Tumour-agnostic plasma assay for circulating tumour DNA predicts outcome in recurrent and/or metastatic squamous cell carcinoma of the head and neck treated with a PD-1 inhibitor.

BACKGROUND: Only 15-20% of recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) patients derive long-term benefit from nivolumab or pembrolizumab. We developed a circulating tumour DNA (ctDNA) tumour-agnostic assay aimed at the early prediction of single agent programmed cell death 1 (PD1) inhibitor efficacy in R/M SCCHN. PATIENTS AND METHODS: Our tumour-agnostic assay included 37 genes frequently mutated in R/M SCCHN and two HPV16 genes. Primary endpoint was the concordance between ctDNA kinetics (ΔctDNA) and the best overall response according to Response Evaluation Criteria in Solid Tumors version 1.1. ΔctDNA was defined as the difference in mean variant allele frequency (VAF) between the on-treatment sample harvested 6-10 weeks (FU1) after PD1 inhibitor initiation and the pre-treatment plasma sample (ΔctDNA = mean FU1 VAF - mean pre-treatment VAF). RESULTS: ctDNA was detected in 35/44 (80%) of the pre-treatment plasma samples. The concordance between ΔctDNA and imaging response was observed in 74%. Median progression-free survival was 8.6 months in the favourable ΔctDNA group and 2.5 months in the unfavourable ΔctDNA group (p = 0.057). Median overall survival (OS) was 18.1 and 8.2 months in the favourable and unfavourable ΔctDNA groups, respectively (p = 0.13). In patients with PD-L1 expressing SCCHN (Combined Positive Score ≥1), OS was significantly better in patients with favourable ΔctDNA compared with patients with unfavourable ΔctDNA: median OS was 41.5 and 8.4 months (p = 0.033), respectively. CONCLUSIONS: Tumour-agnostic ctDNA analysis for human papillomavirus (HPV)-negative and HPV-positive R/M SCCHN is feasible. ctDNA kinetics show promising results in predicting the efficacy of PD1 inhibitors in R/M SCCHN.

Regression of a melanoma brain metastasis that had appeared after immune checkpoint inhibitor discontinuation: a hypothesis-generating case.

We present the case of a 50-year-old woman previously treated with nivolumab-ipilimumab combination therapy for a metastatic melanoma. Despite premature discontinuation of these immune checkpoint inhibitors (ICIs) after 2 cycles due to severe immune-related hepatitis, the patient achieved a complete response. Nine months later, brain magnetic resonance imaging (MRI) showed progression of a single cerebral lesion, and the patient was referred for stereotactic radiosurgery. Unexpectedly, the brain MRI acquired one month later as part of radiosurgery planning showed a spontaneous regression of this lesion, allowing for radiosurgery cancellation. Follow-up imaging showed a sustained response, although the patient did not receive any other oncological treatment. We discuss here the potential immune mechanisms involved in this unusual course and the importance of better understanding the behaviour of tumours in the era of ICIs.

Liquid Biopsy to Detect Minimal Residual Disease: Methodology and Impact.

One reason why some patients experience recurrent disease after a curative-intent treatment might be the persistence of residual tumor cells, called minimal residual disease (MRD). MRD cannot be identified by standard radiological exams or clinical evaluation. Tumor-specific alterations found in the blood indirectly diagnose the presence of MRD. Liquid biopsies thus have the potential to detect MRD, allowing, among other things, the detection of circulating tumor DNA (ctDNA), circulating tumor cells (CTC), or tumor-specific microRNA. Although liquid biopsy is increasingly studied, several technical issues still limit its clinical applicability: low sensitivity, poor standardization or reproducibility, and lack of randomized trials demonstrating its clinical benefit. Being able to detect MRD could give clinicians a more comprehensive view of the risk of relapse of their patients and could select patients requiring treatment escalation with the goal of improving cancer survival. In this review, we are discussing the different methodologies used and investigated to detect MRD in solid cancers, their respective potentials and issues, and the clinical impacts that MRD detection will have on the management of cancer patients.

A phase II study of monalizumab in patients with recurrent/metastatic squamous cell carcinoma of the head and neck: The I1 cohort of the EORTC-HNCG-1559 UPSTREAM trial.

PURPOSE: Monalizumab is a monoclonal antibody targeting the inhibitory natural killer group 2A (NKG2A) receptor localised on natural killer (NK) and T cells. Its ligand, the human leukocyte antigen E (HLA-E), is overexpressed in squamous cell carcinoma of the head and neck (SCCHN). By targeting the HLA-E-NKG2A pathway, monalizumab may enhance NK and T cell activity. EXPERIMENTAL DESIGN: The UPSTREAM trial is a biomarker-driven umbrella trial studying targeted therapies and immunotherapies in patients with recurrent/metastatic (R/M) SCCHN progressing after platinum therapy. The immunotherapy 1 (I1) cohort was a phase II, single-arm substudy evaluating monalizumab (10 mg/kg intravenously on day 1 of a 14-day cycle). The primary end-point was the objective response (OR) rate (Response Evaluation Criteria in Solid Tumours 1.1) over the first 16 weeks. A two-stage Simon design was used (H1 15%, H0 3%, α 8%, power 90%) with pre-planned interruption of accrual if no OR was observed after the first 25 patients. RESULTS: Twenty-six eligible patients were enrolled. Seventeen (65%) patients had received ≥2 previous lines of systemic treatment, and 15 (58%) patients were PD(-L)1 inhibitor pretreated. No OR was observed. Stable disease was observed in 6 patients (23%) with a median duration of 3.8 months (95% confidence interval [CI]: 2.7-NE). The median progression-free survival and overall survival were 1.7 months (95% CI: 1.5-1.8) and 6.7 months (95% CI: 3.0-9.6), respectively. The most frequent treatment-related adverse event was grade I/II fatigue (19%). CONCLUSIONS: Monalizumab monotherapy has limited activity in R/M SCCHN. The I1 cohort did not meet its primary objective. Monalizumab combined with durvalumab is under investigation within UPSTREAM.

