Oral hygiene, dentition, sexual habits and risk of oral cancer

Poor Dental Health as a Risk Factor for Alveolar Ridge Malignancies

OBJECTIVE

To determine the association between poor dental health and risk of oral cavity squamous cell cancer (OCSCC) at individual tumor subsites.

STUDY DESIGN

Case-control and cross-sectional METHODS: A case-control study was performed using a population-based cohort in North Carolina (Carolina Head and Neck Cancer Epidemiology Study [CHANCE]). A secondary cross-sectional analysis was performed with an institutional cohort (WashU/Siteman). Cases were adults with primary OCSCC and an identifiable tumor subsite. In the CHANCE cohort, controls were adults without head and neck cancer. In the Washington University/Siteman cohort, patients with tongue cancer served as the comparator group. We used number of missing teeth (categorized 0-6, 7-24, 25-28) as a surrogate for poor dental health, which was self-reported in CHANCE and measured on a pretreatment computed tomography scan in the WashU/Siteman study. Adjusted odds ratios (aORs) for missing teeth were estimated for each tumor subsite using binomial logistic regression models.

RESULTS

Near complete tooth loss (25-28 teeth) was associated with a 3.5-fold increased risk of alveolar ridge malignancy (aOR: 3.51; 95% confidence interval [CI]: 1.14-11.01, P = .03) in the CHANCE study. This association was confirmed in our cross-sectional analysis (WashU/Siteman study) where missing 25-28 teeth was associated with an increased risk of alveolar ridge compared to tongue cancer (aOR: 4.60; 95% CI: 1.97-11.10, P = .001).

CONCLUSIONS

This study suggests an association between poor dental health and risk of alveolar ridge cancer independent of smoking, alcohol use, age, race, and sex. Future prospective and translational studies are needed to confirm this association and elucidate the mechanism of dental disease in alveolar ridge malignancies.

Human Papilloma Virus Positive Oropharyngeal Squamous Cell Carcinoma and the Immune System: Pathogenesis, Immunotherapy and Future Perspectives

Oropharyngeal squamous cell carcinoma (OPSCC), a subset of head and neck squamous cell carcinoma (HNSCC), involves the palatine tonsils, soft palate, base of tongue, and uvula, with the ability to spread to adjacent subsites. Personalized treatment strategies for Human Papillomavirus-associated squamous cell carcinoma of the oropharynx (HPV+OPSCC) are yet to be established. In this article, we summarise our current understanding of the pathogenesis of HPV+OPSCC, the intrinsic role of the immune system, current ICI clinical trials, and the potential role of small molecule immunotherapy in HPV+OPSCC.

The association between oral hygiene and head and neck cancer: a meta-analysis

OBJECTIVE

Oral hygiene has been suspected to contribute to the aetiology of head and neck cancer (HNC). Based on the meta-analysis, we evaluated the impact of oral hygiene on head and neck cancer (HNC) and its survival.

MATERIALS AND METHODS

Relevant case-control and cohort studies reporting survival data, oral hygiene data were searched via PubMed, Embase, Cochrane Library, and Web of Science databases. The odds ratios (ORs), hazard ratios (HRs), and 95% confidence intervals (CIs) were used. Subgroup analysis was performed.

RESULTS

Oral hygiene was associated with HNC. Tooth brushing ≥2 a day, dental floss use, denture wearing, caries ≥3, and dental visit ≥1 reduced the risk of oral cavity cancer while mouth wash use, missing teeth >5, gum bleeding, and periodontal disease increased the risk of oral cavity cancer. For oropharynx cancer, tooth brushing ≥2 and caries ≥3 were associated with reduced risk of it. Tooth brushing ≥2 and dental visits ≥1 decreased the risk of pharynx cancer risk and larynx cancer risk, however, missing teeth >5 increased both of them.

CONCLUSION

Oral hygiene was associated with HNC and its sub sites. Oral hygiene should be strengthened, a dental floss use and dentist's visits can be recommended.

Is High-Risk Sexual Behavior a Risk Factor for Oropharyngeal Cancer?

(1) Background: Several lines of evidence established a link between high-risk (HR) sexual behavior (SB), the persistence of human papillomavirus (HPV) DNA in saliva, and the presence of oncogenic HR-HPV subtypes in oropharyngeal squamous cell carcinoma (OPSCC). A highly influential case-control study by D'Souza et al. comparing OPSCC patients and ENT patients with benign diseases (hospital controls) established HR-SB as a putative etiological risk factor for OPSCC. Aiming to replicate their findings in a nested case-control study of OPSCC patients and propensity score (PS)-matched unaffected controls from a large population-based German cohort study, we here demonstrate discrepant findings regarding HR-SB in OPSCC. (2) Methods: According to the main risk factors for HNSCC (age, sex, tobacco smoking, and alcohol consumption) PS-matched healthy controls invited from the population-based cohort study LIFE and HNSCC (including OPSCC) patients underwent interviews, using AUDIT and Fagerström, as well as questionnaires asking for SB categories as published. Afterwards, by newly calculating PSs for the same four risk factors, we matched each OPSCC patient with two healthy controls and compared responses utilizing chi-squared tests and logistic regression. (3) Results: The HNSCC patients and controls showed significant differences in sex distribution, chronologic age, tobacco-smoking history (pack years), and alcohol dependence (based on AUDIT score). However, PS-matching decreased the differences between OPSCC patients and controls substantially. Despite confirming that OPSCC patients were more likely to self-report their first sexual intercourse before age 18, we found no association between OPSCC and HR-SB, neither for practicing oral-sex, having an increased number of oral- or vaginal-sex partners, nor for having casual sex or having any sexually transmitted disease. (4) Conclusions: Our data, by showing a low prevalence of HR-SB in OPSCC patients, confirm findings from other European studies that differ substantially from North American case-control studies. HR-SB alone may not add excess risk for developing OPSCC.

Is Systemic Immunosuppression a Risk Factor for Oral Cancer? A Systematic Review and Meta-Analysis

Even if the relationship between immunosuppression and increased incidence of systemic cancers is well known, there is less awareness about the risk of developing oral cancer in immunosuppressed patients. The aim of this review was to evaluate the association between immunosuppression and the development of oral cancer. Two authors independently and, in duplicate, conducted a systematic literature review of international journals and electronic databases (MEDLINE via OVID, Scopus, and Web of Science) from their inception to 28 April 2023. The assessment of risk of bias and overall quality of evidence was performed using the Newcastle-Ottawa Scale and GRADE system. A total of 2843 articles was identified, of which 44 met the inclusion criteria and were included in either the qualitative or quantitative analysis. The methodological quality of the included studies was generally high or moderate. The quantitative analysis of the studies revealed that immunosuppression should be considered a risk factor for the development of oral cancer, with a percentage of increased risk ranging from 0.2% to 1% (95% CI: 0.2% to 1.4%). In conclusion, the results suggest that a constant and accurate follow-up should be reserved for all immunosuppressed patients as a crucial strategy to intercept lesions that have an increased potential to evolve into oral cancer.

