Detection of HPV-16 genome in human oral cancers and potentially malignant lesions from India

Prevalence of human papillomavirus in head and neck cancer patients in India: a systematic review and meta-analysis

BACKGROUND

Human papillomavirus (HPV) is increasingly recognized as a significant risk factor in the development of head and neck cancers (HNCs), with varying prevalence and impact. This study aims to systematically review and analyze the prevalence of HPV in HNCs in India, providing insights into regional variations.

METHODS

A comprehensive literature search was carried out using PubMed, Embase, and Web of Science up to November 10, 2023. Inclusion criteria focused on original research reporting HPV-positive cases among HNC patients in India. We used Nested-Knowledge software, for screening, and data extraction. The modified Newcastle-Ottawa Scale was used for quality assessment of included studies. We pooled the prevalence of HPV among HNC patients and performed a random-effects model meta-analysis using R software (version 4.3).

RESULTS

The search yielded 33 studies, encompassing 4654 HNC patients. The pooled prevalence of HPV infection was found to be 33% (95% CI: 25.8-42.6), with notable heterogeneity (I² = 95%). Analysis of subgroups according to geographical location indicated varying prevalence rates. Specifically, the prevalence was 47% (95% CI: 32.2-62.4) in the eastern regions and 19.8% (95% CI: 10.8-33.4) in the western regions. No evidence of publication bias was detected.

CONCLUSION

The observed considerable regional disparities on the prevalence of HPV in HNC patients in India emphasizes the need for integrated HPV vaccination and screening programs in public health strategies. The findings underline the necessity for further research to explore regional variations and treatment responses in HPV-associated HNCs, considering the impact of factors such as tobacco use and the potential benefits of HPV vaccination.

Evaluation of Oral Squamous Cell Carcinoma Patients Using Polymerase Chain Reaction Regarding the Prevalence of Human Papillomavirus Types 16 and 18

BACKGROUND

Epstein-Barr virus, human papillomavirus (HPV), and herpes simplex virus type 1 (HSV-1) are examples of viruses that have been associated with the development of oral squamous cell carcinoma (OSCC). These viruses can infect various epithelial tissues in the human body. The use of incredibly accurate cellular biology techniques, such as the polymerase chain reaction (PCR), which permits the rapid identification of viruses following infection, has increased. The parameters of human head and neck oncology have been widened.

AIM

In this study, using the PCR, the presence of HPV variants such as HPV 18 and HPV 16 in patients with OSCC was assessed.

MATERIALS AND METHODS

Tissue specimens were obtained from clinically presumed OSCC individuals taken as cases, and tissues from the retromolar region were obtained from people who experienced an operation for partially and completely impacted tooth and taken as controls. The study included 80 samples divided into two separate categories: case category (n = 40) = OSCC-diagnosed individuals; control category (n = 40) = controls with a comparable age. For verification of the diagnosis, a specimen of the tissue has been processed and sections have been stained and inspected for standard hematoxylin and eosin stain. Deoxyribonucleic acid (DNA) was extracted from the leftover histopathologically verified tissue specimens and then exposed to PCR for the assessment of HPV infiltration.

RESULTS

It was observed in this research that 22 cases out of 40 cases of OSCC were found positive for HPV-DNA. While 12 out of 40 age-matched healthy controls were found positive for HPV-DNA. Out of 40 cases of OSCC, 12 cases were found positive for HPV 16. While six out of 40 age-matched healthy controls were found positive for HPV 16. Six cases out of 40 cases of OSCC were found positive for HPV 16. While two out of 40 age-matched healthy controls were found positive for HPV 18. Four cases out of 40 cases of OSCC were found positive for HPV 16. While four out of 40 age-matched healthy controls were found positive for HPV 16 and HPV 18. On carrying out statistical analysis, the variation between the two categories was non-meaningful statistically (p = 0.662). However, the prevalence was greater in the case (OSCC) subgroup.

CONCLUSION

When evaluated against controls in the current investigation, OSCC cases had a greater level of HPV expression and a greater proportion of HPV 16 positives. However, there was no statistically noteworthy change.

Prevalence of novel gamma HPV types 223 and 225 in oral cavity and skin of Indian normal and neoplastic participants

Gamma-papillomaviruses, though traditionally classified as cutaneotropic, actual tissue tropism is largely unexplored. This study aimed to evaluate the tissue-specific prevalence of two novel-HPV 223 and 225 in samples of oral mucosa and keratinized epithelium of varied skin parts from 226 female and male subjects, with or without neoplastic/dysplastic lesions in oral cavity or cervix. The gamma-human papillomavirus (gamma-HPV) 223 and 225 DNA presences were determined by polymerase chain reaction (PCR) ursing the HPV type-specific primers and confirmed by Sanger sequencing. Viral load in the HPV 223 and HPV 225 positive samples were determined by absolute real-time quantification method. Alpha-HPV DNA prevalence was also checked in oral mucosa to ascertain coinfection status. Novel HPV 223 was present in 4.4% (10/226) oral mucosal samples of the study population; interestingly all were females with no prevalence in their corresponding skin swab samples. Whereas, the prevalence of HPV 225 was found both in the skin and oral mucosa of 28.2% (N = 37/131) female and 17.9% (N = 17/95) male participants. Alongside, HPV 223 viral load was found to be significantly higher (p = 0.02 < 0.05) in the oral mucosa of diseased participants, whereas, HPV 225 viral load was higher in the oral mucosa of normal participants. Our results suggest that gamma-HPV 223 has its prevalence only in the oral mucosal epithelium, whereas, HPV 225 has its prevalence on both mucosal and keratinized skin epithelium, indicating its dual tropism nature.

Status and Determinants of Early Detection of Oral Premalignant and Malignant Lesions in India

It has been over four decades since the launch of the National Cancer Control Programme in India, yet the cancer screening rates for oral cancer remain unremarkable. Moreover, India is bracing a large burden of oral cancer with poor survival rates. An effective public health programme implementation relies on a multitude of factors related to cost-effective evidence-based interventions, the healthcare delivery system, public health human resource management, community behaviour, partnership with stakeholders, identifying opportunities and political commitment. In this context, we discuss the various challenges in the early detection of oral premalignant and malignant lesions and potential solutions.

An Observational Study Depicting Role of p16 in Detecting Human Papilloma Virus in Oral and Oropharyngeal Cancer and Associated Factors

The longstanding phrase, traditional risk factors like-smoking, tobacco and alcohol are the only causative agents of oral and oropharyngeal squamous cell carcinoma (SCC) is changing now. Etiological divergence is taking place which we have to know to reach upon an exact cause of the disease. Human papilloma virus (HPV) infection is a well-established cause of oral cancer. Escalating incidence of HPV associated cancer has a strong impact on its management. So, a concern clinician needs to get aware for it. Among various types of HPV, HPV-16 is more frequently associated with oral cancers. HPV detection will become a game changer in management of oral cancers. HPV infection and p16 protein expression has a strong and consistent correlation. Therefore, immunohistochemical analysis of p16 protein can be a surrogate biomarker in high risk groups. This hospital based prospective observational study recruited 180 subjects of oral and oropharyngeal SCC. We underwent immunohistochemical analysis of p16 in biopsy specimen of subjects and studied HPV status and associated environmental, clinical and behavioral factors. We observed 9.4% (17/180) incidence of p16 positivity with female predominance. Our observations showed that its prevalence was higher in urban patients who were non tobacco users, had sexually transmitted disease, early stage (T1-T2), poorly differentiated SCC with nodal metastasis. We conclude that keeping in mind HPV as a cause of oral and oropharyngeal SCC, p16 should be use as a biomarker for its detection in high risk cases.

