Periodontal Disease Assessed Using Clinical Dental Measurements and Cancer Risk in the ARIC Study

The role of Fusobacterium nucleatum in cancer and its implications for clinical applications

Fusobacterium nucleatum, a gram-negative anaerobic bacterium abundantly found in the human oral cavity, is widely recognized as a key pathobiont responsible for the initiation and progression of periodontal diseases due to its remarkable aggregative capabilities. Numerous clinical studies have linked F. nucleatum with unfavorable prognostic outcomes in various malignancies. In further research, scholars have partially elucidated the mechanisms underlying F. nucleatum's impact on various types of cancer, thus gaining a certain comprehension of the role played by F. nucleatum in cancer. In this comprehensive review, we present an in-depth synthesis of the interplay between F. nucleatum and different cancers, focusing on aspects such as tumor initiation, metastasis, chemoresistance, and modulation of the tumor immune microenvironment and immunotherapy. The implications for cancer diagnosis and treatment are also summarized. The objective of this review is to enhance our comprehension of the intricate relationship between F. nucleatum and oncogenic pathogenesis, while emphasizing potential therapeutic strategies.

Blood Leukocyte DNA Methylation Markers of Periodontal Disease and Risk of Lung Cancer in a Case-Control Study Nested in the CLUE II Cohort

BACKGROUND

Periodontal disease and DNA methylation markers have separately been associated with lung cancer risk. Examining methylation levels at genomic regions previously linked to periodontal disease may provide insights on the link between periodontal disease and lung cancer.

METHODS

In a nested case-control study drawn from the CLUE II cohort, we measured DNA methylation levels in 208 lung cancer cases and 208 controls. We examined the association between 37 DNA-methylated 5'-C-phosphate-G-3' (CpG) sites at three genomic regions, homeobox 4 (HOXA4), zinc finger protein (ZFP57), and a long noncoding RNA gene located in Chr10 (ENSG00000231601), and lung cancer risk.

RESULTS

Statistically significant associations with lung cancer risk were observed for all 14 CpG sites from HOXA4 (OR ranging 1.41-1.62 for 1 SD increase in the DNA methylation level, especially within 15 years) and 1 CpG site on gene ENSG00000231601 (OR = 1.34 for 1 SD increase in the DNA methylation level). Although CpG sites on gene ZFP57 were not associated with lung cancer risk overall, statistically significant inverse associations were noted for six CpG sites when restricting follow-up to 15 years (OR = 0.73-0.77 for 1 SD increase in the DNA methylation level).

CONCLUSIONS

Key methylation levels associated with periodontal disease are also associated with lung cancer risk. For both HOXA4 and ZFP57, the associations were stronger within 15 years of follow-up, which suggest that, if causal, the impact of methylation is acting late in the natural history of lung cancer.

IMPACT

Identifying biological pathways that link periodontal disease and lung cancer could provide new opportunities for lung cancer detection and prevention.

Association between periodontal disease and malignant soft tissue sarcomas

OBJECTIVE

Malignant soft tissue sarcoma (MSTS) is a rare disease, but is seen in patients undergoing orthopedic surgery. Although the association of periodontal disease with various cancers occurring in the oral cavity, gastrointestinal tract, lungs, and prostate, has been reported, the association between periodontal disease and MSTS remains unclear. This study investigated the association between periodontal disease and MSTS in patients undergoing orthopedic surgery.

SUBJECTS AND METHODS

One hundred fifteen patients who underwent orthopedic surgery between 2017 and 2021 were retrospectively enrolled (mean age = 66.8 ± 10.7 years). The patient background was adjusted by the propensity score (PS). Subsequently, the association of periodontal disease with MSTS was analyzed using PS inverse probability of treatment weighting (IPTW). Periodontal status was determined by evaluating the periodontal inflamed surface area, which was calculated by measuring the periodontal probing pocket depth and detecting bleeding on probing.

RESULTS

Multivariate logistic regression analysis after adjustment by the PS showed that severe periodontitis was significantly associated with MSTS (odds ratio 2.81, p = 0.04). Furthermore, IPTW showed that severe periodontitis was significantly associated with MSTS (odds ratio 3.21, p = 0.01).

CONCLUSION

The results indicate an association between periodontal inflammation and MSTS.

Direct, Broad-Spectrum Antimicrobial Activity of Ag+-Doped Hydroxyapatite against Fastidious Anaerobic Periodontal and Aerobic Dental Bacteria

Periodontitis and caries, while seemingly innocuous medical conditions, actually pose significant challenges because of their potential etiology with far more serious conditions. Efficacious treatment is hindered by bacterial antibiotic resistance. Standard AgNPs are ineffective against periodontal anaerobic bacteria, because they require oxidative dissolution to release Ag+ ions, which are the actual antimicrobial agents, but oxidation is not possible under anaerobic conditions. Prior studies on Ag-based periodontal antimicrobial materials either did not confirm a silver oxidation state or did not use strictly anaerobic growth media or both, causing spurious antimicrobial efficacy estimates. Here, we prove that silver ion-doped hydroxyapatite nanoparticles (AgHAp NPs) synthesized at various pHs contain an Ag+ oxidation state and directly release Ag+ even in a strictly anerobic medium. Thus, these AgHAp NPs exhibit direct antimicrobial activity against the fastidious anaerobic Gram-negative periodontal bacterium Fusobacterium nucleatum (F. nucleatum) and against caries-causing aerobic, Gram-positive bacterium Streptococcus mutans (S. mutans). The synthesis pH (6-11) correlates inversely with the Ag+ content (4.5-0.45 wt %) of AgHAp NPs and, hence, with antimicrobial efficacy, thus providing tunable efficacy for the target application. AgHAp NPs had greater antimicrobial efficacy than Ag0-containing AgNPs and were less cytotoxic to the mouse fibroblast L929 cell line. Thus, AgHAp NPs (especially AgHAp7) are superior to AgNPs as effective, broad-spectrum, biocompatible antimicrobials against both anaerobic periodontal and aerobic dental bacteria. AgHAp NP synthesis is also inexpensive and scalable, which are significant factors for treating large global populations of indigent people affected by periodontitis and dental caries.

Epidemiological associations between periodontitis and cancer

There is a postulated association of periodontitis with a number of human cancers. This narrative review provides current epidemiological evidence on the association between periodontitis and cancer. A PubMed search with the relevant keywords (periodontal disease, periodontitis, cancer, and malignancy) was completed to identify relevent articles. We present a narrative review on the association between periodontal disease and a range of cancers, including oral cancer, stomach and esophageal cancer, colorectal cancer, lung cancer, pancreatic cancer, prostate cancer, hematological malignancies, liver cancer, breast cancer, and ovarian cancer. While there is a considerable body of epidemiological evidence that supports the association between periodontal disease and cancer, this is largely from cohort and case-control studies and the association may therefore be circumstantial as little evidence exists in the form of treatment trials that would validate the role of periodontal disease in the process of cancer initiation and development.

Global Research Trends in the Links between Periodontal Disease and Cancer: A Bibliometric Analysis

Both periodontal disease and cancer are prevalent conditions with significant impacts on individuals and society. Extensive research has suggested a potential link between these two diseases. This study conducted a bibliometric analysis using the Thomson Reuters Web of Science Core Collection database, focusing on publications from 2014 to 2023. The analysis included data extraction and examination of authors, affiliations, publication dates, journals, countries, citation counts, keywords, and the H-index. A total of 253 relevant articles were identified, showing an increasing trend in both publications and citations over the years. The analysis highlighted the most productive authors, institutions, and countries/regions, with Michaud DS and Abnet CC leading in the number of publications. Highly cited articles emphasized the role of specific oral microbiota, particularly F. nucleatum and P. gingivalis, in various cancers, suggesting their potential as diagnostic markers and therapeutic targets. Four key thematic clusters emerged from the keyword analysis: the broader health implications of periodontal disease, the microbiome's role in carcinogenesis, inflammation, and specific bacteria in cancer, and epidemiological methods in studying the disease-cancer association. This bibliometric analysis underscores the growing interest in the connection between periodontal disease and cancer. Future research should adopt interdisciplinary approaches, focus on large-scale microbiome studies and longitudinal research to understand the systemic effects of periodontal disease, identify cancer-associated bacterial profiles, and investigate the molecular mechanisms of bacterial carcinogenesis. Additionally, public health interventions aimed at improving oral hygiene and reducing cancer risk factors are recommended.

