Immunotherapy of head and neck cancer: Emerging clinical trials from a National Cancer Institute Head and Neck Cancer Steering Committee Planning Meeting

Molecular characterization of the evolution of premalignant lesions in the upper aerodigestive tract

Introduction

Early relapse and development of metastatic disease are some of the primary reasons for the poor prognosis of patients with head and neck squamous cell carcinoma (HNSCC). HNSCC is a heterogeneous disease which may develop in large premalignant fields of genetically altered cells. Yet knowing which individuals will progress and develop clinically significant cancers during their lifetimes remains one of the most important challenges of reducing HNSCC morbidity and mortality. To further elucidate the molecular mechanisms, we performed a focused analysis of the genome and immune microenvironment from multiple, matched normal squamous tissue, premalignant lesions, as well as primary and recurrent tumors from seven patients with p16-negative HNSCC.

Methods

We performed targeted panel Next Generation Sequencing (161 genes) to analyze somatic variants from sequentially collected, matched formalin-fixed paraffin-embedded tissue (normal, premalignant, HNSCC) from two patients. These samples plus samples from five additional patients were analyzed with the Nanostring PanCancer Immune Panel. In addition, we performed shallow whole genome sequencing (0.5x coverage on average) on samples from three of these patients. Patients were, apart from one case, primarily treated with curative-intent surgery, and received subsequent adjuvant treatment, if indicated.

Results

The most frequently mutated genes were TP53 and NOTCH1. Other mutated genes included NOTCH3 and CDKN2A, among others. A significant number of mutations were private to dysplasia and invasive carcinoma, respectively, however, almost 20% were shared between them. Increasing genomic instability was observed when comparing histologically normal squamous mucosa with higher levels of dysplasia. High-grade dysplasia showed similarly rearranged genomes as invasive carcinoma. Pathways related to interferon alpha and gamma response were upregulated even in moderate dysplastic lesions with increasing expression in higher grades of dysplasia and carcinoma. SPINK5, a known tumor suppressor gene in HNSCC, was already downregulated in low-grade dysplastic lesions, indicating an early deactivation in the evolution of the disease.

Conclusion

Genomic alterations as well as aberrant immune gene expression can be observed early in the evolution of tumors of the upper aerodigestive tract, highlighting the potential for targeting early mechanisms of disease progression.

Surgical Treatment for Advanced Oropharyngeal Cancer: A Narrative Review

Background and Objectives: to describe current scientific knowledge regarding the treatment options in advanced oropharyngeal cancer. The standard care for advanced oropharyngeal cancer (OPSCC) has been chemoradiotherapy, although surgical approaches followed by adjuvant treatment have been proposed. The best therapy for each patient should be decided by an interdisciplinary tumour-board. Different strategies should be considered for the specific patient's treatment: surgery, chemotherapy and radiation therapy or combinations of them. The treatment choice is influenced by tumour variability and prognostic factors, but it also depends on cancer extension, extranodal extension, nervous invasion, human papilloma virus (HPV) presence, making the decisional algorithm not always clear. HPV-related OPSCC is strongly associated with a favourable overall survival (OS) and disease-free survival rate (DSS); by contrast, HPV-negative OPSCC often flags a worse prognosis. Consequently, the American Joint Committee on Cancer (AJCC) differentiates OPSCC treatment and prognosis based on HPV status. Methods: we carried out a review of current scientific literature to analyze the different indications and limitations of surgical treatment options in OPSCC stage III and IV. Conclusion: robotic surgery or open approaches with reconstructive flaps can be considered in advanced stages, resulting in the de-intensification of subsequent systemic therapy and fewer related side effects. Furthermore, in the event of the primary failure of systemic therapy or disease recurrence, the surgical approach constitutes an additional therapeutic option which lengthens patient survival functions.

Tumor heterogeneity: preclinical models, emerging technologies, and future applications

Heterogeneity describes the differences among cancer cells within and between tumors. It refers to cancer cells describing variations in morphology, transcriptional profiles, metabolism, and metastatic potential. More recently, the field has included the characterization of the tumor immune microenvironment and the depiction of the dynamics underlying the cellular interactions promoting the tumor ecosystem evolution. Heterogeneity has been found in most tumors representing one of the most challenging behaviors in cancer ecosystems. As one of the critical factors impairing the long-term efficacy of solid tumor therapy, heterogeneity leads to tumor resistance, more aggressive metastasizing, and recurrence. We review the role of the main models and the emerging single-cell and spatial genomic technologies in our understanding of tumor heterogeneity, its contribution to lethal cancer outcomes, and the physiological challenges to consider in designing cancer therapies. We highlight how tumor cells dynamically evolve because of the interactions within the tumor immune microenvironment and how to leverage this to unleash immune recognition through immunotherapy. A multidisciplinary approach grounded in novel bioinformatic and computational tools will allow reaching the integrated, multilayered knowledge of tumor heterogeneity required to implement personalized, more efficient therapies urgently required for cancer patients.

Therapeutic approaches for the treatment of head and neck squamous cell carcinoma-An update on clinical trials

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common non-skin cancer with a tobacco consumption and infection with high-risk human papillomavirus (HPV) being major risk factors. Despite advances in numerous therapy modalities, survival rates for HNSCC have not improved considerably; a vast number of clinical outcomes have demonstrated that a combination strategy (the most well-known docetaxel, cisplatin, and 5-fluorouracil) is the most effective treatment choice. Immunotherapy that targets immunological checkpoints is being tested in a number of clinical trials, either alone or in conjunction with chemotherapeutic or targeted therapeutic drugs. Various monoclonal antibodies, such as cetuximab and bevacizumab, which target the EGFR and VEGFR, respectively, as well as other signaling pathway inhibitors, such as temsirolimus and rapamycin, are also being studied for the treatment of HNSCC. We have reviewed the primary targets in active clinical studies in this study, with a particular focus on the medications and drug targets used.

