Immunotherapy for Head and Neck Squamous Cell Carcinoma: A Review of Current and Emerging Therapeutic Options

Characterization of macrophages in head and neck squamous cell carcinoma and development of MRG-based risk signature

Macrophages are immune cells in the TME that can not only inhibit angiogenesis, extracellular matrix remodeling, cancer cell proliferation, and metastasis but also mediate the phagocytosis and killing of cancer cells after activation, making them key targets in anti-tumor immunotherapy. However, there is little research on macrophages and their relation to disease prognosis in HNSCC. Initially, we collected scRNA-seq, bulk RNA-seq, and clinical data. Subsequently, we identified macrophages and distinguished MRGs. Using the K-means algorithm, we performed consensus unsupervised clustering. Next, we used ssGSEA analysis to assess immune cell infiltration in MRG clusters. A risk model was established using multivariate Cox analysis. Then, Kaplan-Meier, ROC curves, univariate and multivariate COX analyses, and C-index was used to validate the predictive power of the signature. The TIDE method was applied to assess the response to immunotherapy in patients diagnosed with HNSCC. In addition, drug susceptibility predictions were made for the GDSC database using the calcPhenotype function. We found that 8 MRGs had prognostic potential. Patients in the MRG group A had a higher probability of survival, and MRG clusters A and B had different characteristics. Cluster A had a higher degree of expression and infiltration in MRG, indicating a closer relationship with MRG. The accuracy of the signature was validated using univariate and multivariate Cox analysis, C-index, and nomogram. Immune landscape analysis found that various immune functions were highly expressed in the low-risk group, indicating an improved response to immunotherapy. Finally, drugs with high sensitivity to HNSCC (such as 5-Fluorouracil, Temozolomide, Carmustine, and EPZ5676) were explored and analyze the malignant characteristics of HNSCC. We constructed a prognostic model using multivariate Cox analysis, consisting of 8 MRGs (TGM2, STC1, SH2D3C, PIK3R3, MAP3K8, ITGA5, ARHGAP4, and AQP1). Patients in the low-risk group may have a higher response to immunotherapy. The more prominent drugs for drug selection are 5-fluorouracil, temozolomide and so on. Malignant features associated with HNSCC include angiogenesis, EMT, and the cell cycle. This study has opened up new prospects for the prognosis, prediction, and clinical treatment strategy of HNSCC.

Identification of factors related to immunotherapy efficacy and prognosis in patients with advanced head and neck squamous cell carcinoma

BACKGROUND

Immunotherapy is an important treatment in oncology, but only a fraction of patients with head and neck squamous cell carcinoma (HNSCC) benefit from it. Therefore, the aim of this study was to identify predictive biomarkers of immunotherapy response for HNSCC in order to improve treatment outcomes.

METHODS

Survival analyses and comparative efficacy evaluation were performed to investigate prognostic and therapeutic impact factors in patients with advanced HNSCC following immunotherapy, and to examine the effects of factors including gene mutations, tumor mutational burden (TMB), mutant-allele tumor heterogeneity (MATH), and immune cell infiltration on the survival and efficacy.

RESULTS

Anti-PD-1 treatment led to a prolonged overall survival (OS) in HNSCC patients with gene mutations compared with those without the mutations, while no significant difference in the OS was found between the two groups of patients. And no marked association between the MATH value and OS was detected in HNSCC patients, whereas patients with either high TMB scores in tissues and blood or high immune cell infiltration displayed a significantly longer OS. Further analysis with efficacy as the primary endpoint revealed no significant differences in the tissue TMB, blood TMB, and MATH value between the patients who responded to immunotherapy and those who did not. Moreover, no significant differences in the expression percentages of positive immune cells in tumor, stroma, and total regions were identified between the above two groups of patients.