Detection of human papillomavirus infection in oral cancers reported at dental facility: assessing the utility of FFPE tissues

Incidence of human papillomavirus (HPV)-associated oral cancers is on the rise. However, epidemiological data of this subset of cancers are limited. Dental hospital poses a unique advantage in detection of HPV-positive oral malignancies. We assessed the utility of formalin-fixed paraffin-embedded (FFPE) tissues, which are readily available, for evaluation of high-risk HPV infection in oral cancer. For protocol standardization, we used 20 prospectively collected paired FFPE and fresh tissues of histopathologically confirmed oral cancer cases reported in Oral Medicine department of a dental hospital for comparative study. Only short PCRs (~ 200 bp) of DNA isolated using a modified xylene-free method displayed a concordant HPV result. For HPV analysis, we used additional 30 retrospectively collected FFPE tissues. DNA isolated from these specimens showed an overall 23.4% (11/47) HPV positivity with detection of HPV18. Comparison of HPV positivity from dental hospital FFPE specimens with overall HPV positivity of freshly collected oral cancer specimens (n = 55) from three cancer care hospitals of the same region showed notable difference (12.7%; 7/55). Further, cancer hospital specimens showed HPV16 positivity and displayed a characteristic difference in reported sub-sites and patient spectrum. Overall, using a xylene-free FFPE DNA isolation method clubbed with short amplicon PCR, we showed detection of HPV-positive oral cancer in dental hospitals.

Efficacy of Diode Laser in Treating Oral Papilloma: A Case Report

Background:

Oral squamous papilloma is the most common lesion caused by the Human Papillomavirus (HPV). They are benign proliferation, often painless, and with cauliflower or verrucous appearance.

Objective:

The aim of this report is to describe a clinical case of oral squamous papilloma and its treatment with a high-intensity diode laser.

Case Presentation:

A 65-year-old female patient sought care at the Special Laboratory of Lasers in Dentistry (LELO), University of São Paulo, Brazil, complaining of growth of a soft tissue mass in the jugal mucosa. Based on these clinical characteristics and history, Papilloma was the initial clinical diagnosis of the lesion. Although the lesion was small in size, measuring approximately 0.5 cm, the diagnostic method used was biopsy, and for treatment, a high-intensity diode laser at a wavelength of 980 nm was used.

Conclusion:

It can be concluded that Laser Therapy can be used by dental clinicians to treat these kinds of oral lesions and should be considered as an effective alternative to conventional surgery.

The prevalence and clinicopathological correlation of human papillomavirus in head and neck squamous cell carcinoma in India: A systematic review article

OBJECTIVE

Head and neck squamous cell carcinoma (HNSCC) pose a great danger to society and now we have shreds of evidence for Human Papillomavirus (HPV) being one of the major causative agents for it. Though the prevalence of HPV varies throughout the world, it is gradually on the rise. The present systematic review aims to retrospect all the available studies on the prevalence of HPV in HNSCC in India and its clinicopathological aspect to study how it is different from HPV negative HNSCC.

METHODS

An objective electronic database search was conducted in PUBMED Central, MeSH, NLM Catalog, Bookshelf, and PUBMED published in 25 years period from 1994 till 2019. A total of 33 articles were shortlisted for the present review.

RESULTS

Studies conducted across India show the prevalence of HPV in Head and Neck Cancers ranging from 0-86.6%. Some studies reported that HPV positive HNSCC is more common in younger age, presents with advanced stage disease, and more commonly presents with nodal metastasis. As opposed to western literature HPV positive HNSCC in India is associated with a well-differentiated tumor grade. There is no difference in treatment outcome and survival among HPV positive and negative HNSCC.

CONCLUSION

Exact prevalence of HPV in HNSCC is still doubtful but now we have some insight into it. The prevalence of HPV in Indian HNSCC patients has risen gradually but treatment outcome and survival may be poorer compared to other countries. However definite conclusions cannot be drawn without proper prospective study.

Association of Human Papillomavirus With Oral Lichen Planus and Oral Leukoplakia: A Meta-analysis

OBJECTIVES

To estimate the association of human papillomavirus (HPV) infection with oral lichen planus (OLP) and oral leukoplakia (OLK), and determine risk cofactors.

STUDY DESIGN

Seven databases were searched for case-control or cross-sectional studies of OLP and OLK with healthy controls, published between 1976 and 2020. The Meta package of R software was applied to calculate the pooled odds ratios (OR) and 95% confidence interval (CI).

RESULTS

Thirty-six articles were finally included. OLP and OLK cases had a higher association with HPV infection than controls (OLP: OR: 4.91, 95% CI: 2.76-8.72; OLK: OR: 2.51, 95% CI: 1.55-4.07). In subgroup analyses, the OR of HPV infection was higher with erosive lesions than with nonerosive lesions (OLP: OR: 5.36 and 3.47, respectively; OLK: OR: 3.34 and 3.21, respectively). Oral lesions were more strongly associated with HPV16/18 than with HPV6/11 (OLP: OR: 7.84 and 1.42, respectively; OLK: OR: 6.05 and 1.87, respectively) and varied by geographic region (OLP: OR: 4.01-7.02; OLK: OR: 1.46-27.13).

CONCLUSIONS

Oral HPV infection, particularly infection with HPV 16/18, was strongly associated with OLP and OLK. Risk cofactors included erosive lesions and geographic region.

Clinical and Histopathological Correlation of p16 and p53 Expression in Oral Cancer

p16 is overexpressed in oral squamous cell carcinoma patients who are positive for human papilloma virus. The p53 tumor suppressor gene is commonly mutated in human cancer. The aim is to correlate clinical and pathological features with p16 and p53 expression. This is a prospective, observational study of 50 consecutive cases (43 males and 7 females) who underwent surgery for oral cancer. p16 and p53 were determined by immunohistological staining. The results were obtained and analyzed using chi-square test (Statistical Software SPSS 21.0 version); p value ≤ 0.05 was considered significant. Of the 50 cases, p16 and p53 were overexpressed in 30% and 54% of patients, respectively. Overexpression of p16 was not significantly associated with age, subsites of oral cavity, or degree of differentiation. However, smokeless tobacco was significantly associated with p16 expression (p = 0.012). Similarly, overexpression of p53 was not correlated with age, subsites of oral cavity, or degree of differentiation. Seventy-five percent of poorly differentiated cancers had overexpression of p53 though this did not reach statistical significance (p = 0.279). p53 was overexpressed in smokers (80.95%) and those consuming alcohol (60%).

Are Histomorphological Features Predictive of p16 Immunopositivity Different for Oral and Oropharyngeal Squamous Cell Carcinoma?

Evidence from current studies show that squamous cell carcinomas at oral and oropharyngeal sites are distinct and unique, with their own separate etiopathogenesis, treatment, and prognosis. The aim of this work is to correlate p16 immunohistochemical expression with histomorphological features suggestive of HPV infection in oral and oropharyngeal squamous cell carcinoma. A total of 50 consecutive biopsy cases of oral squamous cell carcinoma (OSCC) and 50 consecutive biopsy cases of oropharyngeal squamous cell carcinoma (OPSCC) were evaluated for features suggestive of HPV infection like focal basaloid appearance, nests, and lobules of tumor cells with pushing borders, absence of stromal reaction, central necrosis, focal lymphoepithelial morphology, presence of koilocytes, and non-keratinizing or hybrid morphology. Immunostaining was performed using p16 monoclonal antibody (clone mouse 16P04). Only cases showing a moderate (2+) to high intensity (3+) staining in more than 75% cells were taken as p16 immunopositive. The histological features were correlated with p16 immunopositivity. A total of 18/50 (36%) cases of oral squamous cell carcinoma and 27/50 (54%) cases of oropharyngeal squamous cell carcinoma were p16 immunopositive. On statistical analysis, only nests/lobules with pushing borders were found to have a significant correlation with p16 immunopositivity (P value = 0.0012) for OSCC cases. For OPSCC cases, four histological features namely nests and lobules with pushing borders (P value = 0.0001), focal basaloid appearance (P value = 0.0041), lymphoepithelial morphology (P value = 0.0029), and non-keratinizing/hybrid morphology (P value = 0.0141) had a significant correlation with p16 immunopositivity. Histomorphological features are more helpful in predicting p16 immunopositivity in OPSCC than OSCC.