Epidermal growth factor receptor signaling in precancerous keratinocytes promotes neighboring head and neck cancer squamous cell carcinoma cancer stem cell-like properties and phosphoinositide 3-kinase inhibitor insensitivity

Head and neck squamous cell carcinoma (HNSCC) is commonly associated with tobacco and alcohol consumption that induce a "precancerous field," with phosphoinositide 3-kinase (PI3K) signaling being a common driver. However, the preclinical effectiveness of PI3K inhibitors has not necessarily translated to remarkable benefit in HNSCC patients. Thus, we sought to determine how precancerous keratinocytes influence HNSCC proliferation, cancer stem cell (CSC) maintenance, and response to PI3K inhibitors. We used the NOK keratinocyte cell line as a model of preneoplastic keratinocytes because it harbors two frequent genetic events in HNSCC, CDKN2A promoter methylation and TP53 mutation, but does not form tumors. NOK cell coculture or NOK cell-conditioned media promoted HNSCC proliferation, PI3K inhibitor resistance, and CSC phenotypes. SOMAscan-targeted proteomics determined the relative levels of >1300 analytes in the media conditioned by NOK cells and HNSCC cells ± PI3K inhibitor. These results demonstrated that NOK cells release abundant levels of ligands that activate epidermal growth factor receptor (EGFR) and fibroblast growth factor receptor (FGFR), two receptor tyrosine kinases with oncogenic activity. Inhibition of EGFR, but not FGFR, blunted PI3K inhibitor resistance and CSC phenotypes induced by NOK cells. Our results demonstrate that precancerous keratinocytes can directly support neighboring HNSCC by activating EGFR. Importantly, PI3K inhibitor sensitivity was not necessarily a cancer cell-intrinsic property, and the tumor microenvironment impacts therapeutic response and supports CSCs. Additionally, combined inhibition of EGFR with PI3K inhibitor diminished EGFR activation induced by PI3K inhibitor and potently inhibited cancer cell proliferation and CSC maintenance.

Current Insights and Advancements in Head and Neck Cancer: Emerging Biomarkers and Therapeutics with Cues from Single Cell and 3D Model Omics Profiling

Head and neck cancer (HNC) is among the ten leading malignancies worldwide, with India solely contributing one-third of global oral cancer cases. The current focus of all cutting-edge strategies against this global malignancy are directed towards the heterogeneous tumor microenvironment that obstructs most treatment blueprints. Subsequent to the portrayal of established information, the review details the application of single cell technology, organoids and spheroid technology in relevance to head and neck cancer and the tumor microenvironment acknowledging the resistance pattern of the heterogeneous cell population in HNC. Bioinformatic tools are used for study of differentially expressed genes and further omics data analysis. However, these tools have several challenges and limitations when analyzing single-cell gene expression data that are discussed briefly. The review further examines the omics of HNC, through comprehensive analyses of genomics, transcriptomics, proteomics, metabolomics, and epigenomics profiles. Patterns of alterations vary between patients, thus heterogeneity and molecular alterations between patients have driven the clinical significance of molecular targeted therapies. The analyses of potential molecular targets in HNC are discussed with connotation to the alteration of key pathways in HNC followed by a comprehensive study of protein kinases as novel drug targets including its ATPase and additional binding pockets, non-catalytic domains and single residues. We herein review, the therapeutic agents targeting the potential biomarkers in light of new molecular targeted therapies. In the final analysis, this review suggests that the development of improved target-specific personalized therapies can combat HNC's global plight.

Role of PD-1/PD-L1 inhibitors in the treatment of recurrent/metastatic head and neck squamous cell carcinoma: A systematic review and meta-analysis

BACKGROUND

The use of immunotherapy to treat recurrent/metastatic squamous cell carcinoma of the head and neck has become a popular research topic in recent years, and many clinical trials have been carried out.

OBJECTIVES

To systematically evaluate the efficacy and safety of PD-1/PD-L1 inhibitors in the treatment of recurrent/metastatic head and neck squamous cell carcinoma.

METHODS

We searched PubMed, Embase, Cochrane Library and other databases up to 1 November 2019 for publications reporting the use of PD-1/PD-L1 inhibitors in the treatment of squamous cell carcinoma of the head and neck. Revman 5.0 was used for combination analysis, and the overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and adverse events were determined.

RESULTS

Five articles were included. Compared with other treatment methods, this meta-analysis showed that treatment with PD-1/PD-L1 inhibitors can significantly improve OS (P < .0001), but there was no significant improvement in PFS or ORR. The risk of anaemia and nausea was significantly reduced by treatment with PD-1/PD-L1 inhibitors.

CONCLUSIONS AND SIGNIFICANCE

Treatment with PD-1/PD-L1 inhibitors alone can improve the overall survival rate for recurrent/metastatic squamous cell carcinoma of the head and neck but there is no obvious advantage in other aspects and adverse events.

Identification and validation of a prognostic signature and combination drug therapy for immunotherapy of head and neck squamous cell carcinoma

Immunotherapy has become a promising therapeutic option for Head and neck squamous cell carcinoma (HNSC). However, only a small percentage of patients could benefit from it, and the overall prognosis was far from satisfactory. In this study, by comprehensively computational analyses of hundreds of HNSC samples, a prognostic signature composed of 13 immune-related genes (IRGs) was constructed. The results of the analyses in multiple datasets indicated that our signature had high predictive accuracy and could serve as an independent prognostic predictor. Based on this signature and multiple clinical variables, we also established a prognostic nomogram to quantitatively predict the survival risk of individual patients. Moreover, this signature could accurately predict survival, reflect the immune microenvironment, and predict immunotherapy efficacy among HNSC patients. Two potential drugs (doxorubicin and daunorubicin) were also identified via Connectivity Map and molecular docking, which could be used for HNSC combination therapy. Taken together, we developed and validated a robust IRG-based prognostic signature to monitor the prognosis of HNSC, which could provide a solid foundation for individualized cancer immunotherapy.

HPV16 drives cancer immune escape via NLRX1-mediated degradation of STING

The incidence of human papillomavirus-positive (HPV+) head and neck squamous cell carcinoma (HNSCC) has surpassed that of cervical cancer and is projected to increase rapidly until 2060. The coevolution of HPV with transforming epithelial cells leads to the shutdown of host immune detection. Targeting proximal viral nucleic acid-sensing machinery is an evolutionarily conserved strategy among viruses to enable immune evasion. However, E7 from the dominant HPV subtype 16 in HNSCC shares low homology with HPV18 E7, which was shown to inhibit the STING DNA-sensing pathway. The mechanisms by which HPV16 suppresses STING remain unknown. Recently, we characterized the role of the STING/type I interferon (IFN-I) pathway in maintaining immunogenicity of HNSCC in mouse models. Here we extended those findings into the clinical domain using tissue microarrays and machine learning-enhanced profiling of STING signatures with immune subsets. We additionally showed that HPV16 E7 uses mechanisms distinct from those used by HPV18 E7 to antagonize the STING pathway. We identified NLRX1 as a critical intermediary partner to facilitate HPV16 E7-potentiated STING turnover. The depletion of NLRX1 resulted in significantly improved IFN-I-dependent T cell infiltration profiles and tumor control. Overall, we discovered a unique HPV16 viral strategy to thwart host innate immune detection that can be further exploited to restore cancer immunogenicity.

