Cell-free human papillomavirus DNA kinetics after surgery for human papillomavirus-associated oropharyngeal cancer

Circulating HPV Tumor DNA and Molecular Residual Disease in HPV-Positive Oropharyngeal Cancers: A Scoping Review

The aim of this review is to assess the utility of circulating HPV tumor DNA (ctHPVDNA) clearance in the monitoring of molecular residual disease in HPV-related oropharyngeal squamous cell carcinoma (OPSCC) patients. Recently, ctHPVDNA in patient plasma was found to be a promising biomarker for HPV OPSCC. Changes in this biomarker appear to be associated with treatment response and may be useful for identifying molecular residual disease. A review of the literature was performed using PubMed/MEDLINE, EMBASE, and Cochrane Library databases according to the PRISMA criteria for scoping reviews (from 2017 to July 2024). A total of 5 articles and 562 patients have been included. Three studies examine the role of ctHPVDNA clearance in CRT, while the remaining two studies consider surgery as a treatment option. The results of this scoping review indicate that ctHPVDNA has a potential role to serve as a valuable biomarker in the assessment of molecular residual disease. Further studies are required to confirm the efficacy of this marker for stratifying this group of patients.

Sensitive and Specific Droplet Digital PCR Assays for Circulating Tumor HPV DNA: Development, Validation, and Clinical Application in HPV-Associated Cancers

BACKGROUND

Human papillomavirus (HPV) has emerged as a significant contributor to cancer incidence globally, particularly in the context of oropharyngeal squamous cell carcinoma (OPSCC) and cancer of unknown primary (HNCUP). This study aimed to develop and validate droplet digital PCR (ddPCR) assays for the detection of circulating tumor HPV DNA (ctHPV-DNA) in plasma, focusing on high-risk HPV genotypes associated with these cancers.

METHODS

ddPCR assays for HPV16, 18, 33, 35, 56, and 59 were developed and tested using gBlocks, HPV cell-free DNA, fragmented tumor HPV+ DNA, and plasma samples from patients with HPV+ OPSCC (n = 110) and HNCUP (n = 9).

RESULTS

Assays demonstrated robust technical sensitivity across all tested HPV genotypes. Clinical application of the assays on a cohort of patients with HPV+ OPSCC and HNCUP revealed high sensitivity (91.6%) and wide variability in ctHPV-DNA levels. Analyses revealed correlations between ctHPV-DNA levels and TNM stage and tumor viral load. The association between ctHPV-DNA and tumor viral load persisted even after adjusting for TNM stage. At posttreatment, 72.5% of samples had reached undetectable ctHPV-DNA levels. Having detectable ctHPV-DNA posttreatment was associated with a higher ctHPV-DNA level at diagnosis and higher viral load at diagnosis.

CONCLUSION

The findings underscore the potential of ctHPV-DNA as a biomarker for monitoring HPV+ cancers and offer insights into tumor dynamics. Implementation of these assays in clinical practice could enhance no-invasive treatment monitoring and recurrence detection in HPV-associated cancers.

CLINICAL TRIALS

NCT05904327.

Preliminary Results from Retrospective Correlation of Circulating Tumor DNA (ct-DNA) with Imaging for HPV-Positive Oropharyngeal Squamous Cell Carcinoma

The role of molecular markers is increasingly being recognized for head and neck tumors, ranging from benign lesions like paragangliomas to malignancies like squamous cell carcinomas. Multiple studies have recently validated blood tests for circulating tumor tissue-modified viral human papillomavirus DNA (HPV ct-DNA) for posttreatment surveillance of HPV-driven oropharyngeal squamous cell carcinomas. This technology quantifies fragments of circulating DNA that are shed into the blood stream with very high (>95%) positive and negative predictive values and are also highly sensitive in distinguishing tumor HPV-DNA from a noncancerous source. This study has a cohort of 34 patients with HPV-driven oropharyngeal squamous cell carcinomas, having at least 3 sequential imaging studies and ct-DNA values. The study showed a strong positive correlation between the imaging findings and the ct-DNA level in recurrent HPV-positive oropharyngeal squamous cell carcinomas. Findings also include the 100% negative predictive value of HPV ct-DNA tests to rule out tumor recurrence. At our institution, we are now routinely performing the ct-DNA assay for surveillance of treated HPV oropharyngeal squamous cell carcinomas. Correlation among clinical, radiologic, and biomarker findings are now part of routine discussions during the multidisciplinary tumor boards.

The landscape of circulating tumor HPV DNA and TTMV-HPVDNA for surveillance of HPV-oropharyngeal carcinoma: systematic review and meta-analysis

BACKGROUND

Human papilloma virus (HPV) related cancers of the oropharynx are rapidly increasing in incidence and may soon represent the majority of all head and neck cancers. Improved monitoring and surveillance methods are thus an urgent need in public health.

MAIN TEXT

The goal is to highlight the current potential and limitations of liquid biopsy through a meta analytic study on ctHPVDNA and TTMV-HPVDNA. It was performed a Literature search on articles published until December 2023 using three different databases: MEDLINE, Embase, and Cochrane Library. Studies that evaluated post-treatment ctHPVDNA and TTMV-HPVDNA in patients with HPV + OPSCC, studies reporting complete data on the diagnostic accuracy in recurrence, or in which the number of true positives, false positives, true negatives, and false negatives was extractable, and methods of detection of viral DNA clearly defined. The meta-analysis was conducted following the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) reporting guidelines. The aim of this meta-analysis was to evaluate the sensitivity, specificity, and accuracy of ctHPVDNA and TTMV by ddPCR to define its efficacy in clinical setting for the follow up of HPV-OPSCC.

