Periodontal disease may associate with breast cancer

The relationship between periodontal disease and cancer: Insights from a Systematic Literature Network Analysis

This paper investigates the relationship between periodontal disease and various cancer types. It provides a comprehensive overview of the existing knowledge about the interaction between periodontal disease and carcinogenesis, explores the underlying biological mechanisms of this connection, and consider the impact of these findings on healthcare practices and future research directions. Utilizing Systematic Literature Network Analysis, which combines bibliometric analysis with Systematic Literature Review, this study analyzes 164 documents from 2000 to 2023. Focus is placed on the 38 most globally cited papers, enabling a targeted and comprehensive analysis of the predominant research within this scope. This review highlights that colorectal, oral, pancreatic, lung, and gastrointestinal cancers have consistent associations with periodontal disease. On the other hand, hematological, breast and prostate cancers show associations with periodontal disease, but these links are less pronounced and more variable, indicating the need for targeted research in these domains. These insights emphasize the necessity for a multidisciplinary healthcare approach, recognizing the systemic implications of periodontal disease.

Systemic Inflammatory Disorders, Immunosuppressive Treatment and Increase Risk of Head and Neck Cancers-A Narrative Review of Potential Physiopathological and Biological Mechanisms

Head and neck cancers (HNCs) are known to present multiple factors likely to influence their development. This review aims to provide a comprehensive overview of the current scientific literature on the interplay between systemic inflammatory disorders, immunosuppressive treatments and their synergistic effect on HNC risk. Both cell-mediated and humoral-mediated systemic inflammatory disorders involve dysregulated immune responses and chronic inflammation and these inflammatory conditions have been associated with an increased risk of HNC development, primarily in the head and neck region. Likewise, the interaction between systemic inflammatory disorders and immunosuppressive treatments appears to amplify the risk of HNC development, as chronic inflammation fosters a tumor-promoting microenvironment, while immunosuppressive therapies further compromise immune surveillance and anti-tumor immune responses. Understanding the molecular and cellular mechanisms underlying this interaction is crucial for developing targeted prevention strategies and therapeutic interventions. Additionally, the emerging field of immunotherapy provides potential avenues for managing HNCs associated with systemic inflammatory disorders, but further research is needed to determine its efficacy and safety in this specific context. Future studies are warranted to elucidate the underlying mechanisms and optimize preventive strategies and therapeutic interventions.

Composition of subgingival microbiota associated with periodontitis and diagnosis of malignancy-a cross-sectional study

Periodontitis is one of the world's most prevalent infectious conditions, affecting between 25 and 40% of the adult population. It is a consequence of the complex interactions between periodontal pathogens and their products, which trigger the host inflammatory response, chronic inflammation, and tissue destruction. Chronic systemic low-grade inflammation is involved in numerous diseases, and it is also known that long-lasting inflammation and chronic infections predispose one to cancer. Here, we characterized and compared the subgingival microbiota associated with periodontitis and diagnosis of malignancy in a longitudinal 10-year follow-up study. The study was conducted on 50 patients with periodontitis and 40 periodontally healthy individuals. The recorded clinical oral health parameters were periodontal attachment loss (AL), bleeding on probing (BOP), gingival index (GI), probing depth (PD), and plaque index (PI). Subgingival plaque was collected from each participant, from which DNA was extracted, and 16S rRNA gene amplicon sequencing performed. Cancer diagnoses data were collected between the years 2008-2018 from the Swedish Cancer Registry. The participants were categorized based on having cancer at the time of sample collection (CSC), having developed cancer later (DCL), and controls without any cancer. The most abundant phyla across all 90 samples were Actinobacteria, Proteobacteria, Firmicutes, Bacteroidetes, and Fusobacteria. At the genus level, Treponema, Fretibacterium, and Prevotella were significantly more abundant in samples of periodontitis patients compared to non-periodontitis individuals. With regard to samples of cancer patients, Corynebacterium and Streptococcus were more abundant in the CSC group; Prevotella were more abundant in the DCL group; and Rothia, Neisseria, and Capnocytophaga were more abundant in the control group. In the CSC group, we also found that the presence of periodontal inflammation, in terms of BOP, GI, and PLI, significantly correlated with species belonging to the genera Prevotella, Treponema, and Mycoplasma. Our results revealed that several subgingival genera were differentially enriched among the studied groups. These findings underscore the need for further research to fully understand the role that oral pathogens may play in the development of cancer.

Periodontal Health and Disease in the Context of Systemic Diseases

During recent years, considerable progress has been made in understanding the etiopathogenesis of periodontitis in its various forms and their interactions with the host. Furthermore, a number of reports have highlighted the importance of oral health and disease in systemic conditions, especially cardiovascular diseases and diabetes. In this regard, research has attempted to explain the role of periodontitis in promoting alteration in distant sites and organs. Recently, DNA sequencing studies have revealed how oral infections can occur in distant sites such as the colon, reproductive tissues, metabolic diseases, and atheromas. The objective of this review is to describe and update the emerging evidence and knowledge regarding the association between periodontitis and systemic disease and to analyse the evidence that has reported periodontitis as a risk factor for the development of various forms of systemic diseases in order to provide a better understanding of the possible shared etiopathogenetic pathways between periodontitis and the different forms of systemic diseases.

Periodontitis and Cancer: Beyond the Boundaries of Oral Cavity

Oral squamous cell carcinoma (OSCC) is the 16th most common cancer and the 15th leading cause of death worldwide, with an incidence of 4 cases per 100,000 people [...]

Modulation of oral cancer and periodontitis using chemotherapeutic agents - A narrative review

Periodontitis, an inflammatory condition, is linked to a higher risk of developing oral cancer. Periodontitis may be a precipitating factor for tumorigenesis and the aggressiveness of specific cancer variants. Although genetics is considered the primary etiologic factor for the development of most cancers, many factors have come to be recognized in the initiation and progression of oral cancer. Consecutively, it is suggestive that periodontitis and oral cancer are distinct disease entities but share common pathogenic mechanisms. Oxidative stress and epigenetic mechanisms are among the most researched mechanisms responsible for initiating apoptotic mechanisms implicated in periodontitis and oral cancer. Current research aims to formulate therapeutic agents to intercede in these mechanisms via host modulation therapy and epigenetic therapy. These advances can revolutionize the treatment of periodontitis and oral cancer. This review aims to shed light on the common pathogenic mechanisms of these diseases and the various host modulation agents that could be beneficial in their treatment.

