The correlation between the quality of oral hygiene and oral HPV infection in adults: a prospective cross-sectional study

Surveillance of human papillomavirus through salivary diagnostics - A roadmap to early detection of oropharyngeal cancer in men

Human papillomavirus (HPV) is the most common sexually transmitted disease. Certain strains have the potential to cause malignancy in multiple anatomical sites if not cleared by the immune system. In most infected people, HPV is cleared within two years. However, HPV may persist in susceptible individuals with certain risk factors, eventually leading to malignancy. New evidence suggests that over 75% of all oropharyngeal cancers (OPC) are directly attributable to HPV. It is estimated that prophylactic HPV vaccination alone may take at least 25 years to have a significant impact on reducing the incidence of OPC. The temporal link between detection of oral HPV, persistence of the infection and the subsequent development of OPC have been well established. Moreover, men have threefold higher risk than women for acquiring HPV-OPC. This comprehensive review focuses on OPC development in men, highlighting the risk factors associated with malignant transformation of HPV-OPC. Current evidence is insufficient to determine whether early identification of at-risk demographics, screening, and prompt diagnosis result in improved outcomes. Hitherto, the effectiveness of an oral HPV screening program in this regard has not been investigated. Nevertheless, the potential to emulate the success of the cervical screening program remains a very real possibility.

Association between human papillomavirus and oral cancer: a literature review

HPV plays a vital role in the development of cervical cancers and oropharyngeal cancers, but it is controversial whether HPV is involved in oral cancer development and to what extent. In this review, the clinical characteristics, diagnosis, treatment, and prognosis of HPV-positive oral cancers are summarized, and the mechanisms of HPV-related oral cancer development are discussed. HPV DNA positivity rates are 20-30% in oral squamous cell carcinoma (OSCC), and HPV16 is the most common high-risk HPV. E6/E7 mRNA positivity rates are 2-6% in OSCC. Detection of both high-risk HPV DNA and E6/E7 mRNA is recommended to determine the presence of active HPV, in agreement with high-risk HPV infection in OSCC. Surgical treatment is the first-line therapy for HPV-positive and -negative oral cancer, but there is no unified view about the prognosis of HPV-positive OSCC patients. HPV16 may play a vital role in malignant transformation in oral epithelial dysplasia, and a model of synergistic carcinogenic impact of HPV and tobacco smoking is predicted. Additionally, it is hypothesized that there are different HPV-associated oral cancers, such as integrated HPV DNA-positive OSCC with stable E6/E7 expression and episomal HPV DNA-positive OSCC. In summary, the role of HPV in oral carcinogenesis seems to be limited because of the low E6/E7 positivity in OSCCs; however, episomal HPV DNA may play a vital role in the malignant transformation of HPV-positive oral premalignant lesions. Further investigation is required to promote new insights into the role of episomal HPV DNA in oral carcinogenesis.

Prevalence of oral HPV in the adult sample population in Sydney

BACKGROUND

Oropharyngeal squamous cell carcinomas are increasing in incidence. Risk factors include sexual behaviour, high-risk oral HPV infection and poor oral hygiene. We aimed to provide initial information on the prevalence and assess the feasibility of testing in dental settings.

METHODS

Patients ≥18 years old attending dental clinics in Sydney, Australia, were recruited, oral hygiene assessed, and 10 mL saline oral rinses obtained. Rinses were tested for HBG and HPV by PCR. Participants completed demographic and behavioural questionnaires.

RESULTS

The mean age was 48 years, of whom 131 (43.6%) were male. HPV genotypes, one each of 16, 66, 51, 35 and 58 in five participants, and 18 and 52 in one participant, were detected in six samples (2.0%), all men. Oral sex was reported by 89 (67.9%) male participants. One participant (4.3%) of the 23 with poor OH had at least one HPV genotype detected.

DISCUSSION

With dental patients willing to provide rinse samples and disclose potentially sensitive information, we found the hrHPV prevalence of 2%. Given large proportions of the general population attending dental clinics regularly, dentists may be ideally placed to screen for oropharyngeal carcinoma and contribute to the currently limited knowledge of oral HPV prevalence in Australian adults. © 2022 Australian Dental Association.

Dental health in patients with and without HPV-positive oropharyngeal and tongue cancer

Background

Human papilloma virus is associated with oral and oropharyngeal cancer. Our aim was to examine oral health in patients with oropharyngeal (OPSCC) and oral tongue cancer (OTSCC), expecting better oral health among OPSCC patients.