A Systematic Review and Meta-Analysis Assessing the Role of Oral Health as a Risk Factor in Oral Cancer

Oral squamous cell carcinoma is the leading type of cancer in Southeast Asian countries and many parts of the world. Many factors increase the risk of oral cancer, like tobacco, betel nuts, alcohol consumption, sharp teeth, infections, and other factors. Oral health-related issues have been reported in many studies of oral cancer, but there is a need to understand the role of the same as a risk factor. The systematic review and meta-analysis were conducted to assess the role of oral health as a risk factor in oral cancer. The population diagnosed with oral cancer (P) of all age groups and both gender, exposure (E) is oral health (includes poor oral hygiene, periodontal disease, and other oral diseases excluding oral potentially malignant disorders (OPMD)), the comparator (C), is patients without oral health issues, outcome (O) is the role of poor oral health as a risk factor for oral cancer. A systematic review and meta-analysis were conducted. The databases used for the search were PubMed, Cochrane Database, Embase, Scopus, and Google Scholar. The unpublished reports, reviews, and grey literature were considered. Case-control studies were included assessing poor oral health as a risk factor with odds ratio as an effective measure. Newcastle Ottawa Scale for risk of bias in the case-control study was considered. The study results showed that tooth loss odds ratio (OR)=1.13, CI (0.99-1.26), I² value of 71.7%, Oral hygiene OR=1.29, CI (1.04-1.54), I² value of 19.7% and in periodontal diseases OR=2.14 CI (1.70-2.58), I² value of 75.3% had a higher risk of developing oral cancer. The risk factors for tooth loss and periodontal disease showed moderate heterogenicity and less heterogenicity for oral hygiene. Poor oral health factors such as periodontal disease, poor oral hygiene, and loss of teeth show higher odds of oral cancer than the control. The periodontal disease shows the highest odds than other factors. These risk factors can be considered for the primordial prevention of oral cancer.

Is Candida albicans a contributor to cancer? A critical review based on the current evidence

The association between Candida albicans (C. albicans) and cancer has been noticed for decades. Whether C. albicans infection is a complication of cancer status or as a contributor to cancer development remains to be discussed. This review systematically summarized the up-to-date knowledge about associations between C. albicans and various types of cancer, and discussed the role of C. albicans in cancer development. Most of the current clinical and animal evidence support the relationship between C. albicans and oral cancer development. However, there is insufficient evidence to demonstrate the role of C. albicans in other types of cancer. Moreover, this review explored the underlying mechanisms for C. albicans promoting cancer. It was hypothesized that C. albicans may promote cancer progression by producing carcinogenic metabolites, inducing chronic inflammation, remodeling immune microenvironment, activating pro-cancer signals, and synergizing with bacteria.

Chronic mechanical trauma/irritation and oral carcinoma: A systematic review showing low evidence to support an association

BACKGROUND

Chronic trauma of oral mucosa, resulting from repeated and persistent mechanical irritative action of an intraoral injury agent, has repeatedly been reported to be possibly implicated in the development of oral squamous cell carcinoma (OSCC).

OBJECTIVES

The present systematic review aimed to assess whether chronic mechanical trauma can be considered a risk factor for OSCC.

DATA SOURCES

PubMed, CENTRAL (Cochrane Central Register of Controlled Trials), Scopus; EMBASE, Web of Science.

STUDY ELIGIBILITY CRITERIA

Cohort studies comparing OSCC incidence among subjects with/without chronic mechanical trauma or case-control or cross-sectional studies comparing chronic mechanical trauma among subjects with/without OSCC.

RESULTS

Only one prospective case-control study fulfilled the inclusion criteria, but the quality of the evidence provided is not enough to define trauma as a risk factor for OSCC. The main limitation is the presence of only one case-control study at high risk of bias. In the absence of strong evidence supporting the role of trauma in OSCC, a thorough discussion on trauma and carcinogenesis has been performed.

CONCLUSIONS

Available evidence does not support an active role for chronic trauma in oral carcinogenesis, neither as promoter nor as progressor factor. Prospective cohort studies able to better assess trauma in OSCC are needed.

Oral Health Status in Patients with Head and Neck Cancer before Radiotherapy: Baseline Description of an Observational Prospective Study

(1) Background: The general hypothesis that HNC patients show compromised oral health (OH) is generally accepted, but it is not evidence-based. The objective of this baseline report of a prospective observational study was to describe the oral health of a cohort of patients with HNC at the time of dental evaluation prior to radiotherapy (RT). (2) Materials and Methods: Two hundred and thirteen patients affected by HNC who had received an indication for RT were examined with the support of orthopantomography (OPT). The DMFt of all included subjects, their periodontal status and the grade of mouth opening were recorded. (3) Results: A total of 195 patients were ultimately included: 146/195 patients (74.9%) showed poor OH (defined as having a DMFt score ≥ 13 and severe periodontitis). The following clinical characteristics were correlated with poor oral health in the univariate analysis: tumor site, smoking habit and age of the patients (in decades); χ2 test, p < 0.05. (4) Conclusions: This study confirms that the OH of HNC patients is often compromised even before the beginning of cancer treatment and, consequently, highlights how important it is to promptly schedule a dental evaluation at the moment of diagnosis of the cancer.

Multifaceted functions of chronic inflammation in regulating tumor dormancy and relapse

Inflammation is a double-edged sword exhibiting multifaceted functions. On one hand, it either induces tumor cell apoptosis, or establishes tumor dormancy by inhibiting tumor cell proliferation; on the other hand, it either facilitates the tumorigenesis process or reawakens dormant tumor cells, resulting in disease recurrences. Each outcome would depend on the balance between type I and type II inflammation as well as the duration of inflammation being acute or chronic. In this essay, we provide a critical review of the empirical evidence suggesting that chronic inflammation, dominated by type I inflammatory cells and cytokines as a result of trauma and microbiome dysbiosis, could facilitate the carcinogenesis process in normal cells and retain nascent transformed cells in a dormant state. On the other hand, an elevated type II inflammation along with inefficient resolution of type I inflammation following trauma or major surgeries could delay the wound healing process and promote the growth and reawakening of dormant tumor cells, resulting in disease recurrences. Finally, cytokines exhibiting type I and II inflammatory functions, simultaneously, tend to promote tumor recurrence when become chronic. Therefore, the risk of reawakening dormant tumor cells should be considered in cancer survivors who experience major surgeries and trauma, or suffer from chronic inflammatory diseases.

Mouthwash Use and the Risk of Oral, Pharyngeal, and Laryngeal Cancer. A Meta-Analysis

Objective: The main aim of this study was to test whether the use of mouthwash is associated with subtypes of squamous cell carcinoma of the head and neck (SCCHN) and to test the potential risk of SCCHN depending on the mouthwash use duration, frequency, or alcoholic content. Materials and methods: We performed a meta-analysis using Web of Science and Scopus databases to detect the risk change associated with mouthwash use depending on the alcohol content, duration and frequency of use, and anatomical location. We used a random-effects model with the Sidik–Jonkman estimator for effect size model measures. Results: We included 17 studies in the meta-analysis containing 17,085 cases and 20,032 controls. The risk difference for SCCHN between mouthwash users and non-users was minimal, with a value of −0.02 [−0.05, 0.01]. Alcoholic mouthwash use was associated with a minimal decrease in risk (of −0.01 [−0.07, 0.05]). Frequent usage of mouthwash was associated with a statistically significant risk increase for SCCHN but the risk increase was marginal (0.04, [0.01, 0.06]). Conclusions: Overall, our study failed to show a statistically significant correlation between mouthwash use and the risk of SCCHN. The only statistically significant correlation that we could identify was between frequent usage and SCCHN, potentially caused by prolonged contact between some constituents of mouthwash (possibly alcohol) and the oral epithelium.

Correlation of p16 immunohistochemistry with clinical and epidemiological features in oropharyngeal squamous-cell carcinoma

BACKGROUND

Oropharyngeal cancer is an important public health problem. The aim of our study was to correlatep16 immunohistochemistry in oropharynx squamous cell carcinomas(OPSCC) with clinical and epidemiological features.

