Characterization of tumor-associated T-lymphocyte subsets and immune checkpoint molecules in head and neck squamous cell carcinoma

Tertiary Lymphoid Structures Gene Signature Predicts Prognosis and Immune Infiltration Analysis in Head and Neck Squamous Cell Carcinoma

Objectives

This study aims to assess the prognostic implications of gene signature of the tertiary lymphoid structures (TLSs) in head and neck squamous cell carcinoma (HNSCC) and scrutinize the influence of TLS on immune infiltration.

Methods

Patients with HNSCC from the Cancer Genome Atlas were categorized into high/low TLS signature groups based on the predetermined TLS signature threshold. The association of the TLS signature with the immune microenvironment, driver gene mutation status, and tumor mutational load was systematically analyzed. Validation was conducted using independent datasets (GSE41613 and GSE102349).

Results

Patients with a high TLS signature score exhibited better prognosis compared to those with a low TLS signature score. The group with a high TLS signature score had significantly higher immune cell subpopulations compared to the group with a low TLS signature score. Moreover, the major immune cell subpopulations and immune circulation characteristics in the tumor immune microenvironment were positively correlated with the TLS signature. Mutational differences in driver genes were observed between the TLS signature high/low groups, primarily in the cell cycle and NRF2 signaling pathways. Patients with TP53 mutations and high TLS signature scores demonstrated a better prognosis compared to those with TP53 wild-type. In the independent cohort, the relationship between TLS signatures and patient prognosis and immune infiltration was also confirmed. Additionally, immune-related biological processes and signaling pathways were activated with elevated TLS signature.

Conclusion

High TLS signature is a promising independent prognostic factor for HNSCC patients. Immunological analysis indicated a correlation between TLS and immune cell infiltration in HNSCC. These findings provide a theoretical basis for future applications of TLS signature in HNSCC prognosis and immunotherapy.

Tumor-specific T cells in head and neck cancer have rescuable functionality and can be identified through single-cell co-culture

BACKGROUND

Human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC) remains a treatment-resistance disease with limited response to immunotherapy. While T cells in HNSCC are known to display phenotypic dysfunction, whether they retain rescuable functional capacity and tumor-killing capability remains unclear.

METHODS

To investigate the functionality and tumor-specificity of tumor-infiltrating lymphocytes (TILs) across HNSCCs, malignant cell lines and TILs were derived from 31 HPV-negative HNSCCs at the time of standard surgical resection. T cell functional capacity was evaluated through ex vivo expansion, immunophenotyping, and IsoLight single-cell proteomics. Tumor-specificity was investigated through both bulk and single-cell tumor-TIL co-culture.

RESULTS

TILs could be successfully generated from 24 patients (77%), including both previously untreated and radiation recurrent HNSCCs. We demonstrate that across HNSCCs, TILs express multiple exhaustion markers but maintain a predominantly effector memory phenotype. After ex vivo expansion, TILs retain immunogenic functionality even from radiation-resistant, exhausted, and T cell-depleted disease. We further demonstrate tumor-specificity of T cells across HNSCC patients through patient-matched malignant cell-T cell co-culture. Finally, we use optofluidic technology to establish an autologous single tumor cell-single T cell co-culture platform for HNSCC. Cells derived from three HNSCC patients underwent single-cell co-culture which enabled identification and visualization of individual tumor-killing TILs in real-time in all patients.

CONCLUSIONS

These studies show that cancer-specific T cells exist across HNSCC patients with rescuable immunogenicity and can be identified on a single-cell level. These data lay the foundation for development of patient-specific T cell immunotherapies in HNSCC.

A senescence-related lncRNA signature predicts prognosis and reflects immune landscape in HNSCC

OBJECTIVE

Long noncoding RNAs (lncRNAs) regulate cancer cell senescence in many cancers. However, their specific involvement in head and neck squamous cell carcinoma (HNSCC) remains unclear. We are looking for an ingenious prognostic signature that utilizes senescence-related lncRNAs (SRlncRNAs) to predict prognosis and provide insights into the immune landscape in HNSCC.

MATERIALS AND METHODS

HNSCC clinical and Cellular senescence genes information were collected from The Cancer Genome Atlas and Human Aging Genomic Resources. Then we performed Cox and Lasso regression to locate SRlncRNAs related to the prognosis of HNSCC and built a predictive signature. Further, prognosis assessment, potential mechanisms, and immune status were assessed by Kaplan-Meier analysis, Gene Set Enrichment Analysis (GSEA), and CIBERSORT, respectively.

RESULTS

A prognosis prediction model based on sixteen SRlncRNAs was identified and internally validated. Then, patients with high-risk scores suffered an unfavorable overall survival (All p < 0.05). The risk score, age, and stage were independent prognostic parameters (all p < 0.001). Our model has good predictive ability (The AUC (area under the curves) 1-year = 0.707, AUC3-year = 0.748 and AUC5-year = 0.779). Subsequently, GESA revealed SRlncRNAs regulated immune responses. Patients in the high-risk group had higher tumor mutation burden and Tumor Immune Dysfunction and Exclusion but lower levels of 37 immune checkpoint genes, immune scores, and immune cells like CD8 + T cells, follicular helper T cells, and regulatory T cells.

CONCLUSIONS

A prognostic model based on SRlncRNAs is the potential target for improving immunotherapy outcomes for HNSCC.