Association between Periodontal Diseases and the Risk of Site-Specific Gastrointestinal Cancers: A Systematic Review and Meta-Analysis

The association between periodontal diseases and the risk of gastrointestinal cancers, especially site-specific gastrointestinal cancers, remains unclear. Here, we comprehensively searched PubMed, EMBASE, Web of Science, and Google Scholar from inception to April 2024 to identify relevant studies. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with a random-effects model. Subgroup analyses and sensitivity analyses were conducted to confirm the robustness of the main findings in different populations. This study was reported according to PRISMA 2020 guidelines. In total, we identified 19 studies, including 16.6 million participants. Individuals with periodontal diseases had an increased risk of overall gastrointestinal cancers compared with those without periodontal diseases (HR 1.31, 95% CI 1.16-1.49). Periodontal diseases significantly increased the risk of esophageal cancer by 39% (HR 1.39, 95% CI 1.15-1.68), gastric cancer by 13% (HR 1.13, 95% CI 1.01-1.26), colorectal cancer by 21% (HR 1.21, 95% CI 1.05-1.39), pancreatic cancer by 35% (HR 1.35, 95% CI 1.00-1.82), and liver cancer by 9% (HR 1.09, 95% CI 1.04-1.13). The risk of gastrointestinal cancers was significantly increased by periodontitis (HR 1.45, 95% CI 1.14-1.85), gingivitis (HR 1.03, 95% CI 1.01-1.04), and periodontitis/gingivitis (HR 1.27, 95% CI 1.07-1.51). Furthermore, severe periodontal diseases showed a significantly increased risk of gastrointestinal cancer (HR 1.79, 95% CI 1.07-2.99). Results of sensitivity analyses for site-specific gastrointestinal cancers were robust with the main findings. In summary, periodontal diseases, especially severe periodontitis, increase the risk of overall and site-specific gastrointestinal cancers. Interventions to prevent and manage periodontal diseases may reduce the risk of developing gastrointestinal cancers.

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.

Banxia Xiexin Decoction delays colitis-to-cancer transition by inhibiting E-cadherin/β-catenin pathway via Fusobacterium nucleatum FadA

ETHNOPHARMACOLOGICAL RELEVANCE

Colitis is an important risk factor for the occurrence of colorectal cancer (CRC), and the colonization of Fusobacterium nucleatum (Fn) in the intestines accelerates this transformation process. Banxia Xiexin Decoction (BXD), originating from Shanghanlun, is a classic prescription for treating gastrointestinal diseases. Current researches indicate that BXD can effectively delay the colitis-to-cancer transition, but it is still unclear whether it can inhibit Fn colonization to achieve this delaying effect.

AIM OF STUDY

This study explored the effect and mechanism of BXD in inhibiting Fn intestinal colonization to delay colitis-to-cancer transition.

MATERIALS AND METHODS

We constructed a mouse model of colitis-to-cancer transition by regularly gavaging Fn combined with azoxymethane (AOM)/dextran sodium sulfate (DSS), and administered BXD by gavage. We monitored the body weight of mice, measured the length and weight of their colons, and calculated the disease activity index (DAI) score. The growth status of colon tumors was observed by hematoxylin and eosin (H&E) staining, and the changes in gut microbiota in each group of mice were detected by 16S rDNA analysis. Immunohistochemistry was used to detect the expression of E-cadherin and β-catenin in colon tissues, and immunofluorescence was used to observe the infiltration of M2 macrophages in colon tissues. In cell experiments, we established a co-culture model of Fn and colon cancer cells and intervened with BXD-containing serum. Malignant behaviors such as cell proliferation, invasion, and migration were detected, as well as changes in their cell cycle. We examined the protein levels of E-cadherin, β-catenin, Axin2, and Cyclin D1 in each group were detected by Western blot. We used US1 strain (fadA-) as a control and observed the effects of BXD-containing serum on Fn attachment and invasion of colon cancer cells through attachment and invasion experiments.

RESULTS

BXD can inhibit the colitis-to-cancer transition in mice infected with Fn, reduce crypt structure damage, improve gut microbiota dysbiosis, upregulate E-cadherin and decrease β-catenin expression, and reduce infiltration of M2 macrophages, thus inhibiting the process of colitis-to-cancer transition. Cell experiments revealed that BXD-containing serum can inhibit the proliferation, migration, and invasion of colon cancer cells infected with Fn and regulate their cell cycle. More importantly, we found that BXD-containing serum can inhibit the binding of Fn's FadA adhesin to E-cadherin, reduce Fn's attachment and invasion of colon cancer cells, thereby downregulating the E-cadherin/β-catenin signaling pathway.

CONCLUSIONS

These findings show that BXD can inhibit Fn colonization by interfering with the binding of FadA to E-cadherin, reducing the activation of the E-cadherin/β-catenin signaling pathway, and ultimately delaying colitis-to-cancer transition.

Chronic periodontitis and risk of lung cancer: a nationwide cohort study

Background

The impact of long-term chronic periodontal conditions on the risk of lung cancer could not be accurately evaluated. Our aim was to provide more evidence on the connection between chronic periodontitis (CP) and lung cancer using a nationwide dataset.

Methods

This study used data from the Korean National Health Insurance Service National Sample Cohort. We enrolled 72,658 individuals with CP (CP cohort) between 2005 and 2019 and 1:1 age- and sex-matched controls without CP (non-CP cohort).

Results

During the median follow-up period of 5.1 (interquartile range, 2.8-8.0) years, 0.56% (n = 405/72,658) of the CP cohort and 0.29% (n = 212/72,658) of the matched non-CP cohort developed lung cancer, with incidence rates of 8.3 and 4.5 per 10,000 person-years. The risk of incident lung cancer was significantly higher in the CP cohort than in the matched non-CP cohort (adjusted hazard ratio = 2.27, 95% confidence interval = 1.94-2.65). The risk of incident lung cancer was 2.45-fold and 2.10-fold higher in mild and moderate-to-severe CP cohorts than in the matched non-CP control. The risk of incident lung cancer was especially higher in the 40-59 age group, females, and never-smokers than their counterparts.

Conclusion

We demonstrate that the risk of incident lung cancer is higher in individuals with CP than in those without. The risk of lung cancer was especially high in individuals with more severe CP, females, never-smokers, and obese populations.

Genetic and environmental contributions for the relationship between tooth loss and oral potentially malignant disorders and oral squamous cell carcinoma

BACKGROUND

To investigate the association between tooth loss and oral potentially malignant disorders and oral squamous cell carcinoma, focusing on epidemiological factors and genetic variants.

METHODS

Case-control study, including histologically confirmed oral potentially malignant disorders and oral squamous cell carcinoma cases and healthy controls. Unadjusted and adjusted odds ratios for this association were calculated. Single-nucleotides polymorphisms were tested for individuals with and without missing teeth.

RESULTS

Case individuals were more edentulous while controls had fewer missing teeth (p = 0.006). There was an increased risk for the outcomes associated with edentulism (OR = 6.95, p = 0.000), even after adjustments for educational level (OR = 4.7, p = 0.034) and smoking habits (OR = 5.01, p = 0.022). Among individuals with tooth loss, rs1533767 (WNT11), rs3923087, and rs11867417 (AXIN2) were associated with the outcomes (OR = 1.67, p = 0.03, OR = 0.53, p = 0.05, and OR = 0.42, p = 0.00, respectively).

CONCLUSIONS

Tooth loss could increase the risk for oral potentially malignant disorders and oral squamous cell carcinoma.

Association between Periodontitis and Hematologic Cancer: An NHIRD Cohort Study in Taiwan

BACKGROUND

Chronic periodontitis, an inflammation-related disorder affecting global populations, has been revealed to be linked to diverse cancers. Numerous epidemiological studies have not shown a link between chronic periodontitis and blood cancers in Taiwan.

METHODS

This study included 601,628 patients, diagnosed with newly chronic periodontitis by the ICD-9-CM classification, who were enrolled from 2001 to 2021 in the National Health Insurance Research Database (NHIRD) in Taiwan. In this study, we employed comprehensive statistical analyses to investigate the association between chronic periodontitis and hematologic cancers. Initially, we calculated incidence density and used a Poisson regression to analyze relative risk. Subsequently, we compared the cumulative incidence of hematological cancer in both chronic and non-chronic periodontitis groups using the Kaplan-Meier method.

RESULTS

The results revealed a significantly lower cumulative incidence of hematologic cancer in individuals with non-chronic periodontitis over a 12-year follow-up period. To further explore the risk factors, a Cox proportional hazard regression analysis was conducted. Being male (adjusted hazard ratio [aHR] = 1.21, 95% CI: 1.04 to 1.42; p = 0.014) and having hypertension (aHR = 1.34, 95% CI: 1.06 to 1.69; p = 0.015) were demonstrated to be associated with an increased risk of hematologic cancers, respectively. In addition, in a subtype multivariate analysis for categorizing hematologic cancers into lymphoma and leukemia, the aHR for leukemia was 1.48 (95% CI: 1.13 to 1.93; p = 0.004) and aHR for lymphoma was 1.15 (95% CI: 0.96 to 1.37; p = 0.140).

CONCLUSIONS

This study found that being male and having hypertension were the significant risk factors for hematological malignancies. Moreover, the association between chronic periodontitis and specific subtypes of hematologic cancers was confirmed.

Pretreatment periodontitis is predictive of a poorer prognosis after esophagectomy for esophageal cancer

BACKGROUND

Poor oral health is an independent risk factor for upper-aerodigestive tract cancers, including esophageal cancer. Several studies have investigated short-term outcomes after esophagectomy and the impact of periodontal disease, but few have examined the impact of periodontal disease on long-term outcomes. The purpose of this study was to investigate the rate of periodontitis among esophagectomy patients and the prognostic value of periodontitis and its effect on prognosis after esophagectomy.

METHODS

A total of 508 patients who underwent esophagectomy received oral health care from a dentist before cancer treatment at Akita University Hospital between January 2009 and December 2021. We assessed the presence and severity of the patients' periodontitis and divided them into no-periodontitis, mild periodontitis, severe periodontitis and edentulous jaw groups. We then assessed 10-year overall survival (OS) and disease-specific survival (DSS) and determined whether periodontitis was an independent prognostic factor affecting OS and DSS.