Assessing the nature of the association of human papillomavirus in oral cancer with and without known risk factors

Background

Published studies assessing the association of human papillomavirus (HPV) and oral cancer, often include cases with additional confounders such as alcohol, tobacco, thus, precluding the assessment of HPV as a independent risk factor. Further apart from eliciting the mere presence of HPV, it is vital that the nature of the association is delineated for eliciting a causal inference. Thus, the present study assessed the presence and nature of the association of HPV in oral cancer cases with and without known risk factors.

Methods

The study compares the prevalence of HPV in oral cancer cases with known risk factors (group 1, n=15) to oral cancer (group 2, n=15) and oral epithelial dysplasia (group 3, n=15) cases with no known risk factors using PCR. Cases which are positive for HPV were subjected to p16 and p53 immunostaining to determine potential causal inference.

Results

HPV 16 was detected in only 1 case of group I, 3 cases of group II, and was absent in group III. HPV 18 was negative in all the 3 groups. All the HPV positive cases were negative for p16 and positive for p53 immunostaining.

Conclusions

Only a minor proportion of oral cancer cases without risk factors were positive for HPV 16. Even among these HPV 16 positive cases, the immunostaining profile (p53 positive and p16 negative) excludes the involvement of E6 and E7 mediated carcinogenesis. Thus even the weak HPV association noted in the present study cases may not be of causal nature.

Human Papillomavirus Detection in Oropharyngeal Squamous Cell Carcinoma Using p16 Immunohistochemistry

Introduction:

Oral cancer ranks third among all cancers in the Indian population with approximately 45% of call cancer cases in India being diagnosed as oral cancer, among which 20%–50% of the cases are observed to be associated with human papillomavirus (HPV) infection.

Aim:

This study aims to detect and evaluate the presence of p16 in oropharyngeal squamous cell carcinoma (OPSCC) patients using immunohistochemistry (IHC).

Materials and Methods:

This study was based on samples collected from 21 patients with primary OPSCC who were diagnosed and treated during the period of December 2017–March 2018. Inclusion criteria were complete clinicopathologic data, adequate clinical follow-up, and availability of sufficient paraffin-embedded tumor material. HPV immunoreactivity was further investigated by means of IHC using p16 as a marker.

Results:

IHC results revealed p16 positivity in six OPSCC cases. There was no statistically significant association of the p16 positivity of HPV with the age, gender, or site.

Conclusion:

Our results suggest that IHC-based detection of p16 provides a suboptimal prognostic information if not combined with detection of HPV DNA. Although p16 expression and HPV DNA infection are correlated with HPV-associated OPSCCs, neither of the tests alone is the optimal method for HPV status detection.

p16 as an independent marker for detection of high-risk HPV in oral submucous fibrosis and oral squamous cell carcinoma

Background

An alarming increase in incidence of high-risk human papillomavirus (HPV) positive tumors in head and neck squamous cell carcinoma (HNSCC) by 25% and 70% in oropharyngeal HNSCC cannot be ignored. The early oncogenes of HPV, E6, and E7 play a key role in carcinogenesis. HPV associated tumors have a better clinical outcome and a favorable prognosis. The p16 expression has high concordance with other methods of HPV detection, ascertaining p16 as a surrogate marker for HPV.

Objective

To assess the immunohistochemical expression of p16 in oral submucous fibrosis (OSF) and oral squamous cell carcinoma (OSCC) with and without coexistent OSF as a marker for high-risk HPV detection. Materials and.

Methods

Tissue blocks of 70 cases including normal, OSF, OSCC with and without OSF were subjected to IHC staining with a p16^INK4A monoclonal antibody. (Biogenex, San Roman). The p16 expression was noted according to percent positivity and pattern. The data were tabulated, statistically analyzed using the Chi-square test and the P value was assessed.

Results

The percentage of p16 positive cells raised from normal to OSF to OSCC with and without OSF. In addition, a shift from nuclear to cytoplasmic expression from normal to OSCC was noted with a statistical significance (P < 0.001). However, no statistical significance was established with any clinicopathologic parameters except age (P = 0.012) and habits (P= 0.023).

Conclusion

The presence of HPV using p16 was not detected in OSF but was positive in OSCC. Altered pattern of expression from normal to OSF to OSCC indicates promising use of p16 as a diagnostic marker.

Human Papillomavirus Detection in Head and Neck Squamous Cell Carcinomas at a Tertiary Hospital in Sub-Saharan Africa

Fewer studies have been done over the years to establish the association of human papillomavirus (HPV) with head and neck squamous cell carcinoma (HNSSC) within the subregions of sub-Saharan Africa, and thus this study was designed to investigate the presence of HPV in HNSCC at a tertiary hospital in Ghana, providing additional evidence on the need to explore similar studies in other subregions. A retrospective cross-sectional study was employed to investigate the presence of the DNA of HPV genotypes in HNSCC archived tissue. A total of 100 HNSCC cases were classified as suitable for HPV genotyping. HPV-DNA was detected in 18% of the HNSCC cases, with 17 being HPV-16 and 1 dual infection with HPV-16 and HPV-18. HPV was prevalent in 50% of oropharyngeal cancers, 27% of laryngeal cancers, and 23% of oral cavity cancers. HPV E6/E7 oncogenic DNA was found in 18% of the HNSCC cases, with HPV-16 being the predominant genotype present. The pattern of HPV association was similar to earlier reported studies, recording a higher prevalence in oropharyngeal cancers, followed by laryngeal cancers and oral cavity cancers.

Detection of High-Risk Human Papillomavirus in Oral Cavity Squamous Cell Carcinoma Using Multiple Analytes and Their Role in Patient Survival

PURPOSE

Accurate detection of human papillomavirus (HPV) in oral cavity squamous cell carcinoma (OSCC) is essential to understanding the role of HPV in disease prognosis and management of patients. We used different analytes and methods to understand the true prevalence of HPV in a cohort of patients with OSCC with different molecular backgrounds, and we correlated HPV data with patient survival.

METHODS

We integrated data from multiple analytes (HPV DNA, HPV RNA, and p16), assays (immunohistochemistry, polymerase chain reaction [PCR], quantitative PCR [qPCR], and digital PCR), and molecular changes (somatic mutations and DNA methylation) from 153 patients with OSCC to correlate p16 expression, HPV DNA, and HPV RNA with HPV incidence and patient survival.

RESULTS

High prevalence (33% to 58%) of HPV16/18 DNA did not correlate with the presence of transcriptionally active viral genomes (15%) in tumors. Eighteen percent of the tumors were p16 positive and only 6% were both HPV DNA and HPV RNA positive. Most tumors with relatively high copy number HPV DNA and/or HPV RNA, but not with HPV DNA alone (irrespective of copy number), were wild-type for TP53 and CASP8 genes. In our study, p16 protein, HPV DNA, and HPV RNA, either alone or in combination, did not correlate with patient survival. Nine HPV-associated genes stratified the virus-positive from the virus-negative tumor group with high confidence ( P < .008) when HPV DNA copy number and/or HPV RNA were considered to define HPV positivity, and not HPV DNA alone, irrespective of copy number ( P < .2).

CONCLUSION

In OSCC, the presence of both HPV RNA and p16 is rare. HPV DNA alone is not an accurate measure of HPV positivity and therefore may not be informative. HPV DNA, HPV RNA, and p16 do not correlate with patients' outcome.

