Potential Therapeutic Targets for the Treatment of HPV-Associated Malignancies

This review article aims to summarize broadly recent developments in the treatment of HPV-associated cancers, including cervical cancer and head and neck squamous cell carcinoma. Relatively new treatments targeting the key HPV E6 and E7 oncoproteins, including gene editing with TALENs and CRISPR/Cas9, are discussed. Given the increased immunogenicity of HPV-related diseases, other therapies such as PRR agonists, adoptive cell transfer, and tumor vaccines are reaching the clinical trial phase. Due to the mechanism, immunogenicity, and reversibility of HPV carcinogenesis, HPV-related cancers present unique targets for current and future therapies.

The molecular characteristics of recurrent/metastatic HPV-positive head and neck squamous cell carcinoma: A systematic review of the literature

OBJECTIVES

About 17% of patients with human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC), which is mainly comprised of oropharyngeal SCC (OPSCC), will experience disease recurrence, which is often considered incurable when manifested at a metastatic and/or recurrent stage. We conducted a critical qualitative systematic review. Our objectives were to provide an overview of the molecular landscape of recurrent/metastatic HPV-positive HNSCC as well as novel molecular biomarkers.

DESIGN

A literature review was conducted to identify studies reporting on the molecular characteristics of recurrent/metastatic HPV-positive HNSCC, novel molecular biomarkers and treatment options. The reviews of abstracts, full articles, and revision of the included studies, followed by data extraction and quality assessment were performed by three independent assessors. All primary literature, such as retrospective, prospective, and clinical trials as well as basic research studies were considered, and the final search was conducted at the end of February 2023. The level of evidence was rated using the guidelines published by the Oxford Centre for Evidence-based Medicine and quality was assessed using the Newcastle-Ottawa Scale criteria.

RESULTS AND CONCLUSIONS

The literature search resulted in the identification of 1991 articles. A total of 181 full articles were screened, and 66 articles were included in this analysis. Several studies reported that recurrent/metastatic HPV-positive HNSCC had higher rates of TP53 mutation and were genomically similar to HPV-negative HNSCC. The detection of circulating tumour tissue-modified HPV DNA (ctHPVDNA) as a specific biomarker has shown promising results for monitoring treatment response and recurrence in the subset of HPV-positive HNSCC. In addition, evidence for targeted therapy in recurrent/metastatic HPV-positive HNSCC has emerged, including agents that inhibit overexpressed EGFR. Studies of combination immunotherapy are also underway. Our review outlines the latest evidence on the distinct molecular profiles of recurrent/metastatic HPV-positive HNSCC as well as the clinical potential of ctHPVDNA testing in routine practice. More controlled and longitudinal studies are needed to identify additional molecular targets and to assess the performance and benefits of novel molecular biomarkers in clinical practice.

Imaging and Biomarker Surveillance for Head and Neck Squamous Cell Carcinoma: A Systematic Review and American Radium Society Appropriate Use Criteria Statement

Surveillance for survivors of head and neck cancer (HNC) is focused on early detection of recurrent or second primary malignancies. After initial restaging confirms disease-free status, the use of surveillance imaging for asymptomatic patients with HNC is controversial. Our objective was to comprehensively review literature pertaining to imaging and biomarker surveillance of asymptomatic patients treated for head and neck squamous cell carcinoma and to convene a multidisciplinary expert panel to provide appropriate use criteria for surveillance in representative clinical scenarios. The evidence base for the appropriate use criteria was gathered through a librarian-mediated search of literature published from 1990 to 2022 focused on surveillance imaging and circulating tumor-specific DNA for nonmetastatic head and neck squamous cell carcinoma using MEDLINE (Ovid), Embase, Web of Science Core Collection, and the Cochrane Central Register of Controlled Trials. The systematic review was reported according to PRISMA guidelines. Using the modified Delphi process, the expert panel voted on appropriate use criteria, providing recommendations for appropriate use of surveillance imaging and human papillomavirus (HPV) circulating tumor DNA. Of 5178 studies identified, 80 met inclusion criteria (5 meta-analyses/systematic reviews, 1 randomized control trial, 1 post hoc analysis, 25 prospective, and 48 retrospective cohort studies [with ≥50 patients]), reporting on 27,525 patients. No large, randomized, prospective trials examined whether asymptomatic patients who receive surveillance imaging or HPV circulating tumor DNA monitoring benefit from earlier detection of recurrence or second primary tumors in terms of disease-specific or quality-of-life outcomes. In the absence of prospective data, surveillance imaging for HNC survivors should rely on individualized recurrence-risk assessment accounting for initial disease staging, HPV disease status, and tobacco use history. There is an emerging surveillance role for circulating tumor biomarkers.

Circulating tumor HPV DNA assessments after surgery for human papilloma virus-associated oropharynx carcinoma

PURPOSE

To understand the utility of circulating tumor human papillomavirus DNA (ctHPVDNA) blood testing for HPV-associated oropharynx squamous cell carcinoma (HPV + OPSCC) after definitive surgery.

MATERIALS AND METHODS

Prospective cohort study of HPV(+)OPSCC patients with ctHPVDNA test data to assess its accuracy in detecting biopsy-confirmed disease at various post-treatment time points. Eligible patients had p16(+)/HPV(+) OPSCC and ctHPVDNA testing performed at any time pre-operatively and/or postoperatively. In cases of recurrence, patients were excluded from analysis if ctHPVDNA testing was not performed within 6 months of biopsy.

RESULTS

196 all-treatment-type patients had at least one PT ctHPVDNA test. The initial post-treatment (PT) ctHPVDNA sensitivity, specificity, PPV, and NPV were 69.2 % (9/13), 96.7 % (177/183), 60.0 % (9/15), and 97.8 % (177/181). 61 surgery alone (SA) patients underwent 128 PT tests. The initial PT SA ctHPVDNA sensitivity, specificity, PPV, and NPV were 100 % (2/2), 96.0 % (48/50), 50 % (2/4), and 100 % (48/48). 35 of 61 (57.4 %) SA patients had NCCN-based histopathologic indications for adjuvant (chemo)radiation but declined. 3 of 35 (8.57 %) had a positive PT ctHPVDNA test of which 1 of 3 (33 %) had biopsy-proven recurrence. Prospectively, ten patients had a PreT positive ctHPVDNA, underwent SA, refused adjuvant treatment, had an undetectable ctHPVDNA within 2 weeks of SA, and remained free of disease (mean 10.3 months).