RESULTS

We found that 101 (19.9%) patients had no periodontitis, 207 (40.8%) had mild periodontitis, 176 (34.6%) had severe periodontitis requiring tooth extraction, and 24 (4.7%) had edentulous jaw. Both OS and DSS were significantly poorer in the periodontitis than no-periodontitis group (p < 0.001). In detail, the edentulous jaw group had the poorest prognosis (p < 0.001). Multivariate analysis showed that periodontitis was an independent risk factor affecting OS and DSS.

CONCLUSION

Esophageal cancer patients had a high prevalence of periodontitis. Moreover, the presence of periodontitis and severity of periodontitis are independent risk factors contributing to a poorer prognosis after esophagectomy.

Patients with periodontitis might increase the risk of urologic cancers: a bidirectional two-sample Mendelian randomization study

BACKGROUND

Numerous observational epidemiological studies have reported a bidirectional relationship between periodontitis and urological cancers. However, the causal link between these two phenotypes remains uncertain. This study aimed to examine the bidirectional causal association between periodontitis and four types of urological tumors, specifically kidney cancer (KC), prostate cancer (PC), bladder cancer (BC), and testis cancer (TC).

METHODS

Based on large-scale genome-wide association study (GWAS) data, we utilized the two-sample Mendelian randomization (MR) approach to evaluate causal relationships between periodontitis and urological cancers. Several MR methods covering various consistency assumptions were applied in this study, including contamination mixture and Robust Adjusted Profile Score to obtain robust results. Summary-level data of individuals with European ancestry were extracted from the UK Biobank, the Kaiser GERA cohorts, and the FinnGen consortium.

RESULTS

Our findings revealed significant positive genetic correlations between periodontitis and kidney cancer (OR 1.287; 95% CI 1.04, 1.594; P = 0.020). We did not find a significant association of periodontitis on prostate cancer, bladder cancer, and testis cancer. In reverse MR, no significant results were observed supporting the effect of urologic cancers on periodontitis (all P > 0.05).

CONCLUSION

Our study provides the evidence of a potential causal relationship between periodontitis and kidney cancer. However, large-scale studies are warranted to confirm and elucidate the underlying mechanisms of this association.

Cancer incidence trends in New York State and associations with common population-level exposures 2010-2018: an ecological study

The impact of common environmental exposures in combinations with socioeconomic and lifestyle factors on cancer development, particularly for young adults, remains understudied. Here, we leveraged environmental and cancer incidence data collected in New York State at the county level to examine the association between 31 exposures and 10 common cancers (i.e., lung and bronchus, thyroid, colorectal, kidney and renal pelvis, melanoma, non-Hodgkin lymphoma, and leukemia for both sexes; corpus uteri and female breast cancer; prostate cancer), for three age groups (25-49, 50-69, and 70-84 year-olds). For each cancer, we stratified by age group and sex, and applied regression models to examine the associations with multiple exposures simultaneously. The models included 642,013 incident cancer cases during 2010-2018 and found risk factors consistent with previous reports (e.g., smoking and physical inactivity). Models also found positive associations between ambient air pollutants (ozone and PM2.5) and prostate cancer, female breast cancer, and melanoma of the skin across multiple population strata. Additionally, the models were able to better explain the variation in cancer incidence data among 25-49 year-olds than the two older age groups. These findings support the impact of common environmental exposures on cancer development, particularly for younger age groups.

Transcriptomic analysis of Porphyromonas gingivalis-infected head and neck cancer cells: Identification of PLAU as a candidate prognostic biomarker

Periodontal disease is a risk factor for head and neck squamous cell carcinoma (HNSCC), and Porphyromonas gingivalis, a major periodontal pathogen, has been identified as a specific and potentially independent microbial factor that increases the risk of cancer mortality. Gene expression in HNSCC due to P. gingivalis infection and how changes in gene expression affect the prognosis of HNSCC patients are not clarified. When P. gingivalis was cultured with HNSCC cells, it efficiently adhered to these cells and enhanced their invasive ability. A transcriptome analysis of P. gingivalis -infected HNSCC cells showed that genes related to migration, including CCL20, CITED2, CTGF, C8orf44-SGK3, DUSP10, EGR3, FUZ, HBEGF, IL1B, IL24, JUN, PLAU, PTGS2, P2RY1, SEMA7A, SGK1 and SIX2, were highly up- or down-regulated. The expression of up-regulated genes was examined using the expression data of HNSCC patients obtained from The Cancer Genome Atlas (TCGA) database, and the expression of 5 genes, including PLAU, was found to be higher in cancer tissue than in solid normal tissue. An analysis of protein-protein interactions revealed that these 5 genes formed a dense network. A Cox regression analysis showed that high PLAU expression levels were associated with a poor prognosis in patients with TCGA-HNSCC. Furthermore, the prognostic impact correlated with tumour size and the presence or absence of lymph node metastasis. Collectively, these results suggest the potential of PLAU as a molecular prognostic marker in HNSCC patients. Further in vivo and in vitro studies are needed to verify the findings of this study.

Dental health and lung cancer risk in the Golestan Cohort Study

BACKGROUND

Poor oral health has been linked to various systemic diseases, including multiple cancer types, but studies of its association with lung cancer have been inconclusive.

METHODS

We examined the relationship between dental status and lung cancer incidence and mortality in the Golestan Cohort Study, a large, prospective cohort of 50,045 adults in northeastern Iran. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between three dental health measures (i.e., number of missing teeth; the sum of decayed, missing, or filled teeth (DMFT); and toothbrushing frequency) and lung cancer incidence or mortality with adjustment for multiple potential confounders, including cigarette smoking and opium use. We created tertiles of the number of lost teeth/DMFT score in excess of the loess adjusted, age- and sex-specific predicted numbers, with subjects with the expected number of lost teeth/DMFT or fewer as the reference group.

RESULTS

During a median follow-up of 14 years, there were 119 incident lung cancer cases and 98 lung cancer deaths. Higher DMFT scores were associated with a progressively increased risk of lung cancer (linear trend, p = 0.011). Compared with individuals with the expected DMFT score or less, the HRs were 1.27 (95% CI: 0.73, 2.22), 2.15 (95% CI: 1.34, 3.43), and 1.52 (95% CI: 0.81, 2.84) for the first to the third tertiles of DMFT, respectively. The highest tertile of tooth loss also had an increased risk of lung cancer, with a HR of 1.68 (95% CI: 1.04, 2.70) compared with subjects with the expected number of lost teeth or fewer (linear trend, p = 0.043). The results were similar for lung cancer mortality and did not change substantially when the analysis was restricted to never users of cigarettes or opium. We found no associations between toothbrushing frequency and lung cancer incidence or mortality.

CONCLUSION

Poor dental health indicated by tooth loss or DMFT, but not lack of toothbrushing, was associated with increased lung cancer incidence and mortality in this rural Middle Eastern population.

Periodontal health status in patients with lung cancer: Case-control study

Objective

The objective of this study was to assess the periodontal health status of individuals with lung cancer in the North Indian population. In addition, the study aimed to determine the levels of human beta-defensin2 (Hbd-2) in the gingival crevicular fluid (GCF) and serum samples collected from the participants.

Methods

The study consisted of a total of 90 participants, who were categorized into three groups: Group 1 included 30 healthy individuals, Group 2 comprised 30 patients with chronic periodontitis, and Group 3 involved 30 patients diagnosed with both lung cancer and chronic periodontitis. Various periodontal parameters, including plaque index, gingival index, probing pocket depth, and clinical attachment level (CAL), were assessed in addition to the analysis of human beta defensin2 levels in both the GCF and serum samples of all participants.

Results

The study results revealed that all clinical parameters assessed were higher in Group 3 compared to both Group 2 and Group 1. Specifically, the levels of hBD-2 in the GCF were measured as 52.29 ± 46.41 pg/mL in Group 1, 27.15 ± 28.76 pg/mL in Group 2, and 86.01 ± 68.82 pg/mL in Group 3. When comparing the hBD-2 levels in serum, the values were found to be 813.72 ± 269.43 pg/mL in Group 1, 591.50 ± 263.91 pg/mL in Group 2, and 1093.04 ± 674.55 pg/mL in Group 3. These intergroup comparisons indicate variations in hBD-2 levels among the different groups.

Conclusions

The study findings demonstrated significantly higher clinical and biochemical markers in patients with both lung cancer and chronic periodontitis, in comparison to individuals with chronic periodontitis alone and healthy participants. These results suggest that Hbd-2 could potentially serve as a valuable diagnostic biomarker for identifying and distinguishing individuals with both lung cancer and chronic periodontitis.

Alveolar bone loss and tooth loss contribute to increase in cancer mortality among older patients

BACKGROUND

Both cancer and periodontitis are more prevalent with age. Information on their relationship in older patients is limited. This study aims to examine whether periodontitis is associated with increased risk of cancer mortality with a ≥ 75-year age group cohort.