Material and methods

Fifty-five OPSCC patients with known HPV status and 59 OTSCC patients were randomly selected from a list of consecutive patients of the Helsinki University Hospital, Finland. Oral health was assessed from panoramic jaw radiographs. Total Dental Index (TDI) summarizing the dental health status was calculated and Finnish population study data were used for comparison. Descriptive statistics were used for analyses.

Results

Patients with HPV-positive OPSCC had higher periapical lesion index compared with HPV-negative OPSCC patients or with OTSCC patients. Residual roots were more common among OPSCC patients compared with OTSCC patients, because of their higher occurrence among HPV-negative OPSCC patients compared with OTSCC patients. Similarly, modified TDI score was significantly higher among OPSCC patients than among OTSCC patients, because of higher TDI score among HPV-negative OPSCC patients compared with OTSCC patients. OPSCC patients more often used a removable prosthesis than OTSCC patients. Dental health of the cancer patients was poorer when compared with the population data.

Conclusions

Our study hypothesis was only partly confirmed. Periapical lesions were more prevalent among HPV-positive OPSCC patients, compared with the other groups. The number of residual roots was higher among HPV-negative subgroup. Thus, OPSCC patients had worse oral health parameters than OTSCC patients.

The ‘Danse Macabre’—Neutrophils the Interactive Partner Affecting Oral Cancer Outcomes

Over the past few decades, tremendous advances in the prevention, diagnosis, and treatment of cancer have taken place. However for head and neck cancers, including oral cancer, the overall survival rate is below 50% and they remain the seventh most common malignancy worldwide. These cancers are, commonly, aggressive, genetically complex, and difficult to treat and the delay, which often occurs between early recognition of symptoms and diagnosis, and the start of treatment of these cancers, is associated with poor prognosis. Cancer development and progression occurs in concert with alterations in the surrounding stroma, with the immune system being an essential element in this process. Despite neutrophils having major roles in the pathology of many diseases, they were thought to have little impact on cancer development and progression. Recent studies are now challenging this notion and placing neutrophils as central interactive players with other immune and tumor cells in affecting cancer pathology. This review focuses on how neutrophils and their sub-phenotypes, N1, N2, and myeloid-derived suppressor cells, both directly and indirectly affect the anti-tumor and pro-tumor immune responses. Emphasis is placed on what is currently known about the interaction of neutrophils with myeloid innate immune cells (such as dendritic cells and macrophages), innate lymphoid cells, natural killer cells, and fibroblasts to affect the tumor microenvironment and progression of oral cancer. A better understanding of this dialog will allow for improved therapeutics that concurrently target several components of the tumor microenvironment, increasing the possibility of constructive and positive outcomes for oral cancer patients. For this review, PubMed, Web of Science, and Google Scholar were searched for manuscripts using keywords and combinations thereof of “oral cancer, OSCC, neutrophils, TANs, MDSC, immune cells, head and neck cancer, and tumor microenvironment” with a focus on publications from 2018 to 2021.

Association between self-reported periodontitis and high-risk oral human papillomavirus infection among Indigenous South Australians: A cross-sectional study

Introduction

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing globally, reflecting an increase in human papillomavirus (HPV)-related lesions. Indigenous populations are disproportionately affected by OPSCCs. Currently, testing for oral HPV is not recommended as a screening tool to permit early detection of OPSCCs due to the high population prevalence of HPV infection. Periodontitis may be a marker of oral HPV infection, but previous research evaluating this association has been inconclusive. Here we report a large population-based study examining the association between high-risk oral HPV infection and periodontitis among Indigenous South Australians.

Methods

We utilised a large convenience sample of Indigenous South Australians aged 18+ years recruited between February 2018 and February 2020. Of the original cohort (n = 1011), 748 (73.9%) participants participated in the 12 month follow-up. Detailed information on sociodemographic characteristics, health-related behaviours, and sexual history were collected at enrolment. Saliva samples were collected at 12 months and tested for the presence of oral HPV DNA using the optimized general primer (GP) + PCR system. The primary outcomes were the prevalence of any high-risk oral HPV DNA, and separately, HPV 16 and/or 18. Periodontitis was assessed at follow-up by using validated self-reported periodontitis screening questions. Logistic regression analyses were undertaken to assess the association between self-reported periodontitis and oral HPV infection with adjustment for potential sociodemographic and behavioural confounders, with estimates presented as odds ratios (OR) and 95% confidence interval (CI).