A study to assess expression of human papillomavirus types 16 and 18 in oral squamous cell carcinoma using polymerase chain reaction

Objective:

The diverse subset of oral squamous cell carcinoma (OSCC) with different clinical appearance and outcome, independent of traditional risk factors has led to increasing attention in human papillomavirus (HPV) infection.

Materials and Methods:

The investigation followed a case–control design. Information pertaining to the subjects was retrieved from hospital records. Twenty cases of OSCC and twenty age-matched controls were analyzed to ascertain the prevalence of HPV types 16 and 18. DNA was extracted from the blocks of formalin-fixed paraffin embedded tissues, and HPV-DNA was amplified using HPV type-specific primers by polymerase chain reaction (PCR) method. Data analysis was carried out using Chi-square test.

Results:

HPV-DNA was detected in 55% of cases (11/20; HPV 16 = 6, HPV 18 = 3 and HPV 16 and 18 = 2) and 30% of controls (6/20; HPV 16 = 3, HPV 18 = 1 and HPV 16 and 18 = 2) indicating higher percentage of HPV presence among OSCC cases. No significant association was found between the presence of HPV and gender, age, site and grade of differentiation of OSCC.

Conclusion:

Although the presence of HPV was higher in cases compared to controls, none of these differences were statistically significant. HPV 16 and 18 are commonly found in normal oral mucosa mandating the need for distinguishing clinical, subclinical and latent HPV infections.

Expression of p-16, Ki-67 and p-53 markers in dysplastic and malignant lesions of the oral cavity and oropharynx

Background:

Understanding the markers for predicting degree of dysplasia and progression to malignancy can help early identification and prompt treatment of patients with oral cancers. In this study, we aim to identify and characterize different tumor suppressor genes such as p-53 and p-16 and proliferation marker Ki-67 in defining stages of dysplasia of oral mucosa and grading of tumor.

Settings and Design:

Oral biopsy tissues (for neoplastic lesions) received for histopathological evaluation were included in the study. The sections were processed for H&E staining, and 112 cases were chosen for immunohistochemical study. The data were analyzed by Chi-square and z-tests using software SPSS.

Results:

We found significant correlation between degree of dysplasia and p-16 immunoexpression with 16.7% of cases showing positivity in oral intraepithelial neoplasia (OIN) I cases as compared to 25% in OIN II and 77.8% in OIN III. Ki-67 immunoexpression correlated significantly with both histological type and grade of tumor with increased expression and intensity seen in malignant cases (66.3%) as compared to benign (10%) and premalignant cases (37%) and higher Ki-67 immunoexpression in poorly differentiated tumors (75%) than well-differentiated tumors (12.2%). Regarding p-53 immunoexpression, positive staining was seen in only malignant cases and premalignant cases.

Conclusions:

Ki-67 and p-16 can be useful as a marker of degree of dysplasia and transformation to malignancy. Ki-67 can also serve as a marker of degree of differentiation of tumors. Hence, they can serve as important ancillary markers to analyze the transition to carcinoma, dysplasia and progression of tumor.

Reviewing the role of human papillomavirus in oral cancer using the Bradford Hill criteria of causation

Human papillomavirus is a well-established risk factor for oropharyngeal cancer, although its role in oral cancer is still debated. Inconclusive evidence of its role in oral cancer is due to conflicting data arising from methodological differences, mostly due to the use of diagnostic tests with varying sensitivity and specificity. In addition, there is a lack of experimental data linking HPV to oral cancer. Recent epidemiological studies provide data on HPV prevalence in oral squamous cell carcinoma and other potentially malignant oral disorders. Further, molecular data from in vivo and in vitro models have led to new insights into the role of human papillomavirus in oral cancer. The clinical significance of identifying HPV as an etiology for oral squamous cell carcinoma is that if proven, vaccination could be an effective prevention tool. Further, like oropharyngeal squamous cell carcinoma, prognostic differences may exist between human papillomavirus positive and negative oral squamous cell carcinoma. This manuscript reviews data from the published literature using Bradford Hill criteria of causation to assess the role of human papillomavirus in oral cancer. Due to the advancement in molecular biology, the requirements of each of the Bradford Hill criteria of causation are modified to include integrated data from both epidemiological studies and experimental studies exploring molecular carcinogenesis.

Prevalence and Impact of Human Papillomavirus on Head and Neck Cancers: Review of Indian Studies

Human papillomavirus (HPV) is an important emerging etiology for head and neck cancers (HNCs) worldwide. Considering its impact on prognosis, it is important to understand the true prevalence of HPV-associated HNCs in India. This article reviews the prevalence of HPV-related HNCs across various studies in India where the population is predominantly tobacco users, and studies its outcomes with respect to HPV.

Prevalence of HPV in Oral Squamous Cell Carcinoma in South West India

There are inconsistent reports regarding the role of HPV in the origin and progression of oral squamous cell carcinoma (OSCC). The observed heterogeneity was mainly attributed to the social and cultural habits of the enrolled cases, discrepancies in the nature of samples procured and varying sensitivity of the assays employed for detection of HPV. The objective of this study was to assess the prevalence of HPV in OSCC in South West India. This was a cross sectional study conducted over a period extending from October 2015 to June 2017. This study involved Department of ENT-Head and Neck Surgery and Department of Virology, Manipal Academy of Higher Education. Fifty histologically confirmed oral squamous cell carcinoma patients undergoing wide local excision of the tumour were enrolled for the study. Intraoperatively 4-5 mm of tissue samples were transported in sterile normal saline at 4-80 °C. The primary screening of tissue samples was performed by nested PCR using PGMY09/11 consensus primers and GP5+/6+ consensus primers and TaqMan based real time multiplex PCR for HPV-16, HPV-18, HPV-31 and HPV-45. All samples tested negative for HPV DNA by conventional nested PCR and TaqMan based real-time Multiplex PCR ruling out four common HPV subtypes such as HPV-16, 18, 31, 45. We did not find presence of HPV DNA in the tissues of patients with OSCC from southwest India. However, studies with more geographic representation from other parts of India are required before generalising our findings.

Detection of Human Papilloma Virus and Risk Factors among Patients with Head and Neck Squamous Cell Carcinoma Attending a Tertiary Referral Centre in South India

Background:

Head and Neck Squamous Cell Carcinomas (HNSCC) is the sixth most common cancer globally. In India, on an average 25-30% of all cancer cases affect the head and neck. The etiological factors associated with HNSCC are tobacco, alcohol and environmental carcinogens. However there are few cases, where there are no obvious risk factors involved. In western counties, there are many reports of human papilloma virus (HPV) association with HNSCC. Hence, we conducted a study to determine the role of HPV infection and risk factors among patients with HNSCC.

Materials and Methods:

A prospective, cross-sectional study was conducted in a tertiary referral centre from January 2014 to March 2016. 88 patients were enrolled in the study. Socio- demographic, behavioural data, site and subsite involvement, histopathology, staging and treatment were documented. Polymerase chain reaction (PCR) was performed to detect the presence of HPV DNA using consensus primers MY 09/11 and GP5+/GP6+ and further the samples were subjected to PCR for detecting HPV type 16 and 18.

Results:

The study included 88 participants with HNSCC. 57 had oral and oropharyngeal squamous cell carcinoma, 11 with laryngeal malignancy and 20 involving hypopharynx. Among the participants buccal mucosa (n=22) was the most common subsite involved, majority (50%) had moderately differentiated squamous cell carcinoma and 53.4% presented in stage IV. 2 (2.6%) cases were positive for HPV consensus and both were positive for HPV 16, one case each in larynx and hypopharynx. There was statistical significance in the association between betel nut chewing, cigarette smoking and alcohol intake as risk factors in the carcinogenesis of HNSCC.

Conclusion:

In our setting in South India, HPV does not play a major role in the carcinogenesis of HNSCC but betel nut chewing, tobacco exposure and alcohol consumption remain major risk factors for HNSCC.