CONCLUSION

The 12 studies included in the meta-analysis provided a total of 1311 patients for the analysis (398 valuated with ctHPVDNA and 913 with TTMV-HPVDNA). Pooled sensitivity and specificity were 86% (95% CI: 78%-91%) and 96% (95% CI: 91%-99%), respectively; negative and positive likelihood ratios were 0.072 (95% CI: 0.057-0.093) and 24.7 (95% CI: 6.5-93.2), respectively; pooled DOR was 371.66 (95% CI: 179.1-918). The area under the curve (AUC) was 0.81 (95% CI, 0.67-0.91). Liquid biopsy for the identification of cell free DNA might identify earlier recurrence in HPV + OPSCC patients. At the present time, liquid biopsy protocol needs to be standardized and liquid biopsy cannot yet be used in clinical setting. In the future, a multidimensional integrated approach which links multiple clinical, radiological, and laboratory data will contribute to obtain the best follow-up strategies for the follow-up of HPV-OPSCC.

The Next Chapter in Cancer Diagnostics: Advances in HPV-Positive Head and Neck Cancer

Human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC), particularly oropharyngeal squamous cell carcinoma (OPSCC), is an increasingly prevalent pathology worldwide, especially in developed countries. For diagnosing HPV in HNSCC, the combination of p16 immunohistochemistry (IHC) and polymerase chain reaction (PCR) offers high sensitivity and specificity, with p16 IHC being a reliable initial screen and PCR confirming HPV presence. Advanced techniques like next-generation sequencing (NGS) and RNA-based assays provide detailed insights but are primarily used in research settings. Regardless of HPV status, standard oncological treatments currently include surgery, radiation, and/or chemotherapy. This conventional approach does not account for the typically better prognosis of HPV-positive HNSCC patients, leading to increased chemo/radiation-induced secondary morbidities and reduced quality of life. Therefore, it is crucial to identify and detect HPV positivity and other molecular characteristics of HNSCC to personalize treatment strategies. This comprehensive review aims to summarize current knowledge on various HPV detection techniques and evaluate their advantages and disadvantages, with a focus on developing methodologies to identify new biomarkers in HPV-positive HNSCC. The review discusses direct and indirect HPV examination in tumor tissue, DNA- and RNA-based detection techniques, protein-based markers, liquid biopsy potentials, immune-related markers, epigenetic markers, novel biomarkers, and emerging technologies, providing an overall insight into the current state of knowledge.

Quantification of human papillomavirus cell-free DNA from low-volume blood plasma samples by digital PCR

The incidence rate of human papillomavirus-driven oropharyngeal cancer (HPV-OPC) is increasing in countries with high human development index. HPV cell-free DNA (cfDNA) isolated from 3 to 4 mL blood plasma has been successfully used for therapy surveillance. A highly discussed application of HPV-cfDNA is early detection of HPV-OPC. This requires sensitive and specific cfDNA detection as cfDNA levels can be very low. To study the predictive power of pre-diagnostic HPV-cfDNA, archived samples from epidemiological cohorts with limited plasma volume are an important source. To establish a cfDNA detection workflow for low plasma volumes, we compared cfDNA purification methods [MagNA Pure 96 (MP96) and QIAamp ccfDNA/RNA] and digital PCR systems (Biorad QX200 and QIAGEN QIAcuity One). Final assay validation included 65 low-volume plasma samples from oropharyngeal cancer (OPC) patients with defined HPV status stored for 2-9 years. MP96 yielded a 28% higher cfDNA isolation efficiency in comparison to QIAamp. Both digital PCR systems showed comparable analytical sensitivity (6-17 copies for HPV16 and HPV33), but QIAcuity detected both types in the same assay. In the validation set, the assay had 80% sensitivity (n = 28/35) for HPV16 and HPV33 and a specificity of 97% (n = 29/30). In samples with ≥750 µL plasma, the sensitivity was 85% (n = 17/20), while in samples with <750 µL plasma, it was 73% (n = 11/15). Despite the expected drop in sensitivity with decreased plasma volume, the assay is sensitive and highly specific even in low-volume samples and thus suited for studies exploring HPV-cfDNA as an early HPV-OPC detection marker in low-volume archival material.IMPORTANCEHPV-OPC has a favorable prognosis compared to HPV-negative OPC. However, the majority of tumors is diagnosed after regional spread, thus making intensive treatment necessary. This can cause lasting morbidity with a large impact on quality of life. One potential method to decrease treatment-related morbidity is early detection of the cancer. HPV cfDNA has been successfully used for therapy surveillance and has also been detected in pre-diagnostic samples of HPV-OPC patients. These pre-diagnostic samples are only commonly available from biobanks, which usually only have small volumes of blood plasma available. Hence, we have developed a workflow optimized for small-volume archival samples. With this method, a high sensitivity can be achieved despite sample limitations, making it suitable to conduct further large-scale biobank studies of HPV-cfDNA as a prognostic biomarker for HPV-OPC.

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.

Assessing the feasibility of a multimodal liquid biopsy for the diagnosis of HPV-associated oropharyngeal squamous cell carcinoma

OBJECTIVES

In this feasibility study, we explored the combined use of circulating tumor human papillomavirus (HPV) DNA (ctHPVDNA) and HPV serology as diagnostic tests for HPV-associated oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

Among patients with research-banked serum or plasma at diagnosis, IgG antibodies to oncoproteins from HPV types 16, 18, 31, 33, 35, 45, 52, and 58 were detected with multiplex serology. Positivity for HPV 16 was defined based on detection of combinations of anti-E6, E1, E2, and E7 and for other high-risk types on detection of anti-E6 and anti-E7. Circulating tumor HPV DNA was detected by custom digital droplet polymerase chain reaction (ddPCR) assays for HPV types 16, 18, 33, 35, and 45. p16 immunohistochemistry and high-risk HPV RNA in situ hybridization (ISH) using a cocktail of 18 high-risk HPV types were performed on tissue.

RESULTS

Of 75 patients, 67 (89.3%) were HPV-associated (p16 and HPV RNA ISH positive) and 8 (10.7%) were HPV-independent. All 8 HPV-independent patients were seronegative and negative for ctHPVDNA (100% specificity). Serology was positive in 53 (79.1%) of 67 HPV-associated patients, while ddPCR was positive for ctHPVDNA in 59 (88.6%) of 67 HPV-associated patients. Requiring both tests to be positive resulted in a sensitivity of 50 (74.6%) of 67 while combining assays (either positive) improved sensitivity to 62 (92.6%) of 67.

