Human papillomavirus (HPV) infection in a case-control study of oral squamous cell carcinoma and its increasing trend in northeastern Thailand

Social determinants of sex disparities in cancer in Southeast Asia

Sex disparities in cancer exist along the cancer spectrum, ranging from genomic predisposition and behavioral risk factors to access to screening, diagnostics, treatment, and survivorship care. A growing body of research is studying the biological underpinnings of these differences, from cancer risk to tumor biology to treatment response. It is well known, however, that the social determinants of health play a large role across the cancer disease continuum, which encompasses risk, prevention, diagnosis, treatment, survivorship, rehabilitation, and palliative care. Less literature focuses on the gendered disparities that are epidemiologic in nature, especially in Southeast Asia (SEA), a diverse region that is home to nearly 670 million people, where most are lower middle income countries, and where socioeconomic and cultural factors increase cancer risk for women. In this review, we highlight the social drivers of gendered disparities, namely the geographic, environmental, sociocultural, economic, and political forces that contribute to the increased mortality and poorer health outcomes in the region.

Genetic diversity of human papillomavirus (HPV) as specified by the detection method, gender, and year of sampling: a retrospective cross-sectional study

PURPOSE

This study assesses HPV prevalence and genotype distribution in Lebanon, and identifies differentials in HPV infection, infection with multiple genotypes, and with high-risk genotypes, by sex, age, and year of data collection.

METHODS

Study participants comprised 1042 female and 160 male participants between 2006 and 2018. HPV genotyping was done by PCR and hybridization (2006-2013) or real-time PCR (2013 onwards). Diversity of HPV genotypes across gender, age groups, and years of data collection was tested by applying Shannon Diversity Index.

RESULTS

The overall HPV prevalence was 44.8% among study participants, and threefold higher in women than men. Single HPV infection was seen in two-third of HPV-positive participants. Women were less likely to be infected with multiple HPV strains, but more likely to be infected with high-risk or mixed-risk HPV genotypes. HPV-16 (11.0%, 9.8%) and HPV-53 (8.5%, 4.9%) were the most prevalent high-risk HPV genotypes in women and men, respectively, while HPV-18 prevalence was 4.9% in men and 3.1% in women, while HPV-59 prevalence was 6.6% in men and 2.1% in women. Samples collected post-2011 from women showed twice higher odds of HPV infection than those collected earlier and were threefold more likely to be infected with multiple HPV strains, and twice more likely to be infected with high-risk genotypes compared to those tested earlier. Women scored higher on Shannon index indicating high diversity in HPV types and frequency, with trend of increased diversity over time. While the odds of HPV infection remained associated with sex and temporal trend in multivariable analysis, odds of having high-risk genotypes was mainly associated with infection with multiple HPV strains.

CONCLUSION

Our study showed high diversity in HPV genotypes and an increasing trend of infection with multiple and high-risk genotypes in recent years. Findings underscore the need for effective screening/surveillance and HPV vaccination programs.

Epidemiological evidence and association of human papillomavirus with esophageal cancer in northeastern Thailand: a case-control study

Recently, epidemiological evidence of high-risk human papillomavirus (hrHPV) and its association with the increasing risk of esophageal cancer (EC) have been described. However, the involvement of such a virus in the pathogenesis of EC is still inconclusive in the literature. Therefore, our objective was to clarify the epidemiology of HPV infections in primarily diagnosed EC cases and validate this correlation with hospital-based control patients using a retrospective study with a case-control model. Here, we reported that the overall prevalence of HPV DNA was statistically associated with an increased risk of EC (OR, 3.3; 95% CI, 2.5-4.3). Interestingly, a history of gastroesophageal reflux disease (GERD) was constituted and significantly associated with HPV prevalence (adjusted OR, 4.6; 95% CI, 2.2-9.5). Furthermore, our meta-analysis in public databases also indicated that the combined OR and 95% CI between HPV infection and EC risk were 3.31 and 2.53-4.34, respectively, with significant heterogeneity (I₂ = 78%). Variations in the geographic study, tissue type, and detection method remain potential predictors of heterogeneity. In addition, publication bias and sensitivity analysis were not observed, and the results exhibited stable outcomes. Collectively, we specify the recent epidemiological evidence in a validation of the distributed HPV, which might be statistically associated with an increased risk of EC. However, additional high-quality studies with larger sample sizes are needed to further verify the link between HPV and EC.