The Role of Oral Fusobacterium nucleatum in Female Breast Cancer: A Systematic Review and Meta-Analysis

INTRODUCTION

Breast cancer is the world's most prevalent malignancy, with an increasing incidence and a predisposition for postpubertal females from all cultural and ethnic backgrounds. More recently, oral Fusobacterium nucleatum species have been observed in cancerous human breast tissue, drawing attention to the role of microbes in cancer pathogenesis.

OBJECTIVES

Investigating oral Fusobacterium nucleatum species as potential biomarkers for female-specific breast cancer.

METHODS

A systematic search in The Central Register of Controlled Trials, EMBASE, EBSCO, NCBI, and MEDLINE databases was undertaken from the 1st January, 1983-31st March, 2022. Articles included were in English and based on women between the ages of 18-96 years with confirmed gingivitis/periodontal disease and breast cancer diagnoses from registered specialists. Authors extracted data independently, and a meta-analysis of risk estimations measuring associations between oral Fusobacterium nucleatum species and female-specific breast cancer was elucidated via calculated relative risks and 95% confidence intervals.

RESULTS

AXIS tool analysis revealed 78.70% of articles with a positive correlation between oral Fusobacterium nucleatum and female-specific breast cancer. The risk of breast cancer development increased with significant levels of oral Fusobacterium nucleatum due to gingivitis/periodontitis (relative risk = 1.78, 95% confidence interval = 1.63-1.91). Low-moderate statistical heterogeneity was found (I 2 = 41.39%; P = 0.02), and the importance of periodontal status on breast cancer pathogenesis was determined (relative risk = 1.24, 95% confidence interval = 1.01-1.30).

CONCLUSIONS

Oral Fusobacterium nucleatum species are a risk factor for breast cancer development, thus elevating their biomarker potentiality.

Prevalence of cancer in relation to signs of periodontal inflammation

We investigated the associations between periodontal inflammation (gingivitis and periodontitis) and all-kind malignancies, specifically breast and prostate cancer, in a cohort followed-up for 30 years. The study hypothesis was based on the oral inflammation vs. systemic health paradigm. A sample of 2,168 subjects from an original cohort of 105,718 individuals from the greater Stockholm area in Sweden that had been followed since 1985 was investigated. Swedish national health registers were used in the study. Chi-square tests and logistic multiple regression analyses were conducted. The results showed that periodontitis was significantly associated with any cancer after adjusting for gender, age, income, and education (p = 0.015). The probability of getting cancer increased on average by 38% if the patient had periodontitis vs. had not; the odds ratio was 1.380 (95% confidence interval l.066-1.786). No significant association was observed between periodontitis and breast cancer (p = 0.608), while the association between periodontitis and prostate cancer tended towards significance (p = 0.082). However, no statistically significant difference was found between the observed and the calculated distribution of any cancer in gingivitis groups (p = 0.079). Thus, the study hypothesis was partly confirmed by showing a statistically significant association between periodontitis and any cancer.

Stratified analysis of the association between periodontitis and female breast cancer based on age, comorbidities and level of urbanization: A population-based nested case-control study

Purpose

To conduct stratified analysis of the association between periodontitis exposure and the risk of female breast cancer based on age, comorbidities and level of urbanization.

Methods

Using claims data taken from the 1997–2013 Taiwanese National Health Insurance Research Database (NHIRD), we identified 60,756 newly-diagnosed female breast cancer patients during the period 2003–2013 from all beneficiaries. We then randomly selected 243,024 women without breast cancer matching (1:4) for age and the year of the index date during 1997–2013 from a one million representative population acting as the control group. A conditional logistic regression analysis was used to examine the association between periodontitis (ICD-9-CM codes 523.3–4) and the risk of breast cancer, shown as an odds ratio (OR) with a 95% confidence interval (CI) after adjustments for the Charlson Comorbidity Index (CCI) and level of urbanization. Subgroup analyses were conducted based on age, CCI and level of urbanization.

Results

The mean ± standard deviation age was 53 ± 14 years. After adjusting for potential confounders, the risk of female breast cancer was found to be associated with a history of periodontitis (OR, 1.12; 95% CI, 1.10–1.14). Such an association was significantly different between patients aged < 65 years (OR, 1.09; 95% CI, 1.06–1.11) and patients aged ≥ 65 years (OR, 1.23; 95% CI, 1.18–1.28; p for interaction <0.001), as well as between patients where the CCI = 0 (OR, 1.17; 95% CI, 1.15–1.20) and patients with CCI > 0 (OR, 0.99; 95% CI, 0.96–1.03; p for interaction <0.001). The highest level of urbanization was also associated with the risk of breast cancer.

Conclusions

This population-based nested case-control study demonstrated that periodontitis was significantly associated with the risk of female breast cancer and such an association was modified by both age and comorbidities.

The Stockholm Study: Over 30 years’ Observation of the Effect of Oral Infections on Systemic Health

The Stockholm Studies are a series of investigations started in 1985 and still ongoing. Out of 105,798 inhabitants, aged 30 and 40 years and living in the greater Stockholm area in Sweden, 3273 subjects were randomly selected. Of them, 1676 were clinically examined focusing on oral health. The subjects were then followed up using national population and health registers in order to study associations between oral health parameters and systemic health outcomes and finally death. The 35 years of observation provides unique possibilities to analyze, for example, how periodontitis links to a number of systemic health issues. The results have consequently provided numerous new associations and confirmed earlier observations on how poor oral health is associated with heart diseases and cancer.

