Association of human papilloma virus infection and oral squamous cell carcinoma in Bangladesh

Frequency and clinical significance of human papilloma virus in oral cancer - A study from Kerala

BACKGROUND

Oral cancer is a major health problem in India. Recently an increase in the oral cancer incidence among young individuals without any habits was observed, which may be due to Human Papilloma Virus (HPV). However, information on the prevalence of HPV in oral cancer in India is sparse. This study aims to document the frequency of HPV16 infection in oral squamous cell carcinoma (SCC) and to study its correlation with treatment outcome.

METHODS

Paraffin-embedded tissue blocks of 183 patients with SCC of the oral cavity were studied. HPV16 prevalence was detected by a polymerase chain reaction and expression of p16INK4a was analyzed by immunohistochemistry. This was correlated with clinical outcomes.

RESULTS

The prevalence of HPV 16 was 6.6% and all were carcinoma tongue. All HPV-positive patients showed intense expression of p16INK4a. The five-year overall survival (OS) and disease-free survival (DFS) for HPV positive patients were higher compared to HPV negative patients (100% versus 74.5% and 100% versus 70.8% respectively). The five-year OS and DFS for patients with p16INK4a intense expression were also higher compared to p16INK4a weak expression (91.2% versus 57.4% and 82% versus 22.5% respectively). Five-year OS and DFS of patients with HPV16 positivity and p16INK4a intense expression were significantly higher than patients with HPV negative and p16INK4a weak expression (100% versus 54.7% and 100% versus 22.5% respectively).

CONCLUSION

The frequency of HPV16 positivity in oral cancer was low in this study with a site predilection to the oral tongue. p16INK4a expression did not correlate with HPV status. A better treatment outcome was observed in HPV-positive cancers. We also observed better treatment outcomes in patients with p16INK4A overexpression irrespective of HPV status.

Human Papillomavirus-Associated Oral Squamous Cell Carcinoma Among Adults Living in South-Central Asia: A Systematic Review

Human papillomavirus (HPV) related oral cancers are increasing and are associated with sexual risk behaviours. An increase in the incidence of oral cancer has been observed in South-central Asian countries. The objective was to systematically review the evidence on the association of HPV and oral squamous cell carcinoma (OSCC) among adults living in South-central Asia. We searched multiple databases and reference lists of relevant articles in December 2018. Quality assessment of the selected articles were done using the Newcastle-Ottawa quality assessment scale. Thirteen out of 150 articles met the eligibility criteria. Most studies were from India (10/13) followed by Pakistan (2/13) and Bangladesh (1/13). Half (7/13) of the studies found a positive association between HPV with OSCC. HPV 16, HPV 18 and HPV 16/18 were found to be the most common types implicated in HPV infection associated with OSCC. Moreover, buccal mucosa was the most common site of oral cancer. The review found equivocal evidence in relation to the association of HPV with oral squamous cell carcinoma among people living in South Asia.

Prevalence of Human Papilloma Virus Sub Genotypes following Head and Neck Squamous Cell Carcinomas in Asian Continent, A Systematic Review Article

Objectives:

In current era of blue brain intelligence and technology access at ease, standardization of disease etiology demands extensive research to drop-down human papilloma virus associated head and neck squamous cell carcinomas impact at large. Present retrospection aims to estimate comparative association of human papilloma virus sub-genotypes in head and neck squamous cell carcinomas, critical analysis of existing research gap, treatment progress, co-infection, gender association, national status and challenges following Human papilloma virus led head and neck squamous cell carcinomas among world largest continent.

Background:

Head and neck squamous cell carcinomas are not just like malignancies of uterine cervix, lymph nodes and breast cancers. Human papilloma virus led head and neck squamous cell carcinomas treatment directly impact Central nervous system in humans. Intriguingly, human papilloma virus mediated immune response increases patient survival, which indirectly transmit human papilloma virus in future generations and act as a potential threat developing neurogenic disorders.

Methods:

An objective based search strategy, following comprehensive and specific search approaches were made to retrieve recent 12 years research data from five different NCBI databases. Out of 300 shortlisted articles, only 24 principal studies met the inclusion criteria.

Results:

Highest human papilloma virus prevalence (10.42 %) was found in South Asia, 5.8 % in South East Asia, 5.7 % East Asia, 2.5% in west Asia and no relevant updated data was found from central Asian continent. Highest prevalence (10%) of HPV genotype-16 was recorded in Asia among 3, 710 enrolled cases including 2201 males, 1149 females and 360 cases of unknown gender. While undifferentiated multiple HPV genotype prevalence was 5.5 % (204 cases). Lowest percentage of HPV sub-types 68, 72, 57, 39 were recorded respectively. Pakistan ranked top reporting highest number of HPV-16 cases, Taiwan HPV-18, India HPV-31, Japan HPV-35 and Singapore in HPV-16 and HPV-18 co-infection rates respectively.

Conclusions:

Exact prevalence of HPV associated head and neck squamous cell carcinomas among Asian population is still debatable. Due to higher heterogeneity (P< 0.00001), I² = 81-88% at 95 % confidence interval), non-availability and limitations of reported studies from Asian sub-continents especially central Asia, western Asia and from south and south east Asia demand large scale collaborative research culture to standardize head and neck squamous cell carcinomas aetiology.

