Periodontal disease may increase risks for several types of cancer in older women

In older women, periodontal disease may increase the risk of total cancer, regardless of smoking status, and had the strongest association with esophageal cancer, according to research published in the journal Cancer Epidemiology, Biomarkers & Prevention.

“This study is the first national study focused on women, particularly older women,” said senior author, Jean Wactawski-Wende, PhD, professor, department of epidemiology and environmental health, and dean of the School of Public Health and Health Professions, State University of New York at Buffalo. “Our study was sufficiently large and detailed enough to examine not just overall risk of cancer among older women with periodontal disease, but also to provide useful information on a number of cancer-specific sites.” 

In this prospective cohort study, Dr. Wactawski-Wende and colleagues included 65,869 women enrolled in the Women’s Health Initiative Observational study. Women were between ages 54 and 86 years, and supplied information on periodontal disease via a self-reported questionnaire administered between 1999 and 2003. Cancer outcomes in these women were assessed through September 2013, with a maximum follow-up of 15 years.

The main outcome of the study was physician-adjudicated incident total cancers, and the secondary outcome was site-specific cancers.

In all, researchers identified 7,149 cancers over a mean follow-up of 8.32 years. They found that a history of periodontal disease was associated with an increased total cancer risk (multivariable-adjusted HR: 1.14; 95% CI: 1.08, 1.20). They also found similar findings between periodontal disease and total cancer risk in 34,097 never-smokers (HR: 1.12; 95% CI: 1.04, 1.22).

Researchers also observed associations between a history of periodontal disease and the following cancers:

• Breast (HR, 1.13; 95% CI, 1.03, 1.23),
• Lung (HR, 1.31; 95% CI, 1.14, 1.51),
• Esophagus (HR, 3.28; 95% CI, 1.64, 6.53),
• Gallbladder (HR, 1.73; 95% CI, 1.01, 2.95), and
• Melanoma skin (HR, 1.23; 95% CI, 1.02, 1.48).

The strongest association was with esophageal cancer, which was more than three times more likely in women with periodontal disease than in women without. Associations with stomach cancers were of borderline significance (HR: 1.58; 95% CI: 0.94, 2.67).

Although the reasons for the connection between periodontal disease and cancer are unknown, one possibility, according to Dr. Wactawski-Wende, is that saliva, dental plaque, and diseased periodontal tissues may carry oral pathogens into the circulation, allowing them to reach other body sites. This may explain the particularly strong association they found between periodontal disease and esophageal cancer.

“The esophagus is in close proximity to the oral cavity, and so periodontal pathogens may more easily gain access to and infect the esophageal mucosa and promote cancer risk at that site,” noted Dr. Wactawski-Wende.

“Our study findings serve to provide further evidence that periodontal disease is linked to cancer, and support the need for further investigation into how periodontal disease contributes to increased cancer risk,” concluded lead author Ngozi Nwizu, BDS, MMSc, PhD, assistant professor, oral and maxillofacial pathology, The University of Texas School of Dentistry, Houston, TX.

The study was supported by the Women’s Health Initiative, which is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, and the U.S. Department of Health and Human Services. The study was also funded by grants from the National Institute of Dental and Craniofacial Research and the US Army.