CONCLUSIONS

Compared to HPV RNA ISH, HPV serology and ctHPVDNA are sensitive and highly specific biomarkers for HPV-associated OPSCC at the time of presentation.

Circulating Tumor DNA in the Immediate Postoperative Setting

BACKGROUND

Circulating tumor DNA (ctDNA) has emerged as an accurate real-time biomarker of disease status across many solid tumor types. Most studies evaluating the utility of ctDNA have focused on time points weeks to months after surgery, which, for many cancer types, is significantly later than decision-making time points for adjuvant treatment. In this systematic review, we summarize the state of the literature on the feasibility of using ctDNA as a biomarker in the immediate postoperative period.

METHODS

We performed a systematic review evaluating the early kinetics, defined here as 3 days of ctDNA in patients who underwent curative-intent surgery.

RESULTS

Among the 2057 studies identified, eight cohort studies met the criteria for evaluation. Across six different cancer types, all studies showed an increased risk of cancer recurrence in patients with detectable ctDNA in the immediate postoperative period.

CONCLUSION

While ctDNA clearance kinetics appear to vary based on tumor type, across all studies detectable ctDNA after surgery was predictive of recurrence, suggesting early postoperative time points could be feasibly used for determining minimal residual disease. However, larger studies need to be performed to better understand the precise kinetics of ctDNA clearance across different cancer types as well as to determine optimal postoperative time points.

De-Escalated Therapy and Early Treatment of Recurrences in HPV-Associated Head and Neck Cancer: The Potential for Biomarkers to Revolutionize Personalized Therapy

Human papillomavirus-associated (HPV+) head and neck squamous cell carcinoma (HNSCC) is the most common HPV-associated cancer in the United States, with a rapid increase in incidence over the last two decades. The burden of HPV+ HNSCC is likely to continue to rise, and given the long latency between infection and the development of HPV+ HNSCC, it is estimated that the effect of the HPV vaccine will not be reflected in HNSCC prevalence until 2060. Efforts have begun to decrease morbidity of standard therapies for this disease, and its improved characterization is being leveraged to identify and target molecular vulnerabilities. Companion biomarkers for new therapies will identify responsive tumors. A more basic understanding of two mechanisms of HPV carcinogenesis in the head and neck has identified subtypes of HPV+ HNSCC that correlate with different carcinogenic programs and that identify tumors with good or poor prognosis. Current development of biomarkers that reliably identify these two subtypes, as well as biomarkers that can detect recurrent disease at an earlier time, will have immediate clinical application.

The role of surgery and deescalation for HPV-related oropharyngeal cancer

Recently published and ongoing trials are helping to define the role of transoral robotic surgery for oropharyngeal cancer. Evidence to date supports the use of surgery as a valuable tool in the multidisciplinary deescalation of low-risk human papillomavirus-related oropharyngeal squamous cell carcinoma.

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.

ctDNA predicts recurrence and survival in stage I and II HPV-associated head and neck cancer patients treated with surgery

Human papillomavirus-associated oropharyngeal squamous cell carcinomas (HPV+OPSCC) release circulating tumor HPV DNA (ctHPVDNA) into the blood which we, and others, have shown is an accurate real-time biomarker of disease status. In a prior prospective observational trial of 34 patients with AJCC 8 stage I-II HPV+OPSCC treated with surgery, we reported that ctHPVDNA was rapidly cleared within hours of surgery in patients who underwent complete cancer extirpation, yet remained elevated in those with macroscopic residual disease. The primary outcomes of this study were to assess 2-year OS and RFS between patients with and without molecular residual disease (MRD) following completion of treatment in this prospective cohort. MRD was defined as persistent elevation of ctHPVDNA at two consecutive time points, without clinical evidence of disease. The secondary outcomes were 2-year OS and RFS between patients with and without detectable MRD after surgery. We observed that patients with MRD after treatment completion were more likely to recur compared to patients without MRD, while there was no difference in recurrence rates between patients with MRD and without MRD on postoperative day 1. OS did not significantly differ between patients with MRD after surgery or treatment completion compared to patients without MRD; however, time to death was significantly different between the groups in both settings, suggesting that with a larger sample size OS would differ significantly between the groups or that the impact of MRD detection on survival is time dependent.

Current and Emerging Diagnostic, Prognostic, and Predictive Biomarkers in Head and Neck Cancer

Head and neck cancers (HNC) are a biologically diverse set of cancers that are responsible for over 660,000 new diagnoses each year. Current therapies for HNC require a comprehensive, multimodal approach encompassing resection, radiation therapy, and systemic therapy. With an increased understanding of the mechanisms behind HNC, there has been growing interest in more accurate prognostic indicators of disease, effective post-treatment surveillance, and individualized treatments. This chapter will highlight the commonly used and studied biomarkers in head and neck squamous cell carcinoma.

Blood-based screening for HPV-associated cancers

Background

HPV-associated oropharyngeal cancer (HPV+OPSCC) is the most common HPV-associated cancer in the United States yet unlike cervical cancer lacks a screening test. HPV+OPSCCs are presumed to start developing 10-15 years prior to clinical diagnosis. Circulating tumor HPV DNA (ctHPVDNA) is a sensitive and specific biomarker for HPV+OPSCC. Taken together, blood-based screening for HPV+OPSCC may be feasible years prior to diagnosis.

Methods

We developed an HPV whole genome sequencing assay, HPV-DeepSeek, with 99% sensitivity and specificity at clinical diagnosis. 28 plasma samples from HPV+OPSCC patients collected 1.3-10.8 years prior to diagnosis along with 1:1 age and gender-matched controls were run on HPV-DeepSeek and an HPV serology assay.

Results

22/28 (79%) of cases and 0/28 controls screened positive for HPV+OPSCC with 100% detection within four years of diagnosis and a maximum lead time of 7.8 years. We next applied a machine learning model classifying 27/28 cases (96%) with 100% detection within 10 years. Plasma-based PIK3CA gene mutations, viral genome integration events and HPV serology were used to orthogonally validate cancer detection with 68% (19/28) of the cohort having multiple cancer signals detected. Molecular fingerprinting of HPV genomes was performed across patients demonstrating that each viral genome was unique, ruling out contamination. In patients with tumor blocks from diagnosis (15/28), molecular fingerprinting was performed within patients confirming the same viral genome across time.