Paradigm shift in the pathogenesis and treatment of oral cancer and other cancers focused on the oralome and antimicrobial-based therapeutics

The oral microbiome is a community of microorganisms, comprised of bacteria, fungi, viruses, archaea, and protozoa, that form a complex ecosystem within the oral cavity. Although minor perturbations in the environment are frequent and compensable, major shifts in the oral microbiome can promote an unbalanced state, known as dysbiosis. Dysbiosis can promote oral diseases, including periodontitis. In addition, oral dysbiosis has been associated with other systemic diseases, including cancer. The objective of this review is to evaluate the epidemiologic evidence linking periodontitis to oral, gastrointestinal, lung, breast, prostate, and uterine cancers, as well as describe new evidence and insights into the role of oral dysbiosis in the etiology and pathogenesis of the cancer types discussed. Finally, we discuss how antimicrobials, antimicrobial peptides, and probiotics may be promising tools to prevent and treat these cancers, targeting both the microbes and associated carcinogenesis processes. These findings represent a novel paradigm in the pathogenesis and treatment of cancer focused on the oral microbiome and antimicrobial‐based therapies.

Periodontal microorganisms and diagnosis of malignancy: A cross-sectional study

BACKGROUND

Oral infections associate statistically with cancer.

OBJECTIVE

We hypothesized that certain periodontal microorganisms might specifically link to malignancies in general and set out to investigate this in our ongoing cohort study.

METHODS

A sample of 99 clinically examined patients from our cohort of 1676 subjects was used to statistically investigate the associations between harboring periodontal microorganisms Aggregatibacter actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g), Prevotella intermedia (P.i), Tannerella forsythia (T.f) and Treponema denticola (T.d). We used oral infection indexes and the incidence figures of malignancies as registered in 2008-2016 in the Swedish National Cancer Register.

RESULTS

The pathogen A.a showed strong association with malignancy in 32 out of the 99 patients while P.g and P.i were more prevalent among patients without malignancy. In principal component analyses, A.a appeared in the strongest component while the second strongest component consisted of a combination of T.f and T.d. The third component consisted of a combination of P.g and P.i, respectively. Of basic and oral health variables, gingival index appeared to be the strongest expression of inflammation (Eigen value 4.11 and Explained Variance 68.44 percent).

CONCLUSIONS

The results partly confirmed our hypothesis by showing that harboring certain periodontal bacteria might link to malignancy. However, the associations are statistical and no conclusions can be drawn about causality.

The Association Between Periodontal Disease and Breast Cancer in a Prospective Cohort Study

Periodontal disease may be associated with increased breast cancer risk, but studies have not considered invasive breast cancer and ductal carcinoma in situ (DCIS) separately in the same population. We assessed the relationship between periodontal disease and breast cancer in a large prospective cohort study. The Sister Study followed women without prior breast cancer ages 35 to 74 years from 2003 to 2017 (N = 49,968). Baseline periodontal disease was self-reported, and incident breast cancer was ascertained over a mean follow-up of 9.3 years. We estimated hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazards regression, adjusting for multiple potential confounders, including smoking status. Heterogeneity in risk for invasive breast cancer versus DCIS was also estimated. About 22% of participants reported a history of periodontal disease at baseline. A total of 3,339 incident breast cancers (2,607 invasive breast cancer, 732 DCIS) were identified. There was no clear association between periodontal disease and overall breast cancer risk (HR = 1.02; 95% CI, 0.94-1.11). However, we observed a nonstatistically significant suggestive increased risk of invasive breast cancer (HR = 1.07; 95% CI, 0.97-1.17) and decreased risk of DCIS (HR = 0.86; 95% CI, 0.72-1.04) associated with periodontal disease, with evidence for heterogeneity in the risk associations (relative HR for invasive breast cancer versus DCIS = 1.24; 95% CI, 1.01-1.52). A case-only analysis for etiologic heterogeneity confirmed this difference. We observed no clear association between periodontal disease and overall breast cancer risk. The heterogeneity in risk associations for invasive breast cancer versus DCIS warrants further exploration.

Bacteria Residing at Root Canals Can Induce Cell Proliferation and Alter the Mechanical Properties of Gingival and Cancer Cells

Understanding the importance of oral microbiota in human health and disease also leads to an expansion of the knowledge on functional, metabolic, and molecular alterations directly contributing to oral and systemic pathologies. To date, a compelling number of studies have documented the crucial role of some oral cavity-occurring microbes in the initiation and progression of cancers. Although this effect was noted primarily for Fusobacterium spp., the potential impact of other oral microbes is also worthy of investigation. In this study, we aimed to assess the effect of Enterococcus faecalis, Actinomyces odontolyticus, and Propionibacterium acnes on the proliferation capability and mechanical features of gingival cells and cell lines derived from lung, breast, and ovarian cancers. For this purpose, we incubated selected cell lines with heat-inactivated bacteria and supernatants collected from biofilms, cultured in both anaerobic and aerobic conditions, in the presence of surgically removed teeth and human saliva. The effect of oral bacteria on cell population growth is variable, with the highest growth-promoting abilities observed for E. faecalis in relation to human primary gingival fibroblasts (HGF) and lung cancer A549 cells, and P. acnes in relation to breast cancer MCF-7 and ovarian cancer SKOV-3 cells. Notably, this effect seems to depend on a delicate balance between the pro-stimulatory and toxic effects of bacterial-derived products. Regardless of the diverse effect of bacterial products on cellular proliferation capability, we observed significant alterations in stiffness of gingival and lung cancer cells stimulated with E. faecalis bacteria and corresponding biofilm supernatants, suggesting a novel molecular mechanism involved in the pathogenesis of diseases in oral cavities and tooth tissues. Accordingly, it is proposed that analysis of cancerogenic features of oral cavity bacteria should be multivariable and should include investigation of potential alterations in cell mechanical properties. These findings corroborate the important role of oral hygiene and root canal treatment to assure the healthy stage of oral microbiota.