MATERIAL AND METHODS

We conducted across-sectional study on patients with OPSCC treated at a single institution from 2014 to 2019. Epidemiological and clinical-pathological data were collected from medical records and a questionnaire was applied to determine alcohol consumption, smoking, and sexual behavior. The HPV status was determined by p16 immunohistochemistry.

RESULTS

A total of 252 patients participated in the study, of these 221 (87.7%) were male. There were 81 (32.14%) p16 positive cases and 171 (67.85%) p16 negative cases. The p16positive group was significantly associated with younger patients (50-59 years), higher education level, lower clinical stage and patients who never drank or smoked. Through univariate logistic regression, we observed that female sex (OR, 3.47; 95% CI, 1.60-7.51) and higher education level (OR, 9.39; 95% CI, 2, 81-31,38) were significantly more likely to be p16 positive. Early clinical stage (AJCC8ed) was more associated with p16 positivity both in univariate (OR, 0.14; 95% CI, 0.07-0.26, p<0.001) and multivariate analysis (OR, 0.18; 95% CI, 0.06-0.49, p = 0.001).

CONCLUSION

This study showed that drinkers and current smokers were less likely to be p16+. Female sex, higher education level and younger age at diagnosis were associated with a higher probability of being p16+. Additionally, there was a higher proportion of patients with early clinical stage (I or II) in the p16 positive group when compared to the p16 negative group.

Noninvasive Imaging Methods to Improve the Diagnosis of Oral Carcinoma and Its Precursors: State of the Art and Proposal of a Three-Step Diagnostic Process

Simple Summary

Oral squamous cell carcinoma (OSCC) accounts for 90–95% of malignant tumors of the lip and oral cavity and is associated with high mortality in the advanced stages. Early diagnosis is a challenge for oral pathologists and dentists, due to the ambiguous appearance of early OSCC, which is often misdiagnosed, mistreated, and associated with diagnostic delay. The gold standards for OSCC diagnosis are biopsy and histopathological assessment, but these procedures are invasive and time-consuming. Adjunctive noninvasive techniques allow the definition of the malignant features of a suspicious lesion in real time and noninvasively, thus improving the diagnostic procedure. The present review aimed to focus on some of the main promising noninvasive imaging techniques, to highlight their perspective adoption in a three-step diagnosis, which is idealistically faster and better, as well as enables the patient’s compliance.

Abstract

Oral squamous cell carcinoma (OSCC) is the most prevalent form of cancer of lips and oral cavity, and its diagnostic delay, caused by misdiagnosis at the early stages, is responsible for high mortality ratios. Biopsy and histopathological assessment are the gold standards for OSCC diagnosis, but they are time-consuming, invasive, and do not always enable the patient’s compliance, mainly in cases of follow-up with the need for more biopsies. The use of adjunctive noninvasive imaging techniques improves the diagnostic approach, making it faster and better accepted by patients. The present review aims to focus on the most consolidated diagnostic techniques, such as vital staining and tissue autofluorescence, and to report the potential role of some of the most promising innovative techniques, such as narrow-band imaging, high-frequency ultrasounds, optical coherence tomography, and in vivo confocal microscopy. According to their contribution to OSCC diagnosis, an ideal three-step diagnostic procedure is proposed, to make the diagnostic path faster, better, and more accurate.

Toothbrushing frequency and gastric and upper aerodigestive tract cancer risk: A meta-analysis

OBJECTIVE

Results of epidemiological studies evaluating the association between toothbrushing and gastric and upper aerodigestive tract (UADT) cancer risk showed inconsistent results. The purpose of this study was to evaluate the association between toothbrushing and gastric and UADT cancer risk and quantify the dose-response association between them.

METHODS

We searched the PubMed, EMBASE and Cochrane Library databases to identify relevant studies on toothbrushing and gastric and UADT cancer risk. Statistical analyses were performed using STATA 12.0 software.

RESULTS

A total of 30 studies of involving 1 194 017 participants met eligibility criteria and were included in the meta-analysis. Meta-analysis using a random-effect model showed that the high frequency of toothbrushing was associated with significantly reduced risk of gastric and UADT cancers (OR: 0.55, 95% CI 0.46-0.64, P < .05). Our dose-response analysis presented that every increased toothbrushing per day might reduce oral cavity cancer risk by 6%, pharyngeal cancer risk by 11%, laryngeal cancer risk by 3%, oesophageal cancer risk by 6% and gastric cancer risk by 4%.

CONCLUSIONS

This meta-analysis suggested the negative relationship between frequency of toothbrushing and risk of gastric and UADT cancers. Toothbrushing may be a protective factor for gastric and UADT cancers. However, this association must be further validated through large prospective studies.

Understanding the impact of high-risk human papillomavirus on oropharyngeal squamous cell carcinomas in Taiwan: A retrospective cohort study

BACKGROUND AND OBJECTIVES

Human papillomavirus (HPV)-driven oropharyngeal squamous cell carcinoma (OPSCC) is increasing globally. In Taiwan, HPV-positive OPSCC is obscured by tobacco, alcohol, and betel quid use. We investigated the role of high-risk HPV (hrHPV) in a large retrospective Taiwan OPSCC cohort.

METHODS AND RESULTS

The cohort of 541 OPSCCs treated at Chang Gung Memorial Hospital from 1998-2016 consisted of 507 men (94%) and 34 women (6%). Most used tobacco (81%), alcohol (51%), and betel quid (65%). Formalin-fixed, paraffin-embedded tissue was used for p16 staining (a surrogate marker for HPV) and testing for HPV DNA presence and type by Multiplex HPV PCR-MassArray. HPV DNA and/or p16 staining (HPV-positive) was found in 28.4% (150/528) tumors. p16 and HPV DNA were strongly correlated (F < 0.0001). HPV16 was present in 82.8%, and HPV58 in 7.5% of HPV-positive tumors. HPV was associated with higher age (55.5 vs. 52.7 years, p = 0.004), lower T-stage (p = 0.008) better overall survival (OS) (hazard ratio [HR] 0.58 [95% CI 0.42-0.81], p = 0.001), and disease-free survival (DFS) (HR 0.54 [95% CI 0.40-0.73], p < 0.0001). Alcohol was strongly associated with recurrence and death (OS: HR 2.06 [95% CI 1.54-2.74], p < 0.0001; DFS: HR 1.72 [95% CI 1.33-2.24], p < 0.0001). OS and DFS in HPV-positive cases decreased for alcohol users (p < 0.0001). Obscured by the strong alcohol effect, predictive associations were not found for tobacco or betel quid.

CONCLUSIONS

As with HPV-positive OPSCC globally, HPV is an increasingly important etiological factor in Taiwanese OPSCC. HPV-positive OPSCC has considerable survival benefit, but this is reduced by alcohol, tobacco, and betel quid use. hrHPV is a cancer risk factor in males and females. Vaccinating both sexes with a multivalent vaccine including HPV58, combined with alcohol and tobacco cessation policies will be effective cancer-prevention public health strategies in Taiwan.

Smoking and Drinking Adjusted Association between Head and Neck Cancers and Oral Health Status Related to Periodontitis: a Meta-Analysis

BACKGROUND

Not so many reports about the association between head and neck cancer (HNC) and oral health status related to periodontitis (OHS-P) has been published in different countries with different methods. So, there is a need for an extensive meta-analysis with the total articles published until 2020. Hence, this study aimed to estimate the association between HNC and OHS-P through a meta-analysis.

