Benign Breast Lumps May Increase Breast Cancer Risk in the Long Term, Research Shows

Having a history of benign breast disease may increase a woman’s risk for developing breast cancer later in life, new research shows, leading researchers to suggest more personalized breast cancer screening recommendations.

The news comes from research presented at the 13th European Breast Cancer Conference in November, which found that women who were diagnosed with any type of benign breast disease—including fibroadenomas and cysts—were nearly twice as likely to develop breast cancer in the next 20 years, compared to women without the noncancerous lumps.

The details of the study were published earlier this year in The International Journal of Environmental Research and Public Health.

“This is important,” lead study author Marta Román, PhD, said in a press release. “It suggests that benign breast disease is a key indicator that a woman has a higher risk of breast cancer, rather than simply being something that could develop into a cancer. In fact, we often find the benign disease in one breast and then cancer develops in the other breast.”

Researchers maintain, however, that despite an elevated risk of breast cancer with benign breast disease, the overall risk is still small. “A nearly two-fold risk may sound scary, but it is not,” Román told Health.

“Mammograms quite often pick up signs of breast disease that are not cancer, such as cysts and fibroadenomas, and it’s important to remember that the majority of women with these conditions will not go on to develop breast cancer,” David Cameron, MD, president of the European Breast Cancer Council and professor of oncology at Edinburgh University, said in a press release.

Benign Breast Disease as a Long-Term Risk Factor for Breast Cancer

Benign breast disease is a group of conditions marked by noncancerous (benign) changes in breast tissue. The list of specific conditions that make up benign breast disease is long, and includes noncancerous lumps like fibroadenomas and cysts, along with inflammatory tissue, and scar tissue, among other noncancerous abnormalities.

Most of these benign breast conditions don’t increase the risk of cancer, but some—including atypical hyperplasia, an overgrowth of cells that line the lobules and ducts inside the breast—are linked with a higher risk of developing breast cancer.

According to Larry Norton, MD, medical director of the Evelyn H. Lauder Breast Center at Memorial Sloan Kettering Cancer Center, these benign conditions aren’t the largest risk factors for developing breast cancer; rather, they’re “motivation for everybody to do what they can to lower their risk for breast cancer,” he said.

Though the link between benign breast disease and increased cancer risk isn’t novel, but the new research sought to uncover the long-term risks of breast cancer diagnosis following detection of benign breast disease, and parse out potential differences in screening frequency among women with benign breast conditions.

For the study, researchers analyzed data from more than 778,000 Spanish women between the ages of 50 and 69 who underwent mammography screening at least once during a 20-year period between 1996 and 2015.

Compared to those who had not had benign breast disease, those who had were nearly twice as likely to develop breast cancer and the elevated risk lasted for at least 20 years. Women with proliferative benign breast disease—marked by an increase in growth of certain cells in the breast—also had a higher risk than those with nonproliferative disease.

Findings Point to Importance of Personalized Breast Cancer Screening

Because the risk of breast cancer was found to persist for more than 20 years after a benign breast disease diagnosis, researchers believe the benign lesions can identify women who have a long-term increased risk of breast cancer—and it begs the question of whether women with benign breast disease may benefit from closer surveillance and more personalized screenings.

According to Dr. Norton, the new study emphasizes the urgent need for cutting-edge cancer diagnostic and prevention tools to be available for people with breasts.

“One of the more exciting approaches to breast cancer is called risk-adjusted screening,” said Dr. Norton. “It isn’t just a one-size-fits-all mammogram for everybody; some people need more than just a mammogram.”

People with dense breasts, for example—breasts that have relatively higher amounts of glandular and fibrous tissue, and less fatty breast tissue—may be more likely to have their breast cancer missed on a mammogram, since dense breasts make mammograms more difficult to interpret. It’s because of this that people with dense breasts may benefit from additional imaging tests.

“People with dense breasts should get both a mammogram and a sonogram and have a consultation with a radiologist who specializes in breast cancer,” said Dr. Norton. “Some women might need MRIs or a new technique called contrast-enhanced mammography.”

A person’s cancer risk is often determined by multiple factors. Better understanding the risk that one of these factors carries will help healthcare providers better design personalized cancer screening.

“Someone at low risk—absence of benign breast disease, fatty breast tissue, and no family history of breast cancer—might be offered screening with standard mammography every three or four years instead of two years,” said Román. Meanwhile, “someone at high risk—high mammographic density, first degree family history of breast cancer, or benign breast disease—might be offered a new screening test with mammography or even MRI, every year.”

Knowing—and Lowering—Your Risk of Breast Cancer

Breast cancer is a multifactorial disease, meaning both genetic and lifestyle factors influence risk. And having a risk factor—or multiple risk factors—does not inherently mean you will get the disease.

The two main risk factors associated with breast cancer are being female and getting older—two things that cannot be changed. Other unavoidable risk factors include: genetic mutations (including BRCA 1 and BRCA 2 genes), reproductive history, and a personal or family history of breast cancer.

Lifestyle factors, however, are risk factors that can be changed—and according to Dr. Norton, it’s extremely important to pay attention to the factors you can control. Those risk factors include: not being physically active, having obesity, taking hormones for an extended period of time, and drinking alcohol.

If you’re unsure about your overall breast cancer risk, you can talk to your healthcare provider or you can visit the National Cancer Institute’s Breast Cancer Risk Assessment tool, which uses a person’s medical, reproductive, and family history to estimate breast cancer risk.