Oral human papillomavirus infection, sexual behaviors and risk of oral squamous cell carcinoma in southeast of China: A case-control study

Risk factors associated with oral Human Papillomavirus (HPV) prevalence within a young adult population

BACKGROUND

The prevalence of, and risk factors for, genital Human Papillomavirus (HPV) infections within the young adult population are well-established; the same is not known for oral HPV. This observational study aimed to determine oral HPV prevalence and abundance within a UK young adult population, and examine if sexual practices and established risk factors of oropharyngeal squamous cell carcinomas (OPSCCs) (such as smoking and alcohol consumption) influenced HPV prevalence.

METHODS

Convenience sampling was used to recruit a small sample of 452 UK-based young adults studying at a higher education (HE) institution to the study; the study was not powered. A highly sensitive real-time PCR HPV screening method was developed for the detection of multiple HPV subtypes from oral swabs. HPV-positive samples were subsequently screened by qPCR for viral subtypes HPV-6, HPV-11, HPV-16, HPV-18. Results were analysed by univariate and multivariate methods and stratified for gender, with lifestyle behaviour data collected via questionnaire. Socio-economic status was not captured within the questionnaire.

RESULTS

We found a high oral HPV prevalence of 22.79%, with a dominance of high-risk viral type HPV-16 (prevalence 19.12%; abundance average 1.08 × 105 copies/million cells) detected within healthy young adults. Frequent smoking (p = .05), masturbation (p = .029), and engagement in multiple sexual activities (p = .057), were found to be associated with oral HPV prevalence, and HPV-16 prevalence, whilst behaviours traditionally associated with genital HPV were not.

CONCLUSIONS

Our results strengthen the link between sexual practices and oral HPV transmission. We suggest that young adults should be considered high-risk for the contraction of oral HPV, although acknowledge that this sample of HE students may not be representative of the wider population. We show that high-risk HPV-16 is prevalent in the healthy population, as well as dominating within OPSCC; this study is one of the first to determine the dominance of oral HPV-16 prevalence and abundance within this population, presenting a clear need for greater awareness of oral HPV infections, and the risk factors for HPV-positive OPSCC within young adults.

Delaying age at first sexual intercourse provides protection against oral cavity cancer: a mendelian randomization study

Aim

To investigate whether age at first sexual intercourse could lead to any changes in the risk of oral cavity cancer.

Methods

A two-sample mendelian randomization was conducted using genetic variants associated with age at first sexual intercourse in UK biobank as instrumental variables. Summary data of Northern American from a previous genome-wide association study aimed at oral cavity cancer was served as outcome. Three analytical methods: inverse variance-weighted, mendelian randomization Egger, and weighted median were used to perform the analysis, among which inverse variance-weighted was set as the primary method. Robustness of the results was assessed through Cochran Q test, mendelian randomization Egger intercept tests, MR PRESSO, leave one out analysis and funnel plot.

Results

The primary analysis provided substantial evidence of a positive causal relationship age at first sexual intercourse and the risk of oral cavity cancer (p = 0.0002), while a delayed age at first sexual intercourse would lead to a decreased risk of suffering oral cavity cancer (β = -1.013). The secondary outcomes confirmed the results (all β < 0) and all assessments supported the robustness, too (all p > 0.05).

Conclusion

The study demonstrates that a delayed sexual debut would provide protection against OCC, thus education on delaying sexual intercourse should be recommended.

Sexual history of patients with human papillomavirus positive and negative oropharyngeal cancer: A systematic review and meta-analysis

BACKGROUND

Increased sexual activity is associated with higher human papillomavirus (HPV) rates; however, there is a lack of analysis comparing the sexual history of patients with HPV positive and HPV negative oropharyngeal cancer (OPC).

METHODS

In this meta-analysis, PubMed, Scopus, and CINAHL were searched for articles that included patients with OPC and reported information regarding HPV status and either history of oral sex, number of sexual partners, or sexually transmitted infections (STI).