Periodontal disease and cancer: Epidemiologic studies and possible mechanisms

Epidemiologic and cancer control studies on the association of periodontal disease and cancer risk mostly suggest a positive association with overall cancer risk and certain specific types of cancer. These findings are generally consistent among cross‐sectional and longitudinal studies. In this paper, we review epidemiologic studies and current knowledge on periodontal disease and cancer, with a focus on those studies conducted in the years following the Joint European Federation of Periodontology/American Academy of Periodontology Workshop on “Periodontitis and Systemic Diseases” in November 2012. This review also explores the role of chronic inflammation as a biologically plausible mechanistic link between periodontal disease and risk of cancer. Furthermore, it highlights studies that have examined the potential importance of certain periodontal pathogens in this association.

Salivary Gland Function, Antioxidant Defence and Oxidative Damage in the Saliva of Patients with Breast Cancer: Does the BRCA1 Mutation Disturb the Salivary Redox Profile?

Oxidative stress plays a key role in breast cancer progression. However, little is still known about the relationship between the BRCA1 mutation, the incidence of breast cancer and oral homeostasis. This is the first study to evaluate the secretory function of salivary glands, biomarkers of redox balance, and oxidative damage to proteins and lipids in the saliva of subjects with the BRCA1 mutation. Ninety eight women were enrolled in the study and allocated to four groups based on molecular DNA testing: generally healthy patients without the BRCA1 mutation, patients with breast cancer but without the BRCA1 mutation, generally healthy patients with the BRCA1 mutation, and patients with both breast cancer and the BRCA1 mutation. We demonstrated that saliva from breast cancer patients with the BRCA1 mutation is characterized by enhanced antioxidant capacity and a higher degree of oxidative damage to proteins and lipids. The BRCA1 mutation can cause a predisposition to early salivary gland dysfunction, both in patients with breast cancer and in healthy individuals, leading to a decrease in salivary proteins. Using cluster analysis, we showed that salivary peroxidase, advanced glycation end-products (AGE), total antioxidant status (TAS) and malondialdehyde (MDA) may have particular clinical significance in non-invasive diagnostics of breast cancer.

Evaluation of cancer risk in patients with periodontal diseases

Background/aim

In this study, we aimed to assess the cancer risk among patients with periodontal disease.

Materials and methods

Patients diagnosed with periodontal diseases at Hacettepe University between 2007 and 2012 were included and data on the diagnosis of any cancer after periodontal disease were collected from patient files. The age- and sex-standardized incidence rates (SIRs) were calculated using Turkish National Cancer Registry 2013 data.

Results

A total of 5199 patients were included. Median follow-up was 7.2 years. Patients with periodontal diseases had 17% increased risk of cancer compared with the expected counts for the corresponding age and sex groups (SIR: 1.17; 95% CI: 1.04–1.3, P = 0.006). The increased cancer risk was statistically significant in women (SIR: 1.24; 95% CI: 1.05–1.45, P = 0.008) but not in men. Among women with periodontal disease, the risks of breast cancer (SIR: 2.19) and head and neck cancer (SIR: 4.71) were significantly increased. Among men, the risks of prostate cancer (SIR: 1.84), head and neck cancer (SIR: 3.55), and hematological cancers (SIR: 1.76) were significantly increased.

Conclusion

This study showed that periodontal diseases were associated with increased risk of several cancers. Besides other well-known benefits for health, the provision of oral/dental health should be considered and employed as a cancer prevention measure.

Is a fusobacterium nucleatum infection in the colon a risk factor for colorectal cancer?: a systematic review and meta-analysis protocol

BACKGROUND

Despite a considerable amount of epidemiological research for identification of risk factors involved in the development of colorectal cancer, the current understanding of the etiology of this disease remains rather poor. Accumulating evidence suggests a potentially important role of infection with Fusobacterium nucleatum in the colon in colorectal carcinogenesis. The objective of this systematic review is to synthesize the epidemiological evidence on the association between infection with Fusobacterium nucleatum in the colon and colorectal cancer.

METHODS

This systematic review will include observational studies (cohort, case-control, cross-sectional) in humans in which the role of Fusobacterium nucleatum in the etiology of colorectal cancer was investigated. MEDLINE, EMBASE, Web of Science, and Cochrane Database of Systematic Reviews will be searched using a comprehensive search strategy and manual screening of references. Two reviewers will independently identify eligible studies and extract the data from the included studies. The quality of studies will be assessed by using the Newcastle-Ottawa scale. Random-effects models will be used to estimate pooled measures of association (where feasible). Meta-regression and subgroup analyses will be conducted to explore the potential sources of heterogeneity. The Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement will be followed for reporting.

DISCUSSION

Deepening knowledge regarding the etiology of colorectal cancer and the potential implications of Fusobacterium nucleatum in this disease is instrumental for prevention, diagnosis, and treatment of this often-fatal disease. This review will produce summarized current evidence on this topic.

SYSTEMATIC REVIEW REGISTRATION

This systematic review protocol has been registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 10 July 2018 (registration number CRD42018095866).

Periodontal Disease and Breast Cancer: A Meta-Analysis of 1,73,162 Participants

Objective: To investigate the correlation between periodontal disease and breast cancer. Materials and Methods: PubMed and China National Knowledge Infrastructure (CNKI) databases were searched up to February 8, 2018 for observational studies examining the association between periodontal disease and breast cancer. Study selection was conducted according to predesigned eligibility criteria, and two authors independently extracted data from included studies. Meta-analysis was performed using the Comprehensive Meta-Analysis v2 software and risk estimates were calculated as relative risks (RRs) with corresponding 95% confidence intervals (CIs). Results: A total of 11 study were included. Meta-analysis indicated that periodontal disease significantly increased the risk of breast cancer by 1.22-fold (RR = 1.22, 95% CI = 1.06-1.40). Amongst participants with periodontal patients and a history of periodontal therapy, the risk of developing breast cancer was not significant (RR = 1.23; 95% CI = 0.95-1.60). The association results between periodontal diseases and breast cancer were found to be robust, as evident in the leave-one-out sensitivity analysis. Conclusions: Periodontal disease may be a potential risk factor for the development of breast cancer among women, and thus effective periodontal therapy may present as a valuable preventive measure against breast cancer.