METHODS

A retrospective cohort study was conducted on 1146 patients who had digital radiographic examinations. Alveolar bone loss and loss of teeth were measured as indicators of periodontitis. Hazard ratio (HR) with 95% confidence interval (CI) were taken as the effect size to summarize the associations between periodontitis and risks of cancer mortality using the multivariate adjusted cox proportional hazards model and competing risk hazard model.

RESULTS

Totally, 104 total cancer, 28 lip, oral cavity and pharynx (LOP) cancer, 39 digestive cancer and 13 respiratory cancer cases were documented over 10 years of follow-up. Total cancer (HR 1.27, 95% CI 1.06-1.53) displayed statistically significant associations with alveolar bone loss and tooth loss after adjusting for relevant confounding variables. We also observed borderline significant association between alveolar bone loss and LOP cancer (HR 1.45, 95% CI 0.99-2.12). The above associations were consistent with the results observed from the competing risk hazard models.

CONCLUSION

Our results indicate that older patients suffering from tooth loss or alveolar bone loss are at increased risks of cancer mortality, especially for total cancer and LOP cancer.

Periodontitis and risk of cancer: Mechanistic evidence

This review aims to critically analyze the pathways of interaction and the pathogenic mechanisms linking periodontitis and oral bacteria with the initiation/progression of cancer at different body compartments. A higher risk of head and neck cancer has been consistently associated with periodontitis. This relationship has been explained by the local promotion of dysbiosis, chronic inflammation, immune evasion, and direct (epi)genetic damage to epithelial cells by periodontal pathobionts and their toxins. Epidemiological reports have also studied a possible link between periodontitis and the incidence of other malignancies at distant sites, such as lung, breast, prostate, and digestive tract cancers. Mechanistically, different pathways have been involved, including the induction of a chronic systemic inflammatory state and the spreading of oral pathobionts with carcinogenic potential. Indeed, periodontitis may promote low-grade systemic inflammation and phenotypic changes in the mononuclear cells, leading to the release of free radicals and cytokines, as well as extracellular matrix degradation, which are all mechanisms involved in carcinogenic and metastatic processes. Moreover, the transient hematogenous spill out or micro-aspiration/swallowing of periodontal bacteria and their virulence factors (i.e., lipopolysaccharides, fimbriae), may lead to non-indigenous bacterial colonization of multiple microenvironments. These events may in turn replenish the tumor-associated microbiome and thus influence the molecular hallmarks of cancer. Particularly, specific strains of oral pathobionts (e.g., Porphyromonas gingivalis and Fusobacterium nucleatum) may translocate through the hematogenous and enteral routes, being implicated in esophageal, gastric, pancreatic, and colorectal tumorigenesis through the modulation of the gastrointestinal antitumor immune system (i.e., tumor-infiltrating T cells) and the increased expression of pro-inflammatory/oncogenic genes. Ultimately, the potential influence of common risk factors, relevant comorbidities, and upstream drivers, such as gerovulnerability to multiple diseases, in explaining the relationship cannot be disregarded. The evidence analyzed here emphasizes the possible relevance of periodontitis in cancer initiation/progression and stimulates future research endeavors.

Interplay between oral health and lifestyle factors for cancer risk in rural and urban China: a population-based cohort study

Background

Although poor oral health and several lifestyle factors have been found to be associated with cancer risk, their joint relationship has rarely been studied.

Methods

We prospectively examined the associations of oral health and healthy lifestyle factors with cancer risk among 0.5 million rural and urban residents from the China Kadoorie Biobank (2004-2015). Oral health status was assessed from self-reported baseline questionnaires. A healthy lifestyle index comprising non-smoking, non-drinking, ideal body shape, physical activity and healthy diet was calculated for each participant, and categorized into favorable, intermediate and unfavorable lifestyle behavior. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) relating oral health and healthy lifestyle index to cancer risk using Cox proportional hazards models. We estimated the population attributable risk percent (PAR%) and 95% CIs using multivariate models.

Results

During a median follow-up of 9 years, 23,805 new cancer cases were documented, with 52% from rural areas and 48% from urban areas. Compared with those with good oral health and favorable lifestyle, participants with poor oral health and unfavorable lifestyle had a higher risk of developing cancer in both rural (adjusted HR, 1.55 [95% CI, 1.39-1.74]; P for trend < 0.001) and urban areas (adjusted HR, 1.44 [95% CI, 1.24-1.67]; P for trend < 0.001). A significant multiplicative interaction between oral health and healthy lifestyle index on cancer risk was found in rural residents (P for interaction = 0.004) rather than in urban residents (P for interaction = 0.973). Assuming poor oral health as an additional risk factor, the PAR% of total cancer increased by 3.0% and 1.1% for participants with intermediate lifestyle and unfavorable lifestyle, respectively.

Conclusions

These findings suggest a joint effect of oral health and common lifestyle factors on cancer risk. Promotion of healthy lifestyle by integration of good oral health would be beneficial to consider in cancer prevention strategies.

Microbiota as the unifying factor behind the hallmarks of cancer

The human microbiota is a complex ecosystem that colonizes body surfaces and interacts with host organ systems, especially the immune system. Since the composition of this ecosystem depends on a variety of internal and external factors, each individual harbors a unique set of microbes. These differences in microbiota composition make individuals either more or less susceptible to various diseases, including cancer. Specific microbes are associated with cancer etiology and pathogenesis and several mechanisms of how they drive the typical hallmarks of cancer were recently identified. Although most microbes reside in the distal gut, they can influence cancer initiation and progression in distant tissues, as well as modulate the outcomes of established cancer therapies. Here, we describe the mechanisms by which microbes influence carcinogenesis and discuss their current and potential future applications in cancer diagnostics and management.

Mapping the Scientific Landscape of Bacterial Influence on Oral Cancer: A Bibliometric Analysis of the Last Decade's Medical Progress

The research domain investigating bacterial factors in the development of oral cancer from January 2013 to December 2022 was examined with a bibliometric analysis. A bibliometric analysis is a mathematical and statistical method used to examine extensive datasets. It assesses the connections between prolific authors, journals, institutions, and countries while also identifying commonly used keywords. A comprehensive search strategy identified 167 relevant articles, revealing a progressive increase in publications and citations over time. China and the United States were the leading countries in research productivity, while Harvard University and the University of Helsinki were prominent affiliations. Prolific authors such as Nezar Al-Hebshi, Tsute Chen, and Yaping Pan were identified. The analysis also highlights the contributions of different journals and identifies the top 10 most cited articles in the field, all of which focus primarily on molecular research. The article of the highest citation explored the role of a Fusobacterium nucleatum surface protein in tumor immune evasion. Other top-cited articles investigated the correlation between the oral bacteriome and cancer using 16S rRNA amplicon sequencing, showing microbial shifts associated with oral cancer development. The functional prediction analysis used by recent studies has further revealed an inflammatory bacteriome associated with carcinogenesis. Furthermore, a keyword analysis reveals four distinct research themes: cancer mechanisms, periodontitis and microbiome, inflammation and Fusobacterium, and risk factors. This analysis provides an objective assessment of the research landscape, offers valuable information, and serves as a resource for researchers to advance knowledge and collaboration in the search for the influence of bacteria on the prevention, diagnosis, and treatment of oral cancer.

The Gum-Gut Axis: Periodontitis and the Risk of Gastrointestinal Cancers

Periodontitis has been linked to an increased risk of various chronic non-communicable diseases, including gastrointestinal cancers. Indeed, dysbiosis of the oral microbiome and immune-inflammatory pathways related to periodontitis may impact the pathophysiology of the gastrointestinal tract and its accessory organs through the so-called "gum-gut axis". In addition to the hematogenous spread of periodontal pathogens and inflammatory cytokines, recent research suggests that oral pathobionts may translocate to the gastrointestinal tract through saliva, possibly impacting neoplastic processes in the gastrointestinal, liver, and pancreatic systems. The exact mechanisms by which oral pathogens contribute to the development of digestive tract cancers are not fully understood but may involve dysbiosis of the gut microbiome, chronic inflammation, and immune modulation/evasion, mainly through the interaction with T-helper and monocytic cells. Specifically, keystone periodontal pathogens, including Porphyromonas gingivalis and Fusobacterium nucleatum, are known to interact with the molecular hallmarks of gastrointestinal cancers, inducing genomic mutations, and promote a permissive immune microenvironment by impairing anti-tumor checkpoints. The evidence gathered here suggests a possible role of periodontitis and oral dysbiosis in the carcinogenesis of the enteral tract. The "gum-gut axis" may therefore represent a promising target for the development of strategies for the prevention and treatment of gastrointestinal cancers.

The increasing importance of the oral microbiome in periodontal health and disease

Herein, the aim is to discuss the current knowledge of microbiome and periodontal diseases. Current treatment strategies include mechanical therapy such as root planing, scaling, deep pocket debridement and antimicrobial chemotherapy as an adjuvant therapy. Among promising therapeutic strategies, dental probiotics and oral microbiome transplantation have gained attention, and may be used to treat bacterial imbalances by competing with pathogenic bacteria for nutrients and adhesion surfaces, as well as probiotics targeting the gut microbiome. Development of strategies to prevent and treat periodontal diseases are warranted as both are highly prevalent and can affect human health. Further studies are necessary to better comprehend the microbiome in order to develop innovative preventative measures as well as efficacious therapies against periodontal diseases.