Microenvironmental regulation of the progression of oral potentially malignant disorders towards malignancy

Oral potentially malignant disorders (OPMD) develop in a complex tissue microenvironment where they grow sustainably, acquiring oral squamous cell carcinoma (OSCC) characteristics. The malignant tumor depends on interactions with the surrounding microenvironment to achieve loco-regional invasion and distant metastases. Unlike abnormal cells, the multiple cell types in the tissue microenvironment are relatively stable at the genomic level and, thus, become therapeutic targets with lower risk of resistance, decreasing the risk of OPMD acquiring cancer characteristics and carcinoma recurrence. However, deciding how to disrupt the OPMD and OSCC microenvironments is itself a daunting challenge, since their microenvironments present opposite capacities, resulting in diverse consequences. Furthermore, recent studies revealed that tumor-associated immune cells also participate in the process of differentiation from OPMD to OSCC, suggesting that reeducating stromal cells may be a new strategy to prevent OPMD from acquiring OSCC characteristics and to treat OSCC. In this review, we discuss the characteristics of the microenvironment of OPMD and OSCC as well as new therapeutic strategies.

Human papillomavirus in head and neck cancer in India: Current status and consensus recommendations

Human papillomavirus (HPV) associated head and neck squamous cell cancers (HNSCC) have become increasingly common in the West, but the same cannot be said about India. These cancers have a different biology and confer a better prognosis, however, its current role in the management of patients in India is not clearly defined. At the 35th Indian Cooperative Oncology Network conference held in September 2016, a panel of radiation, surgical and medical oncologists, pathologists, and basic scientists from across the country having experience in clinical research with respect to HPV in HNSCC reviewed the available literature from India. All the ideas and facts were thereafter collated in this report. Various topics of controversy in dealing with the diagnosis and management of HPV-associated HNSCC have been highlighted in this report in context to the Indian scenario. Furthermore, the prevalence of the same and its association with tobacco and high-risk sexual behavior has been touched on. Conclusively, a set of recommendations has been proposed by the panel to guide the practicing oncologists of the country while dealing with HPV-associated HNSCC.

Human papilloma virus (HPV) infection leads to the development of head and neck lesions but offers better prognosis in malignant Indian patients

Head and neck cancers constitute a multifactorial global disease burden and are associated with human papilloma virus (HPV) as a possible risk factor. The aim of the study is to understand the relationship between HPV and the development of head and neck lesions in Indian patients. To this end, frequency of HPV was assessed in relation to different demographic and etiological features and correlated with patient survival. The prevalence of HPV significantly increased from mild dysplastic lesions (43.6%) to head and neck squamous cell carcinoma (HNSCC) stage IV (68.5%) with HPV 16 being pre-dominant in both dysplasia (43.8%) and HNSCC (61.5%). Similar trend was observed in increasing grades of the tumour. In invasive lesions, patients aged below the median age of onset showed significantly higher occurrence of HPV than those above it. Patients harbouring HPV showed a significantly better survival irrespective of age of onset. Likewise, better survival was observed in tobacco habit negative/HPV-positive patients, and as reflected in both univariate and multivariate analysis. Majority of the HPV 16-positive samples showed moderate/high nuclear expression of HPV E6 and E7 proteins in tumours and respective basal layer of adjacent normal tissues. Thus, our data indicate that frequent HPV infection, along with tobacco habit, is a pre-requisite factor for the development of HNSCC of Indian patients but offers a better survival even during tobacco usage, implicating its diagnostic and prognostic importance.

Do Human Papilloma Viruses Play Any Role in Oral Squamous Cell Carcinoma in North Indians?

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy among males in India. While tobacco and alcohol are main aetiological factors, human papilloma virus (HPV) presence has surprisingly increased in head and neck Squamous Cell Carcinoma (HNSCC) in the past two decade but its frequency in OSCCS is still uncertain. We aim to explore the frequency of HPV and its major genotypes in North Indian patients and their association with clinicopathological and histopathological features and p16 expression pattern.

MATERIALS AND METHODS

The study group comprised 250 histologically proven cases of OSCC. HPV was detected by real time PCR in tumor biopsy specimens and confirmed by conventional PCR with PGMY09/ PGMY11 primers. Genotyping for high-risk types 16/ 18 was conducted by type specific PCR. p16 expression was assessed by immunohistochemsitry.

RESULTS

HPV presence was confirmed in 23/250 (9.2%) OSCC cases, of which 30.4% had HPV 16 infection, 17.4%were positive for HPV 18 and 26.1% had co-infections. HPV presence was significantly associated with male gender (p=0.02) and habit of pan masala chewing (p=0.01). HPV positive cases also had a history of tobacco consumption in 91.3% cases. p16 over expression was observed in 39.1% of HPV positive cases but this was not significantly different from negative cases (p=0.54).

CONCLUSIONS

The frequency of HPV in OSCC is low in North-India and majority of cases are associated with a tobacco habit. It appears that tobacco shows a confounding effect in HPV positive cases and use of p16 protein as a reliable marker to assess the potential etiological role of HPV in OSCC in our population is not suggested.

Gene polymorphisms and oral cancer risk in tobacco habitués

Oral cancer incidence of 77,003 poses a major health concern in India, with 5-10 % tobacco habitués developing oral cancer. The current study examined the role of specific genomic variants in oral cancer. We examined five genomic variants represented as single nucleotide polymorphisms (SNPs) in genes associated with cell proliferation and cellular invasion. The SNPs rs2124437 (RASGRP3), rs1335022 (GRIK2), rs4512367 (PREX2), rs4748011 (CCDC3), and rs1435218 (LNX1) were analyzed in 500 histopathologically confirmed oral cancers and 500 healthy controls with a minimum of 10 years of tobacco usage. Allelic discrimination real-time PCR SYBR Green assay was used. The genotypic and allelic frequencies between cases and controls were analyzed using SPSS software (version 19) and odds ratio (OR) using Hutchon.net, indicating increased risk to oral cancers. A significant association of the SNPs in oral cancer was observed in RASGRP3 AA (rs2124437) (p < 0.000, OR 1.34, 95 % confidence interval (CI) 1.01-1.76), GRIK2 TT (rs1335022) (p = 0.008, OR 1.58, 95 % CI 1.23-2.03), PREX2 CC (p = 0.008, OR 1.56, 95 % CI 1.15-2.1), and TT (p < 0.000, OR 2.77, 1.68-4.57) genotypes, whereas the heterozygous genotypes showed higher frequencies in controls, i.e., GRIK2 CT (rs1335022) (p = 0.029, OR 0.68, 95 % CI 0.53-0.87) and PREX2 CT (p = 0.004, OR 0.49, 95 % CI 0.37-0.64), indicating protection. Coinheritance of the SNPs was associated with further increase in the risk. Thus, the SNP genotypes in the three genes, present singly or as a coinherited panel constituted "Predictive Biomarkers" indicating increased risk of oral cancer in tobacco habitués.

HPV-associated head and neck cancers in the Asia Pacific: A critical literature review & meta-analysis

BACKGROUND

Malignancies of the upper aero-digestive tract are a major public health problem, especially in the Asia Pacific. Certain Human papillomaviruses (HPVs) are well-established risk factors for carcinoma of the uterine cervix and for a subset of head and neck carcinomata: however their true importance in different populations and anatomical subsites remains unclear. The major risk factors in Asia Pacific remain smoked/smokeless tobacco, areca nut, alcohol abuse and poor diet, with limited evidence for HPVs. We review published studies of association of HPV with anatomical site-specific Head & Neck Squamous Cell Carcinoma (HNSCC) in these populations and attempt a meta-analysis.