Conclusions

We demonstrate accurate blood-based detection of HPV-associated cancers with lead times up to 10 years before clinical cancer diagnosis and in doing so, highlight the enormous potential of ctDNA-based cancer screening.

TERT promoter mutation positive oral cavity carcinomas, a clinically and genetically distinct subgroup of head and neck squamous cell carcinomas

BACKGROUNDS

The importance of TERT promoter (pTERT) mutation of oral cavity squamous cell carcinoma (OCSCC) with clinical features and genetic alterations are not well recognized.

METHODS

We retrospectively analyzed genetic data from multiple databases, including 260 cases from the C-CAT database, 407 cases from the MSK-MetTropism database, and 40 OCSCC datasets from in-house clinical samples.

RESULTS

From C-CAT database, TP53 (66%), CDKN2A (51%), and pTERT (29%) were the most frequent mutations observed. pTERT mutations were more prevalent in OCSCC (63%), younger individuals, and women (46%), with lower rates of alcohol abuse and smoking and co-mutated with TP53, HRAS, and CASP8. MSK-MetTroposim data validated with the enrichment of pTERT mutations in OCSCC, among women and Asian individuals. In-house datasets OCSCC with pTERT mutation (50%) characterized by fewer recurrent neck metastases.

CONCLUSION

The study suggests that OCSCC with pTERT mutation represents a distinct subgroup with unique clinical and genetic characteristics.

Determinants of the level of circulating-tumor HPV16 DNA in patients with HPV-associated oropharyngeal cancer at the time of diagnosis

Circulating tumor HPV DNA (ctHPV16) assessed in liquid biopsy may be used as a marker of cancer in patients with HPV-associated oropharyngeal cancer (HPV + OPC). Factors influencing the initial ctHPV16 quantity are not well recognized. In this study we aimed to establish what factors are related to the level of ctHPV16 at the time of diagnosis. 51 patients (37 men and 14 women, median age of 57 years old) with HPV + OPC prior to definitive treatment were included. ctHPV16 was measured by qPCR. Tumor and nodal staging were assessed according to AJCC8. Blood derived factors included squamous cell carcinoma antigen (SCC-Ag), serum soluble fragment of cytokeratin 19 (CYFRA 21-1), C-reactive protein (CRP), albumin level (Alb), neutrophils (Neut), thrombocytes (Plt) and lymphocyte (Lym) count, Neut/Lym ratio were assessed. The volumes of the primary tumor (TV) and involved lymph nodes (NV) were calculated using MRI, CT or PET-CT scans. Data were analysed using parametric and nonparametric methods. Variables for multivariable linear regression analysis were chosen based on the results from univariable analysis (correlation, univariable regression and difference). There were 9 (18%), 10 (19%) and 32 (63%) patients who had TV and NV assessed in MRI, CT or PET respectively. Primary tumor neither as T-stage nor TV was related to ctHPV16 level. Significant differences in the ctHPV16 between patients with high vs low pain (P = 0.038), NV (P = 0.023), TV + NV (P = 0.018), CYFRA 21-1 (P = 0.002), CRP (P = 0.019), and N1 vs N3 (P = 0.044) were observed. ctHPV16 was significantly associated with CYFRA 21-1 (P = 0.017), N stage (P = 0.005), NV (P = 0.009), TV + NV (P = 0.002), CRP (P = 0.019), and pain (P = 0.038). In univariable linear regression analysis the same variables predicted ctHPV16 level. In multivariable analyses, CYFRA 21-1 and CRP (both as categorical variables) were predictors of ctHPV16 level even above NV. ctHPV16 at presentation is driven by tumor volume measured mostly by N. CYFRA 21-1 and CRP are additional factors related to ctHPV16 prior to the treatment.

It is time to improve the diagnostic workup of oropharyngeal cancer with circulating tumor HPV DNA: Systematic review and meta-analysis

The possibility of detecting circulating tumor HPV DNA (ctHPVDNA) in plasma in patients with oropharyngeal cancer has been demonstrated in several reports. However, these data are from small cohorts and available tests for detection of ctHPVDNA are not fully validated. The aim is to evaluate sensitivity, specificity, and accuracy of ctHPVDNA by ddPCR to define its efficacy in the clinical setting for the diagnosis of HPV + OPSCC. A comprehensive search of three different databases: MEDLINE, Embase, and Cochrane Library databases. A total of 998 patients were evaluated from the 13 studies. OPSSC p16+ were 729, while controls p16- were 269. The meta-analytic study estimated the diagnostic performance of ctHPVDNA as follows: pooled sensitivity and specificity of 0.90 (95% CI: 0.82-0.94) and 0.94 (95% CI: 0.85-0.98), respectively; positive and negative likelihood ratios of 12.6 (95% CI: 4.9-32.1) and 0.05 (95% CI: 0.02-0.13), respectively. ddPCR for ctHPVDNA has good accuracy, sensitivity, and specificity for diagnosis of HPV + OPSCC. ctHPVDNA kinetic represents a great reliable opportunity to improve diagnostic and therapeutic management of cancer patients and could open new perspectives for understanding tumor biology.

Digital droplet PCR-based quantification of ccfHPV-DNA as liquid biopsy in HPV-driven cervical and vulvar cancer

PURPOSE

More than 99% of cervical cancers and up to 40% of vulvar cancers are human papillomavirus (HPV) related. HPV 16 and 18 are the most relevant subtypes. Novel technologies allow the detection of minimal amounts of circulating cell-free HPV DNA (ccfHPV-DNA). The aim of this study was to evaluate ccfHPV-DNA assessed by droplet digital PCR (ddPCR) as a biomarker for molecular therapy monitoring in early, advanced, relapsed and metastatic HPV-driven cervical and vulvar cancer.