Periodontal disease and susceptibility to breast cancer: A meta-analysis of observational studies

OBJECTIVE

While some individual studies have suggested an association between periodontal disease and breast cancer, there has not been a formal meta-analysis that collates the existing evidence supporting the hypothesis that periodontal disease leads to a higher risk of developing breast cancer. Accordingly, this meta-analysis was conducted.

METHODS

Relevant studies published until April 2018 were retrieved and were screened according to established inclusion criteria. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated to assess the association between periodontal disease and the risk of breast cancer and fixed effect models were used according to the results of the heterogeneity test.

RESULTS

Eight studies, involving 168,111 individuals, were identified as having explored the association between periodontal disease and breast cancer. Summary estimates in view of adjusted data showed that periodontal disease did increase susceptibility to breast cancer (RR = 1.18, 95%CI: 1.11-1.26, I²  = 17.6%), with robust results confirmed by sensitivity analysis.

CONCLUSION

Our results provided evidence of a modest positive association between periodontal disease and breast cancer. Implementation of practical measures to prevent and treat periodontal disease is of great public health significance. Moreover, additional studies are recommended to explore this topic in more detail.

Increased cancer risk in patients with periodontitis

BACKGROUND

Previous studies have noted a possible association between periodontal diseases and the risk of various cancers. We assessed cancer risk in a cohort of patients with moderate to severe periodontitis.

METHODS

Patients diagnosed with moderate to severe periodontitis by a periodontist between 2001 and 2010 were identified from the hospital registry. Patients younger than 35 years of age or with a prior cancer diagnosis were excluded. The age- and gender-standardized incidence rates (SIR) were calculated by dividing the number of observed cases by the number of expected cases from Turkish National Cancer Registry 2013 data.

RESULTS

A total of 280 patients were included (median age 49.6, 54% female). Median follow-up was 12 years. Twenty-five new cancer cases were observed. Patients with periodontitis had 77% increased risk of cancer (SIR 1.77, 95% CI 1.17-2.58, p = .004). Women with periodontitis had significantly higher risk of breast cancer (SIR 2.40, 95% CI 0.88-5.33) and men with periodontitis had significantly higher risk of prostate cancer (SIR 3.75, 95% CI 0.95-10.21) and hematological cancers (SIR 6.97, 95% CI 1.77-18.98).

CONCLUSION

Although showing a causal association necessitates further investigation, our results support the idea that periodontitis might be associated with increased cancer risk, particularly with hematological, breast and prostate cancers.

The oral cavity microbiota: between health, oral disease, and cancers of the aerodigestive tract

Many studies show that the human microbiome plays a critical role in the chronic pathologies of obesity, inflammatory bowel diseases, and diabetes. More recently, the interaction between cancer and the microbiome has been highlighted. Most studies have focused on the gut microbiota because it represents the most extensive bacterial community, and the body of evidence correlating it with gut syndromes is increasing. However, in the strict sense, the gastrointestinal (GI) tract begins in the oral cavity, and special attention should be paid to the specific flora of this cavity. This study reviewed the current knowledge about the various microbial ecosystems of the upper part of the GI tract and discussed their potential link to carcinogenesis. The overall composition of the microbial communities, as well as the presence or absence of "key species", in relation to carcinogenesis is addressed. Alterations in the oral microbiota can potentially be used to predict the risk of cancer. Molecular advances and the further monitoring of the microbiota will increase our understanding of the role of the microbiota in carcinogenesis and open new perspectives for future therapeutic and prophylactic modalities.

WITHDRAWN: Community-based population-level interventions for promoting child oral health

BACKGROUND

Dental caries and gingival and periodontal disease are commonly occurring, preventable chronic conditions. Even though much is known about how to treat oral disease, currently we do not know which community-based population-level interventions are most effective and equitable in preventing poor oral health.

OBJECTIVES

Primary • To determine the effectiveness of community-based population-level oral health promotion interventions in preventing dental caries and gingival and periodontal disease among children from birth to 18 years of age. Secondary • To determine the most effective types of interventions (environmental, social, community and multi-component) and guiding theoretical frameworks.• To identify interventions that reduce inequality in oral health outcomes.• To examine the influence of context in the design, delivery and outcomes of interventions.

SEARCH METHODS

We searched the following databases from January 1996 to April 2014: MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Education Resource Information Center (ERIC), BIOSIS Previews, Web of Science, the Database of Abstracts of Reviews of Effects (DARE), ScienceDirect, Sociological Abstracts, Social Science Citation Index, PsycINFO, SCOPUS, ProQuest Dissertations & Theses and Conference Proceedings Citation Index - Science.

SELECTION CRITERIA

Included studies were individual- and cluster-randomised controlled trials (RCTs), controlled before-and-after studies and quasi-experimental and interrupted time series. To be included, interventions had to target the primary outcomes: dental caries (measured as decayed, missing and filled deciduous teeth/surfaces, dmft/s; Decayed, Missing and Filled permanent teeth/surfaces, DMFT/S) and gingival or periodontal disease among children from birth to 18 years of age. Studies had to report on one or more of the primary outcomes at baseline and post intervention, or had to provide change scores for both intervention and control groups. Interventions were excluded if they were solely of a chemical nature (e.g. chlorhexidine, fluoride varnish), were delivered primarily in a dental clinical setting or comprised solely fluoridation.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed screening, data extraction and assessment of risk of bias of included studies (a team of six review authors - four review authors and two research assistants - assessed all studies). We calculated mean differences with 95% confidence intervals for continuous data. When data permitted, we undertook meta-analysis of primary outcome measures using a fixed-effect model to summarise results across studies. We used the I2 statistic as a measure of statistical heterogeneity.

