Tumor-agnostic plasma assay for circulating tumor DNA detects minimal residual disease and predicts outcome in locally advanced squamous cell carcinoma of the head and neck

Tumor-informed ctDNA assay to predict recurrence in locally advanced squamous-cell carcinoma of the head and neck (SCCHN)

BACKGROUND

Despite multimodal treatment, locally advanced (LA) squamous-cell carcinoma of the head and neck (SCCHN) has a recurrence rate of ∼50%. Circulating tumor DNA (ctDNA) has emerged as a potential biomarker for minimal residual disease detection after curative-intent treatment. This strategy could be used to identify the patients at greater risk of recurrence, for whom extended or intensified therapy and/or surveillance imaging may be considered.

MATERIALS AND METHODS

A personalized, tumor-informed 16-plex multiplex PCR-next-generation sequencing assay was used for the detection of ctDNA in banked plasma samples collected pre-treatment (baseline time point) and within 12 weeks from the end of curative-intent treatment (post-treatment time point). The primary and secondary endpoints were recurrence-free-survival (RFS) and overall survival (OS) of post-treatment ctDNA-positive and -negative patients, respectively.

RESULTS

Out of a cohort of 50 patients with LA SCCHN, personalized ctDNA assays were successfully designed for 43 patients. Among these 43 patients, ctDNA was detected in 42 of 43 (97.6%) patients at baseline. At the post-treatment time point, ctDNA was detected in 4 of 42 (9.5%) patients, 3 of whom relapsed. Of the 43 patients, 11 (26%) experienced disease recurrence within 2 years of follow-up. Patients with post-treatment ctDNA positivity demonstrated a significantly inferior RFS and OS (P ≤ 0.05), compared with ctDNA-negative patients. The median lead time for ctDNA positivity over clinical recurrence was 7.0 months (range 3.6-7.1 months).

CONCLUSIONS

The personalized, tumor-informed assay detected pre-treatment ctDNA in the majority of the patients with LA SCCHN. ctDNA positivity within 12 weeks of completing curative-intent treatment was predictive of worse RFS and OS. These results support studies to assess the value of longitudinal testing for surveillance and may open the path to initiating treatment upon molecular recurrence in patients with LA SCCHN.

Role of circulating tumor DNA and cell-free DNA biomarkers in diagnosis and prognosis of oral cancer - a systematic review

BACKGROUND

Oral squamous cell carcinoma is the most common malignant neoplasm of the oral cavity, contributing significantly to cancer-related mortality worldwide. Circulating tumor DNA could be a promising biomarker for the early diagnosis and prognosis of oral cancer.

OBJECTIVE

The aim of this systematic review was to consolidate the existing literature on the role of circulating tumor DNA (ctDNA) and cell-free DNA (cfDNA) in the diagnosis and prognosis of oral cancer.

METHODOLOGY

The review protocol followed PRISMA guidelines. A systematic search was conducted across PubMed, Web of Science, Google Scholar and SCOPUS. Only English-language studies were included, while narrative reviews, HPV-positive OSCC, systematic reviews, meta-analyses, abstracts, and letters to the editor were excluded. Data were extracted on study design, country, sample size, participant characteristics, assessment methods, type of oral cancer and measured outcomes. Risk of bias was evaluated using Newcastle-Ottawa Scale (NOS).

RESULTS

A total of 3,155 records were identified, out of which 17 studies met the inclusion criteria. These comprised eleven cohort studies, one was a case series, two were descriptive studies, and three were case-control studies. The studies primarily addressed oral squamous cell carcinoma (OSCC) and head and neck squamous cell carcinoma (HNSCC). Findings revealed that elevated cfDNA levels are associated with poor prognosis, lymph node metastasis, larger tumor size and advanced disease stages. ctDNA acts as a predictive tool for monitoring cancer progression, treatment response, recurrence risk, and overall survival. Among 12 studies evaluated using NOS, 8 were of good quality, while 4 were fair quality.

CONCLUSION

ctDNA and cfDNA exhibit promising prognostic and diagnostic potential for OSCC and HNSCC. Elevated cfDNA levels correlate with poor prognosis, while ctDNA shows potential for monitoring cancer progression and treatment response.