METHODS

Inclusion criteria of the study were histologically proven HPV 16/18-driven cervical and vulvar cancer with first diagnosed disease, newly diagnosed recurrence, or progression of disease. Blood samples were taken pre- and post-therapeutically. Circulating cell-free HPV DNA was quantified using ddPCR and the results were correlated with clinical data.

RESULTS

The mean copy number of ccfHPV-DNA was 838.6 (± 3089.1) in pretreatment and 2.3 (± 6.4) in post-treatment samples (p < 0.05). The copy number of ccfHPV-DNA increased with higher FIGO stages (p < 0.05), which are commonly used for clinical staging/assessment. Furthermore, we compared the distribution of copy numbers between T-stage 1 versus T-stage 2/3. We could show higher copy number level of ccfHPV-DNA in T-stage 2/3 (p < 0.05).

CONCLUSIONS

Therapy monitoring with determination of ccfHPV-DNA by ddPCR with a small amount of plasma reflects response to therapy and appears feasible for patients in advanced cancer stages of cervical and vulvar cancer. This promising tool should be examined as marker of therapy monitoring in particular in novel HPV-directed therapies.

Negative Predictive Value of Circulating Tumor Tissue Modified Viral (TTMV)-HPV DNA for HPV-driven Oropharyngeal Cancer Surveillance

PURPOSE

Human papillomavirus (HPV) is causally linked to oropharyngeal squamous cell carcinoma (OPSCC). Consensus guidelines recommend clinical exams and imaging in decreasing frequency as part of posttreatment surveillance for recurrence. Plasma tumor tissue modified viral (TTMV)-HPV DNA testing has emerged as a biomarker which can inform disease status during surveillance.

EXPERIMENTAL DESIGN

This retrospective observational cohort study involved 543 patients who completed curative-intent therapy for HPV-associated OPSCC between February 2020 and January 2022 at eight U.S. cancer care institutions. We determined the negative predictive value (NPV) of TTMV-HPV DNA for recurrence when matched to physician-reported clinical outcome data (median follow-up time: 27.9 months; range: 4.5-154).

RESULTS

The cohort included mostly men with a median age of 61 who had locoregionally advanced disease. HPV status was determined by p16 positivity in 87% of patients, with a positive HPV PCR/ISH among 55%; while pretreatment TTMV-HPV DNA status was unknown for most (79%) patients. Patients had a mean of 2.6 tests and almost half had three or more TTMV-HPV DNA results during surveillance. The per-test and per-patient sensitivity of the assay was 92.5% [95% confidence interval (CI): 87.5-97.5] and 87.3% (95% CI: 79.1-95.5), respectively. The NPV for the assay was 99.4% (95% CI: 98.9-99.8) and 98.4% (95% CI: 97.3-99.5), respectively.

CONCLUSIONS

TTMV-HPV DNA surveillance testing yields few false negative results and few missed recurrences. These data could inform decisions on when to pursue reimaging following first disease restaging and could inform future surveillance practice. Additional study of how pretreatment TTMV-HPV DNA status impacts sensitivity for recurrence is needed.

circulating tumor DNA in the immediate post-operative setting

Background

Circulating tumor DNA (ctDNA) has emerged as an accurate real-time biomarker of disease status across most solid tumor types. Most studies evaluating the utility of ctDNA have focused on time points weeks to months after surgery, which for many cancer types, is significantly later than decision-making time points for adjuvant treatment. In this systematic review, we summarize the state of the literature on the feasibility of using ctDNA as a biomarker in the immediate postoperative period.

Methods

We performed a systematic review evaluating the early kinetics, defined here as three days, of ctDNA in patients who underwent curative-intent surgery across several cancer types.

Results

Among the 2057 studies identified, we evaluated eight cohort studies with ctDNA levels measured within the first three days after surgery. Across six different cancer types, all studies showed an increased risk of cancer recurrence in patients with a positive early postoperative ctDNA level.

Discussion

While ctDNA clearance kinetics appear to vary based on tumor type, across all studies- detectable ctDNA after surgery was predictive of recurrence, suggesting early postoperative timepoints could be feasibly used for determining minimal residual disease. However, larger studies need to be performed to better understand the precise kinetics of ctDNA clearance across different cancer types as well as to determine optimal postoperative time points.

Synopsis

This systematic review analyzed the use of ctDNA as a biomarker for minimal residual disease detection in the early postoperative setting and found that ctDNA detection within three days after surgery is associated with an increased risk of recurrence.

[ctHPV-DNA based precision oncology for patients with oropharyngeal cancer - Where are we?]

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.

Blood and saliva-derived ctDNA is a marker of residual disease after treatment and correlates with recurrence in human papillomavirus-associated head and neck cancer

BACKGROUND

There is an alarming increase in human papillomavirus-associated head and neck cancer (HNC), reaching epidemic levels. While patient prognosis is generally good, off-target treatment effects are associated with decreased quality of life. Thus, non-invasive strategies to predict treatment response and risk of recurrence could help de-escalate treatment. In this study, we tested circulating tumor (ct)DNA in liquid biopsies (blood/saliva) of HPV-positive HNC patients to assess treatment response and disease progression.

METHODS

A total of 235 blood and saliva samples were collected from 60 HPV-positive and 17 HPV-negative HNC patients (control group) before and/or after treatment. Samples were analyzed using ddPCR for HPV16/18/31/33/35/45 and correlated with imaging and pathological examination.

RESULTS

HPV-ctDNA detection was significantly higher prior to treatment (91%) than after treatment (8.0%) (χ2 p < 0.00001), with high concordance between saliva and blood (93%). In matched samples, all patients positive for ctDNA before treatment showed significant reductions in ctDNA levels post treatment (p < 0.0001). All but one patient with persistent ctDNA after treatment showed residual tumor and subsequent recurrence. Finally, fragmentomic analysis revealed shifts in cell-free DNA fragment size after treatment, suggesting a complementary biomarker for treatment response.