CONCLUSION

HNSCC is characterized by high mutation rate, high mutation burden, and high level of immune cell infiltration, and a subset of HNSCC patients respond to immunotherapy. Here, we showed that high mutation burden and immune cell infiltration may improve the prognosis of HNSCC patients with immunotherapy, while there was no remarkable effect on the efficacy.

PD-L1 expression in recurrent head and neck squamous cell carcinoma

PURPOSE

To evaluate the Programmed Cell Death Ligand (PD-L1) expression at diagnosis and relapse in patients with head and neck carcinoma (HNSCC) treated with radio(chemo)therapy.

METHODS

PD-L1 immunohistochemistry was performed in tumor cells (TC) and immune cells (IC) in 44 patients and scored as 0 = 0%, 1 =  < 5%, 2 = 6-49% or 3 =  ≥ 50% cells.

RESULTS

PD-L1 expression on TC before RT was scored as 0, 1, 2 and 3 in 28, 4, 8 and 4 patients, respectively. In 10 patients, IC did not show any PD-L1 expression; while in 8, 16, and 10 patients, PD-L1 expression was scored 1, 2 and 3, respectively. At relapse, 7/36 patients had a PD-L1 expression positivation in TC, while the opposite was observed in 6 patients. Overall, survival at 2 years was higher in patients with PD-L1 expression (90% versus 62.5%, p = 0.032).

CONCLUSION

PD-L1 expression may vary throughout the course of the disease. A re-evaluation of PD-L1 expression on biopsies at the time of recurrence should be recommended.

Genetic Drivers of Head and Neck Squamous Cell Carcinoma: Aberrant Splicing Events, Mutational Burden, HPV Infection and Future Targets

Head and neck cancers include cancers that originate from a variety of locations. These include the mouth, nasal cavity, throat, sinuses, and salivary glands. These cancers are the sixth most diagnosed cancers worldwide. Due to the tissues they arise from, they are collectively named head and neck squamous cell carcinomas (HNSCC). The most important risk factors for head and neck cancers are infection with human papillomavirus (HPV), tobacco use and alcohol consumption. The genetic basis behind the development and progression of HNSCC includes aberrant non-coding RNA levels. However, one of the most important differences between healthy tissue and HNSCC tissue is changes in the alternative splicing of genes that play a vital role in processes that can be described as the hallmarks of cancer. These changes in the expression profile of alternately spliced mRNA give rise to various protein isoforms. These protein isoforms, alternate methylation of proteins, and changes in the transcription of non-coding RNAs (ncRNA) can be used as diagnostic or prognostic markers and as targets for the development of new therapeutic agents. This review aims to describe changes in alternative splicing and ncRNA patterns that contribute to the development and progression of HNSCC. It will also review the use of the changes in gene expression as biomarkers or as the basis for the development of new therapies.

Integrated Analysis Reveals ENDOU as a Biomarker in Head and Neck Squamous Cell Carcinoma Progression

Background

Head and neck squamous cell carcinoma (HNSCC) is a leading cancer with high morbidity and mortality worldwide. The aim is to identify genes with clinical significance by integrated bioinformatics analysis and investigate their function in HNSCC.

Methods

We downloaded and analyzed two gene expression datasets of GSE6631 and GSE107591 to screen differentially expressed genes (DEGs) in HNSCC. Common DEGs were functionally analyzed by Gene ontology and KEGG pathway enrichment analysis. Protein-protein interaction (PPI) network was constructed with STRING database and Cytoscape. ENDOU was overexpressed in FaDu and Cal-27 cell lines, and cell proliferation and migration capability were evaluated with MTT, scratch and transwell assay. The prognostic performance of ENDOU and expression correlation with tumor infiltrates in HNSCC were validated with TCGA HNSCC datasets.