METHODS

Based on Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines, 22 studies were selected through PubMed and Cochrane Library databases. Meta-analysis using them was performed to evaluate the association. The risk of bias assessment using the Newcastle-Ottawa Scale (NOS) was applied to evaluate the quality of non-randomized studies. Publication bias was evaluated by funnel plot and Egger's regression test.

RESULTS

Since heterogeneity was significant (I² = 88%, P < 0.001), we adopted the random effect model for 22 studies. Those with bad OHS-P, compared to those with good OHS-P, were more likely to have the risk of HNC by 2.4 times (odds ratio [OR], 2.42; 95% confidence interval [CI], 1.88-3.13) for random effect model. The association included publication bias (Egger's regression, P value < 0.001). The association among five studies (I² = 39%, P = 0.16) using alveolar bone loss (ABL) or clinical attachment level (CAL) for assessing periodontitis increased to OR of 3.85 (CI, 3.04-4.88) in the fixed effect model without publication bias (Egger's regression, P = 0.66). Moreover, the association was higher in 10 fair or good NOS studies (OR, 3.08) and in 7 Asian studies (OR, 2.68), which were from the fixed model without publication bias.

CONCLUSION

Our meta-analysis showed that bad OHS-P was associated with the risk of HNC. The association was stronger in studies using ABL or CAL for assessing periodontitis.

Association between interleukin-10 gene polymorphisms and risk of oral carcinoma: A meta-analysis

BACKGROUND

The single nucleotide polymorphisms (SNPs) of Interleukin-10 (IL-10) gene have been linked with the risk of oral carcinoma (OC) in a relatively small sample size. Our study aims to investigate the pooled associations by conducting a meta-analysis of published studies.

METHODS

PubMed, Web of Science and Google Scholar databases were searched to identify eligible studies published in English before October 2019. The odds ratio (OR) with a 95% confidence interval (CI) was used to assess association. The publication bias was detected by Begg's test. Sensitivity and cumulative analyses were performed to evaluate the stability of crude results.

RESULTS

The meta-analysis involved eight studies. Significant associations were certified between IL-10 gene -1082A/G polymorphism and susceptibility of OC for A vs. G (OR=1.817, 95% CI: 1.481-2.230), AA vs. GG (OR=3.436, 95% CI: 2.281-5.175), dominant genetic model (OR=2.913, 95% CI: 1.939-4.376), and recessive genetic model (OR=1.886, 95% CI: 1.372-2.594) in overall population, East Asians and South Asians. In addition, the significant association between -592A/C polymorphism of the gene and susceptibility of OC were detected in South Asians.

CONCLUSIONS

The meta-analysis results support that the IL-10 gene -1082G allele is a risk factor for OC in East Asians and South Asians, and IL-10 gene -592C allele is a protective factor for the disease.

Novel Prognostic Model Based on Immune Signature for Head and Neck Squamous Cell Carcinoma

Background

Deciphering the immune characteristics within tumors and identifying the immune signals related to the prognostic factor are helpful for the treatment and management of tumor patients. However, systematic analysis of immune signatures in head and neck squamous cell carcinoma (HNSCC) remains largely unstudied.

Methods

A total of 718 immune-related genes were extracted from RNA sequencing data from 519 HNSCC patients in the TCGA database, and survival analysis with integrated bioinformatics analyses was performed to build the final predictive prognosis model.

Results

The 178 survival-associated genes (P < 0.05) participated in important immune functions, including immune cell activation and migration. Multivariate regression analysis using 93 genes (P < 0.01), together with survival-associated clinicopathological parameters, identified 35 independent prognostic factors. The most significant 8 independent factors were CD3E, CD40LG, TNFRSF4, CD3G, CD5, ITGA2B, ABCB1, and TNFRSF13b. The final prognostic model achieved outstanding predictive efficiency with the highest AUC of 0.963.

Conclusion

Our prognostic model based on the immune signature could effectively predict the prognosis of HNSCC patients, providing novel predictive biomarkers and potential therapeutic targets for HNSCC patients.

Possible association of periodontal disease with oral cancer and oral potentially malignant disorders: a systematic review

Background: Periodontitis has been associated with several systemic diseases and medical conditions, including oral cancer (OC). However, most studies reporting an association between OC and periodontal disease have used different clinical and radiographic criteria to define periodontal disease. This review aimed to evaluate the currently available evidence to determine an association between periodontal disease (extension and severity), OC, and oral potentially malignant disorders (OPMDs).Material and methods: A systematic search of studies published up to August 2018 was performed following the PRISMA guidelines in the electronic databases MEDLINE (PubMed) and COCHRANE (OVID). A methodological evaluation was made using the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) checklist.Results: Eight studies (case-control, cross-sectional and cohort) were included. An increased clinical attachment loss, plaque index, bleeding on probing, and radiographic bone loss was found in patients with OC and OPMDs. Differences in the methodological characteristics, case definition used for periodontal diseases, and OC location did not allow estimating the odds ratio required to conduct a meta-analysis.Conclusion: Some studies suggest a positive relationship between periodontal disease, OC, and OPMDs; however, the currently available evidence is insufficient to draw solid conclusions.

World Small Animal Veterinary Association Global Dental Guidelines

Dental, oral, and maxillofacial diseases are some of the most common problems in small animal veterinary practice. These conditions create significant pain as well as localized and potentially systemic infection. As such, the World Small Animal Veterinary Association (WSAVA) believes that un- and under treated oral and dental diseases pose a significant animal welfare concern. Dentistry is an area of veterinary medicine which is still widely ignored and is subject to many myths and misconceptions. Effective teaching of veterinary dentistry in the veterinary school is the key to progression in this field of veterinary medicine, and to the improvement of welfare for all our patients globally. These guidelines were developed to provide veterinarians with the information required to understand best practices for dental therapy and create realistic minimum standards of care. Using the three-tiered continuing education system of WSAVA, the guidelines make global equipment and therapeutic recommendations and highlight the anaesthetic and welfare requirements for small animal patients. This document contains information on common oral and dental pathologies, diagnostic procedures (an easily implementable and repeatable scoring system for dental health, dental radiography and radiology) and treatments (periodontal therapy, extractions). Further, there are sections on anaesthesia and pain management for dental procedures, home dental care, nutritional information, and recommendations on the role of the universities in improving veterinary dentistry. A discussion of the deleterious effects of anaesthesia free dentistry (AFD) is included, as this procedure is ineffective at best and damaging at worst. Throughout the document the negative effects of undiagnosed and/or treated dental disease on the health and well-being of our patients, and how this equates to an animal welfare issue, is discussed.

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.

Periodontal Diseases as Putative Risk Factors for Head and Neck Cancer: Systematic Review and Meta-Analysis

Whether "periodontal disease" can be considered as an independent risk factor for head and neck cancer (HNC) remains controversial. The aim of the current meta-analysis was to quantitatively assess this relationship in order to determine whether this represents a true risk factor, with implications for cancer prevention and management. PubMed, Scopus, and Embase databases were systematically searched. Selective studies were reviewed, and meta-analysis was performed to estimate the pooled odds ratio (OR) with 95% confidence intervals (CIs) on eligible studies using a random effects model. In total, 21 eligible observational studies (4 cohorts and 17 case-controls) were identified for qualitative synthesis after a review of 1051 articles. Significant heterogeneity could be identified in measures utilized for reporting of periodontal disease. Meta-analysis performed on nine studies that employed objective measures for reporting periodontal disease demonstrated a significant association between periodontal disease and HNC [OR 3.17, 95% CI, 1.78-5.64]. A diseased periodontium represents an independent risk marker, and a putative risk factor, for HNC. Prospective studies with standardized measures of periodontal disease severity and extent, integrated with microbiological and host susceptibility facets, are needed to elucidate the mechanisms of this positive association and whether treatment of the former influences the incidence and outcomes for HNC.