Results

Data on 673 participants (89.9% of the follow-up cohort) were available. Participants ranged in age from 18 to 80 (mean age 42.2, SD 14.7) and 31.5% were male. Overall, 115 (17.1%) participants had self-reported periodontitis, 40 (5.9%) had any high-risk oral HPV and 14 (2.1%) had HPV 16 and/or 18. Any high-risk HPV was detected among seven (17.5%) participants and HPV 16 and/or 18 was detected in three (21.4%) who self-reported periodontitis. In the regression analyses no significant association was found between self-reported periodontitis and high-risk oral HPV (adjusted OR: 1.10; 95% CI: 0.45–2.70) or HPV 16 and/or 18 (adjusted OR: 1.27; 95% CI: 0.32–5.03).

Conclusion

This study did not find any association between self-reported periodontitis and high-risk oral HPV among Indigenous South Australians. Further targeted studies with standardized clinical measures of periodontal disease are needed to clarify the link between high-risk oral HPV and periodontal disease. If confirmed this would add further weight to the importance of recommendations about the utility of periodontitis screening to identify individuals at risk of carrying high-risk oral HPV, who may benefit from more intensive screening and ongoing monitoring.

Human Papillomavirus Oral Infection: Review of Methodological Aspects and Epidemiology

Oral infection by Human Papillomavirus (HPV) has recently gained great attention because of its involvement in the development of a subset of head and neck squamous cell carcinoma. The role of specific Alpha-HPVs in this regard has been well established, whereas the contribution of other genera is under investigation. Despite their traditional classification as “cutaneous” types, Beta and Gamma HPVs are frequently detected in oral samples. Due to the lack of a standardized protocol, a large variety of methodologies have been used for oral sample collection, DNA extraction, HPV detection and genotyping. Laboratory procedures influence the evaluation of oral HPV prevalence, which largely varies also according to the population characteristics, e.g., age, gender, sexual behavior, Human Immunodeficiency Virus (HIV) status. Nevertheless, oral infection by Beta and Gamma HPVs seems to be even more common than Alpha-HPVs. The latter is 5–7% in the general population, and increases up to 30% approximately in HIV-infected men who have sex with men. Despite major advances in the evaluation of oral HPV prevalence, its natural history is still little understood, especially for Beta and Gamma HPVs. The latest technologies, such as Next Generation Sequencing (NGS), can be exploited to gain new insights into oral HPV, and to improve the identification of novel HPV types.

Relationship between the prevalence of oral human papillomavirus DNA and periodontal disease (Review)

Human papillomavirus (HPV) is a small DNA virus that infects the basal keratinocytes of squamous epithelium in the skin, and in the oral and genital mucosa. Smoking and sexual behavior have been recognized as significant risk factors for oral HPV infection. In the present review, the findings of recent studies of oral HPV infection in relation to periodontitis are discussed, as well as periodontopathic bacteria and periodontal herpes virus. Previous research suggests that HPV localizes to the inflammatory periodontal tissue. Inflammatory periodontal pockets may thus act as a reservoir for HPV. The interactions between HPV and periodontopathic bacteria remain unclear, but it is hypothesized that oral HPV infection may be related to a characteristic oral microbiome. Smoking is associated with HPV and periodontitis, as smoking induces destruction of periodontal tissue and suppresses the host defense, allowing HPV to infect periodontal tissue. Carcinogenic HPV and periodontitis may lead to the development of oral cavity cancer. However, oral HPV E6/E7 expression (transcriptionally active HPV) has not yet been fully investigated in patients with periodontitis. Collectively, the evidence suggests that oral HPV prevalence may be associated with periodontitis. The effect of clinical factors (age, sex, smoking, immunosuppressive condition and vaccination) on oral HPV DNA prevalence should be considered when clarifying the relationship between oral HPV and periodontitis. Additionally, the sampling method should be carefully chosen to directly detect HPV DNA in periodontal tissues.