Radiomic analysis identifies tumor subtypes associated with distinct molecular and microenvironmental factors in head and neck squamous cell carcinoma

PURPOSE

To identify whether radiomic features from pre-treatment computed tomography (CT) scans can predict molecular differences between head and neck squamous cell carcinoma (HNSCC) using The Cancer Imaging Archive (TCIA) and The Cancer Genome Atlas (TCGA).

METHODS

77 patients from the TCIA with HNSCC had imaging suitable for analysis. Radiomic features were extracted and unsupervised consensus clustering was performed to identify subtypes. Genomic data was extracted from the matched patients in the TCGA database. We explored relationships between radiomic features and molecular profiles of tumors, including the tumor immune microenvironment. A machine learning method was used to build a model predictive of CD8 + T-cells. An independent cohort of 83 HNSCC patients was used to validate the radiomic clusters.

RESULTS

We initially extracted 104 two-dimensional radiomic features, and after feature stability tests and removal of volume dependent features, reduced this to 67 features for subsequent analysis. Consensus clustering based on these features resulted in two distinct clusters. The radiomic clusters differed by primary tumor subsite (p = 0.0096), HPV status (p = 0.0127), methylation-based clustering results (p = 0.0025), and tumor immune microenvironment. A random forest model using radiomic features predicted CD8 + T-cells independent of HPV status with R² = 0.30 (p < 0.0001) on cross validation. Consensus clustering on the validation cohort resulted in two distinct clusters that differ in tumor subsite (p = 1.3 × 10^-7) and HPV status (p = 4.0 × 10^-7).

CONCLUSION

Radiomic analysis can identify biologic features of tumors such as HPV status and T-cell infiltration and may be able to provide other information in the near future to help with patient stratification.

How Can Immune Checkpoint Inhibitors Cause Hyperprogression in Solid Tumors?

Following the administration of immune checkpoint inhibitors, an unexpected pattern of response designated as hyperprogression may be observed in certain patients. This paradoxical response corresponds to an acceleration in tumor growth and a dramatic decrease of patient survival. The reported incidence rates of hyperprogressive disease are highly variable, ranging between 4 and 29%. In this review, we have performed a literature search on hyperprogressive disease, including both retrospective studies and case reports, and discuss potential predictive biomarkers as well as potential mechanisms associated with immune-checkpoint inhibitor associated hyperprogression.

Boron neutron capture therapy at the crossroads - Where do we go from here?

As elegant as is the concept upon which Boron Neutron Capture Therapy (BNCT) is based, unfortunately it has not gained widespread acceptance by the physicians who are treating cancer patients on a daily basis. The question is why? Very simply put, the clinical results obtained in treating patients with high grade gliomas and recurrent tumors of the head and neck region have not been convincing enough to produce more interest in BNCT as a cancer treatment modality. There are a variety of reasons for this, one of the most important of which has been its dependency on nuclear reactors as neutron sources. With the advent of accelerator based neutron sources (ABNS), this hopefully will be addressed. If the results obtained from ongoing and soon to be initiated clinical trials can at least demonstrate equivalency to those obtained with nuclear reactors, this should address the first problem. The second problem relates to boron delivery agents, and despite the considerable efforts of chemists and biologists over the past 50 years, there are only two drugs that currently are being used clinically, sodium borocaptate (BSH) and boronophenylalanine (BPA). It is widely recognized that these two drugs are less than ideal. Perhaps new and more effective boron delivery agents will finally appear on the scene, but barring that, we will address the question of what can be done now to make BNCT a more effective cancer treatment modality.

Fenretinide, Tocilizumab, and Reparixin Provide Multifaceted Disruption of Oral Squamous Cell Carcinoma Stem Cell Properties: Implications for Tertiary Chemoprevention

Locoregional recurrence of oral squamous cell carcinoma (OSCC) dramatically reduces patient survival. Further, as many OSCC recurrences are inoperable, radiotherapy and chemotherapy with or without biological adjuncts are the remaining treatment options. Although the tumors may initially respond, radiotherapy- and chemotherapy-resistant cancer stem cells (CSC) can readily repopulate OSCC tumors. Currently, following the initial OSCC treatment, patients are closely monitored until a recurrence or a second primary is detected. Identification of agents with complementary mechanisms to suppress CSC tumorigenic functions could change this passive approach. The goals of this study were twofold: (1) develop and validate CSC-enriched (CSCE) OSCC cell lines and (2) identify chemopreventive agents that obstruct multiple CSCE protumorigenic pathways. CSCE cultures, which were created by paclitaxel treatment followed by three tumorsphere passes, demonstrated CSC characteristics, including increased expression of stem cell and inflammatory genes, increased aldehyde dehydrogenase (ALDH) activity, and enhanced in vitro/in vivo proliferation and invasion. Three chemopreventives, fenretinide, tocilizumab, and reparixin, were selected due to their distinct and complementary CSC-disruptive mechanisms. The CSCE selection process modulated the cells' intermediate filaments resulting in an epithelial-predominant (enhanced cytokeratin, proliferation, IL6 release) line and a mesenchymal-predominant (upregulated vimentin, invasive, IL8 release) line. Our results confirm that 4HPR binds with appreciably higher affinity than Wnt at the Frizzled binding site and significantly inhibits CSC-enabling Wnt-β-catenin downstream signaling. Notably, combination fenretinide-tocilizumab-reparixin treatment significantly suppressed IL6 and IL8 release, stem cell gene expression, and invasion in these diverse CSCE populations. These promising multiagent in vitro data provide the basis for our upcoming in vivo CSCE tertiary chemoprevention studies.

Publication statuses of clinical trials supporting FDA-approved immune checkpoint inhibitors: a meta-epidemiological investigation

Background

The low data publication rate for Food and Drug Administration (FDA)-approved drugs, and discrepancies between FDA-submitted versus published data, remain a concern. We investigated the publication statuses of sponsor-submitted clinical trials supporting recent anticancer drugs approved by the FDA, with a focus on immune checkpoint inhibitors (ICPis).

Methods

We identified all ICPis approved between 2011 and 2014, thereby obtaining 3 years of follow-up data. We assessed the clinical trials performed for each drug indication and matched each trial with publications in the literature. The primary benchmark was the publication status 2 years post-approval. We examined the association between time to publication and drug type using a multilevel Cox regression model that was adjusted for clustering within drug indications and individual covariates.