Results

Ninety-eight genes shared common differential expression in both datasets, with core functions like extracellular matrix organization significantly enriched. 15 genes showed prognostic significance, and COBL and ENDOU serve as independent survival markers in HNSCC. In-vitro ENDOU overexpression inhibited FaDu and Cal-27 cells proliferation and migration, indicating its tumor-suppressing role in HNSCC progression. GSEA analysis indicated ENDOU down-stream pathways like DNA replication, mismatch repair, cell cycle and IL-17 signaling pathway. ENDOU showed relative lower expression in HNSCC, especially HPV-positive HNSCC samples. At last, ENDOU showed negative correlation with tumor purity and tumor infiltrating macrophages, especially M2 macrophages.

Conclusion

This study identified ENDOU as a biomarker with prognostic significance in HNSCC progression.

Assessing the analytical efficacy of TEX in diagnosing oral cancer using a systematic review approach

The 5-year survival rates in OSCC depend on the stage at diagnosis. Patients have better survival and favourable outcomes if detected early, as compared to those diagnosed in advanced stages. Apart from biopsy and mucosal scraping examinations, exosomes from saliva and blood are emerging as an accessible source for diagnosis and providing additional information about the tumour's characteristics. Hence, the study of tumour-derived exosomal (TEX) biomarkers obtained from a liquid biopsy is emerging as a promising diagnostic tool. In this systematic review, our effort is to assess the role of TEX as a biomarker.

Association between APOBEC3H-Mediated Demethylation and Immune Landscape in Head and Neck Squamous Carcinoma

Immunotherapy has been demonstrated as a promising strategy in controlling head and neck squamous cell carcinoma (HNSC). The AID/APOBEC family is well characterized as DNA mutator and considered to play critical roles in immune responses in HNSC. However, the expression pattern and deamination-dependent demethylation roles of AID/APOBECs in HNSC are unclear. In this study, the RNA-seq and DNA methylation profiles of HNSC from TCGA database and cell-based experiments were applied to analyze the relationships between AID/APOBEC expression levels, patients' clinical outcomes, methylation alterations, and immune responses. Here, we found that APOBEC3H was abnormally upregulated in HNSC patients. HPV+ patients tended to have higher APOBEC3H levels than HPV- patients. Remarkably, patients with high APOBEC3H levels showed a favorable overall survival. Furthermore, tumors with high APOBEC3H levels exhibited a genome-wide DNA hypomethylation pattern. APOBEC3H was identified to demethylate and upregulate CXCL10 and improve CD8+ T cell tumor infiltration in the tumor microenvironment. Collectively, APOBEC3H plays critical roles in CD8+ T cell immune infiltration and activation in HNSC, which may be a potential biomarker for oncoimmunotherapy in HNSC.

M2 macrophages reduce the radiosensitivity of head and neck cancer by releasing HB‑EGF

The aim of the present study was to examine the potential role of human heparin‑binding epidermal growth factor (HB‑EGF) secreted by M2 macrophages in the development of radioresistance in head and neck squamous cell carcinoma (HNSCC). Immunohistochemistry was used to detect radiosensitivity in human papilloma virus (HPV)‑positive and HPV‑negative HNSCC tissues and immunohistochemical staining with specific antibodies for macrophage surface markers was used to assess the infiltration of M1 and M2 macrophages in HPV‑positive and ‑negative HNSCC tissues. The expression of HB‑EGF in HPV‑positive and ‑negative HNSCC tissues was determined by multi‑cytokine detection in order to determine the relationship between HB‑EGF and radiosensitivity. M1 and M2 macrophages were co‑cultured with the HNSCC cell line CAL27 and treated with HB‑EGF and its neutralizing antibodies to assess radiation sensitivity. Finally, the major DNA double‑strand break repair pathways required for the activation of HB‑EGF and promotion of epidermal growth factor receptor (EGFR) were identified. The results revealed that radiosensitivity was higher in HPV‑positive HNSCC compared with HPV‑negative. There was a higher infiltration of M2 macrophages in HPV‑negative HNSCC, which were revealed as the main source of HB‑EGF secretion. Furthermore, it was determined that overexpression of HB‑EGF induced radioresistance in HPV‑negative HNSCC. HB‑EGF promoted the activation of the non‑homologous end‑joining pathway by activating EGFR. To the best of our knowledge, this is the first study to demonstrate the association between HB‑EGF and radiosensitivity in HNSCC. These results indicated that the secretion of HB‑EGF by M2 macrophages could induce radioresistance of HPV‑negative HNSCC.