CONCLUSIONS

Blood and saliva were found to be good sources of HPV-ctDNA. The presence of ctDNA strongly correlated with treatment response, demonstrating clinical utility as a non-invasive biomarker to monitor tumor progression in HPV-positive HNC. Liquid biopsy based ctDNA testing could be an effective approach to predict recurrence and stratify patients for de-escalation of treatment, thereby improving quality of life.

The Clinical Utility of Circulating HPV DNA Biomarker in Oropharyngeal, Cervical, Anal, and Skin HPV-Related Cancers: A Review

Human papillomavirus (HPV) is recognized as being related to a wide variety of known cancers: cervical, oropharyngeal, anal, vaginal, penile, and skin. For some of these cancers, rigorous algorithms for screening, therapeutical interventions, and follow-up procedures have been established. Vaccination using the nonvalent anti-HPV vaccine, which prevents infection regarding the most frequently involved high-risk HPV types (16, 18, 31, 33, 45, 52, and 58) and low-risk HPV types (6 and 11), has also extensively prevented, controlled, and even eradicated HPV infections. Still, even with all of these multidisciplinary interventions, the burden of HPV cancers is still high worldwide. The circulating DNA of HPV-induced cancers is thought to be an adequate biomarker for optimizing the control of these virus-related cancers. We analyzed the literature published in the last 5 years regarding ctDNA and four of the above-mentioned cancers. The most frequently used assay for ctDNA detection was the droplet digital PCR assay, used for the management of therapy in the late stages of cancer. ctDNA could not be used for early detection in any of the studied cancers. The OPSCCs were the most frequent cancers analyzed via ctDNA assays. Larger, properly designed cohort studies might establish the clinical utility of this biomarker.

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.

Double trouble: Synchronous and metachronous primaries confound ctHPVDNA monitoring

BACKGROUND

Human papillomavirus-associated head and neck squamous cell carcinoma (HPV + HNSCC) occurs in the oropharynx (HPV + OPSCC), sinonasal cavity (HPV + SNSCC), and nasopharynx (HPV + NPC). Circulating tumor HPV DNA (ctHPVDNA) is an accurate tool for diagnosis, treatment monitoring, and recurrence detection. An emerging challenge with ctHPVDNA is that ~7.4% of HPV + HNSCC patients develop synchronous or metachronous HPV+ primaries, which could confound ctHPVDNA monitoring.

METHODS

We describe a 65-year-old patient with T2N1M0 HPV16 + OPSCC and a 55-year-old patient with T2N2M0 HPV16 + OPSCC. Both patients were enrolled in our prospective observational ctHPVDNA study with longitudinal blood collections throughout treatment. Both patients developed multiple HPV+ primaries.

RESULTS

Detailed discussion of the patients' treatment courses, the subsequent diagnoses of their second HPV+ primaries, and their ctHPVDNA monitoring is presented.

CONCLUSIONS

As ctHPVDNA use becomes more prevalent, it is important to recognize that an increase in ctHPVDNA can come not only from the primary tumor or metastatic clones, but also from synchronous or metachronous second primaries.

Circulating HPV DNA in HPV-associated cancers

Human papillomavirus (HPV) infections are the primary cause of almost all cervical cancers, anal cancers, and a variable proportion of other anogenital tumors, as well as head and neck cancers. Circulating HPV DNA (cHPV-DNA) is emerging as a biomarker with extensive potential in the management of HPV-driven malignancies. There has been a rapid advancement in the development of techniques for analyzing cHPV-DNA for the detection, characterization, and monitoring of HPV-associated cancers. As clinical evidence accumulates, it is becoming evident that cHPV-DNA can be used as a diagnostic tool. By conducting clinical trials assessing the clinical utility of cHPV-DNA, the full potential of cHPV-DNA for the screening, diagnosis, and treatment of HPV-related malignancies can be corroborated. In this review, we examine the current landscape of applications for cHPV-DNA liquid biopsies throughout the cancer care continuum, highlighting future opportunities for research and integration into clinical practice.

Treatment of oropharyngeal squamous cell carcinoma: Is swallowing quality better after TORS or RT?

BACKGROUND AND PURPOSE

To answer an important question regarding the long-term morbidity of two oncological equivalent treatment for oropharyngeal squamous cell carcinoma (OPSCC), namely a comparison of swallowing function results between patients treated with trans-oral robotic surgery (TORS) versus patients treated with radiotherapy (RT).

MATERIALS AND METHODS

Studies included patients with OPSCC treated with TORS or RT. Articles reporting complete data on MD Anderson Dysphagia Inventory (MDADI) and comparing the two treatments (TORS vs RT) were included in the meta-analysis. Swallowing assessed with MDADI was the primary outcome, the evaluation with instrumental methods was the secondary aim.

RESULTS

Included studies provided a total of 196 OPSCC primarily treated with TORS vs 283 OPSCC primarily treated with RT. The mean difference in MDADI score at the longest follow-up was not significantly different between TORS and RT group (mean difference [MD] -0.52; 95% CI -4.53-3.48; p = 0.80). After treatment, mean composite MDADI scores demonstrated a slight impairment in both groups without reaching a statistical difference compared to the baseline status. DIGEST score and Yale score showed a significantly worse function in both treatment groups at 12-month follow-up compared to baseline status.

CONCLUSION

The meta-analysis demonstrates that up-front TORS (+- adjuvant therapy) and up-front RT (+- CT) appear to be equivalent treatments in functional outcomes in T1-T2, N0-2 OPSCC, however, both treatments cause impaired swallowing ability. Clinicians should have a holistic approach and work with patients to develop an individualized nutrition plan and swallowing rehabilitation protocol from diagnosis to post-treatment surveillance.