Japan society of clinical oncology position paper on appropriate clinical use of molecular residual disease (MRD) testing

Although the 5-year relative survival rates for resectable solid tumors have improved over the past few years, the risk of postoperative recurrence necessitates effective monitoring strategies. Recent advancements in molecular residual disease (MRD) testing based on circulating tumor DNA (ctDNA) analysis have shown considerable promise in the context of predicting recurrence; however, significant barriers to widespread clinical implementation remain-mainly, low awareness among healthcare professionals, high costs, and lack of standardized assays and comprehensive evidence. This position paper, led by the Japan Society of Clinical Oncology, aims to establish a common framework for the appropriate clinical use of MRD testing in a tumor type-agnostic manner. It synthesizes currently available evidence, reviews region-specific clinical trends, addresses critical clinical questions related to MRD testing, and offers recommendations to guide healthcare professionals, biotechnology and pharmaceutical companies, and regulatory authorities. These recommendations were developed based on a voting process involving 15 expert members, ensuring a consensus-driven approach. These findings underscore the importance of collaborative efforts among various stakeholders in enhancing the clinical utility of MRD testing. This project aimed to foster consensus and provide clear guidelines to support the advancement of precision medicine in oncology and improve patient outcomes in the context of perioperative care.

Plasma ctDNA kinetics as a predictor of systemic therapy response for advanced non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

Predicting early treatment response in advanced non-small cell lung cancer (NSCLC) is challenging. Longitudinal monitoring of circulating tumor DNA (ctDNA) can track tumor response to treatments like immune checkpoint blockade (ICB) and correlate with outcomes. This meta-analysis evaluated whether ctDNA clearance or decrease is associated with improved survival across various settings in NSCLC.

METHODS

A systematic review of MEDLINE, EMBASE, and Cochrane databases (up to April 2024) identified studies evaluating the impact of ctDNA kinetics on survival outcomes in non-curative NSCLC settings. Pooled hazard ratios (HR) for progression-free survival (PFS) and overall survival (OS) were calculated using a random effects model.

RESULTS

We included 32 studies with 3047 NSCLC patients receiving systemic therapies such as targeted therapy (TT), ICB, and chemotherapy. Meta-analysis of 31 studies showed that ctDNA decrease/clearance was linked to improved PFS (HR: 0.32 [0.26, 0.40], I² = 63%, P < .01). Subgroup analysis indicated strong PFS benefits from ctDNA clearance (HR: 0.27 [0.20, 0.36]). Similar improvements were seen across patients undergoing targeted therapy (HR: 0.34) and ICB (HR: 0.33). Analysis of 25 studies revealed a significant association between ctDNA reduction and better OS (HR: 0.31 [0.23, 0.42], I² = 47%, P < .01). Subgroup findings were consistent for both TT (HR: 0.41) and ICB (HR: 0.32). Sensitivity analysis demonstrated that ctDNA clearance/decrease was consistently associated with improved PFS across study designs and ctDNA analysis methods. There was no significant variation in hazard ratios for PFS based on NSCLC subtypes, smoking status, or sex.

CONCLUSION

Plasma ctDNA kinetics was associated with improved survival outcomes in patients diagnosed with advanced NSCLC undergoing treatment with TT and ICB.

Immediate postoperative minimal residual disease detection with MAESTRO predicts recurrence and survival in head and neck cancer patients treated with surgery

Purpose

While circulating tumor DNA (ctDNA) is a promising biomarker for minimal residual disease (MRD) detection in head and neck squamous cell carcinoma (HNSCC), more sensitive assays are needed for accurate MRD detection at clinically-relevant timepoints. Ultrasensitive MRD detection immediately after surgery could guide adjuvant therapy decisions, but early ctDNA dynamics are poorly understood.

Experimental Design

We applied MAESTRO, a whole-genome, tumor-informed, mutation-enrichment sequencing assay, in a pooled testing format called MAESTRO-Pool, to plasma samples from HNSCC patients collected immediately after surgery and during surveillance. We evaluated whether early MRD detection could predict outcomes.