Results

Between 2011 and 2014, 36 anticancer drugs including 3 ICPis were newly approved by the FDA. Of 19 trials investigating the 3 ICPis, 11 (58%) were published within 2 years post-approval. We randomly selected 10 of the 33 remaining anticancer drugs; 68 of 101 trials investigating these drugs (67%) were published. Overall, the publication rate was 66% at 2 years post-approval with a median time to publication of 2.3 years. There was no significant difference in the time to trial publication between ICPis and other anticancer drugs (adjusted hazard ratio [HR], 1.1; 95% confidence interval [CI], 0.8–1.7; P = 0.55). However, findings related to non-ICPis investigated specifically in randomized phase 2 or phase 3 trials were significantly more likely to be published earlier than those related to ICPis (adjusted HR, 7.4; 95% CI, 1.8–29.5; P = 0.005).

Conclusion

One in 3 sponsor-submitted trials of the most recently approved anticancer drugs remained unpublished 2 years post-FDA approval. We found no evidence that the drug type was associated with the time to overall trial publication.

Role of Unani Medicines in Cancer Control and Management

Background:

Cancer is a havoc and killer disease. Several ways including allopathic chemotherapy have been used in the cancer treatment. Allopathic chemotherapy has several limitations and side effects. Unani medicine is also one of the therapies to cure cancer.

Objective:

In this type of treatment, herbal drugs are used for the treatment and prevention of cancer. The main attractive thing about herbal drug is no side effect as compared to allopathic chemotherapy.

Methods:

Actually, herbal drugs are the extracts of medicinal plants. The plant extracts are obtained by crushing and heating the main part of the plants; showing anticancer activity. The main plants used in the treatment of cancer are oroxylum indicum, dillenia indica, terminalia arjuna etc.

Results:

Mainly the cancers treated are of digestive system, breast, cervical, brain, blood, bone, lungs, thyroid, uterine, bladder, throat etc.

Conclusion:

The present review article discusses the importance of Unani system of medicine for the treatment of cancer. Besides, the future perspectives of Unani medicine in cancer treatment are also highlighted.

Head and Neck Cancer Immunotherapy beyond the Checkpoint Blockade

The success of immune checkpoint receptor blockade has brought exciting promises for the treatment of head and neck squamous cell carcinoma (HNSCC). While patients who respond to checkpoint inhibitors tend to develop a durable response, <15% of patients with HNSCC respond to immune checkpoint inhibitors, underscoring the critical need to alleviate cancer resistance to immunotherapy. Major advances have been made to elucidate the intrinsic and adaptive resistance mechanisms to immunotherapy. Central genomic events in HNSCC have been found to possess previously unknown roles in suppressing immune sensing. Such inhibitory function affects both the innate and adaptive arms of tumor-specific immunity. While checkpoint blockade effectively reinvigorates adaptive T-cell responses, additional targeting of the oncogenic inhibitors of innate immune sensing likely informs a novel and potent strategy for immune priming. This review discusses the recent advances on the identification of key HNSCC oncogenes that impair antitumor immunity and emerging immune-priming approaches that sensitize poorly immunogenic HNSCCs to checkpoint blockade. These approaches include but are not limited to cancer vaccine systems utilizing novel type I interferon agonists as immune adjuvants, radiation, DNA damage-inducing agents, and metabolic reprogramming. The goal of these multipronged approaches is to expand tumor-specific effector T-cells, break checkpoint receptor-mediated tolerance, and metabolically support sustained T-cell activation. The translation of therapeutics that reverses oncogenic inhibition of immune sensing requires thorough characterization of the HNSCC regulators of innate immune sensors, development of additional immunocompetent HNSCC mouse models, as well as engineering of more robust immune adjuvant delivery systems. Built on the success of checkpoint blockade, validation of novel immune-priming approaches holds key promises to expand the pool of responders to immunotherapy.

Current Treatment Landscape of Nasopharyngeal Carcinoma and Potential Trials Evaluating the Value of Immunotherapy

Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer with a distinctive regional and racial prevalence. It is associated with Epstein-Barr virus infection and has a high propensity for regional and distant metastases, while it is very sensitive to radiation and chemotherapy. A common feature of Epstein-Barr virus-positive NPC is the dense infiltration of lymphocytes in the tumor stroma and positive programmed death-ligand 1 expression in tumor cells, making it an attractive target for immunotherapy, especially immune checkpoint inhibitors. As new immunotherapeutic agents are being rapidly adopted in many cancers, including head and neck cancer, the National Cancer Institute sponsored a clinical trial planning meeting to identify opportunities for developing phase II and III trials testing immunotherapy in different stages of NPC. The meeting started with the summary of the biology of the disease, current standards of care, and evidence of immunotherapy in this cancer. Three subcommittees were tasked to develop clinical trials: loco regionally advanced, nonmetastatic NPC; widely metastatic NPC; and either local recurrence after initial treatment or presenting with oligometastatic disease. This article summarizes the proceedings of this clinical trial planning meeting and provides a road map for future trials incorporating immune checkpoint inhibitors for therapeutic management of NPC. This road map, though specific for NPC, may also be applicable to other virally driven cancers that have similar ability to evade the host's immune system.

DNA methylation at an enhancer of the three prime repair exonuclease 2 gene (TREX2) is linked to gene expression and survival in laryngeal cancer

Background

Genetic aberrations in DNA repair genes are linked to cancer, but less is reported about epigenetic regulation of DNA repair and functional consequences. We investigated the intragenic methylation loss at the three prime repair exonuclease 2 (TREX2) locus in laryngeal (n = 256) and colorectal cancer cases (n = 95) and in pan-cancer data from The Cancer Genome Atlas (TCGA).

Results

Significant methylation loss at an intragenic site of TREX2 was a frequent trait in both patient cohorts (p = 0.016 and < 0.001, respectively) and in 15 out of 22 TCGA studies. Methylation loss correlated with immunohistochemically staining for TREX2 (p < 0.0001) in laryngeal tumors and improved overall survival of laryngeal cancer patients (p = 0.045). Chromatin immunoprecipitation, demethylation experiments, and reporter gene assays revealed that the region of methylation loss can function as a CCAAT/enhancer binding protein alpha (CEBPA)-responsive enhancer element regulating TREX2 expression.