Liquid biopsy for mutational profiling of locoregional recurrent and/or metastatic head and neck squamous cell carcinoma.

OBJECTIVES: The molecular landscape of head and neck squamous cell carcinoma (HNSCC) harbors potentially actionable genomic alterations. We aimed to study the utility of liquid biopsy to (i) characterize the mutational landscape of recurrent/metastatic HNSCC using a comprehensive gene panel and (ii) estimate the concordance between DNA mutations identified from circulating tumor DNA (ctDNA) and matched tumor tissues. MATERIALS AND METHODS: Targeted next-generation sequencing (NGS) was performed on cell-free DNA (cfDNA) of 39 patients with locoregional recurrent (n = 19) and/or metastatic (n = 20) HNSCC. Tumor biopsy (n = 18) was sequenced using the same technique. RESULTS: ctDNA was detected in 51% of patients (20/39) with a higher probability of detection in metastatic than locoregional recurrent disease (70% versus 30%, p = 0.025). 81% and 58% of the tissue tumor variants were not detected in plasma when considering all patients and only metastatic patients with detectable ctDNA, respectively. In a multivariate analysis, the likelihood of detecting the tissue tumor variant in plasma was related to metastatic status (p = 0.012), tumor variant allele frequency (p < 0.001) and ctDNA quantity (p < 0.001). 26% of the variants were detected only in liquid and not in the solid biopsy. Three patients without an available tumor sample had plasma containing three different potentially actionable PIK3CA mutations. CONCLUSION: CtDNA detection and characterization using targeted NGS is feasible in metastatic HNSCC. Liquid biopsies do not reflect the complete mutation profile of the tumor but have the potential to identify actionable mutations when tumor biopsies are not available as well as variants not found in matched tumor tissue.

Current applications and challenges of circulating tumor DNA (ctDNA) in squamous cell carcinoma of the head and neck (SCCHN).

Liquid biopsies (LB) are emerging in the oncology field, with promising data as new diagnostic, prognostic and treatment-monitoring tools. Squamous cell carcinoma of the head and neck (SCCHN) is a heterogenous disease and many challenges remain to improve patient outcomes. Liquid biopsy could be of interest at different stages of SCCHN disease, including better screening to diagnose more patients at an early stage, early detection of relapse after curative treatment, and the implementation of precision medicine. As LB is very attractive by the ease of sampling, this field is moving fast. Therefore, it is important to be aware of the potential applications but also the limitations of these new tools in regards to technical aspects and interpretation of the data. In this review, we will first give an overview of potential clinical applications and technical challenges of circulating tumor DNA (ctDNA) and then focus on current available data of ctDNA in SCCHN. Although the literature on ctDNA analysis for SCCHN is scarce compared to other tumors, preliminary results seem to hold promise for the future, including the detection of minimal residual disease or the detection of potentially targetable events through liquid biopsy. Prospective liquid-biopsy driven clinical trials are needed to validate its clinical relevance.

Safety of drug treatments for head and neck cancer.

INTRODUCTION: The treatment of squamous cell carcinoma of the head and the neck depends on the disease's stage. In locally-advanced stage disease, multimodal treatment strategies, including surgery, radiotherapy and chemotherapy, give the best outcome in terms of overall survival. Those treatments are not without negligeable adverse events, which can lead to late debilitating toxicities. In recurrent/metastatic disease, not amenable to surgery or radiation therapy, palliative chemotherapy is the most appropriate treatment. Areas covered: This review aims to provide an overview of the safety of standard drug regimens used to treat SCCHN in daily practice, including platinum-based chemoradiation, induction chemotherapy, cetuximab and immunotherapy. The toxicities induced by single modality radiotherapy, or those resulting from surgery, are not part of the discussion. Expert opinion: Toxicities observed with multimodal treatment of SCCHN are the highest we can tolerate in terms of treatment-related mortality, morbidity and late consequences. Patients at high risk of developing such complications should be identified upfront for optimal prevention and management. There is a medical need to identify less toxic regimens without compromising the treatment efficacy, especially for patients with Human Papilloma Virus-induced oropharyngeal cancers. Finally, it is crucial in future trials to better standardize the scales used to report treatment related adverse events.

Unusual presentation of bladder cancer resurgence and efficacy of radiotherapy.

A 68-year-old man with a history of bladder cancer presented with perineal pain and penile priapism. The work up showed multiple lesions strictly located in the penis; biopsy confirmed metastases of bladder cancer. Surgery was judged unfeasible and chemotherapy failed to improve symptoms. Radiotherapy was therefore delivered on the whole penis and resulted in a rapid clinical benefit and persistent control of the disease. Penile metastases are very rare and no consensus exists concerning their management; radiotherapy appears as a promising therapeutic option not only to palliate pain but also to control the disease.