ctDNA transiting into urine is ultrashort and facilitates noninvasive liquid biopsy of HPV+ oropharyngeal cancer.

BACKGROUNDTransrenal cell-free tumor DNA (TR-ctDNA), which transits from the bloodstream into urine, has the potential to enable noninvasive cancer detection for a wide variety of nonurologic cancer types.MethodsUsing whole-genome sequencing, we discovered that urine TR-ctDNA fragments across multiple cancer types are predominantly ultrashort (<50 bp) and, therefore, likely to be missed by conventional ctDNA assays. We developed an ultrashort droplet digital PCR assay to detect TR-ctDNA originating from HPV-associated oropharyngeal squamous cell carcinoma (HPV+ OPSCC) and confirmed that assaying ultrashort DNA is critical for sensitive cancer detection from urine samples.ResultsTR-ctDNA was concordant with plasma ctDNA for cancer detection in patients with HPV+ OPSCC. As proof of concept for using urine TR-ctDNA for posttreatment surveillance, in a small longitudinal case series, TR-ctDNA showed promise for noninvasive detection of recurrence of HPV+ OPSCC.ConclusionOur data indicate that focusing on ultrashort fragments of TR-ctDNA will be important for realizing the full potential of urine-based cancer diagnostics. This has implications for urine-based detection of a wide variety of cancer types and for facilitating access to care through at-home specimen collections.FundingNIH grants R33 CA229023, R21 CA225493; NIH/National Cancer Institute grants U01 CA183848, R01 CA184153, and P30CA046592; American Cancer Society RSG-18-062-01-TBG; American Cancer Society Mission Boost grant MBGI-22-056-01-MBG; and the A. Alfred Taubman Medical Research Institute.

Advances in testing for human papillomavirus -mediated head and neck cancer.

PURPOSE OF REVIEW: New evidence has recently emerged regarding the utility and benefits of dual p16 INKa (p16) and Human papillomavirus (HPV) status testing when determining the diagnosis and prognosis of patients with oropharyngeal cancer. RECENT FINDINGS: HPV RNA polymerase chain reaction (PCR) is the most accurate diagnostic test. The other assays (HPV DNA PCR, HPV DNA/RNA in-situ hybridization (ISH) and p16) applied to formalin fixed tumour tissue have varying but high sensitivities and specificities. Dual p16 and HPV testing identifies discordant (p16+/HPV- or p16-/HPV+) results in 9.2% of cases, who have significantly poorer prognoses than p16+/HPV+, particularly in smokers. The proportion of discordant cases varies by region, and appears to be highest in regions with lowest attributable (p16+/HPV+) fractions. Dual testing improves prognostication for oropharyngeal cancer cases by identifying discordant cases and improving the prognostic power of the Tumour Node Metastasis (TNM) classification, especially in regions with high discordant rates. SUMMARY: Dual testing is essential when considering patients for clinical trials of treatment de-escalation, and may be important when counselling patients on prognosis, especially in regions with high discordant rates and in smokers.

Mapping the research landscape of HPV-positive oropharyngeal cancer: a bibliometric analysis.

OBJECTIVE: The aim of the study is to evaluate the scientific interest, the collaboration patterns and the emerging trends regarding HPV+ OPSCC diagnosis and treatment. MATERIALS AND METHODS: A cross-sectional bibliometric analysis of articles reporting on HPV+ OPSCC within Scopus database was performed and all documents published up to December 31th, 2022 were eligible for analysis. Outcomes included the exploration of key characteristics (number of manuscripts published per year, growth rate, top productive countries, most highly cited papers, and the most well-represented journals), collaboration parameters (international collaboration ratio and networks, co-occurrence networks), keywords analysis (trend topics, factorial analysis). RESULTS: A total of 5200 documents were found, published from March, 1987 to December, 2022. The number of publications increased annually with an average growth rate of 19.94%, reaching a peak of 680 documents published in 2021. The 10 most cited documents (range 1105-4645) were published from 2000 to 2012. The keywords factorial analysis revealed two main clusters: one on epidemiology, diagnosis, prevention and association with other HPV tumors; the other one about the therapeutic options. According to the frequency of keywords, new items are emerging in the last three years regarding the application of Artifical Intelligence (machine learning and radiomics) and the diagnostic biomarkers (circulating tumor DNA). CONCLUSIONS: This bibliometric analysis highlights the importance of research efforts in prevention, diagnostics, and treatment strategies for this disease. Given the urgency of optimizing treatment and improving clinical outcomes, further clinical trials are needed to bridge unaddressed gaps in the management of HPV+ OPSCC patients.