MATERIALS AND METHODS

From MEDLINE/PubMed/WEB-of SCIENCE/EMBASE/Scopus databases we found 67 relevant studies with a total of 7280 cases: 15 case-control studies met our inclusion criteria for meta-analysis, totaling 1106 cases & 638 controls. HPV detection rates, sample site and size, and methods of tissue preservation and HPV detection were tabulated for each study.

RESULTS

Studies were heterogeneous in terms of sample selection and method of detection of HPVs. Most were of limited quality. Averaging data from 67 studies of HNSCC, the prevalence of HPV of any subtype is approximately 36%. PCR (polymerase chain reaction) was the most used detection method and HPV16 the most common genotype reported. Meta-analyses of case-control studies from this region reveal significant heterogeneity but suggest higher HPV prevalence in oropharyngeal cancer (OR: 14.66; 95%CI: 6.09-35.26) compared to oral cavity cancer and laryngeal cancer; (OR: 4.06; 95%CI: 3.05-5.39 & OR: 3.23; 95%CI: 1.37-7.61) respectively.

CONCLUSION

In view of the significant association of HPV with HNSCC, studies with accurate subsite classification and more sensitive detection methods are necessary. Accurate data from this geographical region are essential to inform public health policies and treatment decisions, especially as studies from Europe and North America reveal HPV-driven cancers to be less aggressive, permitting treatment de-intensification.

No role for human papillomavirus infection in oral cancers in a region in southern India

Oral cancer is a major public health issue in India with ∼ 77,000 new cases and 52,000 deaths yearly. Paan chewing, tobacco and alcohol use are strong risk factors for this cancer in India. Human papillomaviruses (HPVs) are also related to a subset of head and neck cancers (HNCs). We examined the association between oral HPV and oral cancer in a sample of Indian subjects participating in a hospital-based case-control study. We recruited incident oral cancer cases (N = 350) and controls frequency-matched by age and sex (N = 371) from two main referral hospitals in Kerala, South India. Sociodemographic and behavioral data were collected by interviews. Epithelial cells were sampled using Oral CDx® brushes from the oral cancer site and the normal mucosa. Detection and genotyping of 36 HPV genotypes were done using a polymerase chain reaction protocol. Data collection procedures were performed by qualified dentists via a detailed protocol with strict quality control, including independent HPV testing in India and Canada. HPV DNA was detected in none of the cases or controls. Associations between oral cancer and risk factors usually associated with HPV infection, such as oral sex and number of lifetime sexual partners, were examined by logistic regression and were not associated with oral cancer. Lack of a role for HPV infection in this study may reflect cultural or religious characteristics specific to this region in India that are not conducive to oral HPV transmission. A nationwide representative prevalence study is needed to investigate HPV prevalence variability among Indian regions.

High-risk human papilloma virus in archival tissues of oral pathosis and normal oral mucosa

Objectives:

Oral cancer ranks third among all cancers in the Indian population. Human papilloma virus (HPV) plays a significant role in oral carcinogenesis. Population-based subtype variations are present in the HPV prevalence. This study gives an emphasis on the parameters to be considered in formalin fixed paraffin embedded tissues for polymerase chain reaction (PCR)-based research work.

Materials and Methods:

Cross-sectional study on archival paraffin-embedded tissue samples of oral squamous cell carcinoma (OSCC), epithelial dysplasia, and normal oral mucosa surrounding impacted tooth was amplified by PCR for the E6 gene of HPV type 16 and E1 gene of HPV type 18.

Results:

HPV 18 was positive in three OSCC cases. There was no statistically significant association of the positivity of HPV with the age, gender or habit. The HPV positive patients had a tobacco habit and were of a younger age group.

Conclusion:

The presence of HPV in carcinomatous tissue highlights the possible role of HPV in carcinogenesis and archival paraffin embedded tissue specimen can be used for this analysis. Recent studies on genomic analyses have highlighted that the HPV positive tumors are a separate subgroup based on genomic sequencing. The results of a larger retrospective study will help further in our understanding of the role of HPV in carcinogenesis, this study could form the baseline for such follow-up studies.

Role of human papillomavirus in oral squamous cell carcinoma and oral potentially malignant disorders: A review of the literature

Human papillomaviruses (HPVs) are epitheliotropic viruses with an affinity for keratinocytes and are principally found in the anogenital tract, urethra, skin, larynx, tracheobronchial and oral mucosa. On the basis of high, but variable frequency of HPV in oral squamous cell carcinoma (OSCC), malignant potential of HPV infection has been hypothesized but not definitely confirmed. The aim of this review was to highlight the genomic structure and possible mechanism of infection and carcinogenesis by HPV in the oral mucosa and to review the frequency of HPV prevalence in OSCC and oral potentially malignant disorders. A computer database search was performed through the use of PubMed from 1994 to 2014. Search keywords used were: HPV and oral cancer, HPV and oral leukoplakia, HPV and oral lichen planus, HPV and OSCC, HPV and verrucous carcinoma, HPV and proliferative verrucous leukoplakia, HPV and oral papilloma.

P53 nuclear stabilization is associated with FHIT loss and younger age of onset in squamous cell carcinoma of oral tongue

BACKGROUND

Squamous cell carcinoma of tongue (SCCT) is expected to harbor unique clinico-pathological and molecular genetic features since a significant proportion of patients are young and exhibit no association with tobacco or alcohol.

METHODS

We determined P53, epidermal growth factor receptor, microsatellite instability, human papilloma virus infection and loss of heterozygosity status at several tumor suppressor loci in one hundred and twenty one oral SCCT (SSCOT) samples and analyzed their association with clinico-pathological features and patient survival.

RESULTS

Our results revealed a significantly higher incidence of p53 nuclear stabilization in early (as against late) onset SCCOT. FHIT loss was significantly associated with p53 nuclear stabilization and the association was stronger in patients with no history of tobacco use. Samples harboring mutation in p53 DNA binding domain or exhibiting p53 nuclear stabilization, were significantly associated with poor survival.

CONCLUSION

Our study has therefore identified distinct features in SCCOT tumorigenesis with respect to age and tobacco exposure and revealed possible prognostic utility of p53.

Detection and typing of human papillomaviruses (HPV) in malignant, dysplastic, nondysplastic and normal oral epithelium by nested polymerase chain reaction, immunohistochemistry and transitional electron microscopy in patients of northern Greece

OBJECTIVES

To evaluate the role of HPV in oral carcinogenesis, we examined the prevalence of HPV in malignant, potentially malignant and normal oral epithelium and studied the relation of HPV prevalence with other factors obtained from the patient's records.

MATERIALS AND METHODS

Our material consisted of 291 tissue specimens from 258 individuals. From every individual formalin fixed and paraffin embedded tissues were examined by nested Polymerase Chain Reaction (NPCR) for the detection of HPV DNA and by immunohistochemistry (IHC) for the in situ detection of HPV L1 protein. Positive PCR products were sequenced in order to type HPVs. Also 33 fresh tissues were obtained, fixed and used to detect HPV particles by transitional electron microscopy (TEM).

RESULTS

HPV was detected in 32.9% of the tissue specimens by NPCR, in 4.7% by immunohistochemistry and in 28.1% by TEM. In detail, by nested PCR HPV L1 DNA was detected in 40% of normal tissues, 40% of fibromas, 35.8% of non-dysplastic leukoplakias, 31.6% of dysplastic leukoplakias and 22.2% of oral squamous cell carcinomas. The HPV viral load of 96.5% of the samples was very low (1 viral copy per 10(2)-10(4) cells). HPV16 prevails in all histological groups in 89-100%.

CONCLUSION

We conclude that HPV does not seem, from the specific sample examined, to play a substantial role in oral carcinogenesis. However, it cannot be excluded that HPV could be involved in oral carcinogenesis only in cases with high viral load or at early stages of carcinogenesis possibly through the hit-and-run mechanism.