CONCLUSION

The high specificity and NPV of ctHPVDNA after SA suggest ctHPVDNA may have a role in determining the omission of PT adjuvant (chemo)radiation in select patients.

Circulating tumour HPV16 DNA quantification - A prognostic tool for progression-free survival in patients with HPV-related oropharyngeal carcinoma receiving curative chemoradiotherapy

BACKGROUND AND PURPOSE

Circulating tumour (ct) human papillomavirus (HPV) DNA is detectable in HPV-related oropharyngeal carcinoma (OPSCC) patients and has the potential to become an important clinical tool. This study aimed to evaluate the prognostic significance of ctHPV16-DNA kinetics during treatment with chemoradiotherapy in HPV-related OPSCC. Patients with p16-positive OPSCC recruited to the ARTSCAN III trial, comparing radiotherapy plus cisplatin with radiotherapy plus cetuximab, constituted the study cohort.

MATERIALS AND METHODS

Blood samples before start and at the end of treatment of 136 patients were analysed. ctHPV16-DNA was quantified by real-time (q)PCR. The correlation between ctHPV16-DNA levels and tumour burden was investigated with Pearson regression analysis. The prognostic value of ctHPV16-DNA levels at baseline and decline during treatment was evaluated by area-under-the-curve (AUC) calculations and analysed with univariable and multivariable Cox proportional hazards models.

RESULTS

ctHPV16-DNA was detectable with qPCR in 108/136 patients before start of treatment and cleared in 74% of these patients at the end of treatment. Disease burden was significantly correlated with baseline ctHPV16-DNA levels (R = 0.39, p=<0.001). Both lower baseline levels and AUC-ctHPV16DNA were associated with improved progression-free survival (p = 0.01 and p < 0.001), overall survival (p = 0.013 and p = 0.002), but not local tumour control (p = 0.12 and p = 0.2, respectively), with a stronger association for AUC-ctHPV16DNA (likelihood ratio test 10.5 vs 6.5 in Cox regression analyses of progression-free survival). In multivariable analysis including tumour volume (GTV-T) and treatment allocation (cisplatin vs cetuximab), AUC-ctHPV16DNA remained a significant prognostic marker of progression-free survival.

CONCLUSION

ctHPV16-DNA is an independent prognostic factor in HPV-related OPSCC.

Predictive impact of human papillomavirus circulating tumor DNA in treatment response monitoring of HPV-associated cancers; a meta-analysis on recurrent event endpoints

BACKGROUND

HPV infection can cause cancer, and standard treatments often result in recurrence. The extent to which liquid biopsy using HPV circulating tumor DNA (HPV ctDNA) can be used as a promising marker for predicting recurrence in HPV-related cancers remains to be validated. Here we conducted a systematic review and meta-analysis to assess its effectiveness in predicting treatment response.

METHODS

We conducted a systematic literature search of online databases, including PubMed, Embase, Scopus, and the Cochrane Library, up to December 2022. The goal was to identify survival studies that evaluated the potential of plasma HPV ctDNA at baseline and end-of-treatment (EoT) in predicting recurrence of related cancers. Hazard ratios were estimated directly from models or extracted from Kaplan-Meier plots.

RESULTS

The pooled effect of HPV ctDNA presence on disease recurrence was estimated to be HR = 7.97 (95% CI: [3.74, 17.01]). Subgroup analysis showed that the risk of recurrence was HR = 2.17 (95% CI: [1.07, 4.41]) for baseline-positive cases and HR = 13.21 (95% CI: [6.62, 26.36]) for EoT-positive cases. Significant associations were also observed between recurrence of oropharyngeal squamous cell carcinoma (HR = 12.25 (95% CI: [2.62, 57.36])) and cervical cancer (HR = 4.60 (95% CI: [2.08, 10.17])) in plasma HPV ctDNA-positive patients.

CONCLUSIONS

The study found that HPV ctDNA detection can predict the rate of relapse or recurrence after treatment, with post-treatment measurement being more effective than baseline assessment. HPV ctDNA could be used as a surrogate or incorporated with other methods for detecting residual disease.

The Current Role of Human Papillomavirus Circulating Tumor DNA in Oropharynx Cancer

ABSTRACT

Human papillomavirus infection is currently implicated in the majority of oropharyngeal squamous cell carcinoma cases diagnosed in the United States. Circulating tumor DNA (ctDNA) has emerged as a potential biomarker for human papillomavirus-related oropharyngeal squamous cell carcinoma and has the opportunity to improve the diagnosis, treatment, and surveillance of patients with this disease. Changes in ctDNA levels during and after primary therapy may be related to disease response, which can possibly have implications for treatment intensification or de-escalation strategies. Further, ctDNA seems to be sensitive and specific for disease recurrence and may improve upon current methods for assessing both treatment response and failure. In this review, we examine the relevant literature on the use of ctDNA for oropharyngeal cancer treatment and surveillance and discuss current limitations and future directions for this promising biomarker.

The timing and methods for detection of recurrence in patients with head and neck cancer

BACKGROUND

Early detection of head and neck cancer recurrence after curative treatment is crucial for effective salvage treatment.

OBJECTIVE

We aimed to examine the timing and method that allowed early detection of recurrence in each primary and recurrence site.

MATERIALS AND METHODS

We enrolled 440 patients with head and neck squamous cell carcinoma (HNSCC) in the oral cavity, oropharynx, hypopharynx, or larynx who underwent curative treatment focusing on surgery at our hospital between 2009 and 2018. We examined the timing and diagnostic method (clinical examination, patient symptoms, or imaging examination) for HNSCC recurrence according to the primary and recurrence sites.

RESULTS

Recurrence was observed in 133 patients. In all primary sites, regional recurrence occurred significantly earlier than local and distant recurrences. Local recurrence occurred later in the larynx than in other primary sites. Furthermore, the clinical examination had a higher ratio of detection of local recurrence in the larynx than in the other primary site. Regardless of the primary site, more than half of the regional recurrences and most of the distant recurrences were detected by imaging examination.