Tumor immune microenvironment in head and neck cancers

Head and neck cancers are a heterogeneous group of tumors that are highly aggressive and collectively represent the sixth most common cancer worldwide. Ninety percent of head and neck cancers are squamous cell carcinomas (HNSCCs). The tumor microenvironment (TME) of HNSCCs consists of many different subsets of cells that infiltrate the tumors and interact with the tumor cells or with each other through various networks. Both innate and adaptive immune cells play a crucial role in mediating immune surveillance and controlling tumor growth. Here, we discuss the different subsets of immune cells and how they contribute to an immunosuppressive TME of HNSCCs. We also briefly summarize recent advances in immunotherapeutic approaches for HNSCC treatment. A better understanding of the multiple factors that play pivotal roles in HNSCC tumorigenesis and tumor progression may help define novel targets to develop more effective immunotherapies for patients with HNSCC.

Digital pathology-aided assessment of tumor-infiltrating T lymphocytes in advanced stage, HPV-negative head and neck tumors

Aim

This study aimed to evaluate the presence and prognostic value of tumor-infiltrating T cells in the tumor epithelium in advanced stage, HPV-negative head and neck squamous cell carcinoma (HNSCC) patients treated with primary chemoradiotherapy using digital pathology.

Methods

Pre-treatment biopsies from 80 oropharyngeal, 52 hypopharyngeal, and 29 laryngeal cancer patients were collected in a tissue microarray (TMA) and immunohistochemically stained for T-cell markers CD3, CD4, CD8, FoxP3, and PD1, and for immune checkpoint PD-L1. For each marker, the number of positive tumor-infiltrating lymphocytes (TILs) per mm² tumor epithelium was digitally quantified and correlated to overall survival (OS), disease-free survival (DFS), and locoregional control (LRC), as well as to clinicopathological characteristics. Differences in clinical outcome were estimated using Cox proportional hazard analysis and visualized using Kaplan–Meier curves.

Results

The patient cohort had a 3-year OS of 58%, with a median follow-up of 53 months. None of the T-cell markers showed a correlation with OS, DFS or LRC. A low N stage was correlated to a better prognosis (OS: HR 0.39, p = 0.0028, DFS: HR 0.34, p =  < 0.001, LRC: HR 0.24, p = 0.008). High TIL counts were more often observed in PD-L1-positive tumors (p < 0.05).

Conclusion

This study showed an objective, digital pathology-aided method to assess TILs in the tumor epithelium. However, it did not provide evidence for a prognostic role of the presence of CD3 + , CD4 + , CD8 + , FoxP3 + , and PD1 + TILs in the tumor epithelium of advanced stage, HPV-negative HNSCC patients treated with primary chemoradiotherapy.

Electronic supplementary material

The online version of this article (10.1007/s00262-020-02481-3) contains supplementary material, which is available to authorized users.

Expression scoring of a small-nucleolar-RNA signature identified by machine learning serves as a prognostic predictor for head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is a common malignancy with high mortality and poor prognosis due to a lack of predictive markers. Increasing evidence has demonstrated small nucleolar RNAs (snoRNAs) play an important role in tumorigenesis. The aim of this study was to identify a prognostic snoRNA signature of HNSCC. Survival-related snoRNAs were screened by Cox regression analysis (univariate, least absolute shrinkage and selection operator, and multivariate). The predictive value was validated in different subgroups. The biological functions were explored by coexpression analysis and gene set enrichment analysis (GSEA). One hundred and thirteen survival-related snoRNAs were identified, and a five-snoRNA signature predicted prognosis with high sensitivity and specificity. Furthermore, the signature was applicable to patients of different sexes, ages, stages, grades, and anatomic subdivisions. Coexpression analysis and GSEA revealed the five-snoRNA are involved in regulating malignant phenotype and DNA/RNA editing. This five-snoRNA signature is not only a promising predictor of prognosis and survival but also a potential biomarker for patient stratification management.