Results

Among 24 predominantly HPV-independent (95.8%) HNSCC patients, rapid ctDNA clearance occurred by the first postoperative sample (1-3 days postoperatively) in 9 patients without an event (recurrence or death). 13/15 patients with an event were MRD+ (PPV = 92.9%; NPV = 80%) with a median tumor fraction (TFx) of 54 ppm (range 6-1,177 ppm). In the first and last sample of the immediate postoperative window, 8/13 and 10/13 patients had TFx below 100 ppm, respectively, the detection limit of leading commercial assays. Early MRD detection correlated with worse overall survival (HR = 8.3; 95% CI: 1.1-66.1; P = 0.02) and event-free survival (HR = 27.4; 95% CI: 3.5-214.5; P < 0.0001) independent of high-risk pathology.

Conclusions

Immediate postoperative MRD detection by MAESTRO was predictive of recurrence and death. Given the ultralow TFxs observed, ultrasensitive assays will be essential for reliable MRD detection during early postoperative timepoints to enable personalized adjuvant therapy decision-making in HNSCC.

Deciphering molecular relapse and intra-tumor heterogeneity in non-metastatic resectable head and neck squamous cell carcinoma using circulating tumor DNA

OBJECTIVES

Head and neck squamous cell carcinoma (HNSCC) is characterized by significant genetic intra-tumor heterogeneity (ITH), which may hinder precision medicine strategies that depend on results from single tumor-biopsy specimens. Treatment response assessment relies on radiologic imaging, which cannot detect minimal residual disease (MRD). We assessed the relevance of circulating tumor DNA (ctDNA) as a biomarker for ITH and MRD in HNSCC.

MATERIALS AND METHODS

We recruited 41 non-metastatic resectable HNSCC patients treated with upfront curative-intent surgery in the prospective biobanking SCANDARE study (NCT03017573). Thirty-one patients (76 %) showed recurrent disease at a median follow-up of 41 months. Targeted next-generation sequencing was performed on resected tumor tissues, as well as on serial blood samples obtained at surgery, within 14 weeks after surgery, at six months and at recurrence.

RESULTS

ctDNA was detected in 21/41 patients at surgery (sensitivity: 51 %; 95 % CI, 35-67 %) and 15/22 patients at recurrence (sensitivity: 68 %; 95 % confidence interval [CI], 45-86 %). Among patients with mutations identified in longitudinal plasma samples, additional mutations missed in tumor tissues were reported in 3/21 patients (14 %), while emerging mutations were reported in 9/21 patients (43 %). In the postoperative surveillance setting, ctDNA-based MRD detection anticipated clinical recurrence with a median lead-time of 9.9 months (interquartile range, 8.0-14.5 months) in 17/27 patients (63 %). When detected within 14 weeks after surgery, MRD correlated with disease recurrence after adjusting for classical prognostic variables (HR = 3.0; 95 % CI, 1.1-7.9; p = 0.03).

CONCLUSIONS

ctDNA detection is a useful biomarker for ITH and MRD in resectable HNSCC patients.

Machine-learning derived identification of prognostic signature to forecast head and neck squamous cell carcinoma prognosis and drug response

Introduction

Head and neck squamous cell carcinoma (HNSCC), a highly heterogeneous malignancy is often associated with unfavorable prognosis. Due to its unique anatomical position and the absence of effective early inspection methods, surgical intervention alone is frequently inadequate for achieving complete remission. Therefore, the identification of reliable biomarker is crucial to enhance the accuracy of screening and treatment strategies for HNSCC.

Method

To develop and identify a machine learning-derived prognostic model (MLDPM) for HNSCC, ten machine learning algorithms, namely CoxBoost, elastic network (Enet), generalized boosted regression modeling (GBM), Lasso, Ridge, partial least squares regression for Cox (plsRcox), random survival forest (RSF), stepwise Cox, supervised principal components (SuperPC), and survival support vector machine (survival-SVM), along with 81 algorithm combinations were utilized. Time-dependent receiver operating characteristics (ROC) curves and Kaplan-Meier analysis can effectively assess the model's predictive performance. Validation was performed through a nomogram, calibration curves, univariate and multivariate Cox analysis. Further analyses included immunological profiling and gene set enrichment analyses (GSEA). Additionally, the prediction of 50% inhibitory concentration (IC50) of potential drugs between groups was determined.