Oral and laryngeal HPV infection: Incidence, prevalence and risk factors, with special regard to concurrent infection in head, neck and genitals

This review focuses on the importance of oral and laryngeal HPV infection which is present in majority of sexually active individuals at least once in their lifetime. Despite testing, still little is known about prevalence rates, determinants and, especially, the concurrent HPV infection in head and neck, and genitals. The purpose of this review is to clarify some issues of oral HPV incidence, prevalence, and to demonstrate the difficulties in identification of asymptomatic oral HPV carriers. The main premise to take up this topic is the high and still increasing risk for development of oropharyngeal cancer, and potential benefit from screening strategies, education programs and HPV vaccination. Transmission of HPV to the oral cavity and oropharynx is hypothesized to occur mainly through sexual contact. The exposure of oropharyngeal mucosa to HPV infection with consequence of increased risk for oropharyngeal carcinoma depends on specific sexual behavior. Male gender, older age, race or ethnicity, oral hygiene and current cigarette smoking are independently associated with any prevalent oral HPV infection.

New Insights into Oral Cancer-Risk Factors and Prevention: A Review of Literature

The oral cancer constitutes 48% of head and neck cancer cases. Ninety percent of oral cancer cases are histologically diagnosed as oral squamous cell carcinomas (OSCCs). Despite new management strategies, the 5-year survival rate of oral cancer is still below 50% in most countries. Head and neck cancers are heterogeneous tumors, and this characteristic of them provides a challenge to treatment plan. Due to the poor outcomes in oral cancer, prevention is a necessity. In this review, a relevant English Literature search in PubMed, ScienceDirect, and Google Scholar from 2000 to mid-2018 was performed. All published articles related to oral cancer and its prevention were included. The risk factors of oral cancer and strategies of oral cancer prevention will be discussed.

Association of oral HPV16 infection with periodontal inflammation and the oral microbiome in older women

The present preliminary study aimed to investigate the association between oral human papillomavirus type 16 (HPV16) DNA prevalence and periodontal inflammation in older women. The association between oral HPV16 infection and oral health status has not been fully elucidated in older Japanese women. The present study investigated older women aged ≥60 years who visited Hiroshima University Hospital. The present study excluded subjects with clinical factors affecting HPV infection, such as current smoking, oral cancer and pre-malignant lesions, and immunodeficiency. Finally, 46 female patients (mean age, 74.6 years) were analyzed. Quantitative PCR analysis was performed to detect HPV16 DNA in oral rinse samples. A total of 4 participants (8.7%) were HPV16 DNA positive. There was a significant association between the HPV16 DNA positivity rate and bleeding on probing (P=0.03). Additionally, Prevotella intermedia positive cases exhibited a significantly higher HPV16 DNA positivity rate than negative cases (33.3 vs 3.8%). Furthermore, analysis of 16S ribosomal RNA in bacterial flora was performed to examine microbiome diversity in participants with ≥6 mm periodontal pockets and bleeding on probing. Importantly, the average percentage of Porphyromonas was significantly higher in HPV16 DNA positive cases compared with in HPV16 DNA negative cases (5.57 vs. 1.44%). By contrast, the average percentage of Veillonella was significantly lower in HPV16 DNA positive cases than in HPV16 DNA negative cases (2.43 vs. 8.51%). Prevotella was also lower in HPV16 DNA positive cases than in HPV16 DNA negative cases (4.0 vs. 8.23%). These results indicated that people with both deep periodontal pocket inflammation and oral HPV16 infection may not have Prevotella- or Veillonella-dominant oral microbiomes, and their microbiomes may exhibit their own distinctive characteristics. In conclusion, the results suggested that oral HPV16 infection may be associated with periodontal inflammation in older Japanese women. Further research is required to clarify the detailed association between oral HPV infection and the oral microbiome.

Awareness of Human Papillomavirus and Its Oncogenic Potential in Head and Neck Cancer among Students: Still More Questions than Answers

In the past years, human papilloma virus (HPV) has been proved to be an important risk factor for head and neck squamous cell carcinomas (HNSCCs), especially in the oropharynx (OPCCS). The aim of this study was to assess the level of knowledge about HPV among students and to raise their awareness on the issue. A 22-question questionnaire was uploaded to an online service. Information about the project was sent out to students from three Universities in Lodz, Poland. All data were collected via questionnaire website tools. A total of 1710 students participated in this study. The group was divided into medical (MS) and non-medical (non-MS) students. Merely 59.38% of the non-MS had ever heard about HPV. Only 44.74% of the non-MS knew about vaccines against HPV. The oncogenic potential of HPV was evident for 81.17% of the MS and only 55.92% of the non-MS. Very similar numbers of respondents from both groups (39.21% vs. 36.47%) knew that HPV may cause cancers other than cervical. Nearly half of the respondents from both groups (46.28% vs. 48.32%) did not know about the risk of developing oral or oropharyngeal cancer. The level of knowledge about the consequences of HPV infection in head and neck cancers in young adults remains insufficient.