Electrochemical Assessment of Anticancer Compounds on the Human Tongue Squamous Carcinoma Cells

The most common oral cancer is squamous cell carcinoma (SCC) and its highest occurrence is in the tongue. Almost 30% of patients with one primary head and neck tumor will have a second primary malignancy. In recent studies, two novel plant extracts, andrographolide and cannabidiol (CBD), have been exploited for their anticancer effects. Here, we investigated the cytotoxic effects of these two compounds on SCC-25 cells, a human tongue squamous carcinoma cell line, and compared the outcomes with two chemotherapeutic drugs, cisplatin and fluorouracil. Electric cell substrate impedance sensing (ECIS) system was applied to measure frequency- and time-dependent impedance of SCC-25 cell-covered electrodes and to further assess subtle changes in cell morphology and micromotion in response to different concentrations (0, 10, 30, 100, and 300 µM) of these compounds. AlamarBlue and Annexin V/7-AAD binding assays were used to measure the concentration dependent changes in viability and apoptosis of SCC-25 cells. Our results demonstrate that 24 hours after exposure to 30 µM CBD can significantly decrease the micromotion rate, damage the integrity of cell morphology, reduce cell viability, and induce higher apoptosis in treated SCC-25 cells, while the other three drugs attain similar effects at the concentration of 100 µM or higher. The apoptosis-induced changes in cell morphology and micromotion monitored by ECIS correlate well with biochemical assays. Thus, both frequency- and time-dependent impedance measurements using ECIS can be used to real-time follow cancer cell activities in response to anticancer drugs with different temporal cytotoxicity profiles.

Association of Periodontitis with Oral Cancer: A Case-Control Study

The association between oral squamous cell carcinoma (OSCC) and periodontitis in large hospital cases with cohort controls has yet to be evaluated. The aim of this study was to investigate the association of periodontitis with OSCC across tumor location and tumor-node-metastasis (TNM) stage among Koreans ( N = 424). OSCC cases ( n = 146) were recruited from Seoul National University Dental Hospital and matched by age, sex, and smoking to controls ( n = 278) from the Yangpyeong health and periodontal cohort in Korea. OSCC was diagnosed through biopsy and radiographs, including computed tomography and magnetic resonance imaging. Tumor location and TNM stage were classified after the surgery. Periodontitis was defined by alveolar bone loss with panoramic radiographs following the guidelines of the Fifth European Workshop in Periodontology. Alcohol intake, education, physical activity, obesity by body mass index, hypertension by blood pressure, diabetes by plasma glucose, and hypercholesterolemia by plasma cholesterol were considered as confounders. Information about age, sex, smoking, alcohol intake, education, and physical activity was obtained through interview; body mass index and blood pressure, through physical examination; and preoperative glucose and cholesterol, through laboratory tests. Bivariate analysis was applied with Fisher’s exact chi-square test. Multivariable conditional logistic regression models were applied to evaluate the adjusted association of periodontitis with OSCC after controlling for confounders. Subgroup analyses were explored by OSCC and periodontitis. Participants with periodontitis were 3.7 times more likely to have OSCC (adjusted odds ratio [aOR] = 3.66, 95% CI = 1.46 to 9.23) than participants without periodontitis. The differences in periodontitis were not statistically significant across TNM stages of OSCC ( P > 0.05) and its location ( P > 0.05). The link was highlighted among males (aOR = 6.55), elders aged >60 y (aOR = 4.98), and those with more tooth loss (aOR = 9.99). Our data showed that periodontitis was independently associated with OSCC. Thus, the risk of OSCC could be modulated by reducing periodontitis.

Evidence of past dental visits and incidence of head and neck cancers: a systematic review and meta-analysis

BACKGROUND

Regular/frequent dental visits, at least annually, can aid in reducing the public health burden of head and neck cancers (HNCs) by facilitating earlier detection of the disease. The aim of this study was to conduct a quantitative assessment of any independent association between past dental visits/check-ups and incidence of cancers of HN/upper aerodigestive tract (UADT) and oral cavity worldwide.

METHODS

PubMed, CINAHL, and Cochrane databases were searched for all observational studies published until August 2017 in any language that assessed an association of past dental visits/dental check-ups among the incident cases of HNC/UADT cancers. Screening and quality assessment of the articles was performed by two independent reviewers. Three different meta-analyses were conducted: two based on the incident cancer reported in the studies (HNCs/cancers of UADT and oral cavity); another included all studies irrespective of the type of cancer reported with the frequency of past dental visits as subgroups.

RESULTS

Searches retrieved 3164 titles: after removing duplicates, 1377 remained. Of these, 62 were reviewed in full, but only 38 were eligible for inclusion. Under the random effects model, odds of past never/irregular/not frequent dental visits were greater in HNC cases and oral cancer cases as compared to the hospital-based/population-based controls [HNCs-unadjusted odds ratio (OR) 2.24; 95% confidence interval (CI) 1.89 to 2.65) and (oral cancers-OR 1.93; 95% CI 1.47 to 2.52]. Similar results were observed for all cancers with frequency of past dental visits as subgroup analysis (OR 2.01; 95% CI 1.76 to 2.30). Meta-regression findings indicate that none of the subgroup influenced the effect estimates for incidence of cancers. There was no publication bias in our study.

CONCLUSION

This systematic review and meta-analysis indicates that individuals with never/irregular/not frequent dental visits are more likely to be incident cases of HNCs/UADT cancers.

The interplay between oral microbiome, lifestyle factors and genetic polymorphisms in the risk of oral squamous cell carcinoma

Poor oral hygiene may lead to overgrowth of pathogenic oral bacteria, which may induce chronic inflammation to promote the oncogenesis of oral squamous cell carcinoma (OSCC). This study investigated the association between oral bacterial profile and OSCC risk in a case-control study of 138 OSCC cases and 151 controls (88 cases and 90 controls for the discovery group and 50 cases and 61 controls for the validation group). Oral bacterial profiles were characterized by targeted sequencing of the 16S rRNA gene. Three species of periodontopathogenic bacteria, Prevotella tannerae, Fusobacterium nucleatum, and Prevotella intermedia, were associated with an increased OSCC risk. This association was modified by the genetic polymorphisms of TLR2 and TLR4. Use of alcohol, betel quids and cigarettes and poor oral hygiene were associated with a higher percentage of oral periodontopathogenic bacteria. The association between alcohol and periodontopathogenic bacteria was modified by the genetic polymorphism of ALDH2, with a stronger positive association observed among the ALDH2-deficient individuals. The percentage of periodontopathogenic bacteria was positively correlated with the level of salivary IL1β, an inflammatory cytokine. Overall, our results showed a positive association between periodontopathogenic bacteria and OSCC risk and this relationship may be influenced by lifestyle and genetic factors. Our results provided further biological support for the established association between poor oral hygiene and OSCC risk. This suggested that improving oral hygiene may reduce OSCC risk and should be part of a public health campaign to prevent the occurrence of OSCC.