RESULTS

A total of 11 studies were included with 3296 patients with OPC. Patients with HPV positive OPC were more likely than patients with HPV negative OPC to report a history of oral sex (92%, 95% CI: 87.0-97.0 vs. 74.5%, 95% CI: 50.6-98.4, p < 0.0001), higher mean number of sexual partners (18.4 partners, 95% CI: 1.5-35.4 vs. 7.2 partners, 95% CI: 1.0-13.4, p < 0.0001), and more frequent history of STI (23.7%, 95% CI: 18.4-29.0 vs. 8.8%, 95% CI: 4.7-12.8, p = 0.0001).

CONCLUSIONS

Compared to patients with HPV negative OPC, our analysis shows a larger proportion of patients with HPV positive OPC had participated in oral sex, had a higher number of sexual partners, and had a higher proportion of STI history.

Prevalence of oral human papillomavirus infection among the general adult population in Hong Kong

A cross-sectional study in 2021-23 collected oral rinse gargle samples from an human papillomaviruses (HPV) vaccine-naïve general adult population in Hong Kong. HPV was detected by a PCR using SPF10 primers, and genotyped by a linear array covering 25 genotypes. Epidemiologic information including sociodemographics, medical history, oral health, and sexual behavior were collected by a self-administered questionnaire. Altogether, 2323 subjects aged 18-75 (median 47) years with 50.1% male were recruited. The prevalence for oral HPV infection with all genotypes combined, high-risk, and low-risk genotypes was 1.5%, 0.7%, and 0.7%, respectively; and with no statistically significant difference between participant gender. The prevalence increased with age and was highest in women at 45-54 years (2.7% for all genotypes combined), and highest in men aged >64 years (4.1% for all genotypes combined). HPV52 was the most common genotype among all participants. Univariate analysis suggested more lifetime sexual or oral sexual partners as risk factors, but they did not reach statistical significance upon multivariate analysis; whereas higher educational level had an independent protective effect. To conclude, oral HPV prevalence increased with age in Hong Kong. Strategies to prevent oral HPV infection and the associated cancers are urgently needed.

Epidemiology of HPV Related Malignancies

Human papillomavirus is the most common sexually transmitted infection in the world and had been linked to both anogenital and oropharyngeal cancers. It causes nearly 100% of cervical cancers and an increasing portion of oropharyngeal cancers. The geographical burden of cervical HPV infection and associated cancers is not uniform and is mainly found in low middle income countries in South America, Africa, and Asia. However, HPV-positive oropharyngeal cancer is rapidly becoming more prevalent in high middle income countries. With the development of vaccines which prevent HPV infection, the World Health Organization has designated the extirpation of HPV and its associated cancers a priority. Countries that have implemented adequate vaccine programs have shown a decrease in HPV prevalence. Understanding the epidemiology of HPV and its associated cancers is fundamental in improving vaccine programs and other health programs.

Model of Human Tongue Squamous Cell Lines Stably Transfected with Human Papillomavirus (HPV)16 E6 and E7 Genes and Biological Characteristic Analysis

BACKGROUND

Human tongue squamous cell carcinoma (TSCC) is the most common oral cancer with the highest human papillomavirus (HPV) infection rate in oral cancer. The purpose of this study was to research the correlation between HPV and TSCC.

METHOD

Plasmid pEGFP/HPV16 E6E7 and plasmid pEGFP/no HPV16 E6E7 were constructed. TSCC cell lines SCC9 and SCC15 were infected by liposome transfection and would be highly selected by antibiotic. Fluorescence imaging, PCR, and Western blot were used to detect the expression of HPV16 E6E7 in cells. The biological characteristics were detected by CCK-8, wound healing assay, qRT-PCR, and Western blot.

RESULT

TSCC cell lines transfected with HPV16 E6E7 gene were successfully established and identified. And the proliferation and migration ability of the TSCC cell lines infected with HPV16 E6E7 gene were significantly stronger than that of the blank group.