Identification of a Biomarker Panel from Genome-Wide Methylation to Detect Early HPV-Associated Oropharyngeal Cancer.

As oropharyngeal cancer (OPC) associated with human papillomavirus (HPV) increases in men, the need for a screening test to diagnose OPC early is crucial. This study agnostically identified differentially methylated CpG sites to identify additional biomarkers to improve screening for early OPC.DNA was extracted from oral gargles of 89 early cases and 108 frequency matched healthy controls, and processed for genome-wide methylation using the Illumina Infinium MethylationEPIC BeadChip. Selected sites were combined with our prior methylation data in the EPB41L3 gene (CpG sites 438, 427, and 425) and oral HPV16 and HPV18 status were considered as binary variables (positive/negative). Lasso regression identified CpG sites strongly associated with early OPC. ROC curves with AUC were generated. The panel was validated utilizing bootstrap resampling.Machine learning analyses identified 14 markers that are significantly associated with early OPC, including one EPB41L3 CpG site (438) and oral HPV16 status. A final model was trained on all available samples using the discovered panel and was able to predict early OPC compared with controls with an AUC of 0.970 on the training set. In the bootstrap validation sets, the average AUC was 0.935, indicating adequate internal validity.Our data suggest that this panel can detect OPC early, however external validation of this panel is needed. Further refinement of a panel of biomarkers to diagnose OPC earlier is urgently needed to prevent complex treatment of OPC and associated comorbidities, while reducing risk of recurrence. PREVENTION RELEVANCE: This study identified biomarkers using genome-wide methylation to create a panel capable of discerning early oropharyngeal cancer (OPC) from those without OPC. Such a biomarker panel would be an effective tool to detect OPC early and prevent complications of treatment associated with later diagnosis.

Unveiling Liquid Gold: Lymph as an HPV Marker in OPSCC to Guide Treatment Decisions.

Distinguishing low- versus high-risk HPV-associated oropharyngeal squamous cell carcinoma (OPSCC) is pivotal for tailoring treatment. Liquid biopsy, measuring cell-free HPV-DNA in serum and saliva, assesses treatment response and early-recurrence risk. Postoperative lymphatic fluid may better guide future adjuvant therapy decisions due to its proximity to primary lesions and lymph nodes. See related article by Earland et al., p. 1409.

Developing and Validating a Multivariable Prognostic-Predictive Classifier for Treatment Escalation of Oropharyngeal Squamous Cell Carcinoma: The PREDICTR-OPC Study.

PURPOSE: While there are several prognostic classifiers, to date, there are no validated predictive models that inform treatment selection for oropharyngeal squamous cell carcinoma (OPSCC).Our aim was to develop clinical and/or biomarker predictive models for patient outcome and treatment escalation for OPSCC. EXPERIMENTAL DESIGN: We retrospectively collated clinical data and samples from a consecutive cohort of OPSCC cases treated with curative intent at ten secondary care centers in United Kingdom and Poland between 1999 and 2012. We constructed tissue microarrays, which were stained and scored for 10 biomarkers. We then undertook multivariable regression of eight clinical parameters and 10 biomarkers on a development cohort of 600 patients. Models were validated on an independent, retrospectively collected, 385-patient cohort. RESULTS: A total of 985 subjects (median follow-up 5.03 years, range: 4.73-5.21 years) were included. The final biomarker classifier, comprising p16 and survivin immunohistochemistry, high-risk human papillomavirus (HPV) DNA in situ hybridization, and tumor-infiltrating lymphocytes, predicted benefit from combined surgery + adjuvant chemo/radiotherapy over primary chemoradiotherapy in the high-risk group [3-year overall survival (OS) 63.1% vs. 41.1%, respectively, HR = 0.32; 95% confidence interval (CI), 0.16-0.65; P = 0.002], but not in the low-risk group (HR = 0.4; 95% CI, 0.14-1.24; P = 0.114). On further adjustment by propensity scores, the adjusted HR in the high-risk group was 0.34, 95% CI = 0.17-0.67, P = 0.002, and in the low-risk group HR was 0.5, 95% CI = 0.1-2.38, P = 0.384. The concordance index was 0.73. CONCLUSIONS: We have developed a prognostic classifier, which also appears to demonstrate moderate predictive ability. External validation in a prospective setting is now underway to confirm this and prepare for clinical adoption.