Targeting Immune-Related Biological Processes in Solid Tumors: We do Need Biomarkers

Immunotherapy has become the standard-of-care in many solid tumors. Despite the significant recent achievements in the diagnosis and treatment of cancer, several issues related to patients’ selection for immunotherapy remain unsolved. Multiple lines of evidence suggest that, in this setting, the vision of a single biomarker is somewhat naïve and imprecise, given that immunotherapy does not follow the rules that we have experienced in the past for targeted therapies. On the other hand, additional immune-related biomarkers that are reliable in real-life clinical practice remain to be identified. Recently, the immune-checkpoint blockade has been approved in the US irrespective of the tumor site of origin. Further histology-agnostic approvals, coupled with with tumor-specific companion diagnostics and guidelines, are expected in this field. In addition, immune-related biomarkers can also have a significant prognostic value. In this review, we provide an overview of the role of these biomarkers and their characterization in the management of lung cancer, melanoma, colorectal cancer, gastric cancer, head and neck cancer, renal cell carcinoma, urothelial cancers, and breast cancer.

Patient-reported outcomes in head and neck cancer: prospective multi-institutional patient-reported toxicity

Purpose

Head and neck cancer is occurring in an increasingly younger patient population, with treatment toxicity that can cause significant morbidity. Using a patient guided, Internet-based survivorship care plan program, we obtained and looked at patterns of patient-reported outcomes data from survivors seeking information after treatment for head and neck cancer.

Methods

The Internet-based OncoLife and LIVESTRONG Care Plan programs were employed, which design unique survivorship care plans based on patient-reported data. Care plans created for survivors of head and neck cancer were used in this evaluation. Demographics, treatment modality, and toxicity were included in this evaluation. Toxicity was further analyzed, grouped into system-based subsets.

Results

A total of 602 care plans were created from self-identified head and neck cancer survivors, from which patient-reported outcome data were attained. A majority of patients were Caucasian (96.2%) with median age at diagnosis of 55 years, living in suburban locations (39.9%), with ~50% receiving care within 20 miles of their residence. There was an equal distribution of education levels from high school only to graduate school. The majority of patients received care through cancer centers (96.7%), with a split between academic and non-academic centers. Ninety-three percent of patients had radiation therapy as part of their treatment modality, with 70.3% having chemotherapy and 60.1% having surgery. The most common system toxicities affected the oropharynx, followed by epithelium (skin/hair/nail), and then general global health. Specifically, the most common side effects were difficulty swallowing (61.5%) and changes in skin color/texture (49.7%). One third of patients experienced hearing/tinnitus/vertigo, xerostomia, loss of tissue flexibility, or fatigue.

Conclusion

The current work demonstrates the ability to obtain patient-reported outcomes of head and neck cancer survivors through an Internet-based survivorship care plan program. For this group dysphagia and dermatitis were the most commonly reported toxicities, as was expected; however, global effects of therapy, such as fatigue, were also significant and should be addressed in future survivorship planning.

Postoperative (chemo) radiation in patients with squamous cell cancers of the head and neck - clinical results from the cohort of the clinical cooperation group "Personalized Radiotherapy in Head and Neck Cancer"

BACKGROUND

Postoperative (chemo) radiation improves tumor control and survival in high-risk patients with head and neck squamous cell carcinoma based on established risk factors. The clinical cooperation group "Personalized Radiotherapy in Head and Neck Cancer" focuses on the identification and validation of new biomarkers, which are aimed at eventually stratifying and personalizing the therapy concept. Hence, we reviewed all patients with head and neck squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx, treated with postoperative (chemo) radiation from 06/2008 until 06/2015 at the Department of Radiation Oncology in the University Hospital, LMU Munich. Here we report the clinical results of the cohort, laying the foundation for further research within the framework of a clinical cooperation group.