Epigenome-wide association study using peripheral blood leukocytes identifies genomic regions associated with periodontal disease and edentulism in the Atherosclerosis Risk in Communities study

AIM

To investigate individual susceptibility to periodontitis by conducting an epigenome-wide association study using peripheral blood.

MATERIALS AND METHODS

We included 1077 African American and 457 European American participants of the Atherosclerosis Risk in Communities (ARIC) study who had completed a dental examination or reported being edentulous at Visit 4 and had available data on DNA methylation from Visit 2 or 3. DNA methylation levels were compared by periodontal disease severity and edentulism through discovery analyses and subsequent testing of individual CpGs.

RESULTS

Our discovery analysis replicated findings from a previous study reporting a region in gene ZFP57 (6p22.1) that was significantly hypomethylated in severe periodontal disease compared with no/mild periodontal disease in European American participants. Higher methylation levels in a separate region in an unknown gene (located in Chr10: 743,992-744,958) was associated with significantly higher odds of edentulism compared with no/mild periodontal disease in African American participants. In subsequent CpG testing, four CpGs in a region previously associated with periodontitis located within HOXA4 were significantly hypermethylated in severe periodontal disease compared with no/mild periodontal disease in African American participants (odds ratio per 1 SD increase in methylation level: cg11015251: 1.28 (1.02, 1.61); cg14359292: 1.24 (1.01, 1.54); cg07317062: 1.30 (1.05, 1.61); cg08657492: 1.25 (1.01, 1.55)).

CONCLUSIONS

Our study highlights epigenetic variations in ZPF57 and HOXA4 that are significantly and reproducibly associated with periodontitis. Future studies should evaluate gene regulatory mechanisms in the candidate regions of these loci.

ASSOCIATION OF ORAL MICROBIOTA AND PERIODONTAL DISEASE WITH LUNG CANCER: A SYSTEMATIC REVIEW AND META-ANALYSIS

OBJECTIVES

Evidence of oral microbiota perturbations has been accumulated for lung cancers. This review focused on the oral microbiota alterations in population suffering from lung cancer. In addition, we also discussed conflicting data about the association between oral microbiota dysbiosis and risk of lung cancer.

METHODS

A systematic search was conducted in Medline, Embase, PubMed, and Cochrane Library databases. The studies evaluated diversity and abundance of oral microbes in healthy and lung cancer individuals as well as association of periodontal disease and pathogens with lung cancer. Of 3559 studies, 28 included studies were performed in qualitative analysis, and 25 studies were used in meta-analyses for quantitative assessment. Heterogeneity was analyzed by using I² and chi-squared Q test statistics. Statistical analyses were performed by using the RevMan 5.4 software.

RESULTS

Compared with the control, lung cancer patients had lower alpha diversity (Shannon: SMD = -0.54; 95% CI, -0.90 to -0.19; P < .01, I2 = 71%). In nested case-control studies, individuals with decreased alpha diversity tended to have an increased risk of lung cancer (observed species: HR = 0.90; 95% CI, 0.85-0.96; P < .01, I2 = 0%; Shannon: HR = 0.89; 95% CI, 0.83-0.95; P < .01, I2 = 0%). Overall, no strong evidence of association of relative abundance with specific oral microbes with lung cancers was found because of inconsistent data. No associations were found between periodontal pathogens and lung cancer risk (red complex: HR = 1.12, 95% CI: 0.42-3.02, P = .82, I2 = 62%; orange complex: HR =1.77, 95% CI: 0.78-3.98, P = .17, I2 = 36%), expect for Fusobacterium nucleatum (HR = 2.27, 95% CI: 1.13-4.58, P = .02, I2 = 0%). The positive association of periodontal disease with lung cancer risk was found (HR = 1.58, 95% CI: 1.25-2.00, P < .001, I2= 0%) with increase of periodontal diseases severity (HR = 2.39, 95% CI: 1.57-3.66, P < .001, I2 = 0%). However, such association was not found in never-smoker participants (HR = 1.00, 95% CI: 0.76-1.31, P = .37, I2= 7%).

CONCLUSIONS

Lower alpha diversity of oral microbiome may be associated with a greater risk of lung cancer and might serve as a predictive signal of lung cancer risk. There was no strong evidence of relative abundance of oral microbial taxa and periodontal pathogens in lung cancer patients. Fusobacterium nucleatum might be a potential microbial candidate of biomarkers in lung cancer. Periodontal disease may be positively associated with lung cancer risk by confounding of smoking, but not an independent risk factor.

Expanding germ-organ theory: Understanding non-communicable diseases through enterobacterial translocation

Diverse microbial communities colonize different habitats of the human body, including gut, oral cavity, nasal cavity and tissues. These microbial communities are known as human microbiome, plays a vital role in maintaining the health. However, changes in the composition and functions of human microbiome can result in chronic low-grade inflammation, which can damage the epithelial cells and allows pathogens and their toxic metabolites to translocate into other organs such as the liver, heart, and kidneys, causing metabolic inflammation. This dysbiosis of human microbiome has been directly linked to the onset of several non-communicable diseases. Recent metabolomics studies have revealed that pathogens produce several uraemic toxins. These metabolites can serve as inter-kingdom signals, entering the circulatory system and altering host metabolism, thereby aggravating a variety of diseases. Interestingly, Enterobacteriaceae, a critical member of Proteobacteria, has been commonly associated with several non-communicable diseases, and the abundance of this family has been positively correlated with uraemic toxin production. Hence, this review provides a comprehensive overview of Enterobacterial translocation and their metabolites role in non-communicable diseases. This understanding may lead to the identification of novel biomarkers for each metabolic disease as well as the development of novel therapeutic drugs.

Associations between missing teeth and the risk of cancer in Korea: a nationwide cohort study

BACKGROUND

Poor dental health is correlated with an increased risk of cancer. Using a nationwide population cohort database, we investigated which cancer is highly associated with poor dental health and which dental indicator mostly influences cancer risk.

METHODS

This study was conducted using the National Health Checkups (NHC) and National Health Insurance System (NHIS) database in Korea. NHC in Korea includes dental examinations. We retrieved subjects who underwent NHC between 2002 and 2003 and their medical information in NHIS database was followed until December 31,2015.

RESULTS

Data for 200,170 who participated in the NHC between 2002 and 2003 were analysed. During the maximum follow-up period of 13 years, 15,506 (7.75%) subjects were diagnosed with cancer. The median time to cancer diagnosis after the dental examination was 87 months (range, 51-119 months). The proportion of people with missing teeth was higher in the cancer-diagnosed group than in the non-diagnosed group (26.27% vs. 22.59%, p < 0.001). Among several dental health factors, missing teeth were significantly associated with higher cancer risk. Subjects with missing teeth showed a 12% increased cancer risk compared to those without missing teeth (odds ratio [OR] 1.12, 95% confidence interval [CI], 1.08-1.16). The risk was significantly higher, especially in lung, head and neck, pancreatic, liver, biliary, and esophageal cancers (OR 1.27 [95% CI, 1.14-1.41], 1.32 [95% CI, 1.13-1.55], 1.27 [95% CI, 1.02-1.58], 1.24 [95% CI, 1.1-1.4], 1.28 [95% CI, 1.03-1.6], 1.4 [95% CI, 1.04-1.88], respectively).

CONCLUSIONS

Missing teeth were the most important dental indicator associated with cancer risk. Korean adults with missing teeth should be cautious about the risk of several cancers, particularly head and neck, lung, gastrointestinal, hepatobiliary, and pancreatic cancer.

Entering, Linked with the Sphinx: Lysophosphatidic Acids Everywhere, All at Once, in the Oral System and Cancer

Oral health is crucial to overall health, and periodontal disease (PDD) is a chronic inflammatory disease. Over the past decade, PDD has been recognized as a significant contributor to systemic inflammation. Here, we relate our seminal work defining the role of lysophosphatidic acid (LPA) and its receptors (LPARs) in the oral system with findings and parallels relevant to cancer. We discuss the largely unexplored fine-tuning potential of LPA species for biological control of complex immune responses and suggest approaches for the areas where we believe more research should be undertaken to advance our understanding of signaling at the level of the cellular microenvironment in biological processes where LPA is a key player so we can better treat diseases such as PDD, cancer, and emerging diseases.

Periodontal and Other Oral Bacteria and Risk of Lung Cancer in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Evidence suggests that periodontal disease is associated with increased lung cancer risk, but whether periodontal pathogens are explanatory is unknown. We prospectively studied associations of prediagnostic circulating antibodies with oral bacteria and of periodontal bacteria in subgingival plaque with lung cancer.

METHODS

We included 4,263 cancer-free participants in the Atherosclerosis Risk in Communities study with previously measured serum IgG antibodies to 18 oral bacteria. In 1,287 participants for whom subgingival plaque was collected, counts for 8 periodontal bacteria were previously measured. Incident lung cancers (N = 118) were ascertained through 2015 (median follow-up = 17.5 years). We used Cox regression to estimate multivariable-adjusted associations, including for sums of antibodies to orange (C. rectus, F. nucleatum, P. intermedia, P. micra, and P. nigrescens) and red (P. gingivalis, T. forsythensis, and T. denticola) complex bacteria.