Contribution of public oral pathology services to the diagnosis of oral and oropharyngeal cancer in Brazil.

This study aimed to evaluate the contribution of oral and maxillofacial pathology laboratories (OMPLs) in Brazilian public universities to the diagnosis of lip, oral cavity, and oropharyngeal squamous cell carcinoma (SCC). A cross-sectional study was performed using biopsy records from a consortium of sixteen public OMPLs from all regions of Brazil (North, Northeast, Central-West, Southeast, and South). Clinical and demographic data of patients diagnosed with lip, oral cavity, and oropharyngeal SCC between 2010 and 2019 were collected from the patients' histopathological records. Of the 120,010 oral and maxillofacial biopsies (2010-2019), 6.9% (8,321 cases) were diagnosed as lip (0.8%, 951 cases), oral cavity (4.9%, 5,971 cases), and oropharyngeal (1.2%, 1,399 cases) SCCs. Most cases were from Brazil's Southeast (64.5%), where six of the OMPLs analyzed are located. The predominant profile of patients with lip and oral cavity SCC was Caucasian men, with a mean age over 60 years, low schooling level, and a previous history of heavy tobacco consumption. In the oropharyngeal group, the majority were non-Caucasian men, with a mean age under 60 years, had a low education level, and were former/current tobacco and alcohol users. According to data from the Brazilian National Cancer Institute, approximately 9.9% of the total lip, oral cavity, and oropharyngeal SCCs reported over the last decade in Brazil may have been diagnosed at the OMPLs included in the current study. Therefore, this data confirms the contribution of public OMPLs with respect to the important diagnostic support they provide to the oral healthcare services extended by the Brazilian Public Health System.

Current status and future perspectives of oral HPV testing in the diagnosis and monitoring of oropharyngeal cancer. A review.

HPV16 status in oropharyngeal cancer (OPC) is an important prognostic factor. Its determination, based on immunistochemical analysis of p16 oncoprotein requires an invasive biopsy. Thus, alternative methods are being sought. Determining oral HPV16 status appears to be a promising alternative. However, it is not used routinely. This prompted us to perform a systematic literature review enabling us to evaluate the diagnostic and predictive ability of this approach. Thirty-four relevant studies were finally selected. For determination of HPV status in OPC, the calculated average sensitivity and specificity for oral sampling was 74% and 91%, respectively, with p16 tumour tissue marker being the gold standard. The method appears to be valuable in monitoring treatment response as well as the biological activity of the tumour, enabling early detection of persistent or relapsing carcinoma sufficiently long before its clinical and/or radiological manifestation. It can also contribute to identification of the primary tumour in cases of metastases of unknown origin. Last but not least, the screening HPV oral testing would help to identify individuals with persistent HPV oral infection who are at increased risk of development of OPC.

Oral/oropharyngeal "selfies" in gay and bisexual men: a pilot study exploring oropharyngeal screening for HPV-related possible malignancies.

Objectives: This study aims to determine the potential uptake and quality of oropharyngeal "selfies" taken by gay/bisexual men as a screening approach for HPV-associated oropharyngeal cancer. Methods: From 1,699 gay/bisexual men in the US, surveyed about knowledge and attitudes to HPV-associated oropharyngeal cancer, a random sample of 320 men were invited to take an oropharyngeal "selfie" by smartphone and send it to the study website: 113 (35.5%) did so. Images were rated for quality by three healthcare professional raters blinded to each other's rating, with an otolaryngologist as the gold standard. In the second wave, those whose images were rated as unacceptable were sent a short instructional video and asked to send another image. Of the 65 invited, 46 did so. An additional 15.2% sent acceptable images, and a total of 28.3% of the sample was acceptable. Results: A total of 1,121 men willing to participate in the future study who believed they could take a quality "oral selfie" were potentially eligible for this activity. A random sample of 320 participated: 153 participants started (47.8%) and 113 participants (35.3%) submitted an image. Responders were more likely to be younger, have higher knowledge scores on oropharyngeal HPV-related cancer, and have had HPV vaccination. There was high agreement between the three raters. Images of good/acceptable quality were 22.1%; oropharynx partially occluded images were 29.2%; oropharynx not visible images were 18.6%; images too dark were 21.2%; and images too small were 8.8%. From the second wave of requests with instructional videos, an additional 15.2% sent in quality images, with the remaining issues being partial occlusion of the tonsils by the tongue. Conclusion: One-third of the invited gay and bisexual men sent oropharyngeal selfie images to the study website and a total of 28.3% were of clinically acceptable quality. Following an instructional video on poorer-quality images, additional quality images were received. One barrier, i.e., partial occlusion of the oropharynx by the tongue remained. Quality oropharyngeal "selfies" are obtainable online.