CONCLUSIONS AND SIGNIFICANCE

Imaging examination is preferable for achieving early detection of regional and distant recurrences.

The role of circulating viral and tumour DNA in the diagnosis and management of HPV associated anogenital cancers, a systematic review and meta-analysis

BACKGROUND

Human papillomavirus associated anogenital cancers are a significant global burden. The detection of biomarkers (circulating tumour DNA; ctDNA or circulating HPV DNA; cHPV DNA) in blood referred to as "liquid biopsy" may support the early diagnosis and monitoring of affected individuals.

METHODS

A systematic review, including meta-analysis of studies available in the literature on the utilization of ctDNA and cHPV DNA as diagnostic, predictive, and monitoring biomarker tests of HPV associated anogenital cancers was performed following the criteria of PRISMA.

RESULTS

A total of 31 studies were eligible for systematic review; 20 used cHPV DNA in cervical cancers; 7 used ctDNA in cervical cancer; 5 used cHPV DNA in anal cancer; no eligible studies on vulva, vaginal or penile cancer were available. The meta-analysis identified low sensitivity (0.36) and high specificity (0.96) of cHPV DNA as diagnostic for cervical cancer. Comparatively, there was high sensitivity (0.95) and specificity (1.0) of cHPV DNA for the diagnosis of anal cancer. cHPV DNA and/or ctDNA in cervical cancer were prognostic markers associated with poor clinical outcomes. Additionally, in anal cancer the post treatment detection of cHPV DNA was informative in the prediction of treatment response or progression-free survival.

CONCLUSION

ctDNA and cHPV DNA are promising diagnostic and prognostic biomarkers for the detection of anogenital disease. Evolution and refinement of molecular tools is likely to improve performance further. Additionally the comparative absence of studies in the vulval, vaginal and penile context warrants further exploration and research.

Viral and Clinical Oncology of Head and Neck Cancers

Purpose of Review

This study assesses the current state of knowledge of head and neck squamous cell carcinomas (HNSCC), which are malignancies arising from the orifices and adjacent mucosae of the aerodigestive tracts. These contiguous anatomical areas are unique in that 2 important human oncoviruses, Epstein-Barr virus (EBV) and human papillomavirus (HPV), are causally associated with nasopharyngeal and oropharyngeal cancers, respectively. Mortality rates have remained high over the last 4 decades, and insufficient attention paid to the unique viral and clinical oncology of the different subgroups of HNSCC.

Recent Findings

We have compared and contrasted the 2 double-stranded DNA viruses and the relevant molecular oncogenesis of their respective cancers against other head and neck cancers. Tobacco and alcohol ingestion are also reviewed, as regard the genetic progression/mutation accumulation model of carcinogenesis. The importance of stringent stratification when searching for cancer mutations and biomarkers is discussed. Evidence is presented for a dysplastic/pre-invasive cancerous phase for HPV+ oropharyngeal cancers, and analogous with other HPV+ cancers. This raises the possibility of strategies for cancer screening as early diagnosis will undoubtedly save lives.

Summary

Staging and prognostication have changed to take into account the distinct biological and prognostic pathways for viral+ and viral− cancers. Diagnosis of pre-cancers and early stage cancers will reduce mortality rates. Multi-modal treatment options for HNSCC are reviewed, especially recent developments with immunotherapies and precision medicine strategies. Knowledge integration of the viral and molecular oncogenic pathways with sound planning, hypothesis generation, and clinical trials will continue to provide therapeutic options in the future.

Salivary detection of high-risk human papillomavirus 16 in oral squamous cell carcinoma using polymerase chain reaction in the South Indian population

Introduction

Human papilloma virus (HPV) has been associated with oral squamous cell carcinoma (OSCC) as a potential carcinogen. There are several types of HPV, of which type 16 has been strongly implicated in carcinogenesis. HPV16 in saliva can potentially facilitate early detection of subclinical cases that may warrant further diagnosis, monitoring and intervention.

Aim

The aim of this study was to evaluate the presence of HPV 16 in saliva and lesional tissue of OSCC and to determine the use of saliva as an alternative non invasive diagnostic tool in HPV16 identification.

Materials and methods

30 cases of Histopathologically confirmed OSCC with HPV positive on ELISA were taken up for the study. The tumour tissue and saliva sample of each patient were obtained to detect the presence of specific HPV16 genotype by polymerase chain reaction (PCR). The data was subjected to statistical analysis using Student t-test.

Results

In our study we found 28/30, 26/30 positive for HPV 16 in tissue and saliva samples respectively on PCR analysis. The P value was statistically significant (0.00).

Conclusion

The study revealed significant prevalence of HPV 16 among both tissue and salivary specimens of OSCC patients in south Indian population. Though, the yielded content was relatively less in saliva, it can be concluded that, saliva being a non invasive tool proved to be as useful as tissue specimen and can be used as an alternative indicator of HPV16 positivity in OSCC.

Cell-Free Human Papillomavirus-DNA for Monitoring Treatment Response of Head and Neck Squamous Cell Carcinoma: Systematic Review and Meta-Analysis

OBJECTIVES/HYPOTHESIS

The aim of this study was to assess the value of cell-free human papillomavirus-DNA (cfHPV-DNA) as a diagnostic test for the post-treatment surveillance of patients with HPV-positive head and neck squamous cell carcinoma (HNSCC) through a systematic review and meta-analysis.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A literature search was conducted in three databases (MEDLINE, Embase, and Scopus) in January 2021. The population included patients with HPV-positive HNSCC. The intervention was the use of the repeated liquid biopsy with circulating HPV-DNA detection during follow-up. The outcome was to establish the value of cfHPV-DNA as a diagnostic test for the post-treatment surveillance of patients with HPV-positive HNSCC.

RESULTS

Ten studies included in the meta-analysis provided a total of 457 patients with HPV-positive HNSCC. The meta-analytic study estimated the diagnostic performance of cfHPV-DNA as follows: pooled sensitivity and specificity of 0.65 (95% confidence interval [CI]: 0.40-0.84) and 0.99 (99% CI: 0.96-0.99), respectively; positive and negative likelihood ratios of 62.5 (99% CI: 22.9-170.2) and 0.05 (99% CI: 0.013-0.24), respectively; and pooled diagnostic odds ratio of 371.66 (99% CI: 60.4-2286.7).

