MedicalResearch.com Interview with:
Jo Freudenheim, PhD
UB Distinguished Professor and Interim Chair
Department of Epidemiology and Environmental Health
School of Public Health and Health Professions
University at Buffalo
Medical Research: What is the background for this study? What are the main findings?
Dr. Freudenheim: There have been a number of studies that have shown an association between periodontal disease and chronic diseases, particularly stroke and heart attacks. There is also some newer evidence that periodontal disease is associated with cancer, particularly cancers of the gastrointestinal tract. Ours is the first large prospective study of periodontal disease and breast cancer.
This was part of a study of more than 70,000 postmenopausal women from throughout the United States, the Women’s Health Initiative. Women provided information about their health and other related factors and then those women were followed to see who developed certain diseases.
We found that women who had been told that they had periodontal disease were more likely to develop breast cancer. In particular, women who were former smokers (quit within the last 20 years) and who had periodontal disease were at increased breast cancer risk. There was a similar increase in risk for current smokers with periodontal disease but it was not statistically significant. (There was a relatively small number of current smokers in the WHI study.)
Medical Research: What should clinicians and patients take away from your report?
Dr. Freudenheim: This study was an observational study and therefore we cannot show that periodontal disease causes breast cancer. We don’t know if people who have periodontal disease also are susceptible to other diseases. It may also be that there is a third factor which is correlated with both periodontal disease and with breast cancer. On the other hand, these results may show us that the microbiome in the mouth affects the rest of the body, either indirectly—the inflammation in the mouth increases inflammation in other parts of the body, or directly—the mouth microbiome gets into the blood and affects other tissues.
There is much to learn about why we see these associations. In particular, we certainly don’t know if treating the periodontal disease would decrease risk of these other diseases.
With regard to a public health message, there are certainly plenty of reasons to not smoke or to quit for those who are currently smoking. Further, good dental care if clearly important for overall health.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Freudenheim: It will be important to examine this association in other large cohorts to see if it is replicated. Future studies could examine the possible mechanisms too to understand the possible connection between the mouth and other tissues.
Citation:Jo L. Freudenheim, Robert J. Genco, Michael J. LaMonte, Amy E. Millen, Kathleen M. Hovey, Xiaodan Mai, Ngozi Nwizu, Christopher A. Andrews, and Jean Wactawski-Wende. Periodontal Disease and Breast Cancer: Prospective Cohort Study of Postmenopausal Women. Cancer Epidemiology, Biomarkers & Prevention, December 2015 DOI:1158/1055-9965.EPI-15-0750
Dr. Jo Freudenheim (2015). Periodontal Disease Linked to Breast Cancer Risk in Postmenopausal Women