RESULTS

Orange complex bacteria antibodies were positively associated with lung cancer [per IQR hazard ratios (HR) = 1.15; 95% confidence intervals (CI), 1.02-1.29], which was stronger in men (HR = 1.27, 95% CI 1.08-1.49), and explained by P. intermedia and P. nigrescens (HR = 1.15; 95% CI, 1.04-1.26). Suggestive positive associations with lung cancer (N = 40) were observed for F. nucleatum, A. actinomycetemcomitans, and P. gingivalis counts. Significant positive associations were found for the count to antibody ratio for P. intermedia and P. gingivalis.

CONCLUSIONS

We identified positive associations with lung cancer for oral bacteria, especially orange complex that are moderately pathogenic for periodontal disease.

IMPACT

This prospective study supports the need for more research on periodontal bacteria in lung cancer etiology. If associations are supported, this may inform novel lung cancer prevention strategies.

Association between Chronic Gingivitis and Cancer: A Retrospective Cohort Study of 19,782 Outpatients from the United Kingdom

Purpose: Recent data argue for the involvement of inflammatory and infectious diseases in cancer development. However, clinical data on the association between chronic gingivitis and cancer have been less conclusive. Here, we systematically evaluated the cancer incidence in a population-based cohort of outpatients with chronic gingivitis from the United Kingdom. Methods: 9891 patients with chronic gingivitis and an identical number of people without gingivitis matched by age, gender, index year, and the Charlson Comorbidity Index were identified from the Disease Analyzer database (IQVIA) between January 2000 and December 2016. Cox regression models were used to study the association between gingivitis and cancer. Results: The probability of cancer was significantly higher among patients with diagnosed chronic gingivitis compared to non-gingivitis individuals (HR = 1.36, 95% CI = 1.15–1.62). In cancer site-stratified analyses, we observed a trend towards higher rates of cancer in almost all cancers (breast cancer, lymphoid system cancer, digestive tract cancers, skin cancer); however, a significant association was only observed for prostate cancer (HR: 3.38; 95% CI: 1.57–7.27). Notably, the largest increase in cancer rates was observed in male patients (HR: 1.46, 95% CI: 1.13–1.89) between 41 and 60 years old (HR: 1.74, 95% CI: 1.30–2.32). Conclusions: Our data suggest that chronic gingivitis represents an important risk factor for the development of cancer. Therefore, in the context of patient dental care, awareness should be raised to refer gingivitis patients to existing screening programs, especially for prostate cancer. Moreover, the consistent treatment of gingivitis could potentially have a positive impact on the morbidity of certain cancers.

Correlation Between Chronic Periodontitis and Lung Cancer: A Systematic Review With Meta-Analysis

Periodontal disease is associated with many systemic diseases, such as cardiovascular diseases, atherosclerosis, diabetes mellitus, stroke, and pulmonary diseases. Interestingly, recent literature suggests that periodontal disease might be a risk factor for various cancers such as lung, colon, oesophageal, head, and neck cancers. However, the precise mechanistic link is lacking. Hence, in this meta-analysis, we aimed to investigate the correlation between periodontal disease and lung cancer in periodontally diseased patients. Data were searched for relevant studies from 2010 to 2022. We correlated periodontal disease and lung cancer based on adjusted ORs/HRs and associated CIs. I2 statistic was used to assess statistical heterogeneity. Publication bias was analyzed by visually inspecting the symmetry of the funnel plot and Egger's test. The study is registered in the International Prospective Register of Systematic Reviews (PROSPERO; registration no: CRD42023390819). A total of 194,850 participants from observational studies (two case-control studies and five cohort studies) were incorporated for the current analysis. The meta-analysis of included studies showed an overall effect size (risk ratio) of the periodontal disease group with respect to the non-periodontal disease group for lung neoplasm to be 1.41 (95% CI: 1.32-1.52). The value was more than 1, indicating that the periodontal disease group had a relatively higher lung cancer prevalence than the non-periodontal disease group. Further, the overall risk ratio was found to be statistically significant (p<0.00001). Moreover, the funnel plot suggested some degree of publication bias. Evidence in our study implicated that there is an increased risk of occurrence of lung cancer in chronic periodontitis patients.

Bacterial Infections and Cancer: Exploring This Association And Its Implications for Cancer Patients

Bacterial infections are common in the etiology of human diseases owing to the ubiquity of bacteria. Such infections promote the development of periodontal disease, bacterial pneumonia, typhoid, acute gastroenteritis, and diarrhea in susceptible hosts. These diseases may be resolved using antibiotics/antimicrobial therapy in some hosts. However, other hosts may be unable to eliminate the bacteria, allowing them to persist for long durations and significantly increasing the carrier's risk of developing cancer over time. Indeed, infectious pathogens are modifiable cancer risk factors, and through this comprehensive review, we highlight the complex relationship between bacterial infections and the development of several cancer types. For this review, searches were performed on the PubMed, Embase, and Web of Science databases encompassing the entirety of 2022. Based on our investigation, we found several critical associations, of which some are causative: Porphyromonas gingivalis and Fusobacterium nucleatum are associated with periodontal disease, Salmonella spp., Clostridium perfringens, Escherichia coli, Campylobacter spp., and Shigella are associated with gastroenteritis. Helicobacter pylori infection is implicated in the etiology of gastric cancer, and persistent Chlamydia infections present a risk factor for the development of cervical carcinoma, especially in patients with the human papillomavirus (HPV) coinfection. Salmonella typhi infections are linked with gallbladder cancer, and Chlamydia pneumoniae infection is implicated in lung cancer, etc. This knowledge helps identify the adaptation strategies used by bacteria to evade antibiotic/antimicrobial therapy. The article also sheds light on the role of antibiotics in cancer treatment, the consequences of their use, and strategies for limiting antibiotic resistance. Finally, the dual role of bacteria in cancer development as well as in cancer therapy is briefly discussed, as this is an area that may help to facilitate the development of novel microbe-based therapeutics as a means of securing improved outcomes.

Periodontitis is associated with an increased hazard of mortality in a longitudinal cohort study over 50 years

AIM

To evaluate the association between periodontal disease and all-cause mortality in a longitudinal cohort study over 50 years.

MATERIALS AND METHODS

Participants (N = 1156) in the Veterans Affairs Dental Longitudinal Study, aged 25-85 years at enrollment in 1968, received comprehensive medical and oral exams approximately every 3 years through 2007. Periodontal status was defined using person-level, mean whole-mouth radiographic alveolar bone loss (ABL) scores using a five-point Schei ruler, each unit representing 20% increments of ABL. Time-varying Cox regression models estimated hazard ratios (HRs) for the association between continuous and categorical ABL and mortality, adjusting for covariates.

RESULTS

Each one-unit increase in mean ABL score was associated with a 14% increase in the hazard of mortality (adjusted HR = 1.14, 95% confidence interval [CI] 1.02, 1.27). When assessed categorically, HRs for average scores of 2 to <3 and 3 to ≤5 showed increasing associations with hazard of mortality, relative to 0 to <1 (adjusted HR = 1.17, 95% CI 0.94, 1.46; and HR = 1.65, 95% CI 0.94, 2.85, respectively). By contrast, we observed null associations for average scores of 1 to <2 relative to 0 to <1 (adjusted HR = 1.00, 95% CI 0.86, 1.17).

CONCLUSIONS

Time-varying periodontal status assessed using radiographic ABL was positively associated with all-cause mortality even after confounder adjustment.

Preoperative evaluation of oral hygiene may predict the overall survival of patients with esophageal cancer

BACKGROUND

Previously, the association between tooth loss and prognosis after esophagectomy was reported; however, the presence of periodontal disease has not been assessed. This study investigated the association between the degree of oral hygiene, as evaluated by tooth loss and periodontal disease, and the prognosis of patients with esophageal cancer.

METHODS

A total of 163 esophageal cancer patients who underwent surgery with perioperative oral care and examination were enrolled. We assessed the periodontal pocket depth for the presence of periodontal disease and established a periodontal pocket index, defined as the sum of the periodontal pocket depth of the remaining tooth divided by the total count of the remaining teeth. Patients were divided into three groups: Group A (tooth loss < 13 and periodontal pocket index < 3.67); Group B (tooth loss < 13 and periodontal pocket index ≥ 3.67); and Group C (tooth loss ≥ 13). Overall survival and cancer-specific survival were analyzed, and a multivariate analysis was performed.

RESULTS

There was a significant difference in the 5-year overall survival rates between the groups (A:B:C = 74.8%:62.8%:50.5%; p = 0.0098), but not in the 5-year cancer-specific survival rates (A:B:C = 80.2%:64.2%:62.2%; p = 0.0849). In multivariate analysis, oral hygiene (tooth loss < 13 and periodontal pocket index ≥ 3.67 + tooth loss ≥ 13; p = 0.041) was a significant independent poor prognostic factor for overall survival.

CONCLUSIONS

Oral evaluation, focusing on tooth loss and periodontal disease, is meaningful in predicting the long-term prognosis of postoperative esophageal cancer patients.