Role of Poor Oral Hygiene in Causation of Oral Cancer-a Review of Literature

Oral squamous cell carcinomas (OSCC) are among the commonest cancers in South East Asia and more so in the Indian subcontinent. The role of tobacco and alcohol in the causation of these cancers is well-documented. Poor oral hygiene (POH) is often seen to co-exist in patients with OSCC. However, the role of poor oral hygiene in the etio-pathogenesis of these cancers is controversial. We decided to evaluate the available literature for evaluating the association of POH with OSCC. A thorough literature search of English-language articles in MEDLINE, PubMed, Cochrane Database of Systematic Reviews, and Web of Science databases was conducted, and 93 relevant articles were short-listed. We found that POH was strongly associated with oral cancers. It aids the carcinogenic potential of other known carcinogens like tobacco and alcohol. Even on adjusting for known confounding factors like tobacco, alcohol use, education, and socio-economic strata, presence of POH exhibits higher odds of developing oral cancer.

Associations Between Poor Oral Health and Risk of Squamous Cell Carcinoma of the Head and Neck: A Meta-Analysis of Observational Studies

PURPOSE

Many epidemiologic studies have reported an association of poor oral health, especially periodontal disease (PD) and tooth loss, with the risk of squamous cell carcinoma of the head and neck (SCCHN). However, these studies have yielded inconsistent results. Therefore, the present study investigated whether poor oral health is an independent predictor of SCCHN through a meta-analysis of observational studies.

MATERIALS AND METHODS

The PubMed, EMBASE, and Cochrane Library databases were systematically searched for relevant observational studies of the association between oral health and risk of SCCHN conducted up to October 2017. The meta-analysis was conducted using STATA 12.0 (StataCorp, College Station, TX). A fixed- or random-effects model was applied to evaluate pooled risk estimates, and sensitivity and subgroup analyses were performed to identify sources of heterogeneity and pooled estimation. Publication bias was assessed using the Begg test, the Egger test, and funnel plots.

RESULTS

Twenty-seven relevant observational studies were identified, consisting of 24 case-and-control studies, 2 prospective studies, and 1 cross-sectional study, with 26,750 participants. Notably, oral health correlated meaningfully with SCCHN (odds ratio [OR] = 2.24; 95% confidence interval [CI], 1.77-2.82). In subgroup analyses, participants with PD (OR = 2.52; 95% CI, 1.43-4.44) had a higher risk of developing SCCHN than those with tooth loss (OR = 2.13; 95% CI, 1.63-2.78). The risk estimates exhibited substantial heterogeneity. Evidence of publication bias was limited.

CONCLUSIONS

The results of this meta-analysis suggest that patients with tooth loss or PD might face a substantial and independent risk of SCCHN, even after adjusting for smoking and alcohol consumption. However, the pooled estimates from observational studies could not establish a causative relation among PD, tooth loss, and SCCHN. Additional investigations of this correlation are warranted.

Oral Health of Korean Patients With Head and Neck Cancer

Background

Association between periodontitis and of head and neck carcinoma was suggested. In the present study, we evaluated the oral health status of patients with head and neck carcinoma and analyzed the relationship between cancer characteristics and oral health.

Methods

Oral health of 40 patients with head and neck carcinoma was examined. Decayed teeth, missing teeth, plaque index, gingival index, and probing depth were measured. Cancer type and site were recorded based on the patients' medical records.

Results

The average age of participants was 60.10 ± 8.99 years, and 35 of participants were male. The decay or missing teeth index was 5.43 ± 5.57, and the plaque index, gingival index, and probing depth were 1.37 ± 1.03, 1.57 ± 0.84, and 4.13 ± 1.45, respectively. These indexes showed no significant difference according to the type or site of cancer (P > 0.05).

Conclusions

This study showed that there was no correlation between oral health parameters and characteristics of head and neck carcinoma.

Periodontal Disease, Tooth Loss, and Cancer Risk

Periodontal disease, which includes gingivitis and periodontitis, is highly prevalent in adults and disease severity increases with age. The relationship between periodontal disease and oral cancer has been examined for several decades, but there is increasing interest in the link between periodontal disease and overall cancer risk, with systemic inflammation serving as the main focus for biological plausibility. Numerous case-control studies have addressed the role of oral health in head and neck cancer, and several cohort studies have examined associations with other types of cancers over the past decade. For this review, we included studies that were identified from either 11 published reviews on this topic or an updated literature search on PubMed (between 2011 and July 2016). A total of 50 studies from 46 publications were included in this review. Meta-analyses were conducted on cohort and case-control studies separately when at least 4 studies could be included to determine summary estimates of the risk of cancer in relation to 1) periodontal disease or 2) tooth number (a surrogate marker of periodontal disease) with adjustment for smoking. Existing data provide support for a positive association between periodontal disease and risk of oral, lung, and pancreatic cancers; however, additional prospective studies are needed to better inform on the strength of these associations and to determine whether other cancers are associated with periodontal disease. Future studies should include sufficiently large sample sizes, improved measurements for periodontal disease, and thorough adjustment for smoking and other risk factors.

Assessment of Influence of Smoking, Drinking, Leukoplakia and Dental Irritation on Local Control of Early Oral Tongue Carcinoma Treated with Brachytherapy: Age and Dental Factors are Potential Prognostic Factors

Background

To examine the background characteristics of elderly patients (65 years or older) with node-negative mobile tongue cancer (T1-2N0M0) who showed worse local control than a younger group.

Materials and methods

We retrospectively analyzed background data for 265 patients treated with brachytherapy with or without external radiotherapy between 1967 and 1999. We examined dental factors (such as irritation by prosthesis), leukoplakia, tobacco smoking and alcohol consumption for comparisons between the elderly (age ≥65 years; n = 83) and a control group (64 years or younger; n = 182).

Results

The elderly patients showed a worse outcome than the control group (respectively 86% and 70% at 5 years; P <0.05). Incidence of dental factors tended to be higher for elderly patients (53%) than the control group (40%, P = 0.07). Dental factors proved to have prognostic importance for local control. Five-year local control rate was 85% for patients with and 76% for patients without dental factors (P = 0.04). The elderly group positive for dental factors showed a lower 5-year local control rate (61%) than the other three groups [(elderly without the dental factor (–) group (80%), control with the dental factor (+) group (84%), and control without the dental factor (–) group (87%)] (P <0.05). Leukoplakia was found more frequently in the control (23%) than in the elderly group (5%) (P = 0.006) but had no effect on treatment outcome.

Conclusions

Age and dental factors (including prosthesis irritation) are potentially important prognostic factors for local control of oral tongue cancer treated with brachytherapy, especially for elderly patients.

Tooth loss and cancer risk: a dose-response meta analysis of prospective cohort studies

Conflicting results to identify the relationship between tooth loss and cancer risk. Therefore, a dose-response meta-analysis was performed to clarify and quantitative assessed the correlation between tooth loss and cancer risk. Up to March 2017, 25 observational epidemiological studies were included in current meta-analysis. Tooth loss was significantly associated with a higher risk of cancer. Additionally, tooth loss was associated with significantly a higher risk of esophageal cancer, gastric cancer, head and neck cancer, colorectal cancer, pancreas cancer, lung cancer, prostate cancer, bladder cancer and hematopoietic cancer. Subgroup analysis showed consistent findings. Furthermore, a significant dose-response relationship was observed between tooth loss and cancer risk. Increasing per 10 of tooth loss was associated with a 9% increment of cancer risk, 14% increment of esophageal cancer risk, 9% increment of gastric cancer risk, 31% increment of head and neck cancer risk, 4% increment of colorectal cancer risk, 7% increment of pancreas cancer risk, 19% increment of lung cancer risk, 2% increment of bladder cancer risk and 3% increment of hematopoietic cancer risk. Considering these promising results, tooth loss might be harmful for health. Large sample size, different ethnic population and different cancer type are warranted to validate this association.

