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

Implications of oral dysbiosis and HPV infection in head and neck cancer: from molecular and cellular mechanisms to early diagnosis and therapy

Head and neck cancer (HNC) is the sixth most common type of cancer, with more than half a million new cases annually. This review focuses on the role of oral dysbiosis and HPV infection in HNCs, presenting the involved taxons, molecular effectors and pathways, as well as the HPV-associated particularities of genetic and epigenetic changes and of the tumor microenvironment occurred in different stages of tumor development. Oral dysbiosis is associated with the evolution of HNCs, through multiple mechanisms such as inflammation, genotoxins release, modulation of the innate and acquired immune response, carcinogens and anticarcinogens production, generation of oxidative stress, induction of mutations. Thus, novel microbiome-derived biomarkers and interventions could significantly contribute to achieving the desideratum of personalized management of oncologic patients, regarding both early diagnosis and treatment. The results reported by different studies are not always congruent regarding the variations in the abundance of different taxons in HNCs. However, there is a consistent reporting of a higher abundance of Gram-negative species such as Fusobacterium, Leptotrichia, Treponema, Porphyromonas gingivalis, Prevotella, Bacteroidetes, Haemophilus, Veillonella, Pseudomonas, Enterobacterales, which are probably responsible of chronic inflammation and modulation of tumor microenvironment. Candida albicans is the dominant fungi found in oral carcinoma being also associated with shorter survival rate. Specific microbial signatures (e.g., F. nucleatum, Bacteroidetes and Peptostreptococcus) have been associated with later stages and larger tumor, suggesting their potential to be used as biomarkers for tumor stratification and prognosis. On the other hand, increased abundance of Corynebacterium, Kingella, Abiotrophia is associated with a reduced risk of HNC. Microbiome could also provide biomarkers for differentiating between oropharyngeal and hypopharyngeal cancers as well as between HPV-positive and HPV-negative tumors. Ongoing clinical trials aim to validate non-invasive tests for microbiome-derived biomarkers detection in oral and throat cancers, especially within high-risk populations. Oro-pharyngeal dysbiosis could also impact the HNCs therapy and associated side-effects of radiotherapy, chemotherapy, and immunotherapy. HPV-positive tumors harbor fewer mutations, as well as different DNA methylation pattern and tumor microenvironment. Therefore, elucidation of the molecular mechanisms by which oral microbiota and HPV infection influence the HNC initiation and progression, screening for HPV infection and vaccination against HPV, adopting a good oral hygiene, and preventing oral dysbiosis are important tools for advancing in the battle with this public health global challenge.

Epidemiology and demographics of head and neck cancer in Africa: A scoping review

BACKGROUND

Low- to middle-income countries account for 70% of global cancer deaths. Evidence of the changing prevalence of head and neck cancer in Africa in terms of gender, race and epidemiology will inform future research and health planning.

AIM

To synthesise epidemiological literature for head and neck cancer in Africa from 2010 to 2020.

METHOD

A scoping review was completed. The Joanna Briggs Institute Population, context and concept framework confirmed the inclusion criteria. Studies from Africa that included participant demographics, the types, stages, signs and symptoms of head and neck cancer were selected. Five databases were used. Descriptive statistics was completed.

RESULTS

The Preferred Reporting Items for Systematic Reviews and MetaAnalysis guided the reporting of the findings. Of the 1891 articles downloaded, 66 were included in the final review. Nigeria produced the most studies and oral cancer at 74% was most prevalent. Substance abuse was the most prevalent cause. Diagnosis of head and neck cancers were in the late stage (stage IV) when signs and symptoms were severe. Males of lower socioeconomic status tended to have less health seeking behaviour.

CONCLUSION

Countries from North Africa produce the most research outputs on head and neck cancers. Gender differences were noted and may be linked to lifestyle choices. A range of head and neck cancers (HNCs) are prevalent however late diagnosis and severe symptomatology impact treatment options.Contribution: Earlier diagnosis and intervention to prevent late-stage diagnosis is necessary. Awareness campaigns linked to evidence on causes, habits and lifestyle choices, signs and symptoms are needed.

The Prevalence of HPV in Oral Cavity Squamous Cell Carcinoma

Human papillomavirus (HPV) is an important risk factor in a subset of head and neck squamous cell carcinomas (HNSCC), but the association with oral cavity squamous cell carcinomas (OCSCC) remains controversial. This study aimed to identify the prevalence of HPV infection in OCSCC. A systematic search on PubMed and EMBASE was performed, including articles assessing the prevalence of HPV-positive (HPV+) OCSCC published from January 2017 to December 2022. OCSCC was considered HPV+ by the detection of HPV DNA, HPV RNA, and/or p16 overexpression in the tumor mass. A meta-analysis was made determining the overall HPV+ OCSCC prevalence. We included 31 studies comprising 5007 patients from 24 countries. The study size ranged from 17 to 940 patients. The HPV+ OCSCC proportion variated widely and ranged from 0% to 37%. Tumors in the tongue were the predominant sublocation for HPV in the oral cavity. The meta-analysis revealed that the overall HPV+ OCSCC prevalence is 6% (95% CI; 3-10%), and only one study found HPV and OCSCC significantly associated. Thus, HPV may not be a necessary or a strong risk factor in OCSCC oncogenesis, and the possibility of a site misclassification of a mobile tongue with the root of the tongue cannot be excluded.