An international report on bacterial communities in esophageal squamous cell carcinoma

The incidence of esophageal squamous cell carcinoma (ESCC) is disproportionately high in the eastern corridor of Africa and parts of Asia. Emerging research has identified a potential association between poor oral health and ESCC. One possible link between poor oral health and ESCC involves the alteration of the microbiome. We performed an integrated analysis of four independent sequencing efforts of ESCC tumors from patients from high- and low-incidence regions of the world. Using whole genome sequencing (WGS) and RNA sequencing (RNAseq) of ESCC tumors from 61 patients in Tanzania, we identified a community of bacteria, including members of the genera Fusobacterium, Selenomonas, Prevotella, Streptococcus, Porphyromonas, Veillonella and Campylobacter, present at high abundance in ESCC tumors. We then characterized the microbiome of 238 ESCC tumor specimens collected in two additional independent sequencing efforts consisting of patients from other high-ESCC incidence regions (Tanzania, Malawi, Kenya, Iran, China). This analysis revealed similar ESCC-associated bacterial communities in these cancers. Because these genera are traditionally considered members of the oral microbiota, we next explored whether there was a relationship between the synchronous saliva and tumor microbiomes of ESCC patients in Tanzania. Comparative analyses revealed that paired saliva and tumor microbiomes were significantly similar with a specific enrichment of Fusobacterium and Prevotella in the tumor microbiome. Together, these data indicate that cancer-associated oral bacteria are associated with ESCC tumors at the time of diagnosis and support a model in which oral bacteria are present in high abundance in both saliva and tumors of some ESCC patients.

Assessment of the association between periodontal disease and total cancer incidence and mortality: a meta-analysis

Background

Periodontal disease (PD) is a chronic inflammatory disease that leads to alveolar bone resorption and tooth loss. Many studies have reported the association between periodontal disease and various cancers including oral cancer, lung cancer, breast cancer and so on. However, there is still no specialized meta-analysis that assesses the association between periodontal disease and cancer incidence and mortality in-deepth. Thus, we conducted this meta-analysis.

Methods

This meta-analysis was registered with PROSPERO: CRD42020183497. We searched five online databases for observational studies about the association between periodontal disease and breast, prostate, lung and bronchial, colorectal, and total cancers by July 2020. Then we evaluated quality of the included studies by the Newcastle-Ottawa scale. Risk ratios (HRs) and their 95% confidence intervals (CIs) were pooled to evaluate the strength of the association between periodontal disease and four cancers, total cancer incidence and mortality. In addition, we analyzed heterogeneity by subgroup analysis and sensitivity analysis. Finally, we inspected publication bias by Begg's and Egger's tests.

Results

None of the studies included in this meta-analysis were of poor quality. PD is not only related to breast cancer incidence (HR = 1.26,95%CI [1.11-1.43], I ² = 75.8%, P = 0.000), but also connected with total cancer mortality (HR = 1.40,95%CI [1.24-1.58], I ² = 0.0%, P = 0.718). Subgroup analyses showed that study population, study design, dental status, follow-up period, adjustment for smoking partially explained the heterogeneity between studies. The results of Begg's test and Egger's test were consistent and indicated that there is no publication bias in this study.

Conclusion

In conclusion, this meta-analysis revealed a positive relationship between periodontal disease and breast cancer incidence and total cancer mortality. Further well-designed studies with specific inclusion and exclusion criteria are required to strengthen the conclusion of this meta-analysis. However, longer follow-up period, multi-center trials and even multinational studies are required to corroborate the results.

Nutritional factors influencing microbiota-mediated colonization resistance of the oral cavity: A literature review

The oral cavity is a key biocenosis for many distinct microbial communities that interact with both the external environment and internal body systems. The oral microbiota is a vital part of the human microbiome. It has been developed through mutual interactions among the environment, host physiological state, and microbial community composition. Indigenious microbiota of the oral cavity is one of the factors that prevent adhesion and invasion of pathogens on the mucous membrane, i.e., the development of the infectious process and thereby participating in the implementation of one of the mechanisms of local immunity-colonization resistance. The balance between bacterial symbiosis, microbial virulence, and host resistance ensures the integrity of the oral cavity. In this review we have tried to address how nutritional factors influence integrity of the oral indigenous microbiota and its involvement in colonization resistance.

Is Periodontitis a Risk Factor for Lung Cancer? A Meta-Analysis and Detailed Review of Mechanisms of Association

Background

Numerous studies have explored the correlation of periodontal disease (PD) with the risk of lung cancers, but the findings were inconsistent. Therefore, we did a meta-analysis to ascertain the correlation of PD with the risk of incident lung cancer.

Methods

The authors searched relevant studies in databases (PubMed, Web of Science, Scopus, Embase, and MEDLINE) till November 2020. We registered the study at the International database of Prospectively Registered Systemic Reviews under the CRD42020198119. The summary relative risk (RR) along with a 95% confidence interval (CI) was calculated using fixed-effects models.

Results

Twelve studies were included in the qualitative synthesis. The pooled analysis revealed that PD was significantly associated with an increased risk of lung cancer (RR 1.71; 95%CI 1.61-1.81; P < 0.01). Subgroup analysis was performed based on gender distribution, geographic location, and type of studies.

Conclusion

From this current evidence, PD is a potential risk factor for the development of lung cancer. The risk for incidence of lung cancer is surged twice in the patients with PD, even though age and smoking are controlled in the studies.

Metastatic cancer and endentulism: Exploring comorbidity to assist with differential diagnosis in a case from Vico nel Lazio (Fr, Italy), 13th-15th century CE

OBJECTIVE

To differentially diagnose cranial lesions noted on a medieval skeleton and explore the importance of comorbidity.

MATERIALS

A skull of an adult female with osteolytic and osteoblastic lesions, edentulism, and an ectopic tooth from an ossuary of the Church of Santa Maria in Vico del Lazio, Frosinone Italy, dating to the Middle Ages.

METHODS

Macroscopic observations of the remains, CT scan, and differential diagnosis was undertaken.

RESULTS

A diagnosis of metastatic cancer (potentially breast cancer) or metastatic neuroblastoma (NBL) is offered.

CONCLUSIONS

Considering the noted comorbidities, this case might represent a rare case of metastatic neuroblastoma.

SIGNIFICANCE

The exploration of comorbidity, in this case the presence of metastatic carcinoma and edentulism, has tremendous potential to expand our knowledge about cancer in the past.

LIMITATIONS

Lack of postcranial elements.

SUGGESTIONS FOR FURTHER RESEARCH

Clinical and paleopathological investigation of comorbidity in modern and archeological populations to develop an evolutionary perspective on the presence of cancer in the past.

A Commentary on the Potential Use of Oral Microbiome in Prediction, Diagnosis or Prognostics of a Distant Pathology

In health, the oral microbiome is in balance with its host. If this balance is lost, this symbiosis is replaced by dysbiotic microbial communities, which are thought to affect the rest of the body either directly or via metabolites or pro-inflammatory molecules. The association of oral microbiome with general health has led to attempts to use oral microbial biomarkers for the prediction, diagnosis or prognosis of distant pathologies such as colorectal carcinoma or pancreatic cancer. These attempts however have no chance to succeed if the complexity of the oral ecosystem and the interplay of environmental, behavioral and biological factors is not taken into account. Standardized, well-documented oral sample collection procedures together with detailed clinical oral examination and behavioral data are the prerequisites for the successful evaluation of the oral microbiome as a potential biomarker for distant pathologies.

Periodontal disease and cancer risk: A nationwide population-based cohort study

Background

Although emerging evidence suggests that periodontitis might increase the risk of cancer, comorbidity and lifestyle behaviors, such as smoking and body mass index (BMI), may have confounded this reported association. This study aimed to investigate whether chronic periodontitis is associated with cancer risk using a large, nationwide database.

Methods

We conducted a population-based, retrospective cohort study using data from the Korean National Health Insurance Cohort Database obtained between January 2003 and December 2015. We included 713,201 individuals without a history of cancer who were followed up to 10 years. Confounding factors included demographic factors (age, sex, income, and residential area), lifestyle behaviors (smoking history and BMI), and comorbidities, such as hypertension, diabetes, heart failure, and pulmonary disease, using the Charlson Comorbidity Index. Multivariable Cox regression analysis was applied to estimate the adjusted hazard ratio (aHR) for cancer risk.

Results

Of the 713,201 participants, 53,075 had periodontitis and were placed in the periodontitis group; the remaining 660,126 individuals were included as the control group. Overall, the cumulative incidence of cancer in the periodontitis group was 2.2 times higher than that in the control group. The periodontitis group had an increased risk of total cancer compared to the control group after adjusting for age, sex, comorbidities, BMI, and smoking history (aHR, 1.129; 95% confidence interval [CI], 1.089-1.171; P<0.0001). When examining specific cancer types, significant associations were also observed between periodontitis and stomach cancer (aHR, 1.136; 95% CI, 1.042-1.239; P=0.0037), colon cancer (aHR, 1.129; 95% CI, 1.029-1.239; P=0.0105), lung cancer (aHR, 1.127; 95% CI, 1.008-1.260; P=0.0353), bladder cancer (aHR, 1.307; 95% CI, 1.071-1.595; P=0.0085), thyroid cancer (aHR, 1.191; 95% CI, 1.085-1.308; P=0.0002), and leukemia (aHR, 1.394; 95% CI, 1.039-1.872; P=0.0270). There was no significant association between the development of secondary malignancy and periodontitis in cancer survivors who were alive 5 years after they were diagnosed with the primary malignancy.