CONCLUSION

Currently, the follow-up protocol for HNSCC patients includes routine clinical evaluation and radiological imaging. Biomarkers to monitor this disease are not established. Considering its high specificity, cfHPV-DNA represents a potential confirmatory test in the case of positive positron emission tomography and computed tomography. In the near future, cfHPV-DNA could be used as a biomarker for monitoring the treatment response during the clinical trials of de-escalation therapy or immunotherapy. Larger sample sizes and the homologation of study protocols and methodology are needed to better establish its utility in the clinical practice. Laryngoscope, 2021.

Cancer of the Oropharynx and the Association with Human Papillomavirus

Squamous cell carcinoma of the oropharynx (OPC) consists of human papillomavirus (HPV)-negative disease caused by tobacco and alcohol use, and HPV-positive disease caused by the sexually transmitted infection HPV. These entities have unique but overlapping risk factors, epidemiologic trends, staging systems, and survival outcomes. HPV-positive tumor status confers a significant survival benefit compared with HPV-negative disease. OPC treatment entails a combination of surgery, radiation, and chemotherapy. Ongoing trials will determine whether treatment of HPV-related disease may be safely deintensified to decrease morbidity. Emerging HPV-related biomarkers are under study as tools to inform screening, diagnosis, treatment, and surveillance for HPV-positive OPC.

Virus-Associated Biomarkers in Oropharyngeal and Nasopharyngeal Cancers and Recurrent Respiratory Papillomatosis

Nasopharyngeal cancer (NPC) is known to be associated with Epstein–Barr virus (EBV). Pre-treatment and post-treatment detection of plasma cell-free EBV DNA has been shown to be useful as a diagnostic as well as a prognostic factor in NPC. On the other hand, the incidence of human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) is increasing. In contrast to cervical cancer, which is classically known to be an HPV-associated malignancy, HPV testing is not clinically applied for OPC, except for p16 immunostaining as a surrogate marker of HPV infection. One of the major characteristics of HPV-associated OPC is its association with a good prognosis compared with non-HPV-associated OPC. However, some patients still have a poor prognosis. Another characteristic of HPV-associated OPC is the distinct risk factor of high sexual activity. Establishing a biomarker for the prediction of the prognosis before and/or after initial treatment, as well as for diagnosis in populations at high risk, is of marked interest. With this background, HPV DNA detection in plasma and oral rinses has become an area of focus. In this review, the current significance of HPV DNA detection in plasma and oral rinse samples, as well as serum HPV antibody levels, is evaluated.

Circulating HPV DNA in the Management of Oropharyngeal and Cervical Cancers: Current Knowledge and Future Perspectives

Human papillomaviruses (HPVs) are associated with invasive malignancies, including almost 100% of cervical cancers (CECs), and 35–70% of oropharyngeal cancers (OPCs). HPV infection leads to clinical implications in related tumors by determining better prognosis and predicting treatment response, especially in OPC. Currently, specific and minimally invasive tests allow for detecting HPV-related cancer at an early phase, informing more appropriately therapeutical decisions, and allowing for timely disease monitoring. A blood-based biomarker detectable in liquid biopsy represents an ideal candidate, and the use of circulating HPV DNA (ct-DNA) itself could offer the highest specificity for such a scope. Circulating HPV DNA is detectable in the greatest part of patients affected by HPV-related cancers, and studies have demonstrated its potential usefulness for CEC and OPC clinical management. Unfortunately, when using conventional polymerase chain reaction (PCR), the detection rate of serum HPV DNA is low. Innovative techniques such as droplet-based digital PCR and next generation sequencing are becoming increasingly available for the purpose of boosting HPV ct-DNA detection rate. We herein review and critically discuss the most recent and representative literature, concerning the role of HPV ctDNA in OPC and CEC in the light of new technologies that could improve the potential of this biomarker in fulfilling many of the unmet needs in the clinical management of OPC and CEC patients.

Blood-based biomarkers of human papillomavirus-associated cancers: A systematic review and meta-analysis

BACKGROUND

Despite the significant societal burden of human papillomavirus (HPV)-associated cancers, clinical screening interventions for HPV-associated noncervical cancers are not available. Blood-based biomarkers may help close this gap in care.

METHODS

Five databases were searched, 5687 articles were identified, and 3631 unique candidate titles and abstracts were independently reviewed by 2 authors; 702 articles underwent a full-text review. Eligibility criteria included the assessment of a blood-based biomarker within a cohort or case-control study.

RESULTS

One hundred thirty-seven studies were included. Among all biomarkers assessed, HPV-16 E seropositivity and circulating HPV DNA were most significantly correlated with HPV-associated cancers in comparison with cancer-free controls. In most scenarios, HPV-16 E6 seropositivity varied nonsignificantly according to tumor type, specimen collection timing, and anatomic site (crude odds ratio [cOR] for p16+ or HPV+ oropharyngeal cancer [OPC], 133.10; 95% confidence interval [CI], 59.40-298.21; cOR for HPV-unspecified OPC, 25.41; 95% CI, 8.71-74.06; cOR for prediagnostic HPV-unspecified OPC, 59.00; 95% CI, 15.39-226.25; cOR for HPV-unspecified cervical cancer, 12.05; 95% CI, 3.23-44.97; cOR for HPV-unspecified anal cancer, 73.60; 95% CI, 19.68-275.33; cOR for HPV-unspecified penile cancer, 16.25; 95% CI, 2.83-93.48). Circulating HPV-16 DNA was a valid biomarker for cervical cancer (cOR, 15.72; 95% CI, 3.41-72.57). In 3 cervical cancer case-control studies, cases exhibited unique microRNA expression profiles in comparison with controls. Other assessed biomarker candidates were not valid.

