Dominique S. Michaud
Elizabeth A. Platz
Individuals with severe periodontitis, or gum disease, had increased risk for developing cancer compared with individuals with mild or no gum disease, according to published findings.
Those with severe periodontitis had more than double the risk for developing lung cancer and twofold higher risk for colorectal cancer, the research showed.
“Periodontal disease can cause bacteremia, endotoxemia and systemic low-grade inflammation. There is accumulating evidence that these conditions are contributing to chronic diseases, including heart disease, rheumatoid arthritis and cancer,” Dominique S. Michaud, ScD, professor of public health and community medicine at Tufts University School of Medicine, told HemOnc Today. “The question of ‘how much’ remains to be determined but, in our study, we noted a 24% higher risk for cancer when evaluating risk among those with severe periodontitis compared with those with no or mild periodontitis.”
Previous studies have shown an association between periodontal disease and cancer risk. As HemOnc Today previously reported, older women with periodontal disease showed increased total cancer risk.
However, the lack of adjustment for smoking, self-reported diagnosis of disease and too few cancer cases created limitations in previous reports. Other studies reported a 14% to 20% increased risk for cancer after adjusting for smoking.
“A lot more work will need to be done to better understand the role of oral bacteria and periodontal disease in cancer,” Michaud said.
The researchers, including Elizabeth A. Platz, ScD, deputy chair of the department of epidemiology at Johns Hopkins Bloomberg School of Public Health, and co-leader of the Cancer Prevention and Control Program at Kimmel Cancer Center, evaluated records from 7,466 patients in the Atherosclerosis Risk in Communities study — a prospective cohort of individuals aged 44 to 66 years — to assess any association between periodontal disease severity and cancer risk.
All patients were edentulous (n = 1,410) or underwent a dental examination (n = 6,056) at fourth visit between 1996 and 1998. Patients with severe periodontitis had more than 30% of sites with attachment loss greater than 3 mm, and patients with mild or no periodontitis had less than 10% of sites with attachment loss greater than 3 mm.
During follow-up, 1,648 new cancer cases occurred.
After adjustment for smoking and other variables, researchers observed an increased risk for total cancer (HR = 1.24; 95% CI, 1.07-1.44) among patients with severe periodontitis compared with patients with no or mild periodontitis.
Patients without teeth — a sign of severe periodontitis — had a 28% increased risk for cancer
(HR = 1.28; 95% CI, 1.09-1.5).
Severe periodontitis and edentulism appeared associated with a greater than twofold increased risk for lung cancer (HR=2.33; 95% CI,1.51-3.6), even after adjustment for smoking status and pack-years of smoking.
Based on 18 cases, severe periodontitis appeared associated with a fourfold risk for lung cancer among individuals who never smoked. Researchers observed high risks for smoking-related cancers in the total study population, but not among patients who never smoked.
For colorectal cancer, researchers observed an 80% significant increase in risk associated with edentulism, but a nonsignificant 50% increase in risk associated with severe periodontitis.
Severe periodontitis and edentulism were more strongly correlated with colorectal cancer among nonsmokers than in the overall population (HR=2.12; 95% CI,1-4.47).
Association between lung and colorectal cancer risk and periodontitis appeared similar among races; however, associations were generally weaker among blacks.
Additional research is needed to understand cancer-site specific and racial differences in findings, the researchers noted.
Variables associated with advancing periodontitis severity included older age, male sex, black race, minimal education, obesity and smoking.
Researchers observed a slight increase in risk for pancreatic cancer among patients with severe periodontitis — similar to other studies — but, due to the limited number of cases, this association did not reach statistical significance. They found no association between breast, prostate, or hematopoietic and lymphatic cancer risk and periodontitis.
“As evidence linking gum disease and cancer risk accumulates, and as science works to uncover the exact mechanisms, it is possible that we are headed toward a future where there might be an oral test for some cancers or, based on gum health, dentists would refer patients to their primary care physicians for cancer screenings,” Michaud said.
The results also could help individuals and stakeholders be more mindful of the importance of having dental insurance.
“Knowing more about the risks that come about with periodontal disease might give more support to having dental insurance in the way that we should be offering health insurance to everyone,” Platz said in a press release. – by Melinda Stevens
: The study was funded by the NCI. The authors report no relevant financial disclosures.