linked to up to a fourfold increased risk of breast cancer. However, a new study suggests that few women see breast density as a significant risk factor.

The study, published in JAMA Network Open, investigated 1,858 women aged 40 to 76 years from 2019 to 2020 who reported having recently had mammograms, had no history of breast cancer and had heard about breast density.

Women were asked to compare their risk of breast density with five other breast cancer risk factors: having a first-degree relative with breast cancer, being overweight or obese, drinking more than one alcoholic drink a day , not having children and having had a previous breast biopsy.

“When compared with other known breast cancer risks, women did not consider breast density to be a significant risk,” said Laura Beidler, study author and researcher at the Dartmouth Institute for Health Policy and Clinical Practice in the United States.

For example, the authors say that dense breast tissue is associated with a 1.2 to four times greater risk of breast cancer compared to a two times greater risk associated with having a first-degree relative with breast cancer – but 93% of women said breast density was a minor risk.

Dense breast tissue refers to breasts that are made up of more glandular and fibrous tissue than fatty tissue. It is something normal and present in about half of the women who have mammograms.

The researchers also interviewed 61 women who reported being notified about their breast density, asking them if they knew what that information could contribute to breast cancer and how it could reduce their risk. Although most women correctly observed that breast density could mask tumors on mammograms, few considered that breast density could be a risk factor.

And approximately one-third of women thought there was nothing they could do to reduce their risk of breast cancer, although there are many ways to do this, including maintaining a healthy, active lifestyle and minimizing alcohol consumption.

Breast tissue density

Breast density changes throughout a woman’s life and is generally higher in women who are younger, have a lower body weight, are pregnant or breastfeeding, or are taking hormone replacement therapy.

The level of breast cancer risk increases with the degree of breast density, however, experts are not sure why this is true.

“One hypothesis is that women who have denser breast tissue also have higher levels of estrogen, circulating estrogen, which contributes to both breast density and the risk of developing breast cancer,” said Harold Burstein, an oncologist. from the Dana-Farber Cancer Institute, which was not involved in the study. “Another hypothesis is that there is something in the tissue itself, making it denser, that somehow predisposes to the development of breast cancer. We don’t really know which one explains the observation.”

Currently, 38 US states mandate that women be notified in writing about their breast density and potential risk of breast cancer following mammography; however, studies have shown that many women find this information confusing.

“Although women are notified in writing after a mammogram that says, ‘Breast density increased,’ it’s something that’s put there at the end of the report. I’m not sure anyone explains to them, in person or in writing, what that means.” “, noted Ruth Oratz, an oncologist at NYU Langone’s Perlmutter Cancer Center, who was not involved in the study.

“I think what we’ve learned from this study is that we have to do a better job of educating not only women, but the general public of health care providers who are providing primary care, who are ordering these mammograms from tracking,” he added.

Screening is not the same for everyone

Current screening guidelines recommend that average-risk women be screened every one to two years between ages 50 and 74, with the option of starting at age 40.

As women with dense breast tissue are considered to have higher than average risks of cancer, the study authors suggest that women with high breast density may benefit from additional tests, such as MRI or breast ultrasound, which can detect cancers that are not detected on mammograms.

The authors further warn that “additional screening may lead not only to higher rates of cancer detection, but may also result in more false-positives and repeat visits.”

“Typically, it’s a discussion between the patient and the medical team. And it will be based on the medical history, if there’s anything worrisome about the mammogram, the patient’s family history. So these are the kinds of things that we often discuss with patients who find themselves in these situations,” explained Burstein.

Breast cancer screening recommendations differ between medical organizations, and experts say women at higher risk due to breast density should discuss with their doctor which method and frequency of screening is most appropriate.

“I think it’s very, very important that everyone understands – and I’m talking about doctors, nurses, women themselves – that screening is not the same for everyone. We can’t just make a general recommendation to the whole population because every woman has different levels of risk of developing breast cancer”, defended Oratz.

Decrease the risk

For nearly a third of women with dense breast tissue who feel there is nothing they can do to prevent breast cancer, experts say there are steps they can take to reduce their risk.

“Maintaining an active and healthy lifestyle and minimizing alcohol consumption are associated with several modifiable factors. Breastfeeding may decrease the risk. On the other hand, hormone replacement therapy increases the risk of breast cancer” , said Puneet Singh, an oncologist at the MD Anderson Cancer Center who was not involved in the study.

The researchers add that there are approved drugs, such as tamoxifen, that can be given to people at significantly increased risk, which can cut their chances of getting breast cancer by about half.

Finally, doctors say that, in addition to proper screening, knowing your risk factors and defending yourself can be powerful tools in preventing and detecting breast cancer.

“At any age, if any woman feels uncomfortable with something that is happening in the breast, if she feels discomfort, if she notices any changes in the breast, she should alert her doctor and make sure that her situation is evaluated and not ignored”, advised Oratz.