Title Limited Evidence Suggests Periodontal Disease Is Associated with a Slightly Increased Risk of Breast Cancer
Clinical Question In female patients with periodontal disease, is there an increased risk for breast cancer when compared to women without periodontal disease?
Clinical Bottom Line Patients with periodontitis have a slightly increased risk of breast cancer according to limited evidence from one meta-analysis and a prospective cohort study. History of smoking may play a role in this relationship and more evidence is required before specific recommendations can be made to patients with periodontitis.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
29974484Shi/20188 studies/168,111 patientsMeta-Analysis
Key resultsFemale patients with periodontitis had a small increased risk for breast cancer (RR = 1.18, 95%CI: 1.11–1.26, I2 = 17.6%). Increased risk was statistically significant for American and Chinese subjects, but not for Turkish or Swedish subjects. The higher quality studies showed a higher risk ratio when compared to the moderate quality studies included in the meta-analysis.
26689418Freudenheim/201673,737 postmenopausal womenProspective Cohort Study
Key resultsThere is an association between periodontal disease and breast cancer. A 36% increased risk of breast cancer was found among former smokers with self-reported periodontal disease who had quit smoking in the previous 20 years (HR = 1.36, 95% CI: 1.05–1.77). No statistically significant association was found in never-smokers.
Evidence Search (("breast neoplasms"[MeSH Terms] OR ("breast"[All Fields] AND "neoplasms"[All Fields]) OR "breast neoplasms"[All Fields] OR ("breast"[All Fields] AND "cancer"[All Fields]) OR "breast cancer"[All Fields]) AND ("periodontal diseases"[MeSH Terms] OR ("periodontal"[All Fields] AND "diseases"[All Fields]) OR "periodontal diseases"[All Fields] OR ("periodontal"[All Fields] AND "disease"[All Fields]) OR "periodontal disease"[All Fields])) AND ("risk factors"[MeSH Terms] OR ("risk"[All Fields] AND "factors"[All Fields]) OR "risk factors"[All Fields])
Comments on
The Evidence
Validity: The Shi 2018 meta-analysis included six cohort studies and one case control study. Despite finding an overall slight increased risk for breast cancer in patients with periodontitis, five of the eight included studies did not find a significant relationship between periodontitis and breast cancer. Nwizu 2017, Soder 2011, and Chung 2016 were of moderate or high quality and found a significant relationship. Most of the studies used self-reported data from patients regarding previous periodontal disease diagnosis. Freudenheim 2016 also relied on self-reported data. This decreases the validity of the data as self-reported data of periodontal disease has a low sensitivity. Four of the studies included in the meta-analysis were adjusted for smoking status and one was matched for smoking. Freudenheim 2016 controlled for smoking as a confounding factor. Freudenheim 2016 and five of the studies included in Shi 2018 had follow-up periods greater than 10 years and large sample sizes, both of which increase validity. Perspective: Evidence remains inconclusive regarding the relationship between periodontal disease and breast cancer. Previous studies hypothesize that periodontal infection induces a chronic systemic inflammation resulting in tumor growth, but direct evidence for a biological mechanism exists. More research should be done in the future with better-defined diagnostic criteria for periodontal disease and greater control for confounding factors before suggesting an increased risk exists.
Applicability Middle-aged women make up a significant portion of patients affected by periodontal disease. Successful treatment of periodontal disease relies on strict patient compliance to regular periodontal therapy and improved oral hygiene measures. Compliance is often poor, but many patients are motivated by the relationship between oral and systemic health. A significant relationship between periodontitis and increased breast cancer risk may lead to increased compliance to periodontal treatment in a susceptible population. Furthermore, if a correlation is found between severity and risk, patients with severe periodontitis can be identified as an at-risk population and be screened accordingly.
Specialty (General Dentistry) (Periodontics)
Keywords Breast cancer, periodontal disease, risk factors
ID# 3364
Date of submission 11/19/2018
E-mail allenh@uthscsa.edu
Author Hunter Allen
Co-author(s)
Co-author(s) e-mail
Faculty mentor David Lasho DDS, MSD
Faculty mentor e-mail lasho@uthscsa.edu
   
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
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Comments and Evidence-Based Updates on the CAT
(FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs)
None available