CONCLUSIONS

HPV-16 E6 antibodies and circulating HPV-16 DNA are the most robustly analyzed and most promising blood-based biomarkers for HPV-associated cancers to date. Comparative validity analyses are warranted. Variations in tumor type-specific, high-risk HPV DNA prevalence according to anatomic site and world region highlight the need for biomarkers targeting more high-risk HPV types. Further investigation of blood-based microRNA expression profiling appears indicated.

Surveillance and Monitoring Techniques for HPV-Related Head and Neck Squamous Cell Carcinoma: Circulating Tumor DNA

OPINION STATEMENT

Human papilloma virus (HPV) related head and neck cancer is rising in prevalence, preferentially affecting young patients and imparting long term toxicities. Despite this, there are no screening tests or clinical biomarkers for treatment monitoring. HPV circulating tumor DNA (HPV ctDNA) represents a novel circulating biomarker which may provide real-time assessment of tumor response to therapy and recurrence. Early work suggests the promise of this assay as a predictive biomarker in numerous clinical settings, namely risk of recurrence after chemoradiation in locally advanced disease. Advancement of these findings to the clinic will require a collaborative effort in the field, including technical harmonization of assay testing characteristics, understanding of the normal kinetics in patients being treated with standard of care therapies, and appropriately designed phase III trials prior to implementation in the clinic. If successful, HPV ctDNA has the potential to revolutionize clinical trial treatment paradigms and transform patient care.

Evaluation of microRNAs as potential biomarkers in circulating HPV-DNA-positive non-small cell lung cancer patients

The aim of the present study was to identify the potential risk of circulating-HPV-DNA in non-small cell lung cancer (NSCLC) and to analyze abnormally expressed miRNAs in circulating HPV-DNA-positive NSCLC. HPV universal primers were used to detect the presence of HPV-DNA in the peripheral blood of 100 patients with NSCLC. The relationship between circulating-HPV-DNA and NSCLC patients characteristics was analyzed. Then, eight differentially expressed miRNAs in NSCLC were screened based on the TCGA database. The levels of miRNAs in circulating HPV-DNA-positive NSCLC patients were detected by real-time quantitative PCR. ROC curves were generated to evaluate the diagnostic performance. Circulating-HPV-DNA was found in 16 patients. The proportion of HPV-DNA-positive patients with poorly differentiated NSCLC, advanced lung cancer and lymph node metastasis was higher than that of HPV-DNA-negative patients. The levels of miR-183, miR-210 and miR-182 were significantly higher and miR-144 was significantly lower in HPV-DNA-positive NSCLC than those in HPV-DNA-negative NSCLC patients. When using a single miRNA to identify circulating HPV-DNA-positive NSCLC patients, miR-210 had a higher area under the ROC curve (AUC) than other miRNAs, and its sensitivity and specificity were also higher. In addition, the combination of two miRNAs was more effective than a single miRNA. Among them, miR-210+ miR-144 had the highest AUC value and showed the best prediction performance. Circulating-HPV-DNA may serve as a risk factor in NSCLC. Plasma miR-183, miR-210, miR-182 and miR-144 can be used as reliable biomarkers to identify circulating HPV-DNA-positive NSCLC.

Clinical relevance of blood-based ctDNA analysis: mutation detection and beyond

Cell-free DNA (cfDNA) derived from tumours is present in the plasma of cancer patients. The majority of currently available studies on the use of this circulating tumour DNA (ctDNA) deal with the detection of mutations. The analysis of cfDNA is often discussed in the context of the noninvasive detection of mutations that lead to resistance mechanisms and therapeutic and disease monitoring in cancer patients. Indeed, substantial advances have been made in this area, with the development of methods that reach high sensitivity and can interrogate a large number of genes. Interestingly, however, cfDNA can also be used to analyse different features of DNA, such as methylation status, size fragment patterns, transcriptomics and viral load, which open new avenues for the analysis of liquid biopsy samples from cancer patients. This review will focus on the new perspectives and challenges of cfDNA analysis from mutation detection in patients with solid malignancies.

Cell-Free HPV-DNA as a Biomarker for Oropharyngeal Squamous Cell Carcinoma-A Step Towards Personalized Medicine?

Simple Summary

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) is a distinct tumor entity with relatively favorable overall survival. Nevertheless, up to 25% of HPV-related OPSCC patients develop recurrent or metastatic disease with a fatal outcomes. Biomarkers to enable early diagnosis and to monitor this disease are not established. Liquid biopsy presents a promising minimally invasive method to monitor the cell-free DNA of oncogenic HPV and to enable personalized therapy concepts. Few studies have investigated the role of cell-free HPV DNA (cfHPV-DNA) as a diagnostic marker in patients with OPSCC with variable outcomes. To emphasize the importance of cfHPV-DNA, we performed a literature review and meta-analysis. Our results demonstrate that cfHPV-DNA in patients with OPSCC presents a promising diagnostic tool with high specificity. Nevertheless, further studies with homogeneous inclusion criteria will be necessary to strengthen the role of cfHPV-DNA as a biomarker in the future.

Abstract

Global incidences of oropharyngeal squamous cell carcinoma (OPSCC) are rising due to an association with high-risk human papillomavirus (HPV). Although there is an improved overall survival of HPV-related OPSCC; up to 25% of the patients develop recurrent or distant metastatic disease with a fatal outcomes. Biomarkers to monitor this disease are not established. This meta-analysis reviews the role of cell-free HPV DNA in liquid biopsy (LB) as a biomarker for HPV-related OPSCC. Pubmed, Livivo, and Cochrane Library databases were searched from inception to August, 2020. All studies were analyzed by Meta-DiSc 1.4 and Stata 16.0 statistical software. In total, 16 studies were considered for systematic review, whereas 11 studies met inclusion criteria for meta-analysis, respectively. Pooled sensitivity of cfHPV-DNA at first diagnosis and during follow-up was 0.81 (95% CI; 0.78–0.84) and 0.73 (95% CI; 0.57–0.86), while pooled specificity was 0.98 (95% CI; 0.96–0.99) and 1 (95% CI; 0.99–1). The diagnostic odds ratio (DOR) at first diagnosis was 200.60 (95% CI; 93.31–431.22) and 300.31 (95% CI; 60.94–1479.88) during follow-up. The area under the curve (AUC) of summary receiver operating characteristic (SROC) was 0.99 at first diagnosis and 1.00 during follow-up, respectively. In conclusion, cfHPV-DNA presents a potential biomarker with high specificity in patients with HPV-related OPSCC.