CONCLUSION

TSCC cell lines infected with HPV16 E6E7 with significantly higher ability of proliferation and migration were more malignant than those not infected with HPV16 E6E7.

Timing, number, and type of sexual partners associated with risk of oropharyngeal cancer

BACKGROUND

Case-control studies from the early 2000s demonstrated that human papillomavirus-related oropharyngeal cancer (HPV-OPC) is a distinct entity associated with number of oral sex partners. Using contemporary data, we investigated novel risk factors (sexual debut behaviors, exposure intensity, and relationship dynamics) and serological markers on odds of HPV-OPC.

METHODS

HPV-OPC patients and frequency-matched controls were enrolled in a multicenter study from 2013 to 2018. Participants completed a behavioral survey. Characteristics were compared using a chi-square test for categorical variables and a t test for continuous variables. Adjusted odds ratios (aOR) were calculated using logistic regression.

RESULTS

A total of 163 HPV-OPC patients and 345 controls were included. Lifetime number of oral sex partners was associated with significantly increased odds of HPV-OPC (>10 partners: odds ratio [OR], 4.3 [95% CI, 2.8-6.7]). After adjustment for number of oral sex partners and smoking, younger age at first oral sex (<18 vs >20 years: aOR, 1.8 [95% CI, 1.1-3.2]) and oral sex intensity (>5 sex-years: aOR, 2.8 [95% CI, 1.1-7.5]) remained associated with significantly increased odds of HPV-OPC. Type of sexual partner such as older partners when a case was younger (OR, 1.7 [95% CI, 1.1-2.6]) or having a partner who had extramarital sex (OR, 1.6 [95% CI, 1.1-2.4]) was associated with HPV-OPC. Seropositivity for antibodies to HPV16 E6 (OR, 286 [95% CI, 122-670]) and any HPV16 E protein (E1, E2, E6, E7; OR, 163 [95% CI, 70-378]) was associated with increased odds of HPV-OPC.

CONCLUSION

Number of oral sex partners remains a strong risk factor for HPV-OPC; however, timing and intensity of oral sex are novel independent risk factors. These behaviors suggest additional nuances of how and why some individuals develop HPV-OPC.

Evidence for different molecular parameters in head and neck squamous cell carcinoma of nonsmokers and nondrinkers: Systematic review and meta-analysis on HPV, p16, and TP53

BACKGROUND

The goal of this review was to present an overview of the currently identified molecular parameters in head and neck squamous cell carcinoma (HNSCC) of nonsmokers and nondrinkers (NSND).

METHODS

Following the PRISMA guidelines, a systematic search was performed using the electronic databases PubMed, Embase, and Google Scholar.

RESULTS

Of the 902 analyzed unique studies, 74 were included in a quantitative synthesis and 24 in a meta-analysis. Human papillomavirus (HPV) was reported as a molecular parameter in 38 studies, followed by p16 and TP53 (23 and 14 studies, respectively). The variety of other molecular parameters concerned sporadic findings in small numbers of NSND.

CONCLUSIONS

HNSCC in NSND is more often related to HPV and p16 overexpression compared to tumors of smokers-drinkers. In a third of virus-negative tumors, TP53 mutations were detected with a mutational profile associated with aging and ultraviolet light exposure rather than to tobacco consumption.

No association between HPV-status in tonsillar tissue and sexual behavior of the patients in a northern German population - Critical view of the link between HPV natural history and HPV-driven carcinogenesis

HPV-infection in patients with HNSCC is reportedly correlated with sexual behavior, age, and tobacco/alcohol-consumption. HPV-infections of the oral cavity are regarded as sexually transmitted. Comparable data of patient populations outside the U.S. are sparse or missing.

Questionnaires regarding sexual behavior, education tobacco- and alcohol-consumption, were given to 28 patients with tonsillar hyperplasia (H) and 128 patients with tonsillar carcinomas (CA), all with tissue-typed HPV-DNA-status performing PCR. Answers were correlated among groups and HPV-status.