Human Papillomavirus 16 E6 Suppresses Transporter Associated with Antigen-Processing Complex in Human Tongue Keratinocyte Cells by Activating Lymphotoxin Pathway

Simple Summary

There is still limited knowledge of the critical pathogenic processes by which HPV16 induces oral carcinogenesis. Therefore, we aimed to illuminate the oncogenic role of HPV16 in the context of oral squamous cell carcinomas (OSCCs). Using human tongue keratinocyte cells, we demonstrated that HPV16 E6 promotes LTα₁β₂ and LTβR expression, thus promoting the lymphotoxin signaling pathway and leading to suppression of the transporter associated with the antigen-processing complex (TAPs; TAP1 and TAP2). Additionally, in vitro, we also demonstrated regulation of the antigenic peptide-loaded machinery in HPV-infected OSCC tissues through analysis of the transcriptomic profiles of the head and neck squamous cell carcinoma (HNSCC) cohort from the TCGA database, which was validated using fresh biopsied specimens. Thus, our study enhances the proposed functional role of HPV16 E6-associated immune-evasive properties in oral epithelial cells, revealing a possible mechanism underlying the development of HPV-mediated OSCCs.

Abstract

Infection by high-risk human papillomaviruses (hrHPVs), including HPV type 16 (HPV16), is a major risk factor for oral squamous cell carcinomas (OSCCs). However, the pathogenic mechanism by which hrHPVs promote oral carcinogenesis remains to be elucidated. Here, we demonstrated that the suppression of a transporter associated with the antigen-processing complex (TAPs; TAP1 and TAP2), which is a key molecule in the transportation of viral antigenic peptides into MHC class-I cells, is affected by the E6 protein of HPV16. Mechanistically, HPV-mediated immune evasion is principally mediated via the signal-transduction network of a lymphotoxin (LT) pathway, in particular LTα₁β₂ and LTβR. Our analysis of transcriptomic data from an HNSCC cohort from the Cancer Genome Atlas (TCGA) indicated that expression of TAP genes, particularly TAP2, was downregulated in HPV-infected cases. We further demonstrated that LTα₁β₂ and LTβR were upregulated, which was negatively correlated with TAP1 and TAP2 expression in HPV-positive clinical OSCC samples. Taken together, our findings imply that HPV16 E6 regulates the machinery of the antigenic peptide-loading system and helps to clarify the role of oncogenic viruses in the context of oral carcinoma.

Epstein-Barr Virus Infection Alone or Jointly with Human Papillomavirus Associates with Down-Regulation of miR-145 in Oral Squamous-Cell Carcinoma

Down-regulation of tumor-suppressive miR-145 has been reported in various malignancies, including oral squamous-cell carcinoma (OSCC) that is influenced by several factors, including Epstein-Barr virus (EBV) and human papillomavirus (HPV). Oncoviruses can modulate the expression of cellular microRNAs. Therefore, we sought to investigate the association of miR-145 down-regulation in OSCC with EBV and/or HPV infection, which might be a possible mechanism of these viruses in oral carcinogenesis. Herein, prevalence of EBV, HPV, and their co-infection was significantly higher in tumors than normal tissues of OSCC. EBV infection alone or jointly with HPV was significantly associated with down-regulation of miR-145 in tumors compared with normal adjacent tissues. In cell lines infected with EBV or HPV, miR-145 was also down-regulated. Consistently, methylation of miR-145 was significantly greater in tumors, and well correlated with increased expression of DNMT3B, which was influenced by infection with EBV and HPV. In cell lines, only EBV infection was associated with increased expression of DNMT3B. Moreover, the level of EBV-LMP1 mRNA in tumors was negatively correlated with miR-145 and positively correlated with DNMT3B. Therefore, EBV alone or jointly with HPV is associated with down-regulation of miR-145 and may influence on miR-145 promoter methylation through the induction of DNMT3B in OSCC.