Decline in circulating viral and human tumor markers after resection of head and neck carcinoma

BACKGROUND

DNA sequencing panels can simultaneously quantify human and viral tumor markers in blood. We explored changes in levels of plasma tumor markers following surgical resection of head and neck carcinoma.

METHODS

In preresection and postresection plasmas, targeted DNA sequencing quantified variants in 28 human cancer genes and levels of oncogenic pathogens (human papillomavirus [HPV], Epstein-Barr virus [EBV], Helicobacter pylori) from 21 patients with head and neck squamous cell carcinoma.

RESULTS

Preresection, 11 of 21 patients (52%) had detectable tumor markers in plasma, most commonly TP53 mutation or HPV genome. Several days postresection, levels fell to undetectable in 8 of 10 evaluable patients, while two high-stage patients retained circulating tumor markers.

CONCLUSIONS

Modern sequencing technology can simultaneously quantify human gene variants and oncogenic viral genomes in plasma. Falling levels of cancer-specific markers upon resection can help identify viral and human markers to track at subsequent timepoints as a means to evaluate efficacy of interventions.

Improving post-CRT neck assessment in patients with HPV-associated OPSCC (Review)

The positive predictive value (PPV) of 12-week post-therapy FDG-PET/CT is low in patients with Human Papillomavirus (HPV)-associated Oropharyngeal Squamous Cell Carcinoma (OPSCC) after treatment with definitive chemoradiation (CRT). Moreover, the diagnostic performance of post-CRT fine needle aspiration (FNA) in detecting persistent disease is unknown in this population. Given these important shortcomings in post-CRT treatment assessment, head and neck oncologists are limited in appropriately selecting patients for consolidative neck dissection, which results in over-treatment of a favorable risk population. Using the PubMed database, we performed a literature review of published series in HPV-associated OPSCC to investigate potential strategies for improvement of post-CRT neck assessment. Several different approaches were found, including continued surveillance with PET/CT, delayed timing of restaging PET/CT, initial response evaluation with multimodality or alternative imaging, and detection of circulating HPV DNA. At present, the optimal approach to post-CRT treatment assessment is unclear; further investigation and incorporation of new technologies and surveillance protocols will be highly beneficial for patients with HPV-associated OPSCC.

Cross validated serum small extracellular vesicle microRNAs for the detection of oropharyngeal squamous cell carcinoma

BACKGROUND

Oropharyngeal squamous cell carcinoma (OPSCC) is often diagnosed at an advanced stage because the disease often causes minimal symptoms other than metastasis to neck lymph nodes. Better tools are required to assist with the early detection of OPSCC. MicroRNAs (miRNAs, miRs) are potential biomarkers for early head and neck squamous cell cancer diagnosis, prognosis, recurrence, and presence of metastatic disease. However, there is no widespread agreement on a panel of miRNAs with clinically meaningful utility for head and neck squamous cell cancers. This could be due to variations in the collection, storage, pre-processing, and isolation of RNA, but several reports have indicated that the selection and reproducibility of biomarkers has been widely affected by the methods used for data analysis. The primary analysis issues appear to be model overfitting and the incorrect application of statistical techniques. The purpose of this study was to develop a robust statistical approach to identify a miRNA signature that can distinguish controls and patients with inflammatory disease from patients with human papilloma virus positive (HPV +) OPSCC.

METHODS

Small extracellular vesicles were harvested from the serum of 20 control patients, 20 patients with gastroesophageal reflux disease (GORD), and 40 patients with locally advanced HPV + OPSCC. MicroRNAs were purified, and expression profiled on OpenArray™. A novel cross validation method, using lasso regression, was developed to stabilise selection of miRNAs for inclusion in a prediction model. The method, named StaVarSel (for Stable Variable Selection), was used to derive a diagnostic biomarker signature.

RESULTS

A standard cross validation approach was unable to produce a biomarker signature with good cross validated predictive capacity. In contrast, StaVarSel produced a regression model containing 11 miRNA ratios with potential clinical utility. Sample permutations indicated that the estimated cross validated prediction accuracy of the 11-miR-ratio model was not due to chance alone.

CONCLUSIONS

We developed a novel method, StaVarSel, that was able to identify a panel of miRNAs, present in small extracellular vesicles derived from blood serum, that robustly cross validated as a biomarker for the detection of HPV + OPSCC. This approach could be used to derive diagnostic biomarkers of other head and neck cancers.

Circulating tumour DNA alterations as biomarkers for head and neck cancer: a systematic review

Background: Head and neck squamous cell carcinoma (HNSCC) is a significant global burden. The development of a diagnostic or recurrence monitoring test could evolve from the exploitation of molecular markers such as tumour-specific DNA alterations in plasma. The aim of this study was to report specific genetic alterations of DNA in plasma from HNSCC patients, report the diagnostic accuracy, and discuss potentials for a diagnostic or recurrence monitoring test based on circulating tumour DNA (ctDNA).Methods: A systematic search was performed in PubMed, Embase, and Cochrane Library for articles published in English between 1 January 1980 and 24 October 2018. The search terms used were related to ctDNA methylations and mutations in HNSCC patients.Results: We identified 16 studies from four countries (p = 1156 patients, c = 601 controls) examining ctDNA alterations of HNSCC patients. CtDNA methylations were significantly increased in HNSCC patients compared to controls. Five studies investigated ctDNA mutations in HNSCC. The most frequent examined gene mutation was TP53. Eleven studies investigated ctDNA methylations in HNSCC. Nine studies calculated the diagnostic accuracy of ctDNA methylations in HNSCC compared to controls. The most frequent examined gene methylations were CDKN2A, DAPK1, RASSF1, and P15.Conclusion: We found that increasing the number of ctDNA genetic methylations resulted in an increase in diagnostic sensitivity accuracy. No studies investigating ctDNA mutations included a control group. A combination of multiple human ctDNA gene alterations with viral ctDNA are promising tools for developing a ctDNA biomarker for HNSCC.