Conclusions

The data highlight a regulatory role of TREX2 DNA methylation for gene expression which might affect incidence and survival of laryngeal cancer. Altered TREX2 protein levels in tumors may affect drug-induced DNA damage repair and provide new tailored therapies.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0666-5) contains supplementary material, which is available to authorized users.

Selective Neck Dissection and Survival in Pathologically Node-Positive Oral Squamous Cell Carcinoma

The most important prognostic factor in oral squamous cell carcinoma (OSCC) is neck metastasis, which is treated by neck dissection. Although selective neck dissection (SND) is a useful tool for clinically node-negative OSCC, its efficacy for neck node-positive OSCC has not been established. Sixty-eight OSCC patients with pN1–3 disease who were treated with curative surgery using SND and/or modified-radical/radical neck dissection (MRND/RND) were retrospectively reviewed. The neck control rate was 94% for pN1–3 patients who underwent SND. The five-year overall survival (OS) and disease-specific survival (DSS) in pN1-3 OSCC patients were 62% and 71%, respectively. The multivariate analysis of clinical and pathological variables identified the number of positive nodes as an independent predictor of SND outcome (OS, hazard ratio (HR) = 4.98, 95% confidence interval (CI): 1.48–16.72, p < 0.01; DSS, HR = 6.44, 95% CI: 1.76–23.50, p < 0.01). The results of this retrospective study showed that only SND for neck node-positive OSCC was appropriate for those with up to 2 lymph nodes that had a largest diameter ≤3 cm without extranodal extension (ENE) of the neck and adjuvant radiotherapy. However, the availability of postoperative therapeutic options for high-risk OSCC, including ENE and/or multiple positive lymph nodes, needs to be further investigated.

Head and Neck Cancer Research and Support Foundations

Ongoing genetic and epigenetic research involving DNA methylation, salivary biomarkers, wild-type p53 tumor suppressor gene proteins, and HPV oncogenes are being directed at identification and treatment of dysplastic and malignant squamous cell mucosal lesions. Research is being conducted to improve immunotherapy drug response rates by increasing the amount of inflammation within the tumor microenvironment. Ongoing research is focused on the application of the antidiabetic drug metformin for the prevention and management of oral squamous cell dysplastic lesions. Professional and nonprofit cancer support organizations are essential for furthering education and research within the area of head and neck cancer.

Loss of CD169+ Subcapsular Macrophages during Metastatic Spread of Head and Neck Squamous Cell Carcinoma

Objective

The purpose of this study is to assess CD169 expression in metastatic and nearby tumor-free lymph nodes of patients with head and neck squamous cell carcinoma (SCC).

Study Design

Retrospective analysis based on immunohistochemistry.

Setting

Tertiary care center.

Subjects and Methods

The abundance of CD169+ cells in the subcapsular sinuses (SCSs) of lymph nodes was assessed immunohistochemically in paraffin-embedded tissue samples derived from 22 patients with oral cavity and oropharyngeal SCC.

Results

SCSs of lymph nodes harboring metastatic SCC contained significantly fewer CD169+ macrophages (106.5 ± 113.6 cells/mm2) compared to nearby tumor-free lymph nodes (321.3 ± 173.4 cells/mm2, P < .001). This observation extended to 21 of the 22 cases investigated. In addition, 6 patients who later developed recurrent disease contained lower numbers of CD169+ cells (268.6 ± 169.5 cells/mm2) in nearby tumor-free lymph nodes compared to 341.0 ± 176.1 cells/mm2 in those who remained disease free ( P = .399). Human papillomavirus (HPV)–positive patients (n = 4) had a 6-fold lower number of CD169+ cells in metastatic nodes (61.2 ± 85.5 cells/mm2) compared to nearby tumor-free lymph nodes (369.5 ± 175.5 cells/mm2, P = .028). In comparison, HPV-negative patients had only a 3-fold reduction (116.6 ± 118.5 cells/mm2 vs 310.6 ± 176.2 cells/mm2, P < .001).

Conclusion

Metastatic spread of SCC to regional lymph nodes is associated with lower abundance of CD169+ macrophages in the SCSs of draining lymph nodes. These results set the stage for an in-depth investigation into the mechanism(s) by which metastatic SCC controls CD169+ macrophage abundance and its significance as it relates to prognosis and treatment response.

The evolving role of immuno-oncology for the treatment of head and neck cancer

Monoclonal antibodies (mAbs) that target immune co‐signaling pathways have the potential to enable immune mediated tumor eradication. While early adoption of these agents for the treatment of advanced squamous cell carcinoma of the head and neck (SCCHN) has produced some astounding clinical successes, the majority of patients fail to respond to therapy. The purpose of this review is to first provide a broad overview of the immuno‐oncology (I‐O) landscape and to then focus on the current status of mAb‐based I‐O (mAb:I‐O) for the treatment of SCCHN, with particular attention to the development of strategies for improving treatment responses.

Associations between skin rash, treatment outcome, and single nucleotide polymorphisms in head and neck cancer patients receiving the EGFR-inhibitor zalutumumab: results from the DAHANCA 19 trial

PURPOSE

To study the associations between development of moderate to severe skin rash, clinical outcome, and single nucleotide polymorphisms (SNPs) in candidate genes in head and neck cancer patients from the DAHANCA 19 trial receiving the EGFR-inhibitor zalutumumab concurrently with radiation treatment.

MATERIAL AND METHODS

310 patients were included from the zalutumumab-arm of the DAHANCA 19 study. Nine SNPs in the candidate genes EGFR, EGF, AREG, FCGR2A, FCGR3A, and CCND1 were successfully determined in 294 patients. Clinical endpoints were moderate to severe skin rash within the first 3 weeks of treatment, loco-regional failure (LRF), disease-specific survival (DSS), and overall survival (OS).

RESULTS

During the first 3 weeks of treatment, 86% of the patients experienced any grade of rash and 17% experienced a moderate to severe rash. Development of moderate to severe rash was not associated with LRF or DSS but was associated with improved OS, HR 0.40 (95% CI: 0.19-0.82). The effect was similar for patients with p16-negative or p16-positive tumors (p = .90). After adjustment for comorbidity and performance status, the minor alleles of SNPs rs9996584 and rs13104811 located near the AREG gene were significantly associated with increased risk of moderate to severe rash with per-allele odds ratios of 1.61 (1.01-2.54) and 1.56 (1.00-2.44). SNP rs11942466 located close to rs9996584 had a borderline significant association, and none of the other SNPS were significantly associated with risk of skin rash.