106 questionnaires were analyzed. Comparisons between H- (n = 25) and CA- (n = 81) patients showed that CA-patients were older (61.1yrs ± 9.3) than H-patients (45.2yrs ± 11.9; p < 0.0001; Student's t-test); had a lower educational level (p = 0.0095); and lower number of sexual partners (p = 0.0222; Fisher's exact test). All groups showed a significant correlation between smoking and lack of HPV-DNA-positivity (p = 0.001). Further Fisher's exact tests and logistic regression analysis revealed in all 106 patients no significant correlations between tissue-HPV-status and the analyzed parameters.

Despite the limited sample size, we were able to confirm the established correlation between smoking and tissue-HPV-status. The correlation between sexual behavior and HPV-infection was not confirmed. No consensus exists in the literature about the latter. Our data does not support the strict classification of oral HPV-infections and HPV-driven HNSCCs as STDs.

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Questionnaires from 81 TSCC and 25 tonsillar hyperplasia (H) patients were analyzed.

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No correlation between HPV positivity and sexual behavior was found.

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HPV positive H had both less sexual partners and oral sex than HPV negatives (trend).

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In TSCC sexual partners and oral sex were similar irrespective of HPV status.

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Incongruent data about sexual behavior, HPV transmission and cancer transgression.

Oncogenic high-risk human papillomavirus in patients with full denture

Human Papillomavirus (HPV) has considerable tropism for epithelial and mucosal tissues and can therefore be found in several anatomical sites, including the oral cavity. This study aimed to investigate the presence of HPV-DNA and the most frequent viral types in patients using full dentures, compare to patients not using full dentures and to associate its presence with socio-epidemiological and behavioral factors. The study consisted of 90 patients with or without full dentures at the time of collection, treated at a public dental clinic. The samples were obtained by exfoliating the oral cavity, and analyzed for HPV-DNA using the nested PCR with PGMY09/11 (450-bp), and general primers GP5+/GP6+ (150-bp). Genotyping was performed by specific-type PCR to HPV 6, 11, 16, 18, 31, 33, and 45; and Restriction Fragment Length Polymorphism (RFLP). Pearson's Chi-square test (x 2 ) or Fisher's exact test were applied and significant variables in these tests were analyzed by multinomial logistic regression analysis to estimate odds ratio (OR). HPV-DNA was detected in 27.7% of samples and, among those obtained from patients using full dentures, positivity for HPV-DNA was 41.9% (p = 0.025). The most frequent viral types were low-risk HPV 6 and 11, and high-risk HPV 31 and 45. Patients who used full dentures had an odds ratio of 2.1 to be positive for HPV DNA. Our results indicate the need for periodic dental follow-up of patients with full dentures in order to preserve the basic conditions of oral health, and also to monitor the appearance of lesions with malignant potential.

Three prognostic indexes as predictors of response to adjuvant chemoradiotherapy in patients with oral squamous cell carcinoma after radical surgery: A large-scale prospective study

BACKGROUND

To develop and validate practical prognostic indexes (PIs) for predicting the prognosis and response to postoperative adjuvant therapy in patients with oral squamous cell carcinoma (OSCC).

METHODS

A large cohort of 1071 OSCC patients were randomized to either training set (N = 708) or validation set (N = 363). Three types of PIs were developed according to the nomogram scores, β coefficients and excess hazard ratios, respectively. Restricted cubic spline was used to demonstrate the relationship between PIs and the risks of death.

RESULTS

First, a nomogram was developed incorporating age at diagnosis, smoking status, clinical stage, tumor differentiation, lymph node status, comorbidity, and neutrophil to lymphocyte ratio levels. Then, three PIs were established with high survival predictive ability, and were superior to AJCC staging system (all P < .05). The risks of death were escalated continuously with the increasing number of PIs. Interestingly, adjuvant chemoradiotherapy was positively associated with poor overall survival in patients with low PIs, but exerted a beneficial effect on patients with high PIs.