Human Papillomavirus-Associated Head and Neck Malignancies in Sub-Saharan Africa: A Systematic Review

PURPOSE

The proportion of head and neck cancers (HNCs) with human papillomavirus (HPV) positivity in sub-Saharan Africa (SSA) is poorly characterized. Characterizing this has implications in staging, prognosis, resource allocation, and vaccination policies. This study aims to determine the proportion of HPV-associated HNC in SSA.

MATERIALS AND METHODS

This systematic review included searches from PubMed, EMBASE, Web of Science, African Index Medicus, Google Scholar, and African Journals Online. All English publications reporting the proportion of HNC specimens from SSA patients who tested positive for HPV and/or p16 were included. Study quality was assessed using the National Institutes of Health Quality Assessment Tool for Case Series Studies.

RESULTS

In this systematic review of 31 studies and 3,850 patients, the overall p16 positivity was 13.6% (41 of 1,037 patients tested) with the highest proportion among oropharyngeal cancers (20.3%, 78 of 384 patients) and the overall HPV polymerase chain reaction positivity was 15.3% (542 of 3,548 samples tested) with the highest proportion among nasopharyngeal cancers (16.5%, 23 of 139 patients). Among the 369 HPV strains detected, the most common genotypes were HPV 16 (226 patients, 59.2%) and HPV 18 (78, 20.4%).

CONCLUSION

HPV was found to be associated with a significant proportion of HNC in SSA. The genotypes reported suggest that the nine-valent vaccine and gender-neutral vaccination policies should be considered. Given that these studies may not accurately capture prevalence nor causation of HPV in HNC subsites, additional research is needed to provide a more thorough epidemiologic understanding of HPV-associated HNC in SSA, including risk factors and clinical outcomes.

Human Papillomavirus-Associated Head and Neck Cancers. Where are We Now? A Systematic Review

BACKGROUND

Human papillomavirus targets the skin and mucous membranes, producing benign hyperplastic lesions and precancerous and cancerous lesions. An increasing number of head and neck cancersin particular, oropharyngeal squamous cell carcinoma, laryngeal squamous cell carcinoma, and oral squamous cell carcinoma, are attributable to HPV infection. HPV-induced HNCs typically affect younger, nonsmoking patients with no prior history of heavy alcohol use, more extensive sexual history, and higher socioeconomic status.

AIM

The purpose of the review is to present the most recent and well-established findings concerning HPV-induced head and neck cancers and consequently to provide medical specialists with essential information regarding the epidemiology, the role of HPV in HNC cancerogenesis, prevention, diagnosis, and treatment.

MATERIAL AND METHODS

All authors independently have searched The EMbase, Medline/Pubmed, and Cochrane databases by using the following keywords "head and neck cancer", "human papillomavirus", "HPV", "HPV biology", "oropharyngeal squamous cell carcinoma", "carcinogenesis", "transoral surgery", "robotic surgery". The last search was conducted in March 2022. The references of the publications of interest were also screened for relevant papers. There were no limitations in regard to the publication date.

CONCLUSION

Aiming to avoid the epidemic of HPV-induced HNC, it is paramount to improve the access to vaccination as well as resolve parental concerns regarding vaccine safety. Physicians should rely on reduced-dose radiation and aim to reduce the overall treatment time. Thanks to a more elaborate understanding of the genomic background of HPV-induced HNC, precision medicine could become a relevant part of patients' management. In comparison to traditional techniques and non-operative treatment, transoral robotic surgery (TORS) offers similar oncologic and functional outcomes, with a possible benefit on long-term quality of life. However, more research is needed to establish clear guidelines indicating when TORS resections should be supported with adjuvant therapy.

The Prevalence of Human Papillomavirus-Positive Oropharyngeal Squamous Cell Carcinoma at One of the Largest Tertiary Care Centers in Sub-Saharan Africa

CONTEXT.—

Limited data exist on the prevalence of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma in sub-Saharan Africa.

OBJECTIVE.—

To determine the prevalence of HPV-positive oropharyngeal squamous cell carcinoma at a large tertiary care center in South Africa.