CONCLUSIONS

Moderate to severe skin rash after zalutumumab during radiation treatment was associated with improved OS, independent of HPV/p16-status. Genetic variants in AREG (member of the EGF family) may be associated with increased risk of skin rash.

Evaluating the PD-1 Axis and Immune Effector Cell Infiltration in Oropharyngeal Squamous Cell Carcinoma

PURPOSE

Programmed death-1 (PD-1) inhibitors are approved for the treatment of patients with recurrent and metastatic squamous cell carcinoma of the head and neck (SCCHN). Ongoing and planned randomized phase 3 trials are testing the benefit of combining PD-1/programmed death-ligand 1 (PD-L1) inhibitors with chemoradiation for patients with locoregionally confined SCCHN. Few studies have investigated relationships among potential predictive pathologic biomarkers such as PD-L1, PD-L2, and PD-1 in this population and associations between these markers and clinical characteristics.

METHODS AND MATERIALS

We retrospectively reviewed records and pathology from 81 patients with locoregional oropharynx SCCHN treated with curative intent. Samples were analyzed for PD-L1, PD-L2, PD-1, CD8, and CD56 expression using immunohistochemistry. Human papilloma virus (HPV) status was determined by p16-immunohistochemistry and confirmed by in situ hybridization or polymerase chain reaction-based HPV typing. Correlations between HPV status, clinical features, and recurrence status with immune markers in both tumor and tumor-associated stroma were determined. Hazard ratios were estimated via Cox proportional hazards model.

RESULTS

Tumor PD-L1 expression was inversely associated with age (P = .01) and the highest levels of expression (>30% of tumor cells) were observed in HPV-associated tumors. There was a correlation between tumor and stromal PD-L1 expression (P = < .0001). PD-1 and CD8 expression within tumor deposits was associated with HPV status (P = 0.003 and P = .008, respectively) and decreased local recurrence (P = .001 and P < .001, respectively). In addition to the association between tumor and stromal PD-1 (P < .0001), PD-1 was also correlated with tumor PD-L1 expression (P < .001). CD56+ natural killer cell infiltrates correlated with PD-L1 expression.

CONCLUSIONS

In patients with untreated oropharyngeal SCCHN, HPV-associated tumors displayed the highest levels of PD-L1 expression and PD-1+ and CD8+ immune cells. Locally recurrent tumors had lower levels of PD-L1, PD-1, and CD-8 positivity. Whereas almost all SCCHN tumors had CD56+ infiltrating natural killer cells, most tumors didn't have PD-L2 expression. These associations may help predict which patients may benefit most from immunotherapeutic approaches.

Checkpoint inhibitors in head and neck cancer: current knowledge and perspectives

The emergence of immunotherapy has provided significant clinical improvements in the treatment of metastatic solid tumors. Recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) has dismal prognosis with median survival ranging between 6and12 months. Our aim is to review the current knowledge on the role of the immune system and immune checkpoint inhibitors in HNSCC. We will focus on the landmark trials that led to the regulatory approvals of pembrolizumab and nivolumab, and discuss a few promising contenders in clinical development and highlight the need to identify better biomarkers other than programmed death-ligand 1 to improve patient selection and help predict response.

Engineering Vaccines to Reprogram Immunity against Head and Neck Cancer

The recent Food and Drug Administration's approval of monoclonal antibodies targeting immune checkpoint receptors (ICRs) for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) offers exciting promise to improve patient outcome and reduce morbidities. A favorable response to ICR blockade relies on an extensive collection of preexisting tumor-specific T cells in the tumor microenvironment (TME). ICR blockade reinvigorates exhausted CD8+ T cells and enhances immune killing. However, resistance to ICR blockade is observed in about 85% of patients with HNSCC, therefore highlighting the importance of characterizing the mechanisms underlying HNSCC immune escape and exploring combinatorial strategies to sensitize hypoimmunogenic cold HNSCC to ICR inhibition. Cancer vaccines are designed to bypass the cold TME and directly deliver cancer antigens to antigen-presenting cells (APCs); these vaccines epitomize a priming strategy to synergize with ICR inhibitors. Cancer cells are ineffective antigen presenters, and poor APC infiltration as well as the M2-like polarization in the TME further dampens antigen uptake and processing, both of which render ineffective innate and adaptive immune detection. Cancer vaccines directly activate APC and expand the tumor-specific T-cell repertoire. In addition, cancer vaccines often contain an adjuvant, which further improves APC function, promotes epitope spreading, and augments host intrinsic antitumor immunity. Thus, the vaccine-induced immune priming generates a pool of effectors whose function can be enhanced by ICR inhibitors. In this review, we summarize the major HNSCC immune evasion strategies, the ongoing effort toward improving HNSCC vaccines, and the current challenges limiting the efficacy of cancer vaccines.

Mitigating SOX2-potentiated Immune Escape of Head and Neck Squamous Cell Carcinoma with a STING-inducing Nanosatellite Vaccine

Purpose: The response rates of Head and Neck Squamous Cell Carcinoma (HNSCC) to checkpoint blockade are below 20%. We aim to develop a mechanism-based vaccine to prevent HNSCC immune escape.Experimental Design: We performed RNA-Seq of sensitive and resistant HNSCC cells to discover central pathways promoting resistance to immune killing. Using biochemistry, animal models, HNSCC microarray, and immune cell deconvolution, we assessed the role of SOX2 in inhibiting STING-type I interferon (IFN-I) signaling-mediated antitumor immunity. To bypass SOX2-potentiated STING suppression, we engineered a novel tumor antigen-targeted nanosatellite vehicle to enhance the efficacy of STING agonist and sensitize SOX2-expressing HNSCC to checkpoint blockade.Results: The DNA-sensing defense response is the most suppressed pathway in immune-resistant HNSCC cells. We identified SOX2 as a novel inhibitor of STING. SOX2 facilitates autophagy-dependent degradation of STING and inhibits IFN-I signaling. SOX2 potentiates an immunosuppressive microenvironment and promotes HNSCC growth in vivo in an IFN-I-dependent fashion. Our unique nanosatellite vehicle significantly enhances the efficacy of STING agonist. We show that the E6/E7-targeted nanosatellite vaccine expands the tumor-specific CD8⁺ T cells by over 12-fold in the tumor microenvironment and reduces tumor burden. A combination of nanosatellite vaccine with anti-PD-L1 significantly expands tumor-specific CTLs and limits the populations expressing markers for exhaustion, resulting in more effective tumor control and improved survival.Conclusions: SOX2 dampens the immunogenicity of HNSCC by targeting the STING pathway for degradation. The nanosatellite vaccine offers a novel and effective approach to enhance the adjuvant potential of STING agonist and break cancer tolerance to immunotherapy. Clin Cancer Res; 24(17); 4242-55. ©2018 AACR.