CONCLUSION

Combined nomogram with further established PIs not only predicts the survival probability of OSCC patients, but also continuously quantifies the risk of death. High PIs could predict a beneficial response to adjuvant chemoradiotherapy, whereas low PIs indicate an unfavorable response.

Prevalence of Human Papillomavirus Type-16 in Head and Neck Cancer Among the Chinese Population: A Meta-Analysis

Background: The burden of head and neck cancer in China is heavier, and studies have shown that it may be associated with HPV infection, especially high-risk HPV. Objectives: We aimed to conduct a meta-analysis to estimate the high-risk HPV-16 prevalence of head and neck cancer in the Chinese population. Methods: The reports on HPV and head and neck cancer in a Chinese population published between Jan 1, 2006 and Oct 23, 2018 were retrieved via WANFANG/CNKI/MEDLINE/EMBASE databases. The pooled prevalence and corresponding 95% confidence intervals was calculated by a random-effect model. Results: The meta-analysis included a total of 2,896 head and neck cancer cases from 28 studies. Overall, the pooled HPV-16 prevalence among head and neck cancer cases was 24.7% (20.2-29.3%) in China, 31.6% (21.7-41.5%) in oropharyngeal cancer, 28.5% (18.2-38.7%) in laryngeal cancer and 14.9% (10.1-19.7%) in oral cancer, 25.3% (14.8-35.8%) in fresh or frozen biopsies and 25.0% (19.5-30.5%) in paraffin-embedded fixed biopsies, 36.5% (17.9-55.1%) by E6/E7 region and 14.3% (6.4-22.1%) by L1 region of HPV gene. The highest HPV-16 prevalence was found in Central China. Conclusions: High prevalence of HPV-16 was found in the samples of Chinese head and neck cancers. Preventive HPV-vaccination may reduce the burden of HPV-related head and neck cancer in China.

Awareness of Polish undergraduate and graduate students regarding the impact of viral infections and high-risk sexual behaviors on the occurrence of oral cancer

With every passing year, more and more studies and observations demonstrate growing incidence of oral cancer, a decrease in patients' age, and an increasing number of epidemiological factors. The aim of the study was to determine the level of awareness among undergraduate and graduate university students regarding the incidence of oral cancer linked with viral infections and high-risk sexual behavior, including oral sex. Self-administered questionnaire-based survey was carried out among 196 Polish students aged 19 to 25 years. It was found that the young adults understood the meaning of human papillomavirus (HPV), but associated it only with the squamous cell carcinoma of the cervix. A total of 43.4% did not realize that there was any correlation between HPV infection and the development of oral cancer. The students who were aware of this correlation constituted 40.3% of the total. The majority of the participants, that is, 82 subjects (41.8%), did not associate the occurrence of malignant neoplasms of the oral cavity with oral sex. The study group did not present adequate awareness of the fact that occurrence of oral cancer may be associated with high-risk sexual behaviors. Knowledge of oral cancer was not significantly related to the level of university education (P < .005).

Nomograms and risk scores for predicting the risk of oral cancer in different sexes: a large-scale case-control study

Background: Although previous studies have explored the associations of modifiable lifestyle factors with oral cancer risk, few studies integrated these factors and established predictive tools for oral cancer risk in different sexes.

Methods: Using a case-control study design, a total of 978 oral cancer cases and 2646 healthy controls were recruited in this study. Nomograms were constructed according to significant factors in multivariable logistic regression. Risk scores were calculated based on the nomograms and quantified the risk of oral cancer using restricted cubic spline.