MAIN RESULTS

This review includes findings from 38 studies (total n = 119,789 children, including one national study of 99,071 children, which contributed 80% of total participants) on community-based oral health promotion interventions delivered in a variety of settings and incorporating a range of health promotion strategies (e.g. policy, educational activities, professional oral health care, supervised toothbrushing programmes, motivational interviewing). We categorised interventions as dietary interventions (n = 3), oral health education (OHE) alone (n = 17), OHE in combination with supervised toothbrushing with fluoridated toothpaste (n = 8) and OHE in combination with a variety of other interventions (including professional preventive oral health care, n = 10). Interventions generally were implemented for less than one year (n = 26), and only 11 studies were RCTs. We graded the evidence as having moderate to very low quality.We conducted meta-analyses examining impact on dental caries of each intervention type, although not all studies provided sufficient data to allow pooling of effects across similar interventions. Meta-analyses of the effects of OHE alone on caries may show little or no effect on DMFT (two studies, mean difference (MD) 0.12, 95% confidence interval (CI) -0.11 to 0.36, low-quality evidence), dmft (three studies, MD -0.3, 95% CI -1.11 to 0.52, low-quality evidence) and DMFS (one study, MD -0.01, 95% CI -0.24 to 0.22, very low-quality evidence). Analysis of studies testing OHE in combination with supervised toothbrushing with fluoridated toothpaste may show a beneficial effect on dmfs (three studies, MD -1.59, 95% CI -2.67 to -0.52, low-quality evidence) and dmft (two studies, MD -0.97, 95% CI -1.06 to -0.89, low-quality evidence) but may show little effect on DMFS (two studies, MD -0.02, 95% CI -0.13 to 0.10, low-quality evidence) and DMFT (three studies, MD -0.02, 95% CI -0.11 to 0.07, moderate-quality evidence). Meta-analyses of two studies of OHE in an educational setting combined with professional preventive oral care in a dental clinic setting probably show a very small effect on DMFT (-0.09 weighted mean difference (WMD), 95% CI -0.1 to -0.08, moderate-quality evidence). Data were inadequate for meta-analyses on gingival health, although positive impact was reported.

AUTHORS' CONCLUSIONS

This review provides evidence of low certainty suggesting that community-based oral health promotion interventions that combine oral health education with supervised toothbrushing or professional preventive oral care can reduce dental caries in children. Other interventions, such as those that aim to promote access to fluoride, improve children's diets or provide oral health education alone, show only limited impact. We found no clear indication of when is the most effective time to intervene during childhood. Cost-effectiveness, long-term sustainability and equity of impacts and adverse outcomes were not widely reported by study authors, limiting our ability to make inferences on these aspects. More rigorous measurement and reporting of study results would improve the quality of the evidence.

Community-based population-level interventions for promoting child oral health

BACKGROUND

Dental caries and gingival and periodontal disease are commonly occurring, preventable chronic conditions. Even though much is known about how to treat oral disease, currently we do not know which community-based population-level interventions are most effective and equitable in preventing poor oral health.

OBJECTIVES

Primary • To determine the effectiveness of community-based population-level oral health promotion interventions in preventing dental caries and gingival and periodontal disease among children from birth to 18 years of age. Secondary • To determine the most effective types of interventions (environmental, social, community and multi-component) and guiding theoretical frameworks.• To identify interventions that reduce inequality in oral health outcomes.• To examine the influence of context in the design, delivery and outcomes of interventions.

SEARCH METHODS

We searched the following databases from January 1996 to April 2014: MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Education Resource Information Center (ERIC), BIOSIS Previews, Web of Science, the Database of Abstracts of Reviews of Effects (DARE), ScienceDirect, Sociological Abstracts, Social Science Citation Index, PsycINFO, SCOPUS, ProQuest Dissertations & Theses and Conference Proceedings Citation Index - Science.

SELECTION CRITERIA

Included studies were individual- and cluster-randomised controlled trials (RCTs), controlled before-and-after studies and quasi-experimental and interrupted time series. To be included, interventions had to target the primary outcomes: dental caries (measured as decayed, missing and filled deciduous teeth/surfaces, dmft/s; Decayed, Missing and Filled permanent teeth/surfaces, DMFT/S) and gingival or periodontal disease among children from birth to 18 years of age. Studies had to report on one or more of the primary outcomes at baseline and post intervention, or had to provide change scores for both intervention and control groups. Interventions were excluded if they were solely of a chemical nature (e.g. chlorhexidine, fluoride varnish), were delivered primarily in a dental clinical setting or comprised solely fluoridation.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed screening, data extraction and assessment of risk of bias of included studies (a team of six review authors - four review authors and two research assistants - assessed all studies). We calculated mean differences with 95% confidence intervals for continuous data. When data permitted, we undertook meta-analysis of primary outcome measures using a fixed-effect model to summarise results across studies. We used the I2 statistic as a measure of statistical heterogeneity.

MAIN RESULTS

This review includes findings from 38 studies (total n = 119,789 children, including one national study of 99,071 children, which contributed 80% of total participants) on community-based oral health promotion interventions delivered in a variety of settings and incorporating a range of health promotion strategies (e.g. policy, educational activities, professional oral health care, supervised toothbrushing programmes, motivational interviewing). We categorised interventions as dietary interventions (n = 3), oral health education (OHE) alone (n = 17), OHE in combination with supervised toothbrushing with fluoridated toothpaste (n = 8) and OHE in combination with a variety of other interventions (including professional preventive oral health care, n = 10). Interventions generally were implemented for less than one year (n = 26), and only 11 studies were RCTs. We graded the evidence as having moderate to very low quality.We conducted meta-analyses examining impact on dental caries of each intervention type, although not all studies provided sufficient data to allow pooling of effects across similar interventions. Meta-analyses of the effects of OHE alone on caries may show little or no effect on DMFT (two studies, mean difference (MD) 0.12, 95% confidence interval (CI) -0.11 to 0.36, low-quality evidence), dmft (three studies, MD -0.3, 95% CI -1.11 to 0.52, low-quality evidence) and DMFS (one study, MD -0.01, 95% CI -0.24 to 0.22, very low-quality evidence). Analysis of studies testing OHE in combination with supervised toothbrushing with fluoridated toothpaste may show a beneficial effect on dmfs (three studies, MD -1.59, 95% CI -2.67 to -0.52, low-quality evidence) and dmft (two studies, MD -0.97, 95% CI -1.06 to -0.89, low-quality evidence) but may show little effect on DMFS (two studies, MD -0.02, 95% CI -0.13 to 0.10, low-quality evidence) and DMFT (three studies, MD -0.02, 95% CI -0.11 to 0.07, moderate-quality evidence). Meta-analyses of two studies of OHE in an educational setting combined with professional preventive oral care in a dental clinic setting probably show a very small effect on DMFT (-0.09 weighted mean difference (WMD), 95% CI -0.1 to -0.08, moderate-quality evidence). Data were inadequate for meta-analyses on gingival health, although positive impact was reported.