[Clinical characteristics and efficacy of oropharyngeal carcinoma with secondary primary tumor].

Objective:To analysis the clinical features and prognosis in oropharyngeal carcinoma with secondary primary tumor. Methods:A retrospective analysis was performed on 468 pathologically confirmed oropharyngeal cancer as the primary tumor patients with p16 status, excluded distant metastasis, and admitted to the Chinese Academy of Medical Sciences from January 2010 to December 2020. The clinical features and prognosis of the secondary primary tumor were analyzed. Results:Among 468 patients with oropharyngeal cancer treated at initial diagnosed, 222 cases were P16-negative. With a median follow-up time of 64.3 months, 66 cases developed second primary cancer, with an incidence of 29.3%, among which 63.6%（42/66） were synchronous and 36.4%（24/66） were heterochronous, esophagus was the most commonly involved site. The 5-year OS of p16-negative oropharyngeal carcinoma with synchronous second primary cancer, without second primary cancer and with heterogeneous second primary cancer were 26.3% and 57.3% and 73.2%（P=0.001）; The second primary cancer accounted for 11.2%（12/107） of the deaths in the whole group, among them, the heterochronous second primary accounted for 75.0%（9/12）. There were 246 patients with p16 positive, with a median follow-up time of 52.4 months, 20 patients developed second primary cancer（8.1%）. Among them, 65.0%（13/20） were synchronous and 35.0%（7/20） were heterochronous. Esophagus was the most commonly involved site. The 4-year OS of p16-positive with synchronous, heterochronous and non-second primary cancer group were 51.9%, 80.7% and 83.3%. Secondary primary cancer accounted for 3.8%（2/52） of all deaths in p16 positvie group. Conclusion:The incidence of second primary cancer of p16 positive and negative oropharyngeal carcinoma were different. The esophagus was the most commonly involved site regardless of p16 status. Regardless of p16 status, the survival of patients with synchronous second primary cancer was worse than those without second primary cancer. For p16-negative oropharyngeal carcinoma, the prognosis was better in patients with heterogeneous second primary cancer, the second primary cancer is one of the main causes of death.

[Research progress in diagnosis and treatment of HPV-associated oropharyngeal squamous cell carcinoma].

Oropharyngeal carcinoma is one of the most common malignant tumors of head and neck. In recent years, the incidence of Human papilloma virus-associated oropharyngeal squamous cell carcinoma（HPV-OPSCC） has been increasing year by year. With the advancement of minimally invasive surgical techniques, the wide application of intensity modulated radiation therapy, and the demand of patients for organ function protection and higher quality of life, the unique biological behavior and better prognosis of HPV-OPSCC have led to the exploration of a series of attenuated treatment modes. This article reviews the diagnosis and treatment status of oropharyngeal cancer and related research progress based on relevant reports.

Lead Time to Recurrence After Posttreatment Plasma and Saliva HPV DNA Testing in Patients With Low-Risk HPV Oropharynx Cancer.