METHODS

Patient data were retrospectively (until 2013) and prospectively (from 2013) collected and analyzed for outcome and treatment failures with regard to previously described and established risk factors.

RESULTS

We identified 302 patients (median follow-up 45 months, average age 60.7 years), having received postoperative (chemo)radiation (median 64 Gy). Chemotherapy was added in 58% of cases, mostly Cisplatin/5- Fluorouracil in concordance with the ARO 96-3 study. The 3-year overall survival, local, locoregional and distant failure estimates were 70.5, 9.7, 12.2 and 13.5%, respectively. Human papillomavirus-associated oropharyngeal cancer was associated with a significant improved overall survival, locoregional, distant and overall tumor control rates in multivariate analysis. Additionally, in multivariate analysis, for local failure, resection status and perineural invasion, for locoregional and distant failure extracapsular extension and for overall survival the presence of nodal disease were significant adverse factors. Moreover, 138 patients have been treated in concordance with the ARO 96-3 protocol, corroborating the results of this study.

CONCLUSIONS

Our cohort represents a large unselected cohort of patients with head and neck squamous cell carcinoma treated with postoperative (chemo)radiation. Tumor control rates and survival rates are consistent with the results of previously reported data.

Immunomodulation by ionizing radiation-impact for design of radio-immunotherapies and for treatment of inflammatory diseases

Ionizing radiation is often regarded as an element of danger. But, danger responses on the cellular and molecular level are often beneficial with regard to the induction of anti-tumor immunity and for amelioration of inflammation. We outline how in dependence of radiation dose and fraction, radiation itself-and especially in combination with immune modulators-impacts on the innate and adaptive immune system. Focus is set on radiation-induced changes of the tumor cell phenotype and the cellular microenvironment including immunogenic cancer cell death. Mechanisms how anti-tumor immune responses are triggered by radiotherapy in combination with hyperthermia, inhibition of apoptosis, the adjuvant AnnexinA5, or vaccination with high hydrostatic pressure-killed autologous tumor cells are discussed. Building on this, feasible multimodal radio-immunotherapy concepts are reviewed including overcoming immune suppression by immune checkpoint inhibitors and by targeting TGF-β. Since radiation-induced tissue damage, inflammation, and anti-tumor immune responses are interconnected, the impact of lower doses of radiation on amelioration of inflammation is outlined. Closely meshed immune monitoring concepts based on the liquid biopsy blood are suggested for prognosis and prediction of cancer and non-cancer inflammatory diseases. Finally, challenges and visions for the design of cancer radio-immunotherapies and for treatment of benign inflammatory diseases are given.

MiR-125b-5p suppressed the glycolysis of laryngeal squamous cell carcinoma by down-regulating hexokinase-2

Laryngeal squamous cell carcinoma (LSCC) is the most common form of laryngeal carcinoma with poor prognosis. Exploring novel factors involved in the progression of LSCC is quite necessary for understanding the mechanisms and designing therapeutic strategies for LSCC. In this study, we showed that miR-125b-5p was significantly down-regulated in LSCC tissues and cell lines. The decreased expression of miR-125b-5p was associated with the tumor differentiation, metastasis and high clinical stage of the LSCC patients. Overexpression of miR-125b-5p suppressed the proliferation and induced apoptosis of LSCC cells. Bioinformatics analysis predicted hexokinase-2 (HK2), an essential enzyme involved in the glycolysis of cancer cells, as one of the downstream targets of miR-125b-5p. Further molecular studies showed that highly expressed miR-125b-5p bound the 3'-UTR of HK2 and decreased both the mRNA and protein levels of HK2. Consistent with the function of HK2 in glycolytic metabolism, overexpression of miR-125b-5p significantly suppressed the glucose consumption and lactate production of LSCC cells. Notably, restoration the expression of HK2 attenuated the inhibitory effect of miR-125b-5p on the glycolysis of LSCC cells. The inverse correlation between the expression of miR-125b-5p and HK2 in LSCC tissues further supported the involvement of miR-125b-5p-HK2 axis in the progression of LSCC. Collectively, these finding suggested the miR-125b-5p-HK2 pathway as a novel mechanism in regulating the glycolysis and progression of LSCC.