Precision Therapy of Head and Neck Squamous Cell Carcinoma

Precision medicine is an approach to disease prevention and treatment that takes into account genetic variability and environmental and lifestyle influences that are unique to each patient. It facilitates stratification of patient populations that vary in their susceptibility to disease and response to therapy. Shared databases and the implementation of new technology systems designed to advance the integration of this information will enable health care providers to more accurately predict and customize prevention and treatment strategies for patients. Although precision medicine has had a limited impact in most areas of medicine, it has been shown to be an increasingly successful approach to cancer therapy. Despite early promising results targeting aberrant signaling pathways or inhibitors designed to block tumor-driven processes such as angiogenesis, limited success emphasizes the need to discover new biomarkers and treatment targets that are more reliable in predicting response to therapy and result in better health outcomes. Recent successes in the use of immunity-inducing antibodies have stimulated increased interest in the use of precision immunotherapy of head and neck squamous cell carcinoma. Using next-generation sequencing, the precise profiling of tumor-infiltrating lymphocytes has great promise to identify hypoimmunogenic cancer that would benefit from a rationally designed combinatorial approach. Continued interrogation of tumors will reveal new actionable targets with increasing therapeutic efficacy and fulfill the promise of precision therapy of head and neck cancer.

Mouse Models for Studying Oral Cancer: Impact in the Era of Cancer Immunotherapy

Model systems for oral cancer research have progressed from tumor epithelial cell cultures to in vivo systems that mimic oral cancer genetics, pathological characteristics, and tumor-stroma interactions of oral cancer patients. In the era of cancer immunotherapy, it is imperative to use model systems to test oral cancer prevention and therapeutic interventions in the presence of an immune system and to discover mechanisms of stromal contributions to oral cancer carcinogenesis. Here, we review in vivo mouse model systems commonly used for studying oral cancer and discuss the impact these models are having in advancing basic mechanisms, chemoprevention, and therapeutic intervention of oral cancer while highlighting recent discoveries concerning the role of immune cells in oral cancer. Improvements to in vivo model systems that highly recapitulate human oral cancer hold the key to identifying features of oral cancer initiation, progression, and invasion as well as molecular and cellular targets for prevention, therapeutic response, and immunotherapy development.

Tumor Immunology and Immunotherapy for Head and Neck Squamous Cell Carcinoma

The immune system plays an important role in the evolution of malignancy and has become an important target for novel antineoplastic agents. This review article focuses on key features of tumor immunology, including the role of immunotherapy in general and as it pertains to head and neck squamous cell carcinoma. Side effects, resistance mechanisms, and therapeutic monitoring strategies pertaining to immunotherapy are discussed.

Head and neck squamous cell carcinoma: Genomics and emerging biomarkers for immunomodulatory cancer treatments

Head and neck squamous cell carcinoma (HNSCC) comprises a heterogeneous group of tumors that arise from the squamous epithelium of the oral cavity, oropharynx, larynx and hypopharynx. While many HNSCCs are related to classical etiologic factors of smoking and alcohol, a clinically, genomically, and immunologically distinct subgroup of tumors arise from the epithelium of the tonsil and the base of tongue as a result of infection with Human Papilloma Virus (HPV). In this review we describe the genomic and immunologic landscape of HNSCC, highlighting differences between HPV-positive and HPV-negative HNSCC. While HPV-negative tumors are characterized by tobacco-associated mutations in genes including TP53 and CDKN2A, in HPV-positive HNSCC integration of viral genome from HPV into the host cellular genome results in expression of the E6 and E7 viral oncoproteins, with consequent degradation of p53 and functional inactivation of Rb. The immune microenvironment of HNSCC is characterized by changes in immune cell populations, immune checkpoints, as well as tumor or microenvironmental factors that alter the balance of the immune milieu in favor of immunosuppression, allowing tumor evasion and escape from immune surveillance. Immune therapies, in particular those targeting the PD1 receptor or its ligand PD-L1, including nivolumab, pembrolizumab, durvalumab, and atezolizumab have shown significant efficacy in subsets of patients with HNSCC. Current trials are evaluating the efficacy of these agents in combination with chemotherapy, radiotherapy and other immune therapies including CTLA-4 and IDO-1 inhibitors. While biomarkers including PD-L1 expression, PD-L2 expression and the interferon-gamma gene signature show potential to predict benefit from checkpoint inhibitor therapy - it is hoped that improved understanding of the genomic and immune landscape will lead to ways to improved strategies to stratify patients and to select which HNSCC are most likely to benefit from these therapies.

Programmed death ligand-1 expression as immunotherapeutic target in sinonasal cancer

BACKGROUND

Sinonasal cancer carries a poor prognosis, especially in recurrent stages, and it is a disease with very limited treatment options.

METHODS

The expression of programmed death ligand-1 (PD-L1) as a marker for immunotherapy was evaluated in 53 sinonasal squamous cell carcinoma (SCC) and 126 intestinal-type adenocarcinoma (ITAC) samples. Results were correlated to clinicopathological characteristics and follow-up data.

RESULTS

Membranous PD-L1 staining of tumor cells was observed in 34% (18/53) of the sinonasal SCC samples and in 17% (22/126) of the ITAC samples. The PD-L1 positivity on infiltrating immune cells occurred in 45% (24/53) of the sinonasal SCC samples and in 33% (41/126) of the ITAC samples. Expression of PD-L1 showed no correlation to clinicopathological parameters and was not an independent risk factor for survival.

CONCLUSION

The PD-L1 positivity does not seem to have prognostic value. However, a proportion of patients with sinonasal SCC and ITAC may benefit from therapy with immune checkpoint inhibitors that recently have been approved for clinical application in head and neck cancer.

Cost-Effectiveness of Nivolumab in Recurrent Metastatic Head and Neck Squamous Cell Carcinoma

BACKGROUND

Treatment options for patients with platinum-refractory, recurrent, metastatic head and neck squamous cell carcinoma (r/m HNSCC) are limited and prognosis is poor. The recent CheckMate 141 clinical trial demonstrated that nivolumab, an anti-programmed cell death protein 1 monoclonal antibody, was efficacious in extending the median overall survival (OS) in this patient population compared with standard therapies. We conducted a cost-effectiveness analysis to determine whether nivolumab is a cost-effective treatment in this patient population and examined various subgroups to determine for which, if any, the treatment is more cost-effective.