DESIGN.—

A total of 266 oropharyngeal squamous cell carcinomas diagnosed during an 11-year period (2007-2017) were selected for evaluation. Cases staining positive for p16 immunohistochemistry were evaluated for high-risk HPV using the BD Onclarity assay (BD Diagnostics, Sparks, Maryland).

RESULTS.—

Of 266 oropharyngeal squamous cell carcinomas, 14% (n = 36) were positive for p16. Polymerase chain reaction for high-risk HPV performed on the p16-positive cases was negative in 23 cases and positive in 13 cases (13 of 266; 5%). p16 showed a positive predictive value of 36.1%. The HPV subtypes were HPV-16 (n = 10), HPV-18 (n = 1), HPV-52 (n = 1), and HPV-31 (n = 1). Human papillomavirus-positive cases occurred in 10 men and 3 women (mean age, 51 years) and arose from the tonsil (n = 10) or base of the tongue (n = 3). The HPV-positive cases were non-keratinizing (n = 10) or partially keratinizing (n = 1). Partially/nonkeratinizing cases revealed a modest improvement in p16 positive predictive value (11 of 21; 52.4%).

CONCLUSIONS.—

The presence of high-risk HPV in 5% of cases suggests that high-risk HPV is a minor etiologic agent in oropharyngeal squamous cell carcinoma in this region. Given its suboptimal positive predictive value, p16 is not a reliable marker for high-risk HPV infection in this region. When p16 is positive, HPV-specific testing is necessary. The identification of less common high-risk HPV types, HPV-52 and HPV-31, may influence current local vaccination strategies.

A Contemporary Systematic Review on Repartition of HPV-Positivity in Oropharyngeal Cancer Worldwide

Significant variation in human papillomavirus (HPV) prevalence in oropharyngeal squamous cell carcinoma (OPSCC) across countries ranging from 11% in Brazil to 74% in New Zealand has been reported earlier. The aim of this study was to systematically review the most recently published studies on the occurrence of HPV in OPSCC globally. PubMed and Embase were systematically searched for articles assessing the occurrence of HPV+ OPSCC published between January 2016 and May 2021. Studies with a study period including 2015 and the following years were included. Both HPV DNA and/or p16 were accepted as indicators of HPV+ OPSCC. 31 studies were enrolled comprising 49,564 patients with OPSCC (range 12-42,024 patients per study) from 26 different countries covering all continents. The lowest occurrences of HPV+ OPSCC were observed in India (0%) and Spain (10%) and the highest occurrences were observed in Lebanon (85%) and Sweden (70%). We observed great variation in HPV prevalence in OPSCC worldwide varying from 0% to 85%. The highest occurrences of HPV+ OPSCC were found in general in Northern European countries, USA, Lebanon, China, and South Korea. We observed a trend of increase in HPV-positivity, indicating a mounting burden of HPV+ OPSCC.

Lymph nodes in the head and neck cancer: would diffusion-weighted magnetic resonance imaging solve the diagnostic dilemma?

Background

Head and neck cancer has been labeled as the fifth most common cancer. Lymph node (LN) metastases were reported as the most important predatory factor for diagnosis and selection of suitable treatment. Diffusion-weighted (DW) magnetic resonance (MR) imaging is a very important tool that gives quantitative data in several compartments. This work aims to evaluate the diagnostic value of diffusion-weighted as a part of the magnetic resonance imaging in patients with head and neck cancer to allow differentiation of lymph nodes, cancer staging, assessment of recurrence, and evaluation of the effects of oncologic therapy.

Results

The size of pathologically proven benign LNs ranged from 1 to 3 cm (1.71 ± 0.724) and malignant LNs ranged from 1.1 to 5.6 cm (2.54 ± 0.92) (P = 0.0103). The ADC value for benign LNs ranged from 1.26 × 10−3 to 2.49 × 10−3 (mean 1.98 × 10−3 ± 0.32 × 10−3), and malignant LNs from 0.608 × 10−3 to 2.1 × 10−3 (mean 0.971 × 10−3 ± 0.305 × 10−3) (P < 0.001) with sensitivity and a specificity of 94% and 100% respectively. The ADC value for metastatic LNs ranged from 0.70 × 10−3 to 2.10 × 10−3 (1.08 × 10−3 ± 0.31 × 10−3) while lymphomatous nodes ranged 0.608 × 10−3 to 1.16 × 10−3 (0.78 × 10−3 ± 0.17 × 10−3). In this study, a significant statistical difference was also observed between the ADC value of the SCC and lymphomatous LN (P = 0.0034) with sensitivity and a specificity of 90% and 75% respectively.

Conclusion

Diffusion-weighted MR imaging is an effective assist in differentiating benign and malignant lymph nodes. It acts as an indicator for recovery or recurrence after chemotherapy and radiotherapy.