Analysis of human papilloma virus in oral squamous cell carcinoma using p16: An immunohistochemical study

Aims:

The aim of this study is to evaluate the expression of human papilloma virus (HPV) in oral squamous cell carcinoma (OSCC) and to correlate the association of HPV in histological grades of OSCC using p16 (p16INK4a) immunohistochemistry (IHC).

Subjects and Methods:

This study consists of 30 histological diagnosed cases of OSCC (10-well-differentiated oral squamous cell carcinoma [WDOSCC], 10-moderately differentiated oral squamous cell carcinoma [MDOSCC] and 10-poorly differentiated oral squamous cell carcinoma [PDOSCC]). The sections were subjected to IHC procedure using p16. Two parameters in immunohistochemical p16 expression were evaluated by 3 observers based on the criteria by Galgano M. Tetal (2010) (a) percentage of p16 positive cases (b) pattern of p16 staining in various grades of OSCC.

Statistical Analysis Used:

Kappa test.

Results:

Totally, 30 samples of 0SCC, p16 positivity was noted in 26/30 (86.66%). Of 26 positive cases, p16 staining was positive in 7/10 (70%) of WDOSCC, 9/10 (90%) in MDOSCC and, 10/10 (100%) PDOSCC. Incidentally, we also found single dispersed cell staining in WDOSCC, patchy staining in MDOSCC and more diffuse staining pattern predominant in PDOSCC.

Conclusions:

Our study revealed an association between HPV and OSCC. Diffuse staining pattern was noted in PDOSCC, which in turn depicts the increase viral overload, which might have an influence on its aggressive behavior.

Head and neck cancers in developing countries

Head and neck cancers are the most common cancers in developing countries, especially in Southeast Asia. Head and neck cancers are more common in males compared to females. This is mainly attributed to tobacco, areca nut, alcohol, etc. Oral cancers are most common amongst all head and neck squamous cell cancers (HNSCC). HNSCC in the developing world differ from those in the Western world in terms of age, site of disease, etiology, and molecular biology. Poverty, illiteracy, advanced stage at presentation, lack of access to health care, and poor treatment infrastructure pose a major challenge in management of these cancers. The annual GDP (gross domestic product) spent on health care is very low in developing countries compared to the developed countries. Cancer treatment leads to a significant financial burden on the cancer patients and their families. Several health programs have been implemented to curb this rising burden of disease. The main aims of these health programs are to increase awareness among people regarding tobacco and to improve access to health care facilities, early diagnosis, treatment, and palliative care.

Prevalence of high-risk human papillomavirus type 16 and 18 in oral and cervical cancers in population from Gujarat, West India

BACKGROUND

Oral and cervical cancers are major malignancies in men and women, respectively, in India. This study evaluated occurrence of human papillomavirus (HPV) 16 and 18 infections in oral and cervical cancers to estimate HPV-associated burden of these cancers in the population from Gujarat, West India.

METHODS

A total of 97 malignant oral carcinoma tissues and 52 cervical carcinoma tissues were analyzed by type-specific PCR for the presence of HPV type 16 and 18 infections.

RESULTS

None of the oral cancer patients revealed the presence of HPV type 16 and 18 infection. In cervical cancer, 31 (59.6%) patients were infected with HPV 16 and 18. Of these 31 HPV-positive cervical cancer patients, 28 (90.3%) were infected with HPV 16 and 3 (9.7%) were infected with HPV 18.

CONCLUSION

The results suggested that HPV 16 and 18 do not play an important role in oral carcinogenesis in the population from Gujarat, West India. However, HPV 16 is highly prevalent in the cervical cancer patients, which may be considered for planning of prevention programs such as screening and vaccination in women from this region.

Evidences suggesting involvement of viruses in oral squamous cell carcinoma

Oral cancer is one of the most common cancers and it constitutes a major health problem particularly in developing countries. Oral squamous cell carcinoma (OSCC) represents the most frequent of all oral neoplasms. Several risk factors have been well characterized to be associated with OSCC with substantial evidences. The etiology of OSCC is complex and involves many factors. The most clearly defined potential factors are smoking and alcohol, which substantially increase the risk of OSCC. However, despite this clear association, a substantial proportion of patients develop OSCC without exposure to them, emphasizing the role of other risk factors such as genetic susceptibility and oncogenic viruses. Some viruses are strongly associated with OSCC while the association of others is less frequent and may depend on cofactors for their carcinogenic effects. Therefore, the exact role of viruses must be evaluated with care in order to improve the diagnosis and treatment of OSCC. Although a viral association within a subset of OSCC has been shown, the molecular and histopathological characteristics of these tumors have yet to be clearly defined.

Human papillomavirus-associated oral intraepithelial neoplasia

This study evaluated an unusual subset of oral epithelial dysplasia for the presence of transcriptionally active high-risk HPV subtypes and to further characterize the histological criteria for this condition. There were 20 cases diagnosed as epithelial dysplasia with marked apoptosis of the anterior oral cavity. Clinical and follow-up data were collected and histopathological features were documented. Immunoperoxidase studies were performed for p16 and in situ hybridization studies were performed for low- and high-risk HPV sub-types. Gender- and site-matched controls of conventional moderate-to-severe oral epithelial dysplasia were similarly evaluated using immunoperoxidase studies for p16 and in situ hybridization; the number of apoptotic cells for study and control cases was counted at two different tissue sites. There were 17 men and 3 women with a median age of 56 years. Seventeen lesions were described as white and five were described as rough or papillary. Thirteen were located on the lateral or ventral tongue, some extending onto the floor of the mouth. Epithelial hyperplasia with marked karyorrhexis and apoptosis were present in all the cases, along with features of conventional oral epithelial dysplasia. A statistically significant number of apoptotic cells were identified in the study cases when compared with controls (P>0.0001). Twenty cases were positive for high-risk HPV by in situ hybridization and all 19 nineteen cases evaluated for p16 demonstrated overexpression. Two patients were diagnosed with squamous cell carcinomas and one patient developed recurrent disease. We report a subset of oral epithelial dysplasia that occurs mostly in adult men on the ventral or lateral tongue and is positive for high-risk HPV and for p16. We propose use of the term 'HPV-associated Oral Intraepithelial Neoplasia' to characterize these lesions of the oral cavity for consistency in nomenclature with HPV-associated lesions of the lower anogenital tract. One case recurred and one developed invasive cancer.

Human papilloma virus lesions of the oral cavity: healing and relapse after treatment with 810-980 nm diode laser

This study evaluated the therapeutic efficacy of laser therapy in treating oral human papilloma virus (HPV) lesions. In particular, mode of action, healing, postoperative patient compliance, visual numeric scale (VNS) pain index, and recurrence were analyzed. During 2001-2012, in 170 patients (80 women and 90 men), 174 intraoral and lip HPV lesions were detected and excised by diode laser of different wavelengths (810-980 nm), with an average power of 2.1 W, in continuous wave mode, using 300 to 320 μm optical fibers. In most cases (95.4%), complete healing occurred in the first 30 days. There were no adverse effects and all patients were carefully followed up until complete healing occurred, documenting any complications. There was only one recurrence, which was later treated successfully; the mean VNS pain score was below one. In treating HPV lesions, the diode laser is not only a valuable tool for their eradication but especially it reduces relapses, thanks to the characteristics of the laser light.

