Study finds link between periodontal disease and increased risk of breast cancer

January 6, 2016

Periodontal disease has been linked to a host of medical problems, but now researchers say there’s another risk to be added to the list: breast cancer. Recent research discovered that postmenopausal women with periodontal disease are more likely to develop the cancer than those without the oral health condition.

While periodontal disease has been consistently linked with chronic disease, no major research had been done on periodontal disease and breast cancer, despite the discovery that oral-associated microbes are present in breast tumors. The new study, out of the University at Buffalo’s School of Public Health and Health Professions, monitored over 73,000 postmenopausal women who had never had breast cancer. 26.1 percent of the women were found to have periodontal disease at the beginning of the study.

After 6.7 years, 2,124 women in the study had been diagnosed with breast cancer. Researchers discovered that across the women in the study, women with periodontal disease had a 14 percent higher risk of breast cancer. Researchers posited several explanations for this correlation, including the possibility that a systemic inflammation from periodontal disease could affect breast tissue, or that oral bacteria that enter the circulatory system could affect the tissue.

“If we can study periodontal disease and breast cancer in other populations, and if we can do more detailed study of the characteristics of periodontal disease, it would help us understand if there is a relationship, said Jo L. Freudenheim, PhD, lead author of the study. “There is still much to understand about the role, if any, of oral bacteria and breast cancer.”

Since smoking has previously been linked to effects of periodontal disease, researchers also broke down the results by smoking status.

“Among women who had quit smoking within the past 20 years, those with periodontal disease had a 36 percent higher risk of breast cancer,” a recent press release stated. “Women who were smoking at the time of this study had a 32 percent higher risk if they had periodontal disease, but the association was not statistically significant. Those who had never smoked or had quit more than 20 years ago had a six percent and eight percent increased risk, respectively, if they had periodontal disease.”

Other factors affecting the study included the fact that the women surveyed self-reported their periodontal disease, meaning some may not have known they had it. Additionally, since the women were already enrolled in a long-term health study, they were probably more likely than the general population to visit a doctor or dentist. Researchers also stated that the general population could have higher rates of periodontal disease than the sample used for the study. Additionally, other potential factors such as obesity or other health conditions were not taken into consideration. These variables would need to be evaluated in future research to determine more definitive correlations.

The full study, “Periodontal disease and breast cancer: Prospective cohort study of post menopausal women,” was published in the American Association for Cancer Research’s journal Cancer Epidemiology, Biomarkers & Prevention.