The Utility of Liquid Biopsies in Radiation Oncology

The use of therapeutic radiation is primarily guided by clinicopathologic factors and medical imaging, whereas molecular biomarkers currently play a comparatively minor role in most settings. Liquid biopsies provide a rich source of noninvasive tumor-specific biomarkers and are amenable to repeated and noninvasive assessment. Here, we review the current status of liquid biopsies and their potential impact on the field of radiation oncology. We focus on established and emerging approaches to analyze circulating tumor DNA and circulating tumor cells from peripheral blood. These promising classes of biomarkers could have an outsized impact on cancer management by meaningfully stratifying patients into risk groups, tracking radiation therapy efficacy during and after treatment, and identifying patients with radiosensitive or radioresistant disease. Finally, we highlight opportunities for future investigation including the need for prospective interventional studies employing liquid biopsies to guide the management of radiation therapy-treated patients.

Molecular Diagnostics in Human Papillomavirus-Related Head and Neck Squamous Cell Carcinoma

The incidence of human papillomavirus (HPV)-related head and neck squamous cell carcinoma continues to increase. Accurate diagnosis of the HPV status of a tumor is vital, as HPV+ versus HPV- tumors represent two unique biological and clinical entities with different treatment strategies. High-risk HPV subtypes encode oncoproteins E6 and E7 that disrupt cellular senescence and ultimately drive tumorigenesis. Current methods for detection of HPV take advantage of this established oncogenic pathway and detect HPV at various biological stages. This review article provides an overview of the existing technologies employed for the detection of HPV and their current or potential future role in management and prognostication.

Clinico-pathological peculiarities of human papilloma virus driven head and neck squamous cell carcinoma: A comprehensive update

AIMS

The current article provides a detailed account of the current understanding of molecular and clinico-pathological aspects of Human papilloma virus (HPV) driven head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

The literature review included most of the landmark trials and clinical studies related to the HPV driven HNSCC.

KEY FINDINGS

HPV positive HNSCC differ distinctly from HPV negative tobacco-related HNSCC, especially in oropharyngeal region. Therefore, the American joint committee on cancer`s latest manual for classification and staging of cancer suggests a separate staging system for HPV positive oropharyngeal cancers. Despite the younger patients being affected and the high propensity for cervical metastasis, the HPV positive oropharyngeal cancers respond much better to the treatment. The association with wild type TP53 and low EGFR expression confers the favorable prognosis in HPV driven HNSCC. Since the association is not universal, we suggest checking for p53 and EGFR expression status before considering de-intensification of therapy. In addition, the presence of matted lymph nodes and five or more nodes could mean relatively poorer prognosis, and are not suitable for de-intensification of therapy. The same is also true probably with higher T stage and co-existing tobacco use. The methods for the detection of p16, HPV DNA, HPV E6/E7 mRNA, anti-E6/E7 antibodies, in tissue, in serum and in saliva of patients, along with their clinical implications are also discussed.

SIGNIFICANCE

This article provides latest developments on the HPV driven HNSCC. 'Diagnosis of transcriptionally active HPV infection,' 'Modalities for surveillance,' 'Implication of de-escalation of therapy' are some of the critical issues that could serve the medical, the research as well as the patient communities.

Circulating human papillomavirus DNA detection in Barrett's dysplasia and esophageal adenocarcinoma

There is evidence to suggest that human papillomaviruses (HPV) are associated with Barrett's dysplasia and esophageal adenocarcinoma. In other HPV-linked cancers such as cervical and oropharyngeal cancer, circulating HPV DNA is a potential biomarker to assist in tumor diagnosis and management. This study aimed to determine whether circulating HPV DNA was detectable in patients with Barrett's dysplasia and esophageal adenocarcinoma, and if so, whether there is any correlation with esophageal tissue HPV status. Plasma from 138 patients representing esophageal adenocarcinoma (N = 41), Barrett's dysplasia (N = 48) and hospital controls (N = 49) were analyzed for the presence of circulating HPV DNA using droplet-digital PCR targeting the E7 gene of HPV types 16 and 18. Circulating HPV DNA was detected in 11/138 (8.0%) study subjects including 1/49 (2.0%) hospital controls, 4/48 (8.3%) Barrett's dysplasia patients, and 6/41 (14.6%) esophageal adenocarcinoma patients. Detection of circulating HPV DNA was higher in patients with HPV-positive esophageal tissue (6/35, 17.1%) compared to those with HPV-negative specimens (5/103; 4.9%) (OR = 4.06; 95% CI 1.15-14.25; P = 0.020). The highest rates of detection occurred in esophageal adenocarcinoma patients, particularly those with invasive tumors that had breached the esophageal submucosa, had regional lymph node involvement or metastatic disease. Circulating HPV DNA was detectable in a subset of Barrett's dysplasia and esophageal adenocarcinoma patients. Detection was associated with tissue HPV positivity and possibly disease severity.

Radiotherapy-Induced Changes in the Systemic Immune and Inflammation Parameters of Head and Neck Cancer Patients

Though radiotherapy is a local therapy, it has systemic effects mainly influencing immune and inflammation processes. This has important consequences in the long-term prognosis and therapy individualization. Our objective was to investigate immune and inflammation-related changes in the peripheral blood of head and neck cancer patients treated with radiotherapy. Peripheral blood cells, plasma and blood cell-derived RNA were isolated from 23 patients before and at two time points after radiotherapy and cellular immune parameters, plasma protein changes and gene expression alterations were studied. Increased regulatory T cells and increased CTLA4 and PD-1 expression on CD4 cells indicated an immune suppression induced by the malignant condition, which was accentuated by radiotherapy. Circulating dendritic cells were strongly elevated before treatment and were not affected by radiotherapy. Decreased endoglin levels in the plasma of patients before treatment were further decreased by radiotherapy. Expression of the FXDR, SESN1, GADD45, DDB2 and MDM2 radiation-response genes were altered in the peripheral blood cells of patients after radiotherapy. All changes were long-lasting, detectable one month after radiotherapy. In conclusion we demonstrated radiotherapy-induced changes in systemic immune parameters of head and neck cancer patients and proposed markers suitable for patient stratification worth investigating in larger patient cohorts.