Conclusions

Periodontal disease, including periodontitis, was associated with increased risk of cancer, which persisted after controlling for confounding factors. Further prospective research is warranted to establish a causal relationship.

Is periodontal disease a risk indicator for urogenital cancer? A systematic review and meta-analysis of cohort studies

Objectives

The objective of the present work was to conduct a systematic review and meta-analysis to assess the association between periodontal disease (PD) and urogenital cancer (UC) risk.

Materials and methods

An electronic search in PubMed, EMBASE, the Cochrane Library, and Web of Science was conducted using MeSH terms to identify cohort studies published before May 17, 2022. Cohort studies examining the association between PD and UC risk were included. We used a random-effects model to summarize the effect sizes with 95% confidence intervals (CIs) of the included studies with PD as the indicator and UC as the outcome.

Results

Eleven cohort studies met the inclusion criteria. Our results suggest that PD patients increases the risk of UC by 1.24-fold (hazard ratio (HR), 1.24; 95% CI, 1.17-1.31; I², 22.4%). The strength of the sensitivity analysis and cumulative meta-analysis confirmed the reliability of the results.

Conclusion

We found that PD is a potential risk factor for UC. Our results indicate that along with the decrease in the incidence of PD,PD treatment may help prevent UC. We hope that our study will raise awareness of periodontal health, thereby reducing the incidence of UC.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021244405.

Presence of periodontitis may synergistically contribute to cancer progression via Treg and IL-6

A close causal relationship has been suggested to exist between cancer and periodontitis. We hypothesized that the immune surveillance system is impaired in patients with periodontitis, which contributes to cancer development and growth. Therefore, the present study investigated the relationship between immune surveillance mechanisms and periodontitis in cancer patients. The presence or absence of periodontitis was assessed and the peripheral blood (PB) concentrations of IL-6, immunosuppressive cytokines (VEGF, TGF-β1, and CCL22) and proportion of T regulatory cells (Treg, CD3 + CD4 + CD25 + Foxp3 +) were measured. Subjects were classified into the following four groups: non-cancer patients without periodontitis (C − P −), non-cancer patients with periodontitis (C − P +), cancer patients without periodontitis (C + P −), and cancer patients with periodontitis (C + P +). The results of a multivariate analysis showed that the PB concentration of IL-6 was significantly higher in C + than in C- and higher in C + P + than in C + P −. The PB proportion of Treg was significantly higher in C + P + than in C + P −, C − P + , and C − P −. The results of this study suggested that the presence of periodontitis and cancer synergistically increased Treg in PB, which may be one of the underlying causes of immunosuppression and immune evasion in cancer. It was also suggested that the presence of periodontal disease and/or cancer also increases IL-6 in PB, which would be associated with cancer progression. These results suggest the possibility that the presence of periodontitis might synergistically contribute to cancer progression.

Periodontal disease measures and risk of incident peripheral artery disease: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

The association of periodontal disease with atherosclerotic cardiovascular diseases is well known, but not specifically with incident peripheral artery disease (PAD). Therefore, we studied the associations of periodontal disease with incident PAD in a population-based setting.

METHODS

Among 9,793 participants (aged 53-75 years) without prevalent PAD, self-reported history of periodontal disease was ascertained. Of these, 5,872 participants underwent full-mouth examinations from which periodontal status was defined using the US Centers for Disease Control and Prevention-American Academy of Periodontology (CDC-AAP) definition. We quantified the association of periodontal disease with incident PAD (defined by hospital admission diagnosis or procedures) using multivariable Cox regression models.

RESULTS

During a median follow-up of 20.1 years, 360 participants (3.6%) developed PAD. In models accounting for potential confounders including diabetes and smoking pack-years, there was higher hazard of PAD in participants with self-reported tooth loss because of periodontal disease (hazard ratio:1.54 [95% CI:1.20-1.98]), history of periodontal disease treatment (1.37 [1.05-1.80]), and periodontal disease diagnosis (1.38 [1.09-1.74]), compared to their respective counterparts. The clinical measure of periodontal disease (n = 5,872) was not significantly associated with incident PAD in the fully adjusted model (e.g., 1.53 [0.94-2.50] in CDC-AAP-defined severe periodontal disease versus no disease).

CONCLUSION

We observed a modest association of self-reported periodontal disease, especially when resulting in tooth loss, with incident PAD in the general population. Nonetheless, a larger study with the clinical measure of periodontal disease is warranted.

A faecal microbiota signature with high specificity for pancreatic cancer

BACKGROUND

Recent evidence suggests a role for the microbiome in pancreatic ductal adenocarcinoma (PDAC) aetiology and progression.

OBJECTIVE

To explore the faecal and salivary microbiota as potential diagnostic biomarkers.

METHODS

We applied shotgun metagenomic and 16S rRNA amplicon sequencing to samples from a Spanish case-control study (n=136), including 57 cases, 50 controls, and 29 patients with chronic pancreatitis in the discovery phase, and from a German case-control study (n=76), in the validation phase.

RESULTS

Faecal metagenomic classifiers performed much better than saliva-based classifiers and identified patients with PDAC with an accuracy of up to 0.84 area under the receiver operating characteristic curve (AUROC) based on a set of 27 microbial species, with consistent accuracy across early and late disease stages. Performance further improved to up to 0.94 AUROC when we combined our microbiome-based predictions with serum levels of carbohydrate antigen (CA) 19-9, the only current non-invasive, Food and Drug Administration approved, low specificity PDAC diagnostic biomarker. Furthermore, a microbiota-based classification model confined to PDAC-enriched species was highly disease-specific when validated against 25 publicly available metagenomic study populations for various health conditions (n=5792). Both microbiome-based models had a high prediction accuracy on a German validation population (n=76). Several faecal PDAC marker species were detectable in pancreatic tumour and non-tumour tissue using 16S rRNA sequencing and fluorescence in situ hybridisation.

CONCLUSION

Taken together, our results indicate that non-invasive, robust and specific faecal microbiota-based screening for the early detection of PDAC is feasible.

Periodontal disease affects oral cancer progression in a surrogate animal model for tobacco exposure

For decades, the link between poor oral hygiene and the increased prevalence of oral cancer has been suggested. Most recently, emerging evidence has suggested that chronic inflammatory diseases from the oral cavity (e.g., periodontal disease), to some extent, play a role in the development of oral squamous cell carcinoma (OSCC). The present study aimed to explore the direct impact of biofilm‑induced periodontitis in the carcinogenesis process using a tobacco surrogate animal model for oral cancer. A total of 42 Wistar rats were distributed into four experimental groups: Control group, periodontitis (Perio) group, 4‑nitroquinoline 1‑oxide (4‑NQO) group and 4NQO/Perio group. Periodontitis was stimulated by placing a ligature subgingivally, while oral carcinogenesis was induced by systemic administration of 4NQO in the drinking water for 20 weeks. It was observed that the Perio, 4NQO and 4NQO/Perio groups presented with significantly higher alveolar bone loss compared with that in the control group. Furthermore, all groups receiving 4NQO developed lesions on the dorsal surface of the tongue; however, the 4NQO/Perio group presented larger lesions compared with the 4NQO group. There was also a modest overall increase in the number of epithelial dysplasia and OSCC lesions in the 4NQO/Perio group. Notably, abnormal focal activation of cellular differentiation (cytokeratin 10‑positive cells) that extended near the basal cell layer of the mucosa was observed in rats receiving 4NQO alone, but was absent in rats receiving 4NQO and presenting with periodontal disease. Altogether, the presence of periodontitis combined with 4NQO administration augmented tumor size in the current rat model and tampered with the protective mechanisms of the cellular differentiation of epithelial cells.

Tooth Loss and Risk of Lung Cancer among Urban Chinese Adults: A Cohort Study with Meta-Analysis

Epidemiological evidence on tooth loss and lung cancer risk remains limited, especially for smoking-specific associations. To investigate the association between tooth loss and lung cancer risk by smoking status, we first analyzed data from the Shanghai Men’s Health Study (n = 49,868) and the Shanghai Women’s Health Study (n = 44,309). Cox regression models were applied to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for lung cancer risk in relation to tooth loss. We also conducted a meta-analysis to summarize epidemiologic findings to date, incorporating results from the current study and six previously published studies. For 7.3 median follow-up years, 973 incident lung cancer cases (613 men and 360 women) were ascertained. After adjustment for major covariates, tooth loss was associated with an increased risk of lung cancer among men (HR [95% CI] for >10 teeth vs. none = 1.59 [1.21−2.11]) but not among women (0.86 [0.50−1.46]). The positive association was stronger among male current smokers (1.75 [1.26−2.45], p-interaction by smoking status = 0.04). In a meta-analysis incorporating 4052 lung cancer cases and 248,126 non-cases, tooth loss was associated with a 1.64-fold increased risk of developing lung cancer (relative risk [RR, 95% CI] for the uppermost with the lowest category = 1.64 [1.44−1.86]). The positive association was more evident among current smokers (1.86 [1.41−2.46]), but no significant associations were found among never or former smokers. Our findings suggest that tooth loss may be associated with an increased risk of lung cancer, and the association could be modified by smoking status.