Alterations in oral bacterial communities are associated with risk factors for oral and oropharyngeal cancer

Oral squamous cell carcinomas are a major cause of morbidity and mortality, and tobacco usage, alcohol consumption, and poor oral hygiene are established risk factors. To date, no large-scale case-control studies have considered the effects of these risk factors on the composition of the oral microbiome, nor microbial community associations with oral cancer. We compared the composition, diversity, and function of the oral microbiomes of 121 oral cancer patients to 242 age- and gender-matched controls using a metagenomic multivariate analysis pipeline. Significant shifts in composition and function of the oral microbiome were observed with poor oral hygiene, tobacco smoking, and oral cancer. Specifically, we observed dramatically altered community composition and function after tooth loss, with smaller alterations in current tobacco smokers, increased production of antioxidants in individuals with periodontitis, and significantly decreased glutamate metabolism metal transport in oral cancer patients. Although the alterations in the oral microbiome of oral cancer patients were significant, they were of substantially lower effect size relative to microbiome shifts after tooth loss. Alterations following tooth loss, itself a major risk factor for oral cancer, are likely a result of severe ecological disruption due to habitat loss but may also contribute to the development of the disease.

Impact of oral hygiene on head and neck cancer risk in a Chinese population

BACKGROUND

Although the impact of oral hygiene on head and neck cancer risk has been investigated, few studies have been conducted among the Asian population.

METHODS

We conducted a multicenter case-control study to investigate this potential association. We performed unconditional multiple logistic regression models adjusted by potential confounders.

RESULTS

We observed an inverse association of frequency of dental visits with head and neck cancer risk, with an adjusted odds ratio (OR) of 3.70 (95% CI 2.51-5.45) for never dental visits compared with ≥1 time/year (Ptrend < .001). We also observed a positive association between the number of missing teeth and head and neck cancer risk, with an adjusted OR for ≥5 missing teeth compared with <5 missing teeth of 1.49 (95% CI 1.08-2.04). Combining multiple oral hygiene indicators, poor oral hygiene scores increased head and neck cancer risk.

CONCLUSION

Poor oral hygiene may increase head and neck cancer risk in the Chinese population. Therefore, improving oral hygiene may contribute to reducing the head and neck cancer risk in the Chinese population.

Associations between oral hygiene habits, diet, tobacco and alcohol and risk of oral cancer: A case-control study from India

OBJECTIVE

This study examines the association between the incidence of oral cancer in India and oral hygiene habits, diet, chewing and smoking tobacco, and drinking alcohol. We also assessed the effects of oral hygiene habits with oral cancer risk among chewers versus never chewers.

METHODS

A hospital-based case-control study was conducted in Pune, India, based on face-to-face interviews, anthropometry, and intra-oral examinations conducted for 187 oral cancer cases and 240 controls.

RESULTS

Poor oral hygiene score was associated with a significant risk of oral cancer (adjusted OR=6.98; 95%CI 3.72-13.05). When stratified by tobacco-chewing habit, the poor oral hygiene score was a significant risk factor only among ever tobacco chewers (adjusted OR=14.74; 95%CI 6.49-33.46) compared with never chewers (adjusted OR=0.71; 95%CI 0.14-3.63). Dental check-ups only at the time of pain by ever-chewers with poor oral hygiene was associated with an elevated risk (adjusted OR=4.22; 95%CI 2.44-7.29), while consumption of green, yellow, and cruciferous vegetables and citrus fruits was protective. A linear dose-response association was observed between oral cancer and chewing tobacco in terms of age at initiation, duration, and frequency of chewing per day (P<0.001). Smoking more than 10 bidis/cigarettes per day (adjusted OR=2.74; 95%CI 1.28-5.89) and for a duration >25 years (adjusted OR=2.31; 95%CI 1.14-4.71) elevated the risk of oral cancer.

CONCLUSION

Good oral hygiene habits - as characterized by healthy gums, brushing more than once daily, use of toothpaste, annual dental check-ups, and a minimal number of missing teeth - can reduce the risk of oral cancer significantly. In addition to refraining from chewing/smoking tobacco, a diet adequate in fruits and vegetables may protect against the disease.

Cancer risk in patients with candidiasis: a nationwide population-based cohort study

BACKGROUND

Candidiasis and certain types of cancer are related to immunocompromised status. This study aimed to evaluate whether Candida infection (CI) is associated with subsequent cancer risk in Taiwan.

METHODS

Data from the National Health Insurance system of Taiwan were used to evaluate the association between CI and cancer risk. The CI cohort comprised 34,829 patients. Each patient was randomly frequency matched with one person from the general population without CI on the basis of age, sex, year of index date of CI diagnosis, and other characteristics to generate the control group. We used Cox's proportional hazard regression analysis to estimate the effects of CI on subsequent cancer risk.

RESULTS

Compared with the control group, patients with CI had a significantly higher risk of overall cancer (adjusted hazard ratio = 1.19, 95% confidence interval = 1.09-1.30). For subsite analysis, the risks of hematologic malignancy and head and neck, pancreatic, skin, and thyroid cancers were significantly higher in the CI group. Stratified analyses by sex, age, and follow-up time revealed different patterns.

CONCLUSION

Our study suggested that CI can significantly increase overall and some individual cancer risks, which is partially compatible with previous findings.

Characterization of Chronic Mechanical Irritation in Oral Cancer

Objective. Oral mucosa could host many lesions originated by chronic mechanical irritation (CMI) from teeth or dentures, and it has been proposed as risk factor for oral cancer. Nevertheless, the features of CMI factors in oral cancer and other lesions are not assessed. The aim of this study is to describe CMI features regarding type (dental, prosthetic, and/or functional), localization, and time span. Materials and Methods. Three groups were studied in this cross-sectional study: Oral Cancer (OC); Chronic Traumatic Ulcer (CTU); and Benign Irritative Mechanical Lesions (BIML). All sources of mechanical irritation were included: dental, prosthetic, and functional. Results. 285 patients (176 females, 109 males) were studied: OC = 38, CTU = 44, and BIML = 203. The most frequent CMI factor was dental, followed by functional and prosthetic in all groups; 76.5% (n = 218) presented functional factors. Buccal mucosa (45%) and tongue (42%) were the most affected sites. Time of action of CMI displayed statistically significant differences between BIML, CTU, and OC groups, with a mean of 21, 33, and 49 months, respectively. Conclusions. CMI should be properly recorded with as much detail as alcohol and tobacco consumption. CMI associated lesions are produced by dental or prosthetic factors, usually in relation to functional factors, involving mainly tongue and buccal mucosa.

Association between Chronic Periodontitis and Oral/Oropharyngeal Cancer

The aim of this case control study was to assess the association between the extent and severity of chronic periodontitis and oral cavity and/or oropharyngeal cancer. The case group comprised 35 patients (mean age 56.1±8.4), diagnosed for oral and/or oropharyngeal cancer. The control group comprised 40 individuals (mean age 55.4±9.4) without diagnostic of cancer. All individuals were subjected to a periodontal examination, including bleeding on probing, plaque index, gingival index, probing pocket depth (PPD), clinical attachment loss (CAL), and decayed, extracted and filled teeth index (DMFT). The case group had significantly more sites with plaque. GI and BOP had similar values in both groups. The median PPD and CAL values were significantly higher for the case group. Chronic generalized periodontitis was predominant in 80% of patients with oral and/or oropharyngeal cancer. Eighty nine percent of the patients in the case group presented severe chronic periodontitis. There was no significant difference between groups for median values of DMFT. The extent and severity of chronic periodontitis remained as risk indicators for oral cavity and/or oropharyngeal cancer even after the adjustments for traditional confound factors, i.e. smoking and alcohol consumption.