Head and Neck Cancer in the Elderly: Frailty, Shared Decisions, and Avoidance of Low Value Care

Head and neck cancer (HNC) is a disease of older adults. Recurrent and metastatic head and neck squamous cell carcinoma portends a poor prognosis, with median overall survival of less than 12 months. Within this vulnerable population, significant treatment-related toxicities and physical and psychosocial sequelae can be devastating to quality of life at the end of life. Shared decision making and early comprehensive palliative and support services are at the crux of the approach to older adults with HNC. In doing so, low-value care that fails to meet the goals of patients and their caregivers at the end-of-life may be avoided.

Immunotherapy in head and neck cancer: evidence and perspectives

Head and neck squamous cell carcinomas evade immune response through multiple immunologic resistance mechanisms. Two of the most commonly involved checkpoint inhibitory mechanisms are CTLA-4 and PD-1/PD-L1, which act at earlier and later stages of immune response to tumors. Pembrolizumab and nivolumab are PD-1 antibodies that interrupt the immunosuppressive pathway of inhibitory checkpoints, which are used by tumor cells to prevent immune reaction. Both recently gained US FDA approval for the treatment of patients with recurrent or metastatic head and neck cancer with disease progression during or following platinum containing chemotherapy. No conclusions can be drawn on the role of PD-L1 in identifying patients responding to immunotherapy, given that similar studies lead to contrasting results. It will be crucial to identify predictive markers of immunotherapy response, and to evaluate them prospectively. A better understanding of the complex network between tumor, immune system and other oncologic treatments will help us to develop more efficient multimodality treatments.

Two immune-enhanced molecular subtypes differ in inflammation, checkpoint signaling and outcome of advanced head and neck squamous cell carcinoma

The immune environment of primary tumor is associated with the clinical response and benefit of immunotherapy. This study aims to investigate the intratumoral immune profile and its clinical relevance in advanced head and neck squamous cell carcinoma (HNSCC). Gene expression profiles of 401 HNSCCs at stage III-IVB from two cohorts (The Cancer Genome Atlas, TCGA, n = 203; the Leipzig Head and Neck Group, LHNG, n = 198) were involved in this analysis. Based on the global immune-related genes, four gene expression subtypes (C1-4) were identified in HNSCCs. Overall, subtypes C2 and C3 showed upregulation of immune profiles and increased tumor lymphocyte infiltration, exhibiting an enhanced immune microenvironment (EIME). However, the two EIME subtypes revealed differences in immune markers and clinical features. Subtype C2 showed higher expression of macrophage signature, whereas subtype C3 was more associated with B cell infiltration. T cell and NK cell infiltration was not different between C2 and C3 subtypes. The subtype C2 tumors were characterized by inflammation compared with subtype C3. Although the checkpoint receptors PD1 and CTLA4 expressed equally between the EIME subtypes, their ligands (PD-L1/PD-L2, CD86/CD80) were significantly upregulated in subtype C2 compared with C3. HPV-positive tumors were predominantly enriched in subtype C3 but not in C2. Furthermore, patients in subtype C2 had a worse outcome than those in C3. In summary, two immune-enhanced subtypes with different immune characteristics and clinical features were identified in advanced HNSCC. The different immune microenvironments among HNSCC subgroups may provide new insights into the strategy of immunotherapy.