Importance: Head and neck squamous cell carcinoma is a highly lethal cancer that is often associated with human papillomavirus (HPV). Recent studies have shown promise in the use of HPV DNA detection in salivary rinses and plasma as a factor associated with a future diagnosis of HPV-positive oropharynx cancer (HPVOPC). However, the use of plasma and salivary HPV DNA detection in defining risk for recurrence in the context of a prospective, phase 3, clinical trial coupled with standardized clinical surveillance has not been reported. Objective: To identify patients with low-risk HPVOPC at risk for recurrence by detection of HPV16 DNA in plasma and salivary rinses. Design, Setting, and Participants: In this cohort study, 233 low-risk patients were recruited from 32 head and neck treatment centers in Ireland (1 [3.1%]), the Netherlands (1 [3.1%]), and the UK (30 [93.8%]) as part of the DE-ESCALATE HPV trial, an open-label, phase 3 randomized clinical trial examining treatment with cetuximab vs cisplatin for HPVOPC. Patients were assayed for the presence of HPV16 DNA in plasma and salivary rinse via a quantitative polymerase chain reaction-based assay. Main Outcomes and Measures: Assay results were associated with risk of recurrence and lead time from HPV16 DNA detection to recurrence. Results: Of 233 patients, 45 (19.3%) were women, and the mean (SD) age was 57.01 (8.45) years. A total 1040 salivary or blood samples were collected during the course of the study. With a median follow-up of 760 days, the sensitivity and specificity of combined plasma and salivary rinse HPV DNA assays for detecting recurrence were 65% and 87%, respectively. There was a median lead time of positive test to event/recurrence date of 19 days (range, 0-536 days) and mean (SD) of 122 (169.8) days. Conclusion and Relevance: The results of this cohort study suggest that in the setting of a randomized, prospective, phase 3 trial for low-risk patients with HPVOPC, posttreatment presence of HPV DNA in plasma and salivary rinses is associated with recurrence; a lead time between test positivity and clinical recurrence offers a potential opportunity for earlier detection of recurrence.

Circulating Tumor DNA in Human Papillomavirus-Mediated Oropharynx Cancer: Leveraging Early Data to Inform Future Directions.

ABSTRACT: Circulating tumor DNA (ctDNA) has become an area of intense study in many solid malignancies including head and neck cancer. This is of particular interest for human papillomavirus-mediated oropharyngeal squamous cell carcinoma as this cohort of patients has excellent survival and is undergoing current clinical trials aimed at treatment de-escalation. Recent studies have demonstrated the prognostic implications of pretreatment ctDNA and the utility of monitoring ctDNA during and posttreatment; however, there is a need for a more critical understanding of ctDNA as it is beginning to be incorporated into clinical trials. This review discusses the current state of ctDNA in oropharynx cancer focusing on ctDNA kinetics and minimal residual disease detection and ends with a discussion of future applications.

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.

Tumor-Derived Exosomes and the Role of Liquid Biopsy in Human Papillomavirus Oropharyngeal Squamous Cell Carcinoma.

ABSTRACT: The global incidence of human papillomavirus-positive (HPV+) head and neck squamous cell carcinoma (HNSCC) has surged in recent decades, with HPV+ HNSCC accounting for >70% of oropharynx cancers in the United States. Its incidence in men has surpassed that of HPV+ cervical cancer in women, and reliable assays are needed for early detection and to monitor response to therapy. Human papillomavirus-positive OPSCC has a more favorable response to therapy and prognosis than HPV-negative (HPV-) HNSCC, motivating regimens to deintensify curative surgery or chemoradiotherapy protocols. A barrier to deintensifying and personalizing therapy is lack of reliable predictive biomarkers. Furthermore, HPV- HNSCC survival rates are static without reliable surveillance biomarkers available. The emergence of circulating plasma-based biomarkers reflecting the tumor-immune microenvironment heralds a new era in HNSCC diagnosis and therapy. We review evidence on tumor-derived extracellular vesicles (exosomes) as biomarkers for diagnosis, prognostication, and treatment in HPV+ and HPV- HNSCC.

Mu and Kappa opioid receptor immunolabeling indicates the prognosis of oropharyngeal squamous cell carcinoma: A cross-sectional observational study.