Results

From analyses in the HNSCC tissues and normal tissues, we found 536 differentially expressed genes (DEGs). Subsequent univariate-cox regression analysis narrowed this list to 18 genes. A robust risk model, outperforming other clinical signatures, was then constructed using machine learning techniques. The MLDPM indicated that high-risk scores showed a greater propensity for immune escape and reduced survival rates. Dasatinib and 7 medicine showed the superior sensitivity to the high-risk NHSCC, which had potential to the clinical.

Conclusions

The construction of MLDPM effectively eliminated artificial bias by utilizing 101 algorithm combinations. This model demonstrated high accuracy in predicting HNSCC outcomes and has the potential to identify novel therapeutic targets for HNSCC patients, thus offering significant advancements in personalized treatment strategies.

Circulating tumor DNA in head and neck squamous cell carcinoma-current status and future prospects

Squamous cell carcinoma (SCC) is the most common malignancy of the head and neck. Stagnating survival rates in recent decades, despite advances in the treatment paradigms, surveillance technologies, and multidisciplinary care, leave clinicians with a need for better options for screening, risk-stratifying, and monitoring patients. A growing proportion of patients with HPV-associated SCC have improved outcomes but continue to have a heterogenous response to treatment. Advances in the platforms and assays measuring circulating tumor DNA offer an opportunity to monitor disease status at the molecular level for both virally mediated and traditional risk-factor-driven SCC of the head and neck. This overview will discuss experimental, clinically used, and commercially available liquid biopsy platforms and their recent applications in patients with head and neck SCC malignancies.

[Update on HPV-associated head and neck cancers-highlights of the 2024 ASCO Annual Meeting]

BACKGROUND

Human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) is becoming increasingly important in head and neck oncology. At this year's conference of the American Society of Clinical Oncology (ASCO), a large number of papers were presented on the topic of HPV-associated HNSCC, particularly with regard to neoadjuvant treatment approaches, radiation de-escalation strategies, therapeutic vaccines, and treatment monitoring. In this context, study results on the treatment of HPV-related recurrent respiratory papillomatosis (RRP) were also presented.

OBJECTIVE

Based on contributions to the 2024 ASCO Annual Meeting, an insight into the latest developments in HPV-associated diseases of the head and neck is provided.

METHODS

The papers were reviewed for clinical relevance and contextualized based on current therapeutic concepts.

RESULTS AND CONCLUSION

A large number of studies on liquid biopsies (LB) were presented. It was shown that although the methods for analyzing LBs for HPV-positive patients are well developed and can be used for diagnostics, risk classification, treatment management, or tumor follow-up, the methods vary considerably, and their clinical application has not yet been sufficiently validated. With regard to therapeutic HPV vaccination, three large studies were presented for the treatment of recurrent/metastatic HPV-positive oropharyngeal squamous cell carcinoma (OPSCC). The only randomized study was on the vaccine ISA101b (peltopepimut-S) and did not reach its primary endpoint; however, the vaccine seemed to be highly effective in patients with a combined positive score (CPS) ≥ 20. Furthermore, data from a phase I study on PRGN2012, an adenovirus-based immunotherapy used therapeutically for the treatment of recurrent respiratory papillomatosis (RRP), were presented. PRGN2012 led to a reduction in surgical interventions for RRP, and the US Food and Drug Administration (FDA) designated PRGN2012 as a breakthrough therapy and orphan drug. However, the vaccine is not yet approved for the treatment of RRP.

The effect of circulating tumor DNA on the prognosis of patients with head and neck squamous cell carcinoma: a systematic review and meta-analysis

BACKGROUND

Circulating tumour DNA (ctDNA) has emerged as a valuable liquid biopsy biomarker in the field of oncology, including head and neck squamous cell carcinomas (HNSCCs), offering potential insights into cancer diagnosis, progression, and prognosis. This review aims to comprehensively evaluate the utility of ctDNA as a prognostic biomarker in HNSCC.

METHODS

PubMed and Ovid were searched as part of our review. Studies that investigated the relationship between ctDNA and prognosis in HNSCC patients were included. Outcomes extracted included basic characteristics, ctDNA details and survival data. Meta-analysis was performed on eligible studies to determine pooled progression-free/recurrence-free survival (RFS/PFS) and overall survival (OS).