Novel association of oral squamous cell carcinoma with GSTP1 Arg187Trp gene polymorphism

AIMS

Glutathione S-transferase subtype pi 1 (GSTP1) is an enzyme that is involved in the detoxification of carcinogenic substances. Arg187Trp is a functional polymorphism in the corresponding GSTP1 gene that reduces the enzymatic activity by 45%. We evaluated, for the first time, the association of Arg187Trp with the risk of oral squamous cell carcinoma and compared it with other established GSTP1 polymorphisms viz, Ile105Val and Ala114Val.

MATERIALS AND METHODS

We carried out a 1:2 case-control study by recruiting 100 patients with oral squamous cell carcinoma and 200 age and gender-matched healthy individuals. Ile105Val, Ala114Val, and Arg187Trp polymorphisms were genotyped by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and their distribution in the study groups was compared by chi-squared test (Fisher's exact).

RESULTS

The minor allele of Ala114Val and Arg187Trp were more common in patients than in controls. In contrast, the distribution of Ile105Val minor allele was similar in the two groups. The differential distribution was also significant at the level of genotypes.

CONCLUSIONS

These results indicate that GSTP1 Arg187Trp is associated with the risk of developing oral squamous cell carcinoma. Our study underlines the importance of detoxification pathway in the risk of carcinogenesis.

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.

GSTP1 c.341C>T gene polymorphism increases the risk of oral squamous cell carcinoma

Glutathione S Transferases (GST) are anti-oxidant enzymes involved in detoxification of cellular and exogenous carcinogens and oxidative products of reactive oxygen species. Genetic polymorphisms can attenuate the detoxification capacity of GST and consequently increase the susceptibility to carcinogenesis. There are eight classes of GST enzymes of which pi subtype is the predominant form expressed in the oral mucosa. c.341C > T single nucleotide polymorphism (rs1138272) in GSTP1 gene, is a functional variation that reduces the enzymatic activity of GST pi. We carried out a 1:2 case-control study involving 270 individuals to determine the association of c.341C > T variation with the risk of oral squamous cell carcinoma. GSTP1 c.341C > T variation was genotyped by PCR-RFLP method. GST pi expression in the tumour sample was determined by immunohistochemistry. Tobacco consumption was the major risk factor among cancer patients. The odds ratio for the risk of oral squamous cell carcinoma in individuals with the minor allele was 4.5 (0.95 CI = 2.3-8.9; P = 0.000004). The genotype was found to follow dominant mode of inheritance (OR 4.4 [0.95 CI = 2.1-9.2]; P = 0.00006). Our results support the conclusion that c.341C > T variation in GSTP1 increases the risk of OSCC in patients habituated to tobacco consumption.

Prevalence and types of high-risk human papillomaviruses in head and neck cancers from Bangladesh

BACKGROUND

There is a dramatic rise in the incidence of Human papillomavirus (HPV) - associated head and neck squamous cell carcinoma (HNSCC) in the world, with considerable variation by geography, gender and ethnicity. Little is known about the situation in Bangladesh, where tobacco- and areca nut-related head and neck cancers (HNCs) are the most common cancers in men. We aimed to determine the prevalence of HPV in HNSCC in Bangladesh and to explore the possible value of cell cycle markers in clinical diagnostic settings.

METHODS

One hundred and ninety six archival HNSCC tissue samples were analysed for the presence of HPV DNA. The DNA quality was assured, and then amplified using a nested PCR approach. The typing of HPV was performed by automated DNA sequencing. Cellular markers p53, Cyclin D1 and pRb were tested on all samples by immunohistochemistry (IHC), as well as p16 as a putative surrogate for the detection of HPV.

RESULTS

HPV DNA was detected in 36/174 (~21%) samples: 36% of cancers from the oropharynx; 31% of oral cancers, and 22% from the larynx. HPV-16 was most common, being present in 33 samples, followed by HPV-33 (2 samples) and HPV-31 (1 sample). Twenty-eight out of 174 samples were positive for p16, predominantly in HPV-positive tissues (p < 0.001). No statistically significant association was observed between the cellular markers and HPV DNA positive cases. However, p16 positivity had excellent predictive value for the presence of HPV by PCR.

CONCLUSION

There is a significant burden of HPV-associated HNSCC in Bangladesh, particularly in the oropharynx but also in oral and laryngeal cancers. Whilst a combination of PCR-based DNA detection and p16 IHC is useful, the latter has excellent specificity, acceptable sensitivity and good predictive value for carriage of HPV in this population and should be used for prognostic evaluation and treatment planning of all HNSCC patients in South Asia, as in the Western world.

Pre-Cancerous Lesions in the Oral and Maxillofacial Region: A Literature Review with Special Focus on Etiopathogenesis

Many types of cancers develop in the oral and maxillofacial region. Squamous cell carcinoma is the most common cancer and constitutes over 90 percent of these tumors. Malignant transformation is a genetic process, which later makes a phenotyping change at the cellular level. Some cancers such as oral squamous cell carcinomas (OSCCs) develop from pre-malignant lesions and conditions. Despite advances in the treatment of OSCC, the 5-year survival rate remains approximately 50% due to inability of early detection of OSCC and precursor lesions. Early detection of oral cancer, especially in the premalignant stage, can decrease mortality and morbidity significantly. This article reviews some clinical, histopathological features and etiopathogenesis of pre-cancerous lesions of the oral cavity and skin of face and lip vermilion. A relevant English literature search in Pubmed, Science Direct, and Google Scholar was performed from 1930 to 2015. Full text of 191 articles met the specific inclusion criteria for this review.

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.

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.