AUTHORS' CONCLUSIONS

This review provides evidence of low certainty suggesting that community-based oral health promotion interventions that combine oral health education with supervised toothbrushing or professional preventive oral care can reduce dental caries in children. Other interventions, such as those that aim to promote access to fluoride, improve children's diets or provide oral health education alone, show only limited impact. We found no clear indication of when is the most effective time to intervene during childhood. Cost-effectiveness, long-term sustainability and equity of impacts and adverse outcomes were not widely reported by study authors, limiting our ability to make inferences on these aspects. More rigorous measurement and reporting of study results would improve the quality of the evidence.

Periodontal Disease and Breast Cancer: Prospective Cohort Study of Postmenopausal Women

BACKGROUND

Periodontal disease has been consistently associated with chronic disease; there are no large studies of breast cancer, although oral-associated microbes are present in breast tumors.

METHODS

In the Women's Health Initiative Observational Study, a prospective cohort of postmenopausal women, 73,737 women without previous breast cancer were followed. Incident, primary, invasive breast tumors were verified by physician adjudication. Periodontal disease was by self-report. HRs and 95% confidence intervals (CI) were estimated by Cox proportional hazards, adjusted for breast cancer risk factors. Because the oral microbiome of those with periodontal disease differs with smoking status, we examined associations stratified by smoking.

RESULTS

2,124 incident, invasive breast cancer cases were identified after mean follow-up of 6.7 years. Periodontal disease, reported by 26.1% of women, was associated with increased breast cancer risk (HR 1.14; 95% CI, 1.03-1.26), particularly among former smokers who quit within 20 years (HR 1.36; 95% CI, 1.05-1.77). Among current smokers, the trend was similar (HR 1.32; 95% CI, 0.83-2.11); there were few cases (n = 74) and the CI included the null. The population attributable fraction was 12.06% (95% CI, 1.12-21.79) and 10.90% (95% CI, 10.31-28.94) for periodontal disease among former smokers quitting within 20 years and current smokers, respectively.

CONCLUSION

Periodontal disease, a common chronic inflammatory disorder, was associated with increased risk of postmenopausal breast cancer, particularly among former smokers who quit in the past 20 years.

IMPACT

Understanding a possible role of the oral microbiome in breast carcinogenesis could impact prevention.

Unique database study linking gingival inflammation and smoking in carcinogenesis

We investigated statistical association between gingival inflammation and cancer in a group of patients followed up for 26 years with the hypothesis that gingival inflammation affects carcinogenesis. Altogether, 1676 30- to 40-year-old subjects from Stockholm were clinically examined in 1985. In 2011, we compared the baseline oral examination and follow-up data with cancer diagnoses sourced from the Swedish national hospital register databases. Of 1676 individuals, 89 (55 women, 34 men) had got cancer by the year 2011. Women were found to be at higher risk for cancer than men. Smoking (expressed in pack-years) had been more prevalent in the cancer group than in those with no cancer diagnosis. Gingival index, marker of gingival inflammation, was higher in the cancer group than in subjects with no cancer. There were no significant differences between the groups regarding age, education, dental plaque and calculus index scores, or in the number of missing teeth. In multiple logistic regression analysis with cancer as the dependent variable and several independent variables, pack-years of smoking appeared to be a principal independent predictor with odds ratio (OR) 1.32 while gingival inflammation showed OR 1.29. Hence, our present findings showed that together with smoking, gingival inflammation indeed associated with the incidence of cancer in this cohort.

Validating of the pre-clinical mouse model for metastatic breast cancer to the mandible

Metastatic breast carcinoma has a great tendency to spread to the mandible. It is concomitantly associated with bone destruction, food intake disorder, and a poorer prognosis. Appropriate animal models need to be developed for a better understanding of the mechanisms underlying the metastatic process of breast cancer cells to mandible and to test the effects of potential lead compounds. Here, we assessed the metastasis model of intracardiac injection using luciferase-transfected metastatic breast cancer cells (MDA-MB-231^Luc+) by determining the incidences of metastasis, mCT images, and histopathological results. A high bioluminescence signal mainly detected mandibular lesions with less frequent distal femora and proximal tibiae lesions. Extensive mandibular bone destruction occurred in nude mice grafted with metastatic breast cancer cells. This type of animal model might be a useful tool in assessing therapeutic implications and the efficacy of anti-cancer drugs for osteolytic cancers.

Periodontal disease with treatment reduces subsequent cancer risks

AIM

The aim of our study was to evaluate the relationship between routine treatment of periodontal disease (PD) and the subsequent risks for cancers in Taiwan.

METHODS

Study participants were selected from the Taiwan National Health Insurance (NHI) system database. The PD with a routine treatment cohort contained 38 902 patients. For each treatment cohort participant, two age- and sex-matched comparison (control) cohort participants were randomly selected. Cox's proportional hazards regression analysis was used to estimate the effects of PD with treatment on the subsequent risk of cancer.