Diagnostic Tumor Markers in Head and Neck Squamous Cell Carcinoma (HNSCC) in the Clinical Setting

Head and neck squamous cell carcinoma (HNSCC) represents a group of tumors arising in the oral cavity, oropharynx, and larynx. Although HNSCC is traditionally associated with tobacco and alcohol consumption, a growing proportion of head and neck tumors, mainly of the oropharynx, are associated with Human Papilloma Virus (HPV). Recurrent/metastatic disease is characterized by dismal prognosis and there is an unmet need for the development of biomarkers for detection of early disease, accurate prediction of prognosis, and appropriate selection of therapy. Based on the REMARK guidelines, a variety of diagnostic and prognostic biomarkers are being evaluated in clinical trials but their clinical significance is doubtful. Herein, we will focus on biomarkers in HNSCC used in the clinical setting and we will illustrate their clinical relevance.

HPV16 E6/E7 expression in circulating tumor cells in oropharyngeal squamous cell cancers: A pilot study

Objectives

Human papillomavirus-related oropharyngeal squamous cell carcinoma (HPV+ OPSCC) is increasing in incidence. Although HPV+ OPSCC has favorable prognosis, 10 to 25% of HPV+ OPSCCs eventually recur. We sought to evaluate the feasibility of detection of HPV16 E6/E7 expression in Circulating Tumor Cells (CTCs) and its utility as a prognostic tool in HPV16-associated OPSCC.

Materials and methods

We developed a highly sensitive RT-qPCR assay for HPV mRNA expression in EpCAM(+) CTCs. In 22 patients with early stage and locally advanced OPSCC we evaluated HPV16 E6/E7 expression in the EpCAM(+) CTC fraction at baseline and at the end of concurrent chemoradiotherapy. HPV status in pre-therapy formalin-fixed paraffin-embedded (FFPE) tumor biopsies was assessed by p16 immunohistochemistry and polymerase chain reaction (PCR) and double positives were subjected to Real-time qPCR assay for detection of HPV16, 18 and 31 types.

Results

Fourteen of 22 OPSCC (63.6%) were HPV DNA+/p16+. Among HPV+/p16+ patients, 10 patients (71.4%) were HPV16 DNA+. HPV16 E6/E7(+) CTCs were detected in 3 of 10 patients (30%) at baseline and 4 of 9 patients (44.4%) at the end-of-treatment, all of which were p16+/HPV16 DNA+. Survival analysis showed a significantly higher risk for disease relapse (p = 0.001) and death (p = 0.005) in patients with HPV16 E6/E7(+) baseline CTCs.

Conclusion

Detection of HPV E6/E7(+) CTCs might be a useful noninvasive test in liquid biopsy samples for determination of a clinically relevant HPV infection in HPV+ OPSCC. Combined interpretation of HPV E6/E7(+) CTCs with UICC staging data may lead to alteration of risk definition of patient subsets, with improved risk discrimination in early-stage disease.

Unlocking the Potential of Saliva-Based Test to Detect HPV-16-Driven Oropharyngeal Cancer

The incidence of human papillomavirus (HPV)-positive oropharyngeal cancer (OPC) is rising in high-income countries, including Australia. Increasing evidence suggests that accurate HPV testing is pivotal for clinical decision making and treatment planning in these patients. Recently, the eighth edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) tumor-node-metastasis (TNM) staging system for OPC (based on the p16INK4a (p16) status) was proposed and has been implemented. However, the applicability of this new staging system is still far from clear. In our study, n = 127 OPC patients from Queensland, Australia were recruited, and the tumor p16 expression in these patients was examined using immunohistochemical (IHC) analysis. HPV-16 genotyping, viral load, and physical status (episomal versus integrated) in the saliva samples of OPC patients were determined using the qPCR method. A good inter-rater agreement (k = 0.612) was found between tumor p16 expression and oral HPV-16 infection in OPC. Importantly, according to the eighth edition staging system, HPV-16 DNA viral load (>10 copies/50 ng) was significantly associated with the advanced stages of OPC. In concordance with previous studies, a mixed HPV-16 form (partially or fully integrated) was predominately found in OPC patients. Taken together, our data support HPV-16 detection in saliva as a screening biomarker to identify people within the community who are at risk of developing OPC.

Putative Role of Circulating Human Papillomavirus DNA in the Development of Primary Squamous Cell Carcinoma of the Middle Rectum: A Case Report

Here we present the case of a patient affected by rectal squamous cell carcinoma in which we demonstrated the presence of Human Papillomavirus (HPV) by a variety of techniques. Collectively, the virus was detected not only in the tumor but also in some regional lymph nodes and in non-neoplastic mucosa of the upper tract of large bowel. By contrast, it was not identifiable in its common sites of entry, namely oral and ano-genital region. We also found HPV DNA in the plasma-derived exosome. Next, by in vitro studies, we confirmed the capability of HPV DNA-positive exosomes, isolated from the supernatant of a HPV DNA positive cell line (CaSki), to transfer its DNA to human colon cancer and normal cell lines. In the stroma nearby the tumor mass we were able to demonstrate the presence of virus DNA in the stromal compartment, supporting its potential to be transferred from epithelial cells to the stromal ones. Thus, this case report favors the notion that human papillomavirus DNA can be vehiculated by exosomes in the blood of neoplastic patients and that it can be transferred, at least in vitro, to normal and neoplastic cells. Furthermore, we showed the presence of viral DNA and RNA in pluripotent stem cells of non-tumor tissue, suggesting that after viral integration (as demonstrated by p16 and RNA in situ hybridization positivity), stem cells might have been activated into cancer stem cells inducing neoplastic transformation of normal tissue through the inactivation of p53, p21, and Rb. It is conceivable that the virus has elicited its oncogenic effect in this specific site and not elsewhere, despite its wide anatomical distribution in the patient, for a local condition of immune suppression, as demonstrated by the increase of T-regulatory (CD4/CD25/FOXP3 positive) and T-exhausted (CD8/PD-1positive) lymphocytes and the M2 polarization (high CD163/CD68 ratio) of macrophages in the neoplastic microenvironment. It is noteworthy that our findings depicted a static picture of a long-lasting dynamic process that might evolve in the development of tumors in other anatomical sites.