Detection of Human Papillomavirus and p16INK4a Expression in Thai Patients with Oral Squamous Cell Carcinoma

This study investigated the prevalence of human papillomavirus (HPV) infection in oral squamous cell carcinoma (OSCC) cases, as well as the association between HPV presence and p16^INK4a expression, in Thai patients with OSCC. Eighty-one formalin-fixed paraffin-embedded specimens of OSCC were obtained. DNA extraction was performed; this was followed by nested polymerase chain reaction analysis to determine HPV DNA status, using consensus primers for the L1 region of HPV. HPV subtypes were determined by DNA sequencing. HPV-positive specimens and HPV-negative specimens from age- and sex-matched patients were subjected to immunohistochemical analysis to determine p16^INK4a expression status. Of the 81 OSCC specimens, eight (9.9%) exhibited HPV DNA; DNA sequencing confirmed that the viral subtype was HPV-18 in all eight specimens. These eight HPV-positive specimens, as well as eight HPV-negative specimens from age- and sex-matched patients, were subjected to immunohistochemical analysis to determine p16^INK4a expression status. Three of eight (37.8%) HPV-positive specimens and three of eight (37.8%) HPV-negative specimens showed positive p16^INK4a expression findings. However, we did not find a significant association between HPV status and p16^INK4a expression status in our OSCC samples. In conclusion, the prevalence of high-risk HPV was low in this group of OSCC patients; no association between HPV status and p16^INK4a expression status was identified.

Human Papillomavirus 16 and 18 Infection in Oral Cancer in Thailand: A Multicenter Study

Objectives:

To identify the prevalence of high-risk human papillomavirus (HPV) genotypes 16 and 18 among patients with oral squamous cell carcinoma (OSCC) in Thailand and investigate the associations of p16 expression and HPV16/18 with the demographic, clinicopathologic, and risk parameters.

Materials and Methods:

A total of 403 formalin-fixed paraffin-embedded OSCC specimens from four centers in four regions were obtained. p16 expression was evaluated by immunohistochemistry. The detection of HPV16/18 DNA was performed by polymerase chain reaction.

Results:

Of all, 172 specimens (42.7%) were presented with amplifiable extracted DNA. Among these, 62.8% were positive for p16, 8.1% were positive for HPV16/18, and 5.8% were positive for both methods. Of all HPV-positive specimens, HPV18 was detected in 57.1%; HPV16 in 14.3%; and HPV16 and 18 (co-infection) in 28.6%. The prevalence of HPV16/18 varied between centers, with the highest rate in the northern center (20.0%). There was no significant correlation between p16 expression and HPV16/18. There were no significant associations of p16 expression and/or HPV16/18 with all variables.

Conclusions:

The prevalence of HPV16/18 infection in OSCC geographically varied in Thailand, with the highest rate in the northern region. Poor correlation between p16 and HPV16/18 suggests p16 not be used as a surrogate marker for HPV-positive OSCC.

Increasing prevalence of HPV in oropharyngeal carcinoma suggests adaptation of p16 screening in Southeast Asia

BACKGROUND

Human papillomavirus (HPV) is etiologically linked to increasing oropharyngeal squamous cell carcinoma (OPSCC) rates in the Western world. However, the role of HPV in Southeast Asia, a high incidence region, hasn't been assessed.

METHODS

96 formalin-fixed, paraffin-embedded (FFPE) tissue blocks and corresponding patient data were obtained from Srinagarind Hospital, Thailand from 2012-2017. DNA from areas of 70 %+ cellularity were genotyped using polymerase chain reaction (PCR) and stained for p16, a surrogate marker for HPV. Inverse probability weights based on data from the hospital-based cancer registry were used in statistical analyses. Adjusted linear regression was used to assess changes in OPSCC HPV prevalence and conduct projections. Kaplan-Meier and Cox proportional hazard models were used to determine HPV-specific survival differences.

RESULTS

14 patients exhibited monoinfection with HPV16, two with HPV18 and one was HPV16/18 coinfected. PCR results were in agreement with p16 staining. On average, HPV + patients were more likely to have tonsil cancer (p-value:0.002). HPV prevalence increased by 2% annually (pvalue: 0.01), from 16 % in 2012 to 26 % in 2017. At the current rate, OPSCC HPV positivity will exceed 50 % by 2030. HPV positivity was shown to be protective in Kaplan-Meier (log-rank p = 0.02) and sex, age and stage adjusted Cox models (HR:0.34 [95 %CI:0.22, 0.52]).