BACKGROUND: Opioids are the most effective drugs currently available for cancer pain management. The administration of morphine, in addition to its analgesic effect, can alter tumor development. OBJECTIVE: To characterize the immunoexpression of opioid receptors µ and κ in oropharyngeal squamous cell carcinoma, and correlate it with prognostic factors, proliferation markers, and cell death. MATERIALS AND METHODS: A retrospective, cross-sectional observational study was carried out with 50 patients diagnosed at Haroldo Juaçaba Hospital. Sociodemographic, clinicopathological, and overall survival data were collected, and excisional biopsies were taken for immunohistochemistry using tissue microarrays for opioid receptors µ and κ, Ki-67, and caspase-3. Immunolabeling was evaluated and correlated with other variables using Mann-Whitney, Kruskal-Wallis, Spearman correlation, log-rank (Mantel-Cox), and Cox regression tests. RESULTS: Immunoexpression of opioid receptors µ and κ, Ki-67, and caspase-3 was significantly higher in p16+ and p16- primary tumors and lymph node metastases than in surgical resection margins. The overall survival of patients with p16- tumors was 57.53 ± 8.43 months and that of patients with p16+ tumors was slightly higher at 75.92 ± 11.14 months. Multivariate analysis showed that the expression of opioid receptors µ and κ in the nucleus was directly associated with a lower and higher risk of death, respectively. CONCLUSION: We found increased expression of opioid receptors µ and κ in tumor tissues. The nuclear expression of opioid receptors µ and κ influences overall survival and may be a prognostic factor of oropharyngeal squamous cell carcinoma.

Salivary micro RNAs as biomarkers for oropharyngeal cancer.

BACKGROUND: Despite the rising incidence, particularly of the human papillomavirus (HPV)-associated fraction of oropharyngeal cancer (OPC), there are no early detection methods for OPC. Considering the close association between saliva and head and neck cancers, this study was designed to investigate salivary micro RNA (miRNAs) associated with OPC, especially focusing on HPV-positive OPC. METHODS: Saliva was collected from OPC patients at diagnosis and patients were clinically followed up ≤5 years. Salivary small RNA isolated from HPV-positive OPC patients (N = 6), and HPV-positive (N = 4) and negative controls (N = 6) were analysed by next-generation sequencing to identify dysregulated miRNAs. Discovered miRNAs were validated by quantitative PCR using two different assays in a separate cohort of patients (OPC = 91, controls = 92). The relative expression was calculated considering SNORD-96A as the normalizer. Candidate miRNAs with diagnostic and prognostic potential were evaluated by generalized logistic regression. RESULTS: A panel consisting of nine miRNAs was identified to have the best diagnostic performance to discriminate HPV-positive OPC from HPV-positive controls (AUC- validation-1 = 94.8%, validation-2 = 98%). Further, a panel consisting of six miRNAs were identified to discriminate OPC from controls regardless of the HPV status (AUC- validation-1 = 77.2%, validation-2 = 86.7%). In addition, the downregulation of hsa-miR-7-5p was significantly associated with poor overall survival of OPC patients (HR = 0.638). A panel consisting of nine miRNAs were identified for the prediction of the overall survival of the OPC patients (log-rank test-p = 0.0008). CONCLUSION: This study highlights that salivary miRNAs can play an essential role in the detection and prognostication of OPC.

[ctHPV-DNA based precision oncology for patients with oropharyngeal cancer - Where are we?] / ctHPV-DNA-basierte Präzisionsonkologie für Patienten mit Oropharynxkarzinom ­ wo stehen wir?

Human papillomavirus (HPV) is an established etiologic factor for cancers in the head and neck region, specifically for Oropharyngeal Squamous Cell Carcinoma (OPSCC). The comparatively good overall survival justifies the current discussion regarding therapy de-escalation for patients with a low-risk profile. In addition to the immunohistochemistry-based biomarker p16INK4a, there is still a need for diagnostic and prognostic biomarkers that allow risk stratification and monitoring during therapy and follow-up of these patients. In recent years, liquid biopsy, especially in the form of plasma samples, has gained importance and is already used to monitor viral DNA in patients with Epstein-Barr virus-associated nasopharyngeal carcinoma. Circulating DNA (ctDNA) released by the tumor into the bloodstream is particularly suitable for a high specificity in detecting virus-associated tumors. Detection of viral E6 and E7 oncogenes in HPV-positive OPSCC is predominantly performed by droplet digital/quantitative PCR as well as next generation sequencing. Detection of circulating HPV-DNA derived from tumor cells (ctHPV-DNA) at diagnosis is associated with advanced tumor stage, locoregional and distant metastases. Longitudinal studies have further demonstrated that detectable and/or increasing ctHPV-DNA levels are associated with treatment failure and disease relapse. However, a standardization of the diagnostic procedure is necessary before introducing liquid biopsy into the clinical routine. In the future, this might allow a valid reflection of disease progression in HPV-positive OPSCC.