RESULTS

Twenty-two studies were included, involving 5062 HNSCC patients from 11 countries. The meta-analysis demonstrated that the positive ctDNA/methylation detection was associated with worse OS (HR = 2.00, 95% CI 1.35-2.96) and worse PFS/RFS (HR = 3.54, 95% CI 1.05-11.85). Positive ctEBV DNA was associated with poorer OS (HR = 2.86, 95% CI 1.84-4.45) and poorer PFS/RFS (HR = 1.93, 95% CI 1.74-2.13). Positive ctHPV DNA was associated with poorer OS (HR = 1.38, 95% CI 1.07-1.38) but not PFS/PFS (HR = 1.33, 95% CI 0.96-1.85).

CONCLUSION

Meta-analysis indicates that the status of ctDNA is significantly associated with the prognosis of HNSCC patients, with ctDNA/methylation-negative patients demonstrating better PFS/RFS and OS.

Bespoke ctDNA for longitudinal detection of molecular residual disease in high-risk melanoma patients

BACKGROUND

Locally advanced melanoma has a variable prognosis. Currently, there are no reliable criteria to stratify the risk of disease relapse and identify those patients who will benefit the most from adjuvant therapies. Circulating tumor DNA (ctDNA) is an emerging biomarker measuring the presence of tumor-derived DNA in blood.

PATIENTS AND METHODS

We used a bespoke, tumor-informed assay (RaDaR®, NeoGenomics, Inc.) to detect ctDNA in 276 prospectively collected plasma samples from 66 melanoma patients receiving definitive treatment. Collection time points included landmark (after completion of local treatment) and every 3-6 months for up to 2 years.

RESULTS

ctDNA was detected in at least one plasma sample in 19 patients (29%), including 6/65 (9%) at landmark (post-surgical sample). Positive ctDNA at landmark was associated with shorter overall survival (OS; median OS 22.7 months versus not reached, log-rank P value = 0.01) and a trend towards a shorter relapse-free survival (RFS; median RFS 15.7 months versus not reached, log-rank P value = 0.07). In 10 patients, ctDNA detection preceded disease relapse by a median of 128 days (range 8-406 days).

CONCLUSIONS

Our data indicate that ctDNA detection after surgery can identify patients with worse prognosis, and serial ctDNA measurements may enable earlier identification of disease recurrence.

Correlation of the treatment sensitivity of patient-derived organoids with treatment outcomes in patients with head and neck cancer (SOTO): protocol for a prospective observational study

INTRODUCTION

Organoids have been successfully used in several areas of cancer research and large living biobanks of patient-derived organoids (PDOs) have been developed from various malignancies. The characteristics of the original tumour tissue such as mutation signatures, phenotype and genetic diversity are well preserved in organoids, thus showing promising results for the use of this model in translational research. In this study, we aim to assess whether we can generate PDOs from head and neck squamous cell carcinoma (HNSCC) samples and whether PDOs can be used to predict treatment sensitivity in HNSCC patients as well as to explore potential biomarkers.

METHODS AND ANALYSIS

This is a prospective observational study at a single centre (Guy's and St Thomas' NHS Foundation Trust) to generate PDOs from patients' samples to assess treatment response and to correlate with patients' treatment outcomes. Patients will be included if they are diagnosed with HNSCC undergoing curative treatment (primary surgery or radiotherapy) or presenting with recurrent or metastatic cancers and they will be categorised into three groups (cohort 1: primary surgery, cohort 2: primary radiotherapy and cohort 3: recurrent/metastatic disease). Research tumour samples will be collected and processed into PDOs and chemosensitivity/radiosensitivity will be assessed using established methods. Moreover, blood and other biological samples (eg, saliva) will be collected at different time intervals during treatment and will be processed in the laboratory for plasma and peripheral blood mononuclear cell (PBMC) isolation. Plasma and saliva will be used for circulating tumour DNA analysis and PBMC will be stored for assessment of the peripheral immune characteristics of the patients as well as to perform co-culture experiments with PDOs. SOTO study (correlation of the treatment Sensitivity of patient-derived Organoids with Treatment Outcomes in patients with head and neck cancer) uses the collaboration of several specialties in head and neck cancer and has the potential to explore multiple areas of research with the aim of offering a valid and effective approach to personalised medicine for cancer patients.

