Human papillomavirus 16 and 18 in squamous cell carcinoma of oral cavity and sexual practices: A pilot study at a Tertiary Care Hospital of North 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.

Human Papillomavirus-Attributable Head and Neck Cancers in India-A Systematic Review and Meta-Analysis

PURPOSE

Head and neck cancer accounts for about one third of the global burden in India. Mucosal high-risk human papillomavirus (HPV) has been hypothesized as a contributory risk factor for head and neck cancer (HNC) but its prevalence in Indian patients is not well established. Therefore, this systematic review and meta-analysis aimed to estimate the prevalence of HPV in HNC in India and their attributable fraction by considering the biomarkers of carcinogenesis, p16, and HPV E6/E7 mRNA.

METHODS

A systematic literature search was done in Medline via PubMed, Embase, Scopus, ScienceDirect, ProQuest, and Cochrane to identify studies on HPV and HNC in the Indian population, published between January 1990 and October 2022. Fifty-four eligible studies were identified and relevant clinical information was collected. Meta-analysis was conducted to estimate the pooled prevalence of HPV DNA, p16INK4a, and E6/E7 mRNA percent positivity by random-effect logistic regression model using Metapreg, STATA 18.

RESULTS

Thirty-four high-quality studies were taken for meta-analysis. The pooled prevalence of HPV in HNC was 20% (95% CI, 12 to 32) with a high level of heterogeneity (I2 = 90.79%). The proportion of HPV in oropharyngeal cancer (OPC; 22% [95% CI, 13 to 34]) and laryngeal cancer (LC; 29% [95% CI, 17 to 46]) was higher than in oral cancer (OC; 16% [95% CI, 8 to 30]). The HPV-attributable fraction of OPC, considering the E6/E7 mRNA and p16 positivity, was 12.54% and 9.68%, respectively, almost similar to LC (11.6% and 9.57%), while it was much lower in OC (3.36% and 4%).

CONCLUSION

The HPV-attributable fraction is considerably lower for OC, suggesting a negligible causative role of HPV in OC. A significant proportion of OPC and LC are attributed to HPV; however, their exact causative role is unclear because of the presence of other known risk factors.

Current Updates on Cancer-Causing Types of Human Papillomaviruses (HPVs) in East, Southeast, and South Asia

Simple Summary

Among the over 200 human papillomavirus (HPV) genotypes identified, approximately 15 of them can cause human cancers. In this review, we provided an updated overview of the distribution of cancer-causing HPV genotypes by countries in East, Southeast and South Asia. Besides the standard screening and treatment methods employed in these regions, we unravel HPV detection methods and therapeutics utilised in certain countries that differ from other part of the world. The discrepancies may be partly due to health infrastructure, socio-economy and cultural diversities. Additionally, we highlighted the area lack of study, particularly on the oncogenicity of HPV genotype variants of high prevalence in these regions.

Abstract

Human papillomavirus (HPV) infection remains one of the most prominent cancer-causing DNA viruses, contributing to approximately 5% of human cancers. While association between HPV and cervical cancers has been well-established, evidence on the attribution of head and neck cancers (HNC) to HPV have been increasing in recent years. Among the cancer-causing HPV genotypes, HPV16 and 18 remain the major contributors to cancers across the globe. Nonetheless, the distribution of HPV genotypes in ethnically, geographically, and socio-economically diverse East, Southeast, and South Asia may differ from other parts of the world. In this review, we garner and provide updated insight into various aspects of HPV reported in recent years (2015–2021) in these regions. We included: (i) the HPV genotypes detected in normal cancers of the uterine cervix and head and neck, as well as the distribution of the HPV genotypes by geography and age groups; (ii) the laboratory diagnostic methods and treatment regimens used within these regions; and (iii) the oncogenic properties of HPV prototypes and their variants contributing to carcinogenesis. More importantly, we also unveil the similarities and discrepancies between these aspects, the areas lacking study, and the challenges faced in HPV studies.

Molecular and Immunohistochemical Cognizance of HPV16 in Oral Leukoplakia, Oral Squamous Cell Carcinoma and Oropharyngeal Squamous Cell Carcinoma

Prior studies have established the carcinogenic role of HPV16 and also demonstrated its unique biological behavior in cervical and oropharyngeal squamous cell carcinoma (OPSCC) but its role in oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC) is not well explored. Therefore, in the present study, we assessed HPV16 prevalence using PCR and Anti-HPV16 antibodies for the first time and correlated its biological behavior using p16^INK4a and Ki67 proliferation index (PI) in OL, OSCC, and OPSCC. This study included 63 subjects comprising of 25 OL, 26 OSCC, and 12 OPSCC cases. Exfoliated cells were collected and processed for PCR followed by immunohistochemistry with primary antibodies p16^INK4a, Anti-HPV16, and Ki67. The expressions were evaluated and statistical analysis included Chi-square and Spearman's test. Cumulatively 37% (OL-7%, OSCC-14% & OPSCC-16%) of cases showed positive PCR expression. PCR positivity was observed to be significantly higher (p 0.00) in OPSCC (9/12) than OSCC (9/26) and OL (5/25) cases. Overall immunohistochemical expression of p16^INK4a, Anti-HPV16, and Ki67 were significantly (p 0.02) higher in HPV16 (PCR) positive cases. HPV16 + OSCC cases showed higher grades of p16^INK4a and Ki67 expression. We have demonstrated a prevalence of HPV16 in OL, OSCC, and OPSCC through PCR, which may be concluded as a gold standard for the detection of HPV16 DNA.

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.

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.

Quantitative polymerase chain reaction-based detection of HPV 16 E6 and E7 DNA in oral squamous cell carcinoma

BACKGROUND

Although human papillomavirus (HPV) is considered as a causative factor in oral squamous cell carcinoma (OSCCs), its pathogenetic role is not well established. Moreover, a limited number of studies have compared the techniques of detecting the HPV infection in OSCC. This study aimed at the detection of HPV 16 E6 and E7 DNA in OSCC by quantitative polymerase chain reaction (qPCR) technique.

METHODOLOGY

This retrospective study included 297 tissue sections obtained from histopathologically confirmed OSCC patients. The classification of tumors as poorly differentiated, moderately differentiated and well differentiated was performed by H&E staining following the WHO criteria for OSCC. The presence of HPV infection was detected by p16^INK4A expression, conventional PCR technique, HPV 16 E6, and E7 by qPCR and flow cytometry. All statistical analysis was performed using MedCalc software v.16.4.3. P < 0.05 is considered as statistically significant.

RESULTS

Of 297 samples, 128 samples were found to be HPV-positive by p16. Of total 128 HPV-positive samples, PCR, E6, and E7 qPCR were positive in 19, 97, and 98 samples, respectively. qPCR techniques were found highly significant in the detection of moderately differentiated (P < 0.0001) and widely differentiated (P < 0.0001) cases. The positivity of E6 qPCR increased as the p16 expression increased. A significant variation in E6 DNA copies was observed in different grades of p16 expression (P < 0.0001). However, overall E7 (5.4 × 10⁵ copies/μL) DNA copies were higher than E6 (7.7 × 10³ copies/μL).

CONCLUSION

qPCR detection of HPV infection is a fast, reliable, and accurate technique gives valuable information about the infection status in terms of viral load.