Human papilloma virus in head and neck cancers-role and relevance in clinical management

The biology and clinical behavior of Head and Neck Squamous Cell Carcinomas (HNSCCs) is very distinct within different subgroups due to the distinct molecular profiles for the HPV positive versus HPV negative tumors. HPV status is the most important independent prognostic variable in multivariate analysis taking into account all other prognostic factors like tumour stage, smoking status, age and performance status. The debate today is whether the intense therapy is too aggressive in this group of patients since they show a superior survival regardless of treatment strategies. A highly divergent prognosis and distinct biology of HPV positive and HPV negative HNSCCs underlines the fact that treating them as distinct diseases is the need of the hour. Infection with HPV is associated with less aggressive disease, better loco regional control and lower rates of second primary cancers. An important caveat that remains is the emergence of intermediate prognosis of HPV positive smokers and HPV negative non smokers. Though molecular biology has provided important data on the interaction of the HPV onco proteins with genes important in cell cycle control, also speculated to be involved in pathogenesis of HNSCC, more basic research is needed to describe the differential mechanisms of tumorigenesis among the HNSCCs that show presence and absence of HPV. This is clinically relevant to reduce morbidity without compromising tumour control in HPV positive patients and improving tumour control and co-morbid illness that could be pre-existing or treatment related in HPV negative patients. There may be a need for treatment intensification and incorporation of newer agents into induction chemotherapy protocols for the HPV negative patients and so HPV detection is important to aid in this selection. HPV tumour status is therefore more important than just providing the prognostic information in these classes of tumours. This article discusses the role and clinical relevance of HPV in HNSCCs.

Prognostic features, human papillomavirus status, and epidermal growth factor receptor expression in oral squamous cell carcinoma in young adults

PURPOSE

There is still debate in literature about the survival outcomes of patients who have cancer of the oral cavity when young. Hence the aims were (1) to estimate disease-free survival, overall survival, and cause-specific survival in patients who developed oral cavity squamous cell carcinoma between 18 and 40 years of age and (2) to assess the clinicopathologic factors including detection of human papillomavirus and epidermal growth factor receptor (EGFR) overexpression in primary lesions affecting recurrence.

METHODS

This is a retrospective case-note review and reevaluation of histopathologic slides of patients treated more than 25 years. Descriptive statistics, Cox proportional hazard models, and Kaplan-Meier survival curves were used for statistical analysis.

RESULTS

A total of 62 patients were treated, with mean follow-up of 11.4 years. Forty-five were oral tongue tumors and 43 had stage I or II disease. The 5-year disease-free survival was 73.5%. The 10-year overall survival and cause-specific survival rates were 81.8% and 83.4%, respectively. Smoking and alcohol intake were not seen as risk factors in this population. Multivariate modeling identified only nodal involvement as significantly associated with overall survival and only extracapsular spread as significantly associated with locoregional recurrence. At 5 years after treatment, the cause-specific survival was 100% for patients with low EGFR expression and 81.1% for patients with high EGFR expression (hazard ratio for high vs low, 3.1; 95% confidence interval, 0.4-406.9; P = .46). Human papillomavirus was not detected in all but 2 tumor specimens.

CONCLUSIONS

Survival outcomes are quite good in young patients with oral cancer.

Promoter hypermethylation of p73 and p53 genes in cervical cancer patients among north Indian population

Hypermethylation of CpG islands leads to transcriptional silencing and it is the predominant mechanism of tumor suppressor gene inactivation in many tumors. Methylation-specific polymerase chain reaction was performed to analyse the methylation status of the promoter region of the tumor suppressor genes. Hypermethylation of the 5' CpG island of the p21 ( CIP1 ), p27 ( KIP1 ), p57 ( KIP2 ), p53, p73 and RB 1 gene promoter were found in 8.8, 8.8, 11.2, 12, 25.6 and 4.8 % of 125 cervical cancer samples from north Indian population, respectively. Methylation of p73 was significantly (P < 0.001) associated with the cervical cancer cases in comparison to controls. Significant correlation was also observed between the methylation of p73 gene and increase in the risk of cervical cancer among passive smokers. Promoter hypermethylation of p53 gene was also observed to be significant among oral contraceptive users and cervical cancer patients having age at first sexual intercourse <20 years whereas hypermethylation of other genes was not found to be significant in the present study. This is the first report showing significant hypermethylation of p73 and p53 genes among cervical cancer patients in north Indian population. This is also the first report on significant p53 hypermethylation in cervical cancer in any population. Our findings did not show any correlation between promoter methylation of p73 and the other genes under study with clinicopathological parameters, including human papillomavirus infection and stage of the disease. The frequency of aberrant methylation of p73 and p53 gene promoter was unchanged according to the age of patients.

Epidemiology of human papillomavirus-related head and neck cancer

Human papillomavirus (HPV) is now recognized to cause a subset of head and neck squamous cell carcinomas (HNSCC). Although excessive tobacco and alcohol use continue to be important risk factors for HNSCC, epidemiologic studies suggest that more than 25% of HNSCC are now caused by HPV. The incidence of HPV-related HNSCC is increasing, highlighting the need to understand the oral HPV infections causing these cancers. This article reviews the evidence for a causal association between HPV and HNSCC, examines the changing epidemiologic trends of HNSCC, and discusses what is currently known about oral HPV infection, natural history, and transmission.

p16(INK4a) and p15(INK4b) gene promoter methylation in cervical cancer patients

The aim of this study was to determine the methylation status of the p16(INK4a), p14(ARF) and p15(INK4b) genes and the subsequent effect of hypermethylation on the expression of these genes in cervical cancer patients. Methylation-specific PCR (MSP) was performed to analyse the methylation status of p16(INK4a), p14(ARF) and p15(INK4b) genes and was confirmed by sequencing. Reverse transcription PCR (RT-PCR) was carried out to determine changes in the expression of the genes due to hypermethylation. Hypermethylation of the p16(INK4a), p14(ARF) and p15(INK4b) gene promoters was observed in 36, 8.8 and 11.2%, respectively, of 125 cervical cancer samples from a north Indian population. Methylation of p16(INK4a) was significantly (P<0.001) associated with the cervical cancer cases. Significant association of p16(INK4a) hypermethylation with passive smoking and oral contraceptive use was also observed. Methylation of p15(INK4b) was also found to be significant (P<0.05). Our findings did not reveal any correlation between the promoter methylation of p16(INK4a), p14(ARF) and p15(INK4b) with factors, including age and human papillomavirus infection. mRNA expression was significantly reduced in patients with a methylated promoter (P<0.001) of p16(INK4a) compared to patients with an unmethylated promoter. In conclusion, this is the first study demonstrating significant hypermethylation of p15(INK4b) and p16(INK4a) genes among cervical cancer patients in a north Indian population, and a significant association of p16(INK4a) hypermethylation with passive smoking and oral contraceptive use.

Abnormal cell-cycle expression of the proteins p27, mdm2 and cathepsin B in oral squamous-cell carcinoma infected with human papillomavirus

Since the role of human papillomavirus (HPV) infection in oral carcinogenesis is still unclear, the purpose of this study was to verify the association between the expression of p27, mdm2 and cathepsin B and by HPV-related oral lesions. Fifty-five oral biopsies were studied and HPV detection and typing (6/11, 16, 18, 31 and 33) were performed using polymerase chain reaction techniques. The distribution p27, mdm2 and cathepsin B was determined by immunohistochemistry. Twenty-one (38%) out of the 55 oral lesions tested positive for HPV, of which 6 (33%) were HPV 6/11, 1 (5%) was HPV 16, 14 (72%) were HPV 18 and none was HPV 33/31. Among the 55 biopsies, immunopositivity for p27, mdm2 and cathepsin B was observed in 17 (30.9%), 37 (67.2%) and 37 (67.2%), respectively. Among 21 HPV-positive oral lesions, immunopositivity of mdm2, p27 and cathepsin B was found, respectively, in 6 (33%) out of 18 benign lesions (BL), 4 (22%) out of 18 potential malignant epithelial lesions (PMEL) and 11 (57.9%) out of 19 malignant lesions (ML). High-risk HPV types may be associated with oral carcinoma, by cell-cycle control dysregulation, contributing to oral carcinogenesis and the overexpression of mdm2, p27 and cathepsin B.