Practical Application of Circulating Tumor-Related DNA of Human Papillomavirus in Liquid Biopsy to Evaluate the Molecular Response in Patients with Oropharyngeal Cancer

Recent findings have shown that human papillomavirus (HPV) DNA is present in the blood as a tumor-specific biomarker (circulating tumor-related HPV; ctHPV) in patients with HPV-related oropharyngeal cancer (HPV-related OPC). The molecular response (MR) in patients with HPV-related OPC can be defined as the change in the number of ctHPV copies in relation to its initial quantity. The optimal model for assessing the MR using a liquid biopsy (LB) should be based on the E6/E7 sequences of the viral genome. MR assessment can help to evaluate the intensity of ongoing treatments in relation to the tumor response. The evaluation of the residual disease at the end of therapy may also be performed by MR assessment. If a partial MR (pMR) is found, caution is indicated and a subsequent LB should be considered, due to the likelihood of disease progression. Complete radiological and clinical responses together with a complete MR (cMR) convincingly indicate a low risk of treatment failure. Moreover, molecular recurrence (Mrec) during a follow-up, confirmed in two consecutive assays, even despite the lack of any other clinical or radiological symptoms of progression, indicates patients at high risk of disease recurrence. In conclusion, MR by ctHPV assessment may hasten the early detection of disease progression, at any stage of the management of the patient with HPV-related OPC.

Clearance Profile of Circulating Tumor Human Papillomavirus DNA During Radiotherapy Predicts Clinical Outcomes in Human Papillomavirus-Related Oropharyngeal Cancer

PURPOSE

This study aimed to examine whether circulating tumor human papillomavirus type 16 (HPV16) DNA (ctHPV16DNA) can help identify patients with locally advanced HPV16-related oropharyngeal squamous cell carcinoma who may benefit from deintensified treatment.

MATERIALS AND METHODS

We serially collected blood samples before, during, and after treatment from 22 patients who received 70 Gy radiotherapy alone and longitudinally quantified ctHPV16DNA using droplet digital polymerase chain reaction. We correlated the clearance profile of ctHPV16DNA with clinical outcomes.

RESULTS

The percentage of patients with detectable ctHPV16DNA decreased after every 10 Gy of radiotherapy. By contrast, the percentage of patients who later developed treatment failure among patients with detectable ctHPV16DNA gradually increased as radiotherapy proceeded, reaching 100% after 60 Gy of radiotherapy. We defined patients with and without detectable ctHPV16DNA after receiving 40 Gy as having slow and rapid clearance profiles, respectively. All 12 patients with a rapid clearance profile remained disease-free after radiotherapy. Of the 10 patients with a slow clearance profile, three had persistent or progressive disease at response evaluation after radiotherapy and one developed distant metastasis during follow-up (ie, four patients experienced treatment failure). The median follow-up for surviving patients was 38.6 months, and the 3-year failure-free survival rates of patients with rapid and slow clearance profiles were 100% and 58%, respectively (P = .02). Neither baseline ctHPV16DNA levels nor metabolic tumor volume was an independent predictor of the pattern of the clearance profile.

CONCLUSION

In patients with HPV16-related oropharyngeal squamous cell carcinoma receiving radiotherapy, a slow ctHPV16DNA clearance profile could prelude unfavorable outcomes. Monitoring ctHPV16DNA is essential for determining the clearance profile, which might help optimize treatment intensity individually.

Surgical clinical trials for HPV-positive oropharyngeal carcinoma

The treatment of HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) continues to evolve as multiple ongoing and recently completed clinical trials investigate the role of surgery, radiation therapy, chemotherapy, and immunotherapy. Current trials are investigating transoral robotic surgery (TORS) in treatment de-escalation protocols in an effort to optimize quality of life, while maintaining historical survival rates. The advantage of TORS is its minimally invasive approach to primary resection of the tumor as well as valuable pathologic staging. The ORATOR trial reported poorer quality of life in patients treated with TORS compared to primary radiotherapy though this was not a clinically meaningful difference. The recently published ECOG 3311 trial showed that surgery can be used to safely de-escalate the adjuvant radiation dose to 50 Gy in intermediate-risk patients. In this review, we summarize and discuss the past and current clinical trials involving surgery in the treatment of HPV-positive OPSCC.

Detection of Occult Recurrence Using Circulating Tumor Tissue Modified Viral HPV DNA among Patients Treated for HPV-Driven Oropharyngeal Carcinoma

PURPOSE

Despite generally favorable outcomes, 15% to 25% of patients with human papillomavirus (HPV)-driven oropharyngeal squamous cell carcinoma (OPSCC) will have recurrence. Current posttreatment surveillance practices rely on physical examinations and imaging and are inconsistently applied. We assessed circulating tumor tissue modified viral (TTMV)-HPV DNA obtained during routine posttreatment surveillance among a large population of real-world patients.

EXPERIMENTAL DESIGN

This retrospective clinical case series included 1,076 consecutive patients across 108 U.S. sites who were ≥ 3 months posttreatment for HPV-driven OPSCC and who had one or more TTMV-HPV DNA tests (NavDx, Naveris Laboratories) obtained during surveillance between February 6, 2020, and June 29, 2021. Test results were compared with subsequent clinical evaluations.

RESULTS

Circulating TTMV-HPV DNA was positive in 80 of 1,076 (7.4%) patients, with follow-up available on all. At first positive surveillance testing, 21 of 80 (26%) patients had known recurrence while 59 of 80 (74%) patients were not known to have recurrent disease. Among these 59 patients, 55 (93%) subsequently had a confirmed recurrence, 2 patients had clinically suspicious lesions, and 2 had clinically "no evidence of disease" (NED) at last follow-up. To date, the overall positive predictive value of TTMV-HPV DNA testing for recurrent disease is 95% (N = 76/80). In addition, the point-in-time negative predictive value is 95% (N = 1,198/1,256).

CONCLUSIONS

These findings highlight the clinical potential for circulating TTMV-HPV DNA testing in routine practice. As a surveillance tool, TTMV-HPV DNA positivity was the first indication of recurrence in the majority of cases, pre-dating identification by routine clinical and imaging exams. These data may inform future clinical and guideline-endorsed strategies for HPV-driven malignancy surveillance. See related commentary by Colevas, p. 4171.