Emerging and established global life-style risk factors for cancer of the upper aero-digestive tract

INTRODUCTION

Upper aero-digestive tract cancer is a multidimensional problem, international trends showing complex rises and falls in incidence and mortality across the globe, with variation across different cultural and socio-economic groups. This paper seeks some explanations and identifies some research and policy needs.

METHODOLOGICAL APPROACH

The literature illustrates the multifactorial nature of carcinogenesis. At the cellular level, it is viewed as a multistep process involving multiple mutations and selection for cells with progressively increasing capacity for proliferation, survival, invasion, and metastasis. Established and emerging risk factors, in addition to changes in incidence and prevalence of cancers of the upper aero-digestive tract, were identified.

RISK FACTORS

Exposure to tobacco and alcohol, as well as diets inadequate in fresh fruits and vegetables, remain the major risk factors, with persistent infection by particular so-called "high risk" genotypes of human papillomavirus increasingly recognised as also playing an important role in a subset of cases, particularly for the oropharynx. Chronic trauma to oral mucosa from poor restorations and prostheses, in addition to poor oral hygiene with a consequent heavy microbial load in the mouth, are also emerging as significant risk factors.

CONCLUSIONS

Understanding and quantifying the impact of individual risk factors for these cancers is vital for health decision-making, planning and prevention. National policies and programmes should be designed and implemented to control exposure to environmental risks, by legislation if necessary, and to raise awareness so that people are provided with the information and support they need to adopt healthy lifestyles.

The Role of Chronic Mucosal Trauma in Oral Cancer: A Review of Literature

Chronic mucosal trauma resulting from sharp teeth, dentures, faulty restoration, or implants has frequently been associated with the development of oral cancer. The definitive evidence for the same is lacking. We undertook a search using the terms – dental trauma, mucosal trauma, oral cancer, squamous cell carcinoma, risk factor, potentially malignant lesion, dental factor, mechanical irritation, dental irritation, and cancer in the following electronic databases: MEDLINE, PubMed, ScienceDirect, Cochrane Database of Systematic Reviews, and Wiley InterScience. The search yielded 788 articles. Of these articles, only 22 articles described chronic mucosal trauma as risk factors for oral cancers and were considered in this review. The review shows that chronic mucosal irritation resulting from ill-fitting dentures may be considered a risk factor for the development of oral cancer, such cancers occur commonly over the lateral border of the tongue. However, no association has been proven between the duration of denture use and cancer formation. In patients without any addiction, such cancers occur more frequently in females. These cancers may present with an early nodal disease but their prognosis and outcomes have not been studied separately till now.

Oral and oropharyngeal cancer and the role of sexual behaviour: a systematic review

OBJECTIVES

This systematic review identified and evaluated the evidence for the role of sexual behaviours in the development of oropharyngeal cancers (OPCs) and oral cavity cancers (OCCs).

METHODS

Following the PRISMA guidelines, we identified observational and interventional studies reporting associations between several different sexual behaviours and OPC or OCC. Study quality was assessed independently by two reviewers using a validated scoring system.

RESULTS

From 513 papers identified, 21, reporting on 20 studies, fulfilled the inclusion criteria. Two cohort studies were rated as moderate quality. The 18 case-control studies were rated as weak; nine comparing people with OPC or OCC to people without cancer, eight comparing HPV-positive to HPV-negative cancer patients and one comparing OPCs to other head and neck cancers. One study was a pooled analysis of seven of the included studies with some additional information. Twelve sexual behaviours were assessed and 69 associations reported. The studies differed in the comparisons made, the sexual behaviours assessed, and how these were reported and categorized, so no quantitative meta-analyses were appropriate. Most studies combined OPC and OCC. Several significantly increased risks were seen with a high number of lifetime sexual partners (nine studies) and with the practice of oral sex (five studies), although two studies found a significant negative association with OCC and ever performing oral sex. Two cohort studies of men and women in homosexual relationships found increases in oral cancer risk, and a cohort study of men married to women who had a history of cervical cancer also showed an increased risk of oral cancers. Results for other sexual behaviours were limited and inconsistent, and these included the following: younger age at first sexual intercourse, number of lifetime oral sex partners, the practice of oral-anal sex, the number of oral-anal sex partners, and ever performing anal sex. Only one study assessed casual sex, never or rare use of a condom and having a sexual partner with a history of genital warts, finding significant associations in the two former behaviours.

CONCLUSION

The current evidence for sexual behaviours being risk factors for oral and oropharyngeal cancer is limited and inconsistent. Evidence suggests that the number of sexual partners and performing oral sex are associated with a greater risk. Furthermore men whose partners have had cervical cancer may have an increased risk. More studies looking at OPC specifically will be useful to determine whether these behaviours are subsite-selective.

Targeting cellular and molecular drivers of head and neck squamous cell carcinoma: current options and emerging perspectives

Despite improvements in functional outcomes attributable to advances in radiotherapy, chemotherapy, surgical techniques, and imaging techniques, survival in head and neck squamous cell carcinoma (HNSCC) patients has improved only marginally during the last couple of decades, and optimal therapy has yet to be devised. Genomic complexity and intratumoral genetic heterogeneity may contribute to treatment resistance and the propensity for locoregional recurrence. Countering this, it demands a significant effort from both basic and clinical scientists in the search for more effective targeted therapies. Recent genomewide studies have provided valuable insights into the genetic basis of HNSCC, uncovering potential new therapeutic opportunities. In addition, several studies have elucidated how inflammatory, immune, and stromal cells contribute to the particular properties of these neoplasms. In the present review, we introduce recent findings on genomic aberrations resulting from whole-genome sequencing of HNSCC, we discuss how the particular microenvironment affects the pathogenesis of this disease, and we describe clinical trials exploring new perspectives on the use of combined genetic and cellular targeted therapies.

Clinical profile and epidemiological factors of oral cancer patients from North India

INTRODUCTION

Tobacco chewing, smoking, and alcohol consumption are major contributing factors in the development of oral carcinoma. India has world's highest number of oral cancers (almost 20%) and approximately 1% of the Indian population has oral premalignant lesions.

AIM

The purpose of the study was to evaluate the epidemiological factors and clinical profile of oral cancer cases in our hospital.

SETTINGS

Department of Surgical Oncology, King George's Medical University, Lucknow, India.

MATERIALS AND METHODS

A retrospective study was conducted from January 2010 to December 2012 on 479 cases with histopathologically confirmed oral carcinoma. Subjects' details of age, sex, occupation, tobacco consumption, site of carcinoma, and stage at presentation were recorded.

RESULTS

Mean age in this study was 47.84 years with male to female ratio of 3.1:1.0. Buccal mucosa and alveolus were the most affected sites. The majority of cases were from socially and economically weaker section, with 93.72% cases being tobacco users. The majority of cases were advance stage (Stage III and IV) with Stage IV being the predominant stage at presentation followed by Stage III.

CONCLUSION

The findings of the study reveal that tobacco consumption is one of the major contributors in the development of cancer of oral cavity with the majority of cases presenting in advance stages posing a big therapeutic challenge.