CONCLUSION

Given the increased prevalence and similarities in presentation of HPV + OPSCC to those observed in Western countries, the data suggest the adaptation of p16 staining and subsequent restaging of OPSCC tumors as suggested by the American Joint Committee on Cancer in Southeast Asia.

Temporal Changes in Head and Neck Cancer Incidence in Thailand Suggest Changing Oropharyngeal Epidemiology in the Region

PURPOSE

Head and neck cancer is the sixth most common cancer in the world, and the largest burden occurs in developing countries. Although the primary risk factors have been well characterized, little is known about temporal trends in head and neck cancer across Thailand.

METHODS

Head and neck squamous cell carcinoma (HNSCC) occurrences diagnosed between 1990 and 2014 were selected by International Classification of Diseases (10th revision; ICD10) code from the Songkhla, Lampang, Chiang Mai, and Khon Kaen cancer registries and the US SEER program for oral cavity (ICD10 codes 00, 03-06), tongue (ICD10 codes 01-02), pharynx (ICD10 codes 09-10, 12-14), and larynx (ICD10 code 32). The data were analyzed using R and Joinpoint regression software to determine age-standardized incidence rates and trends of annual percent change (APC). Incidence rates were standardized using the Segi (1960) population. Stratified linear regression models were conducted to assess temporal trends in early-onset HNSCC across 20-year age groups.

RESULTS

Although overall HNSCC rates are decreasing across all registries, subsite analyses demonstrate consistent decreases in both larynx and oral cavity cancers but suggest increases in tongue cancers among both sexes in the United States (APC_men, 2.36; APC_women, 0.77) and in pharyngeal cancer in Khon Kaen and US men (APC, 2.1 and 2.23, respectively). Age-stratified APC analyses to assess young-onset (< 60 years old) trends demonstrated increased incidence in tongue cancer in Thailand and the United States as well as in pharyngeal cancers in Khon Kaen men age 40 to 59 years and US men age 50 to 59 years.

CONCLUSION

Although overall trends in HNSCC are decreasing across both Thailand and the United States, there is reason to believe that the etiologic shift to oropharyngeal cancers in the United States may be occurring in Thailand.

Low prevalence of p16-positive HPV-related head-neck cancers in Thailand: tertiary referral center experience

Background

There has been a sharp rise in the incidence of human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) in many countries. Patients with HPV-positive OPSCC have a more favorable prognosis compared with HPV-negative OPSCC, leading to investigation and adoption of de-escalation treatment protocols. The baseline rate of HPV prevalence in certain populations is of epidemiologic significance. We aimed to evaluate the rate of high-risk HPV in a large cohort of Thai patients, including OPSCC, oral SCC (OSCC) and laryngeal SCC (LSCC).

Methods

In total, 504 patients with HN cancer (110 OPSCC, 260 OSCC and 134 LSCC) who had been treated in Chulalongkorn University between 2010 and 2016 formed the sample set. All histological slides were reviewed to validate the diagnosis and render the histological type as keratinizing (K), non-keratinizing (NK) or non-keratinizing with maturation (NK-M). Immunohistochemistry with p16 was performed in all cases and scored semiquantatively. Positive and equivocal cases were tested by the high-risk HPV DNA in situ hybridization (ISH). Validation with quantitative polymerase-chain reaction (qPCR) was performed in p16-positive OPSCC.

Results

The OPSCC were represented by NK (7.3%), NK-M (16.4%) and K (76.4%) types, with an HPV incidence of 100, 22.2 and 4.7%, respectively. The average HPV prevalence in OPSCC was 14.5%. The concordance with p16/ISH was 51.6%, while concordance of the NK morphology with positive HPV ISH was 100%. ISH-qPCR concordance in p16-positive OPSCC was 72.7%. Patients with HPV-positive OPSCC had significantly more tumors with a NK histologic type, tonsillar location, earlier clinical stage, less association with smoking, and, finally, better outcome and longer survival time. In non-OPSCC, p16-positive HPV-associated cancers were found in only 1.5% of OSCC (4/260) and LSCC (2/134).