The Sinai Robotic Surgery Trial in HPV-related oropharyngeal squamous cell carcinoma (SIRS 2.0 trial) – study protocol for a phase II non-randomized non-inferiority trial

Background

Human papillomavirus associated oropharyngeal squamous cell carcinoma (HPVOPSCC) usually affects a younger patient population. As such, the risk for long term toxicity associated with therapy is an important consideration. Multiple trials focused on de-escalation of therapy to preserve survival outcomes while minimizing treatment toxicity are currently in progress, however the question of which patients are ideal candidates for de-escalation remains unanswered. Circulating tumor DNA (cfHPVDNA) has emerged as a means of monitoring disease in patients with HPVOPSCC. Undetectable postoperative cfHPVDNA levels portend a better prognosis and by extension, may identify ideal candidates for de-escalation therapy. We propose an overview and rationale for a new institutional clinical trial protocol focusing on the use of cfHPVDNA to risk stratify patients for adjuvant therapy. We hypothesize that many surgical patients currently receiving radiation therapy may be clinically observed without adjuvant therapy.

Methods

Patients with measurable cfHPVDNA and clinically resectable HPVOPSCC will undergo TORS resection of tumors and neck dissection. Patients with undetectable cfHPVDNA at 3 weeks post-op will be allocated to low or high-risk treatment protocol groups. The low risk group consists of patients with <4 positive lymph nodes, ≤2 mm extranodal extension (ENE), and perineural invasion (PNI) or lymphovascular invasion (LVI) alone. The high-risk group is made up of patients with ≥4 positive lymph nodes, gross ENE, positive margins, N2c disease and/or the combination of both PNI and LVI. The low-risk group will be allocated to an observation arm, while the high-risk group will receive 46 Gy of adjuvant radiotherapy and weekly cisplatin therapy. The primary outcome of interest is 2-year disease recurrence with secondary outcomes of 2-year disease free survival, locoregional control, overall survival, and quality of life measures. A sample of 126 patients in the low-risk group and 73 patients in the high-risk group will be required to evaluate non-inferiority to the standard of care.

Discussion

This study will provide much needed recurrence and survival data for patients that undergo primary TORS followed by observation or de-escalated adjuvant therapy. Additionally, it will help delineate the role of cfHPVDNA in the risk stratification of patients that undergo treatment de-intensification.

Current perspectives on recurrent HPV-mediated oropharyngeal cancer

In the recent years, the prevalence of HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) has increased significantly. Currently, nearly 80-90% of all oropharynx tumors are HPV-positive. In addition, it is now recognized that HPV-positive tumor status is associated with good prognosis and improved response to chemoradiation. However, within this setting, there are still patients with HPV-positive OPSCC who will experience recurrence. With the increasing incidence of HPV-mediated OPSCC, recurrent HPV disease is also becoming more prevalent and there is an increasing need to understand the unique presentation and treatment of recurrent HPV-mediated disease. In this review, we will discuss epidemiology of recurrent HPV-positive OPSCC, role of surgical salvage, re-irradiation, and the role of upcoming novel treatments and immunotherapy. Historically, recurrent oropharyngeal disease has been associated with poor prognosis and high morbidity. However, recent advances have transformed the landscape for salvage treatment of HPV-mediated OPSCC. Liquid biomarkers offer potential for early detection of recurrence, robotic techniques may reduce morbidity of surgical salvage, improvements in re-irradiation approaches reduce toxicities, and novel immune based therapies on the horizon are offering promising results. These advances combined with the improved prognosis of HPV-positive disease offer to transform our approach to recurrent disease of the oropharynx.

The Promise of Circulating Tumor DNA in Head and Neck Cancer

As the seventh most common cancer globally, head and neck cancers (HNC) exert considerable disease burden, with an estimated 277,597 deaths worldwide in 2020 alone. Traditional risk factors for HNC include tobacco, alcohol, and betel nut; more recently, human papillomavirus has emerged as a distinct driver of disease. Currently, limitations of cancer screening and surveillance methods often lead to identifying HNC in more advanced stages, with associated poor outcomes. Liquid biopsies, in particular circulating tumor DNA (ctDNA), offer the potential for enhancing screening, early diagnosis, and surveillance in HNC patients, with potential improvements in HNC patient outcomes. In this review, we examine current methodologies for detecting ctDNA and highlight current research illustrating viral and non-viral ctDNA biomarker utilities in HNC screening, diagnosis, treatment response, and prognosis. We also summarize current challenges and future directions for ctDNA testing in HNC patients.

Liquid Biopsy in Head and Neck Cancer: Current Evidence and Future Perspective on Squamous Cell, Salivary Gland, Paranasal Sinus and Nasopharyngeal Cancers

Simple Summary

Head and neck cancer is the sixth most common type of solid tumor and harbors a poor prognosis since most patients are diagnosed at an advanced stage. The study of different tumor components in the blood, saliva or other body fluids is called liquid biopsy. The introduction of novel diagnostic tools such as liquid biopsy could aid in achieving earlier diagnoses and more accurate disease monitoring during treatment. In this manuscript, the reader will find an in-depth review of the current evidence and a future perspective on the role of liquid biopsy in head and neck cancer.

Abstract

Head and neck cancer (HNC) is currently the sixth most common solid malignancy, accounting for a 50% five-year mortality rate. In the past decade, substantial improvements in understanding its molecular biology have allowed for a growing development of new biomarkers. Among these, the field of liquid biopsy has seen a sustained growth in HNC, demonstrating the feasibility to detect different liquid biomarkers such as circulating tumor DNA (ctDNA), circulating tumor cells (CTC), extracellular vesicles and microRNAs. Liquid biopsy has been studied in HPV-negative squamous cell carcinoma of the head and neck (SCCHN) but also in other subentities such as HPV-related SCCHN, EBV-positive nasopharyngeal cancer and oncogene-driven salivary gland cancers. However, future studies should be internally and externally validated, and ideally, clinical trials should incorporate the use of liquid biomarkers as endpoints in order to prospectively demonstrate their role in HNC. A thorough review of the current evidence on liquid biopsy in HNC as well as its prospects will be conducted.

Circulating tumor DNA in head and neck cancer: Early successes and future promise

LAY SUMMARY

The genetic components (DNA) of human papillomavirus-related throat cancer (in the oropharynx) might be measured after surgery to help to predict whether treatment has been successful.