Results: Multivariate analyses demonstrated that smoking, alcohol drinking, tea, intake of fish, seafood, vegetables, fruits, teeth loss, regular dental visits and repetitive dental ulcer were independent factors for male oral cancer. Passive smoking, age at first intercourse, cooking oil fumes exposure, tea, intake of beans, vegetables, fruits, teeth loss, regular dental visits and repetitive dental ulcer were associated with female oral cancer. Then, two nomograms were developed for predicting the probability of oral cancer in men and women with the C-index of 0.768 (95% CI: 0.723-0.813) and 0.700 (95% CI: 0.635-0.765), respectively. Restricted cubic splines graphically revealed the risk of oral cancer in individuals with different risk scores. Moreover, the risk escalated continuously with the increasing number of the risk scores among both sexes.

Conclusions: Combining nomograms with risk scores developed in this study could precisely predict oral cancer occurrence and provide an accurate risk assessment.

A functional haplotype of NFKB1 influence susceptibility to oral cancer: a population-based and in vitro study

Genetic variations of NF‐κB and its inhibitor IκB genes and their biological mechanism in oral cancer were not well recognized. The purpose of this study was to evaluate the associations of polymorphisms in NFKB1 and NFKBIA with oral cancer susceptibility, and further explore their potential mechanism in vitro. First, the polymorphisms of NFKB1 and NFKBIA were genotyped through iPLEX Sequenom MassARRAY platform in a case–control study with 425 oral cancer patients and 485 healthy controls. Then, the function was explored by a luciferase reporter assay and an electrophoretic mobility shift assay (EMSA) in human tongue squamous cell carcinoma cell lines. The results indicated that NFKB1 rs28362491 Del/Del and rs72696119 G/G genotypes were associated with the risk of oral cancer, with a strong linkage disequilibrium (D′ = 0.991, r² = 0.971). Moreover, DG haplotype of NFKB1 also showed a significant increased risk (OR = 1.25, 95% CI: 1.02–1.53, P = 0.030). Dual‐luciferase reporter assays further revealed that the plasmids with DG or IG or DC haplotype transfected with Tca‐8113 cells or CAL‐27 cells had a lower luciferase expression than that with IC haplotype. EMSA demonstrated that 4‐bp ATTG deletion in the promoter of NFKB1 abolished the binding site of transcription factor. Our preliminary findings suggest that the haplotype of rs28362491 and rs72696119 in NFKB1 could act as a novel genetic marker to predict oral cancer risk in the southeast of China, but much more extensive researches still need to be conducted.

Prevalence of current oral HPV infection among 100 betel nut chewers or cigarette smokers in Northern Taiwan

BACKGROUND

The incidence of HPV positive oropharyngeal cancer is increasing in Taiwan. Given this, it is critical to understand the prevalence of oral HPV infection since this cancer is potentially preventable. A community-based study was conducted to evaluate the prevalence of oral HPV infection and sexual behavior changes.

METHODS

Between January and December 2016, 100 subjects between 20 and 70 years-old with current/ever betel nut chewing or current cigarette smoking visited the Department of Health, New Taipei City. Subjects with cancer history or known HIV/AIDS were excluded. Sexual behavior information was collected through a questionnaire. Oral rinse samples and oropharyngeal swabs were obtained for HPV genotyping using the EasyChip HPV genotyping array (King-Car, Taiwan).

RESULTS

92 men and 8 women were recruited. The prevalence of oral HPV infection was 3%, present between 60 and 70 (11%) and between 30 and 40 years old (4%). The prevalence of the first sexual contact at younger than 20 years old were 71.4%, 53.6%, 15.4% and 44% in <40, 40-49, 50-59 and 60+ years old, respectively (p for trend = 0.0036). The prevalence of 3 or more lifetime sexual partners were 60.7%, 57.1%, 23.1% and 16.7%, respectively for <40, 40-49, 50-59 and 60+ years old (p for trend = 0.0005).

CONCLUSION

The prevalence of oral HPV infection is 3%, in current/ever betel nut chewers or current cigarette smokers in Northern Taiwan. Younger generation have more lifetime sexual partners and younger first sexual contact. This could explain the rising incidence of HPV positive oropharyngeal cancer in Taiwan.