MATERIALS AND METHODS

We implemented a state transition model for HNSCC with a patient cohort who had tumor progression 6 months after the last dose of platinum-containing chemotherapy and compared the cost-effectiveness of nivolumab with docetaxel. Treatment effect estimates and adverse event rates were obtained from CheckMate 141. Costs, utilities, and other model inputs were gathered from published sources. We used a Canadian perspective, a 5-year time horizon, and a 1.5% discount rate for the analysis.

RESULTS

Nivolumab extended mean OS by 4 months compared with docetaxel and resulted in fewer treatment-related adverse events, producing an incremental effectiveness of 0.13 quality-adjusted life years (QALY). The incremental cost of treatment with nivolumab was $18,823. At a willingness-to-pay threshold of $100,000/QALY, nivolumab was not a cost-effective treatment option for r/m HNSCC, with an incremental cost-effectiveness ratio of $144,744/QALY. Nivolumab would be cost-effective if its price was reduced by 20%. Our subgroup analysis seemed to indicate that nivolumab might be cost-effective for tumors with expression of programmed death-ligand 1 >5%.

CONCLUSION

We conclude that although nivolumab offers clinical benefit for the treatment of r/m HNSCC over current regimens, it is not cost-effective based on its list price. We have also established a value-based price estimate for nivolumab to be cost-effective in this patient population. Further study is required to draw a definitive conclusion on biomarkers for cost-effectiveness.

IMPLICATIONS FOR PRACTICE

In health care settings in which cost considerations are a constraint on choice of therapy, patient selection should be carefully considered to maintain efficiency in the system. Until a biomarker for response to therapy is identified for nivolumab, this medication is unlikely to be cost-effective for most patients with recurrent, metastatic head and neck squamous cell carcinoma.

Profile of pembrolizumab in the treatment of head and neck squamous cell carcinoma: design development and place in therapy

Head and neck squamous cell cancer (HNSCC) is the sixth most common malignancy worldwide, and despite advances in cytotoxic, surgical and radiation techniques, outcomes are still poor in those with both locally advanced and metastatic diseases. The need for development of better therapeutics along with a greater understanding of the relationship between the immune system and malignancies has led to a new therapeutic modality, immune modulators, particularly checkpoint inhibitors in HNSCC. It is now well recognized that HNSCC circumvents crucial pathways utilized by the immune system to escape surveillance. These hijacked pathways include impairing tumor antigen presentation machinery and co-opting checkpoint receptors. This understanding has led to the development of monoclonal antibodies targeting checkpoint receptors and has resulted in promising outcomes in HNSCC. This article describes the mechanisms that HNSCC utilizes to escape immune surveillance, clinical impact of checkpoint inhibitors (with a focus on pembrolizumab), ongoing studies, and future directions.

Response assessment after induction chemotherapy for head and neck squamous cell carcinoma: From physical examination to modern imaging techniques and beyond

Significant correlations between the response to induction chemotherapy and success of subsequent radiotherapy have been reported and suggest that the response to induction chemotherapy is able to predict a response to radiotherapy. Therefore, induction chemotherapy may be used to tailor the treatment plan to the individual patient with head and neck cancer: following the planned subsequent (chemo)radiation schedule, planning a radiation dose boost, or reassessing the modality of treatment (eg, upfront surgery). Findings from reported trials suggest room for improvement in clinical response assessment after induction chemotherapy, but an optimal method has yet to be identified. Historically, indices of treatment efficacy in solid tumors have been based solely on systematic assessment of tumor size. However, functional imaging (eg, fluorodeoxyglucose‐positron emission tomography (FDG‐PET) potentially provides an earlier indication of response to treatment than conventional imaging techniques. More advanced imaging techniques are still in an exploratory phase and are not ready for use in clinical practice.

Immunotherapy in head and neck cancer: aiming at EXTREME precision

BACKGROUND

Locoregionally advanced, recurrent, and metastatic squamous cell carcinomas of the head and neck (SCCHN) remain difficult to treat disease entities, in which systemic treatment often forms an integral part of their management. Immunotherapy is based on functional restoration of the host immune system, helping to counteract various tumour evasion strategies. Broadly, immunotherapeutic approaches encompass tumour-specific antibodies, cancer vaccines, cytokines, adoptive T-cell transfer, and immune-modulating agents. Until 2015, the epidermal growth factor receptor inhibitor cetuximab, a tumour-specific antibody, represented the only Food and Drug Administration (FDA)-approved targeted therapy for SCCHN. Subsequently, in 2016, the results from two prospective trials employing the immune-modulating antibodies nivolumab and pembrolizumab heralded a new era of anticancer treatment.

DISCUSSION

Nivolumab and pembrolizumab are monoclonal antibodies against programmed cell death protein-1 (PD-1), an 'immune checkpoint' receptor. Found on the surface of T-cells, PD-1 negatively regulates their activation and can thus be exploited during carcinogenesis. The second-line phase III trial CheckMate-141 randomly assigned 361 patients with recurrent and/or metastatic SCCHN in a 2:1 ratio to receive either single-agent nivolumab (3 mg/kg intravenously every 2 weeks) or standard monotherapy (methotrexate, docetaxel, or cetuximab). Nivolumab improved the objective response rate (13% versus 6%) and median overall survival (OS; 7.5 versus 5.1 months, p = 0.01) without increasing toxicity. Exploratory biomarker analyses indicated that patients treated with nivolumab had longer OS than those given standard therapy, regardless of tumour PD-1 ligand (PD-L1) expression or p16 status. In the non-randomised, multicohort phase Ib study KEYNOTE-012, treatment with pembrolizumab achieved comparable results. Importantly, most of the responding patients had a long-lasting response.

CONCLUSION

Based on recent results, nivolumab and pembrolizumab have been approved by the FDA as new standard-of-care options for the second-line treatment of recurrent and/or metastatic SCCHN. Generally well tolerated, these novel drugs demonstrated modest response rates, with tumour regressions usually being durable, even in platinum-resistant/refractory cases. The next step will be to extend the observed benefit to first-line treatment, currently dominated by the EXTREME regimen (platinum/5-fluorouracil/cetuximab), and to the locoregionally advanced setting, where concurrent chemoradiation with cisplatin is standard. Regimens combining immunotherapy with other modalities will probably further improve outcomes.