ETHICS AND DISSEMINATION

This study was approved by North West-Greater Manchester South Research Ethics Committee (REC Ref: 22/NW/0023) on 21 March 2022. An informed consent will be obtained from all participants prior to inclusion in the study. Results will be disseminated via peer-reviewed publications and presentations at international conferences.

TRIAL REGISTRATION NUMBER

NCT05400239.

Evolution of Liquid Biopsies for Detecting Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy characterised by late diagnosis and poor prognosis. Despite advancements, current diagnostic and prognostic strategies remain limited. Liquid biopsy techniques, including circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), circulating tumour exosomes, and proteomics, offer potential solutions to improve PDAC diagnosis, prognostication, and management. A systematic search of Ovid MEDLINE identified studies published between 2019 and 2024, focusing on liquid biopsy biomarkers for PDAC. A total of 49 articles were included. ctDNA research shows some promise in diagnosing and prognosticating PDAC, especially through detecting mutant KRAS in minimal residual disease assays. CTC analyses had low sensitivity for early-stage PDAC and inconsistent prognostic results across subpopulations. Exosomal studies revealed diverse biomarkers with some diagnostic and prognostic potential. Proteomics, although relatively novel, has demonstrated superior accuracy in PDAC diagnosis, including early detection, and notable prognostic capacity. Proteomics combined with CA19-9 analysis has shown the most promising results to date. An update on multi-cancer early detection testing, given its significance for population screening, is also briefly discussed. Liquid biopsy techniques offer promising avenues for improving PDAC diagnosis, prognostication, and management. In particular, proteomics shows considerable potential, yet further research is needed to validate existing findings and comprehensively explore the proteome using an unbiased approach.

Oropharyngeal cancer and human papillomavirus: a visualization based on bibliometric analysis and topic modeling

Objectives

The incidence of oropharyngeal cancer (OPC) is increasing. This study used bibliometric analysis and topic modeling to explore the research trends and advancements in this disease over the past 10 years, providing valuable insights to guide future investigations.

Methods

7,355 English articles from 2013 to 2022 were retrieved from the Web of Science Core Collection for bibliometric analysis. Topic modeling was applied to 1,681 articles from high-impact journals, followed by an assessment of topic significance ranking (TSR). Medical Subject Headings (MeSH) terms were extracted using R and Python, followed by an analysis of the terms associated with each topic and on an annual basis. Additionally, genes were extracted and the number of genes appearing each year and the newly emerged genes were counted.

Results

The bibliometric analysis suggested that the United States and several European countries hold pivotal positions in research. Current research is focused on refining treatments, staging and stratification. Topic modeling revealed 12 topics, emphasizing human papillomavirus (HPV) and side effect reduction. MeSH analysis revealed a growing emphasis on prognosis and quality of life. No new MeSH terms emerged after 2018, suggesting that the existing terms have covered most of the core concepts within the field of oropharyngeal cancers. Gene analysis identified TP53 and EGFR as the most extensively studied genes, with no novel genes discovered after 2019. However, CD69 and CXCL9 emerged as new genes of interest in 2019, reflecting recent research trends and directions.

Conclusion

HPV-positive oropharyngeal cancer research, particularly treatment de-escalation, has gained significant attention. However, there are still challenges in diagnosis and treatment that need to be addressed. In the future, more research will focus on this issue, indicating that this field still holds potential as a research hotspot.

Molecular and nutritional markers in head and neck cancer

PURPOSE OF REVIEW

There is still a need of biomarkers in the induction and neoadjuvant settings for squamous cell carcinoma of the head and neck (SCCHN). The objective of this concise review article is to give an overview on both predictive and prognostic biomarkers potentially useful for the management of SCCHN.

RECENT FINDINGS

Human papilloma virus (HPV) positivity translated by the presence of the protein indicator p16 is synonymous of favorable prognosis SCCHN. However, there is some disparity for disease evolution among p16 positive SCCHN. A lack of correlation between immunohistochemistry (IHC) and precise quantification of active epidermal growth factor receptors (EGFRs) may explain the absence of link between EGFR expression performed by IHC and response to EGFR targeting therapies reported in SCCHN. Circulating tumor cells (CTCs) have the property to share the main somatic mutations and genetic rearrangements with the primary tumors. A particular potential interest lies on the possibility to predict patient outcome based on a single-CTC analysis.

