How can gum disease raise your cancer risk? The exact mechanism isn’t clear but a new long-term study provides additional evidence of a link between advanced gum disease, also called periodontitis, and increased risk of cancer. Gum disease has also been implicated in heart disease.
The new study, led by researchers at the Johns Hopkins Bloomberg School of Public Health, found a 24 percent increase in the relative risk of developing cancer among participants with severe periodontitis, compared to those with mild to no periodontitis. The highest risk was observed in cases of lung cancer, followed by colorectal cancer.
Among patients who had no teeth–which can be a sign of severe periodontitis or past periodontal treatment–the increase in risk was 28 percent, the researchers noted.
Periodontitis is caused by bacterial infection that damages the soft tissue and bone that support the teeth. The best defense is regular brushing and flossing. The American Dental Association recommends flossing at least once daily.
In the new study, published in the Journal of the National Cancer Institute, the research team used data from comprehensive dental exams performed on 7,466 participants as part of their participation in the Atherosclerosis Risk in Communities (ARIC) study, then followed the participants from the late 1990s until 2012.
The association is not strong enough to recommend screening for risk of particular cancers based on a periodontal disease diagnosis, said Elizabeth Platz, Sc.D., deputy chair of the department of epidemiology at the Johns Hopkins Bloomberg School of Public Health. “But we see a modest to moderate risk increase in cancer that seems to be holding up across studies, so perhaps dentists should say to their patients that there are risks related to periodontal disease, and this is one of them.”
Platz noted that the research team was also able to account for the impact of smoking among the patients, since people who smoke are more likely to get periodontal disease, and smoking raises the risk of lung and colon cancers.
“When we looked at the people who had never smoked in this group, we still saw evidence that having more periodontal disease was related to an increased risk of lung cancer and colorectal cancer,” she said.
Patients with little or no access to health care, including dental exams and cancer screenings such as colonoscopy, and prevention programs, such as smoking cessation, also have an increased risk of both periodontal disease and cancer, Platz noted. “However, after taking into account socio-economic factors and access to and uptake of care, these factors did not appear to explain these associations between periodontitis and cancer risk,” she said.
Platz said the study also points to the importance of expanding dental insurance to more individuals.
“Knowing more about the risks that come about with periodontal disease, not just the disease itself, might give more support to having dental insurance in the way that we should be offering health insurance to everyone,” Platz said.