Conclusion

A low rate of HPV-related OPSCC was found in Thai patients. The NK morphology was an excellent predictor of high-risk HPV infection in OPSCC. For OPSCC patients, HPV-positive ones had a significantly longer survival time than HPV-negative ones. There was a lack of p16-positive HPV-related OSCC and LSCC. Morphology and p16 status had a poor predictive value for detecting HPV in OSCC and LSCC.

Overall and disease-specific survival outcomes following primary surgery for oral squamous cell carcinoma: analysis of consecutive 67 patients

Objectives

This study evaluated the predictive factors for survival of patients with oral squamous cell carcinoma (OSCC) and investigated the overall and disease-specific survival (DSS) outcomes.

Materials and Methods

A total of 67 consecutive patients who underwent surgery for OSCC from January 2006 to November 2014 were included in this study. Patients were classified according to age, sex, pTNM stages, primary sites, smoking and alcohol drinking habits, depth of invasion, perineural and lymphovascular invasion, cell differentiation and postoperative radiotherapy. Kaplan-Meier methods were used to estimate the survival categorized by patient groups. Cox regression methods were used to investigate the main independent predictors of survival.

Results

Nineteen patients died of OSCC during follow-up periods. Another five patients died of other diseases including lung adenocarcinoma (n=1), cerebral infarction (n=1), general weakness (n=2), and pneumonia (n=1). The tongue (n=16) was the most common site for primary origin, followed by buccal mucosa (n=15), mandibular gingiva (n=15), maxillary gingiva (n=9), floor of mouth (n=9), retromolar trigone (n=2), and palate (n=1). Eleven patients had pTNM stage I disease, followed by stage II (n=22) and stage IV (n=34). No patients had pTNM stage III disease in this study. The overall survival of all patients was 64.2% and the DSS was 71.6%. DSS of patients with stage I and II disease was 100%. Stepwise Cox regression showed the two predictors for DSS were pTNM stage (P<0.0001, odds ratio=19.633) and presence of metastatic lymph nodes (P=0.0004, odds ratio=0.1039).

Conclusion

OSCC has been associated with poor prognosis; however, there were improved survival outcomes compared with past studies. Advanced-stage disease and presence of metastatic lymph nodes were associated with poorer survival compared with early-stage OSCC and absence of neck node metastasis. Stage I and II OSCC were associated with excellent survival results in this study.

Characteristics and impact of programmed death-ligand 1 expression, CD8+ tumor-infiltrating lymphocytes, and p16 status in head and neck squamous cell carcinoma

BACKGROUND

No predictive biomarker of immune checkpoint inhibitors in head and neck squamous cell carcinoma (HNSCC) has been well established. The impact of programmed death-ligand 1 (PD-L1) expression, CD8+ tumor-infiltrating lymphocytes (TILs), and p16 status in HNSCC is unclear and may vary according to ethnicity.

METHODS

HNSCC patients treated between 2007 and 2013 were reviewed. Archival tissues were retrieved for PD-L1, CD8+ TILs, and p16 analyses. PD-L1 expression was evaluated by using the validated SP142 assay on the VENTANA platform. CD8+ TILs were defined by using semiquantitative scoring.

RESULTS

A total of 203 patients were analyzed. PD-L1 expression was observed in 80% of patients and was significantly associated with older age (P < 0.001). A high CD8+ TIL score (≥ 6) was significantly associated with never-smoking (P = 0.020), oral cavity cancer (P < 0.001), and stage M0 at presentation (P = 0.025). The p16 status was positive in 12% of patients. Patients with a high TIL score had a significantly longer OS (P = 0.032). Patients with PD-L1 expression of 1-49% and ≥ 50% were associated with a significantly shorter OS compared with those with PD-L1 < 1% (P = 0.027 and P = 0.011, respectively). Multivariate analysis showed that PD-L1 ≥ 50% was significantly associated with a poor OS. (HR 2.98 [95% CI 1.2-7.39]; P = 0.019.) CONCLUSIONS: A high prevalence of PD-L1 expression was observed in HNSCC using the validated SP142 assay. PD-L1 expression was associated with older age, while highly PD-L1 expression (≥ 50%) was an independent prognostic factor for poor OS in anti-PD1/PD-L1 untreated HNSCC patients.

Prevalence of human papillomavirus in oral rinse samples from healthy individuals in northern Thailand

BACKGROUND

The incidence of oral cancers associated with human papillomavirus (HPV) has been increasing in recent years. Therefore, it is necessary to elucidate HPV prevalence in oral cells and exposure to risk factors in various age groups.