SUMMARY

This short review indicates that key biological marker reflecting disease outcome is not yet emerging for a clinical use in SCCHN. Hopes can be put into the so-called liquid biopsies incorporating circulating tumor cells and circulating tumor DNA.

Multimodal detection of molecular residual disease in high-risk locally advanced squamous cell carcinoma of the head and neck

Up to 30% of patients with locally advanced head and neck squamous cell carcinoma (LA-HNSCC) relapse. Molecular residual disease (MRD) detection using multiple assays after definitive therapy has not been reported. In this study, we included patients with LA-HNSCC (stage III Human Papilloma virus (HPV)-positive, III-IVB HPV-negative) treated with curative intent. Plasma was collected pre-treatment, at 4-6 weeks (FU1) and 8-12 weeks (FU2) post-treatment. Circulating tumor DNA (ctDNA) was analyzed using a tumor-informed (RaDaR®) and a tumor-naïve (CAPP-seq) assay. HPV DNA was measured using HPV-sequencing (HPV-seq) and digital PCR (dPCR). A total of 86 plasma samples from 32 patients were analyzed; all patients with at least 1 follow-up sample. Most patients were stage III HPV-positive (50%) and received chemoradiation (78%). No patients had radiological residual disease at FU2. With a median follow-up of 25 months, there were 7 clinical relapses. ctDNA at baseline was detected in 15/17 (88%) by RaDaR and was not associated with recurrence free survival (RFS). Two patients relapsed within a year after definitive therapy and showed MRD at FU2 using RaDaR; detection of ctDNA during follow-up was associated with shorter RFS (p < 0.001). ctDNA detection by CAPP-seq pre-treatment and during follow-up was not associated with RFS (p = 0.09). HPV DNA using HPV-seq or dPCR during follow-up was associated with shorter RFS (p < 0.001). Sensitivity and specificity for MRD at FU2 using RaDaR was 40% and 100% versus 20 and 90.5% using CAPP-seq. Sensitivity and specificity for MRD during follow-up using HPV-seq was 100% and 91.7% versus 50% and 100% using dPCR. In conclusion, HPV DNA and ctDNA can be detected in LA-HNSCC before definitive therapy. The RaDaR assay but not CAPP-seq may detect MRD in patients who relapse within 1 year. HPV-seq may be more sensitive than dPCR for MRD detection.

T-cell receptor determinants of response to chemoradiation in locally-advanced HPV16-driven malignancies

Background

The effect of chemoradiation on the anti-cancer immune response is being increasingly acknowledged; however, its clinical implications in treatment responses are yet to be fully understood. Human papillomavirus (HPV)-driven malignancies express viral oncogenic proteins which may serve as tumor-specific antigens and represent ideal candidates for monitoring the peripheral T-cell receptor (TCR) changes secondary to chemoradiotherapy (CRT).

Methods

We performed intra-tumoral and pre- and post-treatment peripheral TCR sequencing in a cohort of patients with locally-advanced HPV16-positive cancers treated with CRT. An in silico computational pipeline was used to cluster TCR repertoire based on epitope-specificity and to predict affinity between these clusters and HPV16-derived epitopes.

Results

Intra-tumoral repertoire diversity, intra-tumoral and post-treatment peripheral CDR3β similarity clustering were predictive of response. In responders, CRT triggered an increase peripheral TCR clonality and clonal relatedness. Post-treatment expansion of baseline peripheral dominant TCRs was associated with response. Responders showed more baseline clustered structures of TCRs maintained post-treatment and displayed significantly more maintained clustered structures. When applying clustering by TCR-specificity methods, responders displayed a higher proportion of intra-tumoral TCRs predicted to recognise HPV16 peptides.

Conclusions

Baseline TCR characteristics and changes in the peripheral T-cell clones triggered by CRT are associated with treatment outcome. Maintenance and boosting of pre-existing clonotypes are key elements of an effective anti-cancer immune response driven by CRT, supporting a paradigm in which the immune system plays a central role in the success of CRT in current standard-of-care protocols.