Human papillomavirus and oral health

Canada is among the world leaders in oral health. Despite this, there are growing concerns about the rising rates of HPV-related mouth and throat cancers. The link between human papillomavirus (HPV) and cervical cancer is well established; fortunately, thanks to detection and vaccination, Canada has one of the lowest incidence rates of cervical cancer in the world. The HPV-related mouth and throat cancers, however, present a different picture. In Canada, about 25% to 35% of mouth and throat cancers are related to oral HPV infection; and in 2012, the incidence rate of HPV-associated oropharyngeal cancer was more than 4.5 times higher in males than females. Furthermore, HPV vaccination uptake in Canada is higher among females than males. Physicians and nurses in public health and clinical settings have a role to play in the fight against HPV transmission, as do oral health professionals. Oral health professionals can play a key role in preventing HPV infection and HPV-related oropharyngeal cancers by raising awareness, educating and offering counselling to their clients, and promoting evidence-based preventive and diagnostic interventions.

A systematic review and meta-analysis of the association between periodontitis and oral high-risk human papillomavirus infection

BACKGROUND

The incidence of human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas (OPSCCs) is increasing globally. Common oral conditions such as periodontitis may contribute. We undertook a meta-analysis to quantify the association between periodontitis, oral HPV and OPSCCs.

METHODS

Multiple electronic databases were searched until 12 February 2020. Studies conducted in males and/or females aged ≥ 18 years that examined periodontitis, periodontal procedures, oral HPV infection, and where possible, oral cancers, were eligible. Meta-analyses were conducted and the GRADE approach was used to examine the quality of evidence.

RESULTS

Of 2709 studies identified, 13 met the eligibility criteria. Five studies could be included in the meta-analyses. There was no significant increase in the odds of high-risk oral HPV infection among individuals with confirmed periodontitis (odds ratio 4.71, 95% confidence interval 0.57-38.97). Individuals with periodontitis had a 3.65 times higher odds of having any type of oral HPV infection compared with those without periodontitis (95% confidence interval 1.67-8.01). The overall body of evidence was rated as low to very-low certainty.

CONCLUSION

Meta-analysis confirms there is a positive association between periodontitis and oral HPV infection, although the overall quality of this evidence is low. Evidence for an association between periodontitis and high-risk oral HPV infection is inconclusive.

Oral HPV16 DNA as a screening tool to detect early oropharyngeal squamous cell carcinoma

Given that oropharyngeal squamous cell carcinoma (OPSCC) have now surpassed cervical cancer as the most common human papillomavirus (HPV)‐driven cancer, there is an interest in developing non‐invasive predictive biomarkers to early detect HPV‐driven OPSCC. In total, 665 cancer‐free individuals were recruited from Queensland, Australia. Oral HPV16 DNA positivity in those individuals was determined by our in‐house developed sensitive PCR method. Individuals with (n = 9) or without (n = 12) oral HPV16 infections at baseline were followed for a median duration of 24 mo. Individuals with persistent oral HPV16 infection (≥ 30 mo) were invited for clinical examination of their oral cavity and oropharynx by an otolaryngologist. Oral HPV16 DNA was detected in 12 out of 650 cancer‐free individuals (1.8%; 95% confidence interval [CI]: 1.0‐3.2). Of the 3 individuals with persistent oral HPV16 infection, the first individual showed no clinical evidence of pathology. The second individual was diagnosed with a 2 mm invasive squamous cell carcinoma (T1N0M0) positive for both p16INK4a expression and HPV16 DNA. The third individual was found to have a mildly dysplastic lesion in the tonsillar region that was negative for p16INK4a expression and HPV16 DNA and she continues to have HPV16 DNA in her saliva. Taken together, our data support the value of using an oral HPV16 DNA assay as a potential screening tool for the detection of microscopic HPV‐driven OPSCC. Larger multicenter studies across various geographic regions recruiting populations at a higher risk of developing HPV‐driven OPSCC are warranted to extend and confirm the results of the current investigation.

