Gum disease, also called periodontal disease, can range from simple inflammation of the gums, called gingivitis by dentists, to periodontitis, when the gums pull away from the teeth leaving open spaces that become infected. The bacteria causing the infection and the body’s response to the infection can break down the bone and connective tissue that hold your teeth in place. If periodontitis isn’t treated, the teeth may become loose and have to be removed.
Gum disease can be prevented by regular tooth brushing and flossing.
Gum disease has been associated with several other diseases, including heart disease, stroke, and diabetes. Past research has found links between gum disease and oral, esophageal, head and neck, pancreatic, and lung cancer, so researchers wondered if there were any links between gum disease and breast cancer.
A study has found that postmenopausal women with gum disease were more likely to develop breast cancer than postmenopausal women who didn’t have gum disease. If the women had a history of smoking, the risk of breast cancer was even higher.
The study was published online on Dec. 21, 2015 by the journal Cancer Epidemiology, Biomarkers & Prevention. Read the abstract of “Periodontal Disease and Breast Cancer: Prospective Cohort Study of Postmenopausal Women.”
The research is part of the very large Women’s Health Initiative Observational Study, commonly called the WHI. The WHI is looking for links between health, diet, lifestyle, and genetic factors and health problems, such as cancer.
In this study, the researchers monitored 73,737 postmenopausal women in the WHI who had never been diagnosed with breast cancer. About 26% of the women told the researchers they had gum disease.
After about 6.5 years, 2,124 women had been diagnosed with breast cancer.
Overall, the risk of breast cancer was 14% higher in women who had gum disease compared to women who didn’t have gum disease. So if average breast cancer risk is about 12%, a woman with gum disease had about a 13.5% risk of breast cancer.
“We thought that periodontal bacteria — either the bacteria themselves or the inflammation that’s part of having periodontal disease — has an effect on other parts of the body, including breast tissue. We know there are bacteria in breast tissue and we know there are bacteria in mother’s milk. Women who had periodontal disease had a small increase in the risk of breast cancer overall,” said Jo Freudenheim, Ph.D., distinguished professor of epidemiology and environmental health at the University of Buffalo and lead author of the study.
Because earlier studies have shown that the effects of gum disease can be more severe if a person smokes, the researchers also grouped the women by smoking history:
- Among women who had quit smoking within the last 20 years, women with gum disease had a 36% higher risk of breast cancer than women who didn’t have gum disease.
- Among women who had never smoked, women with gum disease had a 6% higher risk of breast cancer than women who didn’t have gum disease.
- Among women who had quit smoking more than 20 years ago, women with gum disease had an 8% higher risk of breast cancer than women who didn’t have gum disease.
“There’s been an explosion of information recently that makes it clear that many different parts of the body that were thought to be sterile contain bacteria and other microbes,” Dr. Freudenheim said. “These bacteria may influence diseases that were previously thought to have no infectious component.”
The researchers said there are several possible reasons for the association between gum disease and breast cancer:
- Bacteria in the mouth can get into the bloodstream through tooth brushing, flossing, and chewing. Even though the bacteria are cleared out of the body quickly, the cumulative exposure to tissues can be considerable. It could be that these bacteria affect breast cancer.
- Inflammation in one part of the body, such as the gums, may have an impact on other diseases.
- There may be other factors that increase the risk of both gum disease and breast cancer.
“This is a new area, so we have to be careful in how we interpret our findings,” said Dr. Freudenheim. “We can’t say, ‘if you treat periodontal disease it will reduce cancer risk.' There are new methodologies that allow us to measure things we weren’t able to before. We are now beginning to understand how much the interaction of the microbiome affects our health both in terms of acute infections and chronic diseases.”
Doing all that you can do to keep your breast cancer risk as low as it can be makes good sense. Besides exercising regularly, eating a healthy diet, maintaining a healthy weight, not smoking, avoiding alcohol, and taking good care of your teeth and gums are steps you can take to control several risk factors.
According to the Centers for Disease Control, gum disease can be kept in check by:
- Brushing and flossing your teeth every day to remove the bacteria that cause gum disease.
- Seeing a dentist at least once a year for a checkup, or more frequently if you have any of the warning signs of gum disease:
- red/swollen gums
- tender/bleeding gums
- loose teeth
- bad breath or a bad taste in the mouth that won’t go way
- gums that have pulled away from your teeth
- sensitive teeth
For more information on breast cancer risk and other steps you can take to minimize your risk, visit the Breastcancer.org Lower Your Risk section.