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

Detection of human papillomavirus and its association with potentially malignant disorders and oral squamous cell carcinoma: A retrospective study

Aim:

This study was carried out with the objective of recognizing the involvement of human papillomavirus (HPV) in conditions of oral squamous cell carcinoma (OSCC) and oral potentially malignant conditions and lesions.

Materials and Methods:

OSCC samples from thirty patients were collected and thirty paraffin-embedded, oral premalignant specimens were collected. It was decided to use as a negative control samples gingiva from healthy individuals who had no prior history of oral proliferative leukoplakia or OSCC. The samples were then processed using a paraffin-embedded tissue block method. Deoxyribonucleic acid will be extracted from the paraffin-embedded tumor sample of sixty case subjects and tested for the presence of HPV DNA using polymerase chain reaction.

Results:

In study Group 1, 24 samples were taken from males and 6 from females. In study Group 2, 26 cases were males and 4 were females. In Group 1, 16 cases of moderately differentiated and 14 cases of well differentiated each were present. No case of poorly differentiated were found. There was statistically no significant difference present between male and female when Group 1 and Group 2 was considered. In study Group 1, 0 samples had positive HPV DNA detection, whereas 30 samples had negative HPV DNA detection. In study Group 2, 0 samples had positive HPV DNA detection, whereas 30 samples had negative HPV expression.

Conclusion:

According to our findings, certain incidences of OSCC may be linked to HPV, however, this was not the case for all of the cancers.

A systematic review and meta-analysis of the association between periodontitis and oral high-risk human papillomavirus infection

BACKGROUND

The incidence of human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas (OPSCCs) is increasing globally. Common oral conditions such as periodontitis may contribute. We undertook a meta-analysis to quantify the association between periodontitis, oral HPV and OPSCCs.

METHODS

Multiple electronic databases were searched until 12 February 2020. Studies conducted in males and/or females aged ≥ 18 years that examined periodontitis, periodontal procedures, oral HPV infection, and where possible, oral cancers, were eligible. Meta-analyses were conducted and the GRADE approach was used to examine the quality of evidence.

RESULTS

Of 2709 studies identified, 13 met the eligibility criteria. Five studies could be included in the meta-analyses. There was no significant increase in the odds of high-risk oral HPV infection among individuals with confirmed periodontitis (odds ratio 4.71, 95% confidence interval 0.57-38.97). Individuals with periodontitis had a 3.65 times higher odds of having any type of oral HPV infection compared with those without periodontitis (95% confidence interval 1.67-8.01). The overall body of evidence was rated as low to very-low certainty.

CONCLUSION

Meta-analysis confirms there is a positive association between periodontitis and oral HPV infection, although the overall quality of this evidence is low. Evidence for an association between periodontitis and high-risk oral HPV infection is inconclusive.

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.

Analyzing the Association between Candida Prevalence, Species Specificity, and Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis— Candida and OSCC

The present review is a qualitative and quantitative analysis of the overall prevalence of Candida, and its species specificity in oral squamous cell carcinoma (OSCC). PubMed, Scopus, and Web of Science databases were searched using the keywords ‘Candida and oral squamous cell carcinoma’. Only case-control observational studies in the English language evaluating the prevalence and species specificity of Candida in OSCC were included. 297 articles were identified (PubMed-106, Scopus-148, Web of Science-43) using the keywords. After screening the titles and abstracts, 206 articles were removed as they were duplicates (118) or irrelevant to the topic (88). Full text of the remaining 91 articles was assessed using the inclusion criteria, based on which only seven articles were included in the systematic review. For the quantitative analysis, the odds ratio and confidence interval were assessed and a forest plot was generated. Based on the meta-analysis, there is an association between the total Candida, Candida albicans (CA) and OSCC, while the association with non-Candida albicans (NCA) is relatively weak. The number of studies included in the meta-analysis was relatively low (four to five). Further, at least one of the studies included in the meta-analysis for the association of CA., NCA and total Candida with OSCC had a Newcastle–Ottawa score below 7. Thus, although the results showed an association, the quality and quantity of the evidence may not be sufficient for conclusive inference.