METHODS

Oral rinse samples from healthy individuals in northern Thailand were investigated for HPV prevalence and genotyped using the polymerase chain reaction (GP5+/6+ primers) and DNA sequencing of the PCR products.

RESULTS

Samples were collected from 594 participants between 4 and 60 years of age. HPV was detected in 3.7% of samples. The prevalence of HPV-positive cases was 8.6% in the 31-50 age group. HPV prevalence increased with age and was the highest (9.2%) in the 41-50 age group, but decreased (to 3%) in the 51-60 age group. Risk factors significantly associated with HPV-positive cases included alcohol consumption, coffee drinking, sexual activity, and having children. HPV 16 and 18 were common genotypes, especially in the 31-50 age group, and were associated with having sexual activity (odds ratio 19.0 [95% CI: 2.5-142.5]). At follow-up of some individuals in the 4-10 age group, a 9-year-old child was found to be positive for HPV18.

CONCLUSIONS

These results suggest that HPV can be acquired at a young age and the prevalence peaks in the middle age class among healthy individuals in northern Thailand, especially in the 31-50 age group.

Peroxiredoxin-2 and zinc-alpha-2-glycoprotein as potentially combined novel salivary biomarkers for early detection of oral squamous cell carcinoma using proteomic approaches

No effective screening method is available for oral squamous cell carcinoma (OSCC) that is recognized to influence by environmental factors as well as human papillomavirus (HPV) and Epstein-Barr virus (EBV). Therefore, we sought to identify salivary biomarkers for screening of OSCC with or without HPV and/or EBV infection. Saliva, lesion and oral exfoliated cells were collected from OSCC patients and cancer-free controls (CFCs) and grouped depending on their HPV- and EBV-infection status. Salivary protein was precipitated and subjected to 2-dimensional gel electrophoresis. Differential expression of proteins was identified by mass spectrometry and validated by Western blotting. Distinctive expression patterns of salivary proteins were detected in OSCC as compared with CFCs. Levels of peroxiredoxin-2 (PRDX-2) and zinc-alpha-2-glycoprotein (ZAG) were significantly up-regulated in OSCC cases (p<0.001) relative to CFCs. Similarly, these proteins were also up-regulated in lesion cells compared with oral exfoliated cells (p<0.001). However, the expression patterns of these proteins were not significantly influenced by patient histories (risk factors). In combination, these proteins yielded the highest discriminatory power (AUC=0.999), sensitivity (100%), and specificity (98.77%) in distinguishing the early stages of OSCC. The detection of PRDX-2 combining with ZAG protein could potentially be used as salivary biomarkers for early screening of OSCC.

SIGNIFICANCE

Our findings demonstrate a useful of combined detection of PRDX-2 and ZAG as a salivary biomarker for the early detection of OSCC.

Epidemiology of head and neck cancer in Thailand

Cancer is the most common cause of death in Thailand, with the mortality almost doubled during 1998-2011 (from 48.4 to 95.2 per 100 000). The estimated number of new cancer cases in 2011 was 112 392. Our review provides baseline data on the current epidemiological situation with head and neck (HN) cancer in Thailand based on reports of the National Cancer Registry and findings from local and international publications. Collectively, HN cancer approaches age-standardized rate (ASR) incidence of 15.7 and 10.7 per 100 000 males and females, respectively, and is ranked among the top five dominant cancers in Thailand. The leading HN malignancies in men are oral (ASR incidence 4.6 per 100 000), nasopharyngeal (ASR 2.8) and laryngeal (ASR 2.7) cancers, while the most common cancers in women are thyroid (ASR 5.1) and oral (ASR 3.2) carcinomas. Some local habits (betel quid chewing, traditional cigarette smoking and alcohol intake) are associated with the high incidence of oral cancer in Northeast Thailand. Despite important prognostic significance, the role of human papillomavirus infection in various HN cancers from Thailand has been scarcely addressed. There is a growing incidence of thyroid cancer over the last two decades. The Thai population overall, compared to worldwide rates of HN malignancies, has a lower incidence of laryngeal and thyroid cancers but higher incidence of nasopharyngeal cancer.