RESULTS

The overall risk of developing cancer was significantly lower in the treatment cohort than in the patients without treatment (adjusted Hazard ratio = 0.72, 95% confidence interval = 0.68-0.76). The risks of developing most gastrointestinal tract, lung, gynecological and brain malignancies were significantly lower in the treatment cohort than in the comparison cohort. In contrast, the risks of prostate and thyroid cancers were significantly higher in the treatment cohort than in the comparison cohort.

CONCLUSIONS

Our findings suggest that PD with treatment is associated with a significantly reduced overall risk of cancer and reduced risks of certain types of cancers.

Epigenetic changes of TIMP-3, GSTP-1 and 14-3-3 sigma genes as indication of status of chronic inflammation and cancer

OBJECTIVES

This study aimed to compare the epigenetic changes via hypermethylation status of TIMP-3, GSTP-1 and 14-3-3σ genes, between healthy subjects and patients with reversible chronic inflammatory disease, and between healthy subjects and patients with irreversible malignant disease, to highlight the genetic changes that occur in the progression from an inflammatory condition to irreversible genetic changes commonly observed in cancer patients.

METHODS

DNA was extracted from the blood of 680 healthy subjects, and tissues and blood of 110 patients with chronic inflammation disease of the gums, as well as neoplastic tissues of 108 breast cancer patients. Methylation-specific polymerase chain reaction (PCR) for TIMP-3, GSTP-1 and 14-3-3σ was performed, and hypermethylation status was analyzed and compared between the 3 groups.

RESULTS

The hypermethylation frequencies of TIMP-3 and GSTP-1 of reversible chronic inflammatory gum disease and the control group were similar, but both were significantly lower than those for malignant disease patients (p<0.0001). The methylation frequency of 14-3-3σ in chronic inflammatory gum disease was higher than in the cancer and control groups (p<0.0001). The methylation of CpG islands in TIMP-3 and GSTP-1 in chronic inflammation patients occurred as frequently as in the control group, but less frequently than in breast cancer patients. However, the epigenetic silencing of 14-3-3σ occurred more frequently in the chronic inflammation group than in cancer patients and healthy controls.

CONCLUSIONS

The epigenetic silencing of 14-3-3σ might be essential for chronic inflammatory gum disease. The epigenetic changes presented in chronic inflammation patients might demonstrate an irreversible destruction in the tissues or organs similar to cancer.

History of dental infections associates with cancer in periodontally healthy subjects: a 24-year follow-up study from sweden

BACKGROUND

Infections of teeth are highly prevalent, often leading to tooth extractions. Missing teeth can thus be considered as proxy for chronic dental infections, caries or periodontitis. We followed-up a cohort for 24 years investigating the association between missing teeth and the incidence of cancer with the hypothesis that dental chronic inflammation links to cancer.

METHODS

WHO ICD-7-9-10 malignant diagnoses were recorded from the Swedish Cancer Registry from 1985 to 2009 in 1 390 individuals who had underwent clinical oral examination in 1985. The subjects appeared periodontally healthy and thus the probable reason for tooth extractions was deep caries. Using Fisher's exact t-test and multiple logistic regression analysis the results were analysed for the association between cancer incidence and baseline oral health parameters and a number of other explanatory factors.

RESULTS

Of the 1 390 subjects 71 had got cancer by year 2009. The results of the multiple regression analysis showed that between any type of cancer as a dependent variable, and several independent explanatory variables, missing second molar in the right mandible and age appeared as the principle independent predictors significantly associating with cancer, with an odds ratio (95% confidence interval) of 2.62 (1.18-5.78) and 1.91 (1.06-3.43), respectively.

CONCLUSIONS

In periodontally healthy subjects extracted molars, proxy for past dental infections, seemed to predict cancer risk in the studied age group - hence supporting a role of chronic dental infection/inflammation in carcinogenesis.

The association of dental plaque with cancer mortality in Sweden. A longitudinal study

OBJECTIVES

To study whether the amount of dental plaque, which indicates poor oral hygiene and is potential source of oral infections, associates with premature death from cancer.

DESIGN

Prospective cohort study.

PARTICIPANTS

1390 randomly selected healthy young Swedes followed up from 1985 to 2009. All subjects underwent oral clinical examination and answered a questionnaire assessing background variables such as socioeconomic status and smoking.

OUTCOME MEASURES

Causes of death were recorded from national statistics and classified according to the WHO International Classification of Diseases. Unpaired t test, χ(2) tests and multiple logistic regressions were used.

RESULTS

Of the 1390 participants, 4.2% had died during the follow-up. Women had died at a mean age of 61.0 (±2.6 SD) years and men at the age of 60.2 (±2.9 SD) years. The amount of dental plaque between those who had died versus survived was statistically significant (p<0.001). In multiple logistic regression analysis, dental plaque appeared to be a significant independent predictor associated with 1.79 times the OR of death (p<0.05). Age increased the risk with an OR of 1.98 (p<0.05) and gender (men) with an OR of 1.91 (p<0.05). The malignancies were more widely scattered in men, while breast cancer was the most frequent cause of death in women.

CONCLUSIONS

This study hypothesis was confirmed by showing that poor oral hygiene, as reflected in the amount of dental plaque, was associated with increased cancer mortality.

Are oral and dental diseases linked to cancer?

OBJECTIVE

Infection and inflammation play a role in carcinogenesis, and highly prevalent oral and dental diseases have been significantly linked to some types of cancer. This article reviews current literature in this area.

MATERIALS AND METHODS

Open literature review using the PubMed database and focused on publications from 2000 to 2010.

RESULTS

Numerous potential mechanisms are implicated in the oral disease/carcinogenesis paradigm, including infection- and inflammation-associated cell pathology and microbial carcinogen metabolism. Poor oral hygiene is associated with oral cancer, but there is also evidence of a possible link between oral or dental infections and malignancies in general.

CONCLUSION

Oral infections may trigger malignant transformation in tissues of the mouth and other organs. However, scientific evidence to date remains weak and further well-conducted studies are warranted before cancer can be properly added to the list of oral infection-related systemic diseases.