Differences in modifiable factors of oral squamous cell carcinoma in the upper and lower of oral fissure

The aim of this study was to explore differences in the effects of modifiable factors on oral squamous cell carcinoma (OSCC) occurring in the lower oral fissure (LOF) and upper oral fissure (UOF). We conducted a case-control study with 697 OSCC patients (119 UOF and 578 LOF) and 1910 frequency-matched controls in Fujian province, China. Data on demographic characteristics and possible modifiable factors was collected using a structured questionnaire. Unconditional logistic regression was utilized to calculate the odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Alcohol drinking was more strongly associated with an increased risk of OSCC-LOF than OSCC-UOF. Tobacco smoking, the number of teeth lost ≥5, wearing denture, and recurrent oral ulceration showed similarly associations with OSCC-LOF and -UOF risk. Similarly, the beneficial effects of tea consumption, tooth-brushing ≥2times per day, high intake of fresh fish, seafood, green-leafy vegetables, other vegetables and fruits were not significantly different on OSCC-LOF and -UOF. Although most of the modifiable factors exert similar effects on both OSCC sites, this study suggests that the sites of oral cavity in LOF may be affected more by alcohol drinking than the sites in UOF. Further studies with larger samples are warranted to confirm our findings.

Human papillomavirus infection in oral potentially malignant disorders and cancer

Human papillomavirus (HPV) infects keratinocytes in the mucosa or skin, and persistent infection with HPV may lead to premalignant lesions and invasive cancer, especially cervical cancer. It has also been hypothesized that HPV infection is an etiological factor of oral squamous cell carcinoma and oral precancerous disorders such as lichen planus, leukoplakia, and erythroplakia. A high percentage of HPV in oral lesions supports the possible viral contribution, but an association of HPV infection with these lesions remains to be established. The current paper will update the latest progress of HPV infection in several oral potentially malignant disorders and oral squamous cell carcinoma and discuss the impact of HPV infection on the progression of oral potentially malignant disorders.

Prevalence of human papillomavirus16 DNA and p16INK4a protein in oral squamous cell carcinoma: A systematic review and meta-analysis

BACKGROUND AND AIM

Indian patients with oral squamous cell carcinoma (OSCC) are etiologically associated with the use of tobacco and alcohol; yet, a proportion of tumors that may harbor human papillomavirus (HPV) infections cannot be neglected. The following meta-analysis was conducted to address the association of p16INK4a and HPV DNA with OSCC. In addition, the study also provides the updated prevalence of HPV-induced OSCC.

MATERIALS AND METHODS

Literature survey was performed using databases such as PubMed with the help of the following keywords - "HPV infection," "oral squamous cell carcinoma," "p16INK4a," "HPV DNA," "E6," "E7," "L1," "L2" and "LCR." Proportion method was performed to derive the forest plot using MedCalc statistical software version 16.4.3.

RESULTS

Among 145 research articles, 33 articles were selected for further analysis, in which 13 articles were related to HPV DNA detection in tissues, 11 articles detected the overexpression of p16INK4a and nine articles reported the detection of both HPV DNA and p16INK4a expression. Meta-analysis revealed significant heterogeneity (P < 0.0001) among the articles. Overall, the study consisted of 3339 patients with OSCC, among which 559 patients were diagnosed with the presence of HPV16 DNA with a random proportion of 20.1% at 95% confidence interval (CI) (13.9-27.1, P < 0.0001). Overexpression of p16INK4a protein was observed in 709 patients with a random proportion of 25.4% at 95% CI (14.3-38.3, P < 0.0001).

CONCLUSION

HPV DNA and expression of p16INK4a was suggested as gold standard for the detection of HPV infection in many cases of cancers. Frequency of HPV infection is significantly higher in patients with OSCC as identified through the detection of HPV DNA and p16INK4a expression. Even though the association of HPV infection has been established in head and neck cancer, this review could further the establishment of molecular level interaction of HPV in patients with oral cancer.