Even though many women with abnormal screening mammogram results don’t go on to get breast cancer, a new study suggests their risk is elevated when these tests turn up noncancerous lumps.
For the study, researchers examined data on more than 778,000 women ages 50 to 69 who had at least one mammogram at a breast cancer screening center in Spain between 1996 and 2015. During a median follow-up period of 7.6 years, mammograms found noncancerous tissue growth, or benign breast disease, in 2.3 percent of the participants and breast cancer in 1.5 percent.
Overall, about 25 out of every 1,000 women with benign breast disease went on to develop breast cancer, compared with 15 out of every 1,000 women without these noncancerous tissue growths, researchers reported February 24, 2022, in the International Journal of Environmental Research and Public Health.
And the risk persisted over time. Women who were followed for up to two decades were roughly twice as likely to get a breast cancer diagnosis when they had a history of benign breast disease.
“This is important,” said the lead study author, Marta Román, PhD, of the Hospital del Mar in Barcelona, in a statement. “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.”
Women 50 to 74 years old who are at average risk for breast cancer are advised to get screening mammograms every other year, according to the U.S. Centers for Disease Control and Prevention (CDC). Some women at higher risk for breast cancer may need to start screening at a younger age or get mammograms more often.
“If a woman is diagnosed with a benign breast disease, and she has other high risk factors, such as a family history of breast cancer, she could benefit from more frequent screening,” Dr. Román said.
One limitation of the study is that researchers lacked data on several factors that can influence breast cancer risk, including obesity, timing of menopause, and use of hormone therapy to manage menopause symptoms. The study also didn’t examine subtypes of benign breast disease, because this information was missing for about one-third of these cases.
Some types of benign breast disease are more apt to lead to cancer in the future, including abnormal cell clusters known as hyperplasia and wart-like growths known as intraductal papilloma. Other types of benign breast disease, like fluid-filled breast cysts and lumps formed by scar tissue don’t tend to increase cancer risk, according to the Cleveland Clinic.
Common causes of benign breast disease are scar tissue, breast infections, and hormone fluctuation during menopause, pregnancy, or menstruation, the Cleveland Clinic notes. Sometimes breast-self exams or mammograms detect these lumps. Other symptoms can include breast pain, nipple discharge, and changes in the size, shape, or appearance of breasts.
Depending on the cause, benign breast disease may be treated by draining fluid from cysts, surgery to remove lumps, or antibiotics to attack infections. While there isn’t a foolproof way to prevent benign breast disease, women can increase their chance of finding it early when it’s easier to treat by doing regular self-exams, getting routine mammograms, and maintaining an overall healthy lifestyle with good eating and exercise habits, according to the Cleveland Clinic.