Oral human papillomavirus infection in HIV-infected and HIV-uninfected MSM: the OHMAR prospective cohort study

OBJECTIVE

We aimed to assess incidence and clearance of oral human papillomavirus (HPV) infection and the respective risk factors in HIV-infected and uninfected men who have sex with men (MSM).

METHODS

Oral rinse and gargles were collected semiannually from 244 MSM (103, 42.2% HIV-infected). HPV-DNA testing was performed with the Linear Array HPV Genotyping test. A Markov model was used for estimation of incidence, clearance and risk factor analysis.

RESULTS

Incidence rates for any HPV were 21.2 and 15.0×1000 person-months in HIV-infected and uninfected MSM, respectively. The respective figures for high-risk HPVs were 10.7 and 6.5×1000 person-months. The clearance rate was 4-12 times higher than the respective incidence rate. HIV-infected MSM with >95 lifetime oral sex partners showed increased incidence of any HPV (adjusted HR, aHR: 8.46, 95% CI 1.89 to 37.92). Condomless oral sex appeared the strongest predictor for incident infection by high-risk HPVs in this group (aHR: 13.40, 95% CI 2.55 to 70.53). Those aged >46 years (aHR: 0.30, 95% CI 0.12 to 0.74) and those with nadir CD4+ T count of <200 cells/mm³ (aHR: 0.14, 95% CI 0.03 to 0.75) displayed a significantly reduced clearance of any and high-risk HPVs, respectively. HIV-uninfected MSM aged >46 years had increased risk of acquiring any HPV (aHR: 3.70, 95% CI 1.30 to 10.52) and high-risk HPV (aHR: 5.33, 95% CI 1.06 to 26.68). Any HPV clearance declined in those with more than six recent oral sex partners (aHR: 0.18, 95% CI 0.05 to 0.65).

CONCLUSIONS

Acquisition of oral HPV infection in MSM seems to occur rarely, whereas clearance seems to be a frequent event. Oral HPV natural history in these at-risk subjects is differently influenced by age and sex behaviour, depending on HIV status.

Elevated prevalence of high-risk HPV in healthy oral mucosa of users and nonusers of drugs in Northeastern Brazil

Variable rates of HPV infection have been reported in healthy oral mucosa worldwide. The main objective of this study was to detect and genotype HPV infection in users and nonusers of drugs with clinically healthy mucosa from the Northeast Brazil. Samples from 105 patients were amplified using the primers MY09/MY11 and GP5+/GP6+, and genotyping was performed by multiplex-PCR for HPV-6/11, 16 and 18. A total of 81.9% samples were positive. Among drug users, 84.5% presented the virus and 20.4% showed multiple infections. Among non-drug users, 78.7% were positive and 13.5% had multiple infections. Limited information is available on oral HPV in Brazilian population, especially for drug users, and our results showed higher HPV infection rates in both users and nonusers of drugs. More studies and researches focused on drug users including factors like sexual behavior, nutrition and cultural habits are necessary to enhance the comprehension of this relationship, and develop preventive strategies.

Oral hygiene and the overall survival of head and neck cancer patients

Poor oral hygiene is an established risk factor of head and neck cancer (HNC); however, its role in the survival of HNC patients is unclear. This study evaluated the association between oral hygiene habits, including regular dental visits, frequency of tooth brushing, and use of dental floss, and the overall survival (OS) of HNC patients using interview data collected from 740 HNC patients. In addition, the interactions between oral hygiene and the polymorphisms of TLR2 and TLR4 on the OS of HNC patients were assessed. The analysis indicated that poor oral hygiene was significantly associated with poorer OS of HNC patients (hazard ratio (HR) = 1.38, 95% confidence interval (CI): 1.03‐1.86). This association was modified by a single nucleotide polymorphism, rs11536889, of TLR4. A significant association between poor oral hygiene and worse survival of HNC was observed among those with the CG or CC genotype (HR = 2.32, 95% CI: 1.41‐3.82) but not among those with the GG genotype (HR = 0.95, 95% CI: 0.65‐1.40). Our results suggested that poor oral hygiene is not only a risk factor but may also be a prognostic factor of HNC.

Poor oral hygiene was associated with a worse survival of head and neck cancer. TLR4 affected the survival of head and neck cancer due to poor oral hygiene. Poor oral hygiene is both a risk and a prognostic factor of head and neck cancer