Changes in breast density over time may be linked to breast cancer risk, study finds

CNN
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Breast density is known to naturally decrease as women age, and research now suggests that the longer it takes for breast density to decrease, the more likely a woman is to develop breast cancer. is suggested.

Researchers have long known that women with dense breasts have a higher risk of breast cancer. However, according to a study published last week in the journal JAMA Oncologythe rate of change in breast density over time also appears to be associated with the risk of being diagnosed with cancer in that breast.

“We know that invasive breast cancer is rarely diagnosed in both breasts at the same time. It is not surprising that we observed that she developed breast cancer,” said Shu Jiang. He is an Associate Professor of Surgery at the Washington University School of Medicine in St. Louis and the first author of the new study.

Breast density refers to the amount of fibrous and glandular tissue in the breast compared to the amount of fatty tissue in the breast. breast density can be seen on a mammogram.

“Because women have annual or biennial mammograms, changes in breast density over time are naturally available,” Jiang said in an email. “We need to make the most of this dynamic information to better inform risk stratification and guide more individualized screening and prevention approaches.”

Researchers at Washington University School of Medicine in St. Louis and Brigham and Women’s Hospital in Boston analyzed health data over a 10-year period of 947 women in the St. Louis area who completed routine mammograms.a A mammogram is an x-ray of the breast that doctors use to look for early signs of breast cancer.

Women participating in this study were recruited from November 2008 to April 2012 and had mammograms through October 2020. The average age of participants was approximately 57 years.

Of the women, 289 were diagnosed with breast cancer, and the researchers found that women who later developed breast cancer had higher breast density at the start of the study compared to women without cancer. Did.

The researchers also found that breast density declined significantly over the 10-year period in all women, regardless of whether they later developed breast cancer, but the rate of density decline over time was slower in cancer-initiated breasts. I also found it to be significantly slower. later diagnosed.

“In this study, we found that assessing longitudinal changes in breast density from digital mammograms may provide an additional tool for assessing breast cancer risk and subsequent risk reduction strategies. ,” wrote the researcher.

Not only is breast density a known risk factor for breast cancer, dense breast tissue can make mammograms difficult to read.

“There are two problems here. First, dense breasts make it difficult to fully ‘see through’ them on a mammogram, like looking through frosted glass. Therefore, detecting breast cancer can be more difficult. Dana-Farber Cancer Institute“Second, breast density is often thought to reflect a woman’s estrogen exposure, or estrogen levels, and the more estrogen exposure, the more likely she is to develop breast cancer,” he said in an email. higher risk of doing so.”

In March, the US Food and Drug Administration released its update. mammography regulationsMammography facilities should inform patients about breast density.

“Breast density can have a masking effect on mammography that can make breast cancers more difficult to find within dense areas of breast tissue,” Jan wrote in her email.

“Even if we remove the problem of discovery, breast density is an independent risk factor for the development of breast cancer. There is a wealth of data showing that dense breast tissue is a risk factor, but it is not clear why.” Density tissue development and cancer may be related to the same biological processes or hormonal influences.”

Results from a new study show that breast density acts as a risk factor for breast cancer, but women should also be aware of other risk factors, says Dr. Memorial Sloan Kettering Cancer Center He was not involved in research.

“In theory, it makes some sense that the longer you have dense breasts, the more likely you are to develop cancer. data,” Jochelson said, adding that women with dense breasts should request supplemental imaging when they have a mammogram.

However, other factors that may increase the risk of breast cancer include having a family history of cancer, excessive alcohol consumption, having a high-risk breast biopsy, or certain genetic mutations. This includes

For example, knowing that women “may be at very high risk of breast cancer and not very high risk, so if they have BRCA 1 or 2 mutations for breast cancer, their density may not affect their risk much.” must be

some way reduce the risk of breast cancer such as maintaining a healthy weight, being physically active, drinking alcohol in moderation or not at all, and taking medications such as tamoxifen if possible, and breastfeeding children. It is included.

“Breast density is a moderate risk factor. 1 in 8 chance in a lifetime About the development of breast cancer. Women with dense breasts are at a slightly higher risk, about 1 in 6 she or 1 in 7 her. Therefore, her lifetime risk rises from 12% to 15%. That means most women with dense breasts will not develop breast cancer.

“Radiologists may recommend additional breast imaging for women who have dense breast tissue on mammograms,” he added.

of U.S. Preventive Services Task Force – A group of independent health professionals whose recommendations help guide physician decisions – recommends screening every two years for women over the age of 50.many medical groups including American Cancer Society and mayo clinicemphasizes that women have the option of starting annual mammogram screening from age 40.

“It is also very clear that breast density tends to be highest in young and premenopausal women, and that it tends to decrease with age in almost all women. So those two things are a bit at odds with each other,” said Dr. Freya Schnabel. Chief of Breast Surgery A professor at NYU Langone’s Perlmutter Cancer Center and a professor of surgery at the NYU Grossman School of Medicine in New York, he was not involved in the new research.

“So if you’re a 40-year-old woman and you have dense breasts, you can consider it really age-appropriate,” she said. The message is that if you have dense breasts, even postmenopausal, regardless of age, you are not getting breasts, even postmenopausal, probably postmenopausal. The presence of other risk factors may be a reason to consider adjunctive imaging, not just mammography, but additional diagnostic tools such as ultrasound or MRI. increase.”