Durvalumab with or without tremelimumab for patients with recurrent or metastatic squamous cell carcinoma of the head and neck: a systematic review and meta-analysis

Objective

Head and neck squamous cell carcinoma (HNSCC) ranks as the sixth most prevalent cancer worldwide, significantly impacting patients' quality of life. Immune checkpoint inhibitors (ICI) have been employed in the treatment of recurrent/metastatic (R/M)-HNSCC patients. This meta-analysis aims to assess the efficacy and safety of durvalumab monotherapy compared to the combination of durvalumab and tremelimumab in R/M-HNSCC patients.

Methods

Relevant studies were systematically searched in PubMed, Embase, and Cochrane Library databases. All articles comparing durvalumab monotherapy with the combination with durvalumab and tremelimumab in R/M-HNSCC treatment were included. Additionally, the references of identified studies were screened if necessary.

Result

A total of 1298 patients from three studies comparing durvalumab with durvalumab and tremelimumab in treating R/M-HNSCC were include in this meta-analysis. Our findings revealed no significant difference in objective response rate (ORR) [odds ratio (OR): 1.15, 95% confidence interval (CI): 0.85 to 1.56, P = 0.36] and disease control rate (DCR) (OR=1.08, 95%CI: 0.86 to 1.37, P = 0.51). Similar outcomes were observed in overall survival (OS), progression-free survival (PFS), and duration of response (DoR). Regarding safety, there was no significant difference in the incidence of treatment-related adverse events (trAEs) between the two groups (OR=1.26, 95%CI: 0.81 to 1.94, P = 0.30). However, patients treated with the combination therapy exhibited a higher incidence of grade 3-4 trAEs (OR=1.93, 95%CI: 1.36 to 2.73, P = 0.0002) and a greater likelihood of discontinuing treatment due to trAEs (OR=2.07, 95%CI: 1.12 to 3.85, P = 0.02). There was no significant difference in the occurrence of severe trAEs leading to death (OR=1.36, 95%CI: 0.47 to 3.96, P = 0.57).

Conclusion

This meta-analysis suggests that R/M-HNSCC patients receiving the combination of durvalumab and tremelimumab may achieve comparable outcomes in terms of ORR, DCR, OS, PFS, and DoR, without significant differences. However, the combination therapy is associated with a higher incidence of grade 3-4 trAEs and an increased likelihood of treatment discontinuation due to trAEs. These findings highlight the need for cautious consideration of the combination of durvalumab and tremelimumab in R/M-HNSCC patients, which should be further evaluated in high-quality studies.

Comparative analysis of immune infiltrates in head and neck cancers across anatomical sites

BACKGROUND

The response rate to immune checkpoint inhibitors targeting programmed cell death 1 (PD-1) receptor is 13%-18% for patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). Detailed understanding of the tumor immune microenvironment (TIME) is crucial in order to explain and improve this response rate. HNSCCs arise at various anatomical locations including the oral cavity, hypopharynx, larynx and oropharynx. Studies directly comparing immune infiltration between anatomical sites are scarce. Since the distinct locations could drive deviating microenvironments, we questioned whether the immune composition varies across these HNSCC sites.

METHODS

Here, we characterized the TIME of 76 fresh tumor specimens using flow cytometry and performed single-cell RNA-sequencing on nine head and neck tumor samples.

RESULTS

We found major differences in the composition of the TIME between patients. When comparing anatomical sites: tumors originating from the oral cavity had higher T cell infiltrates than tumors from other anatomical sites. The percentage of tumor-infiltrating T-lymphocytes positive for the immune checkpoint PD-1 varied considerably between patients, with the highest fraction of PD-1+ T cells found in larynx squamous cell carcinomas (SCCs). While we had hypothesized that the anatomical sites of tumor origin would drive sample clustering, our data showed that the type of TIME was more dominant and was particularly driven by the fraction of T cells positive for PD-1. Moreover, a high proportion of PD-1+ CD8+ T cells associated with an improved overall survival. Using single-cell RNA-sequencing, we observed that PD-1 expression was highest in the CD8-ENTPD1 tissue resident memory T cell/exhausted T cell and CD4-CXCL13 type 1 T helper cell clusters.

CONCLUSIONS

We found that oral cavity SCCs had the highest frequencies of T cells. We also observed considerable interpatient heterogeneity for PD-1 on T cells, with noticeably higher frequencies of PD-1+ CD4+ T helper cells in larynx SCCs. Within the entire cohort, a higher fraction of CD8+ T cells positive for PD-1 was linked to improved overall survival. Whether the fraction of PD-1+ T cells within the TIME enables immune checkpoint inhibitor response prediction for patients with head and neck cancer remains to be determined.

Identification and validation of N6-methyladenosine (m6A)-related lncRNAs signature for predicting the prognosis of laryngeal carcinoma, especially for smoking patients

Laryngeal cancer (LC), a highly fatal tumor in the head and neck region, has been the focus of research in recent years. The study of LC has primarily focused on the role of long non-coding RNAs (lncRNAs) in regulating gene expression, as they have emerged as pivotal factors in this biological process. Additionally, a reversible RNA modification called N6-methyladenosine (m6A) has been observed to have a significant impact on gene expression as well. The purpose of this research is to investigate the impact of m6A-related lncRNAs on the prognosis of laryngeal squamous cell carcinoma (LSCC). Specifically, this investigation analyzed the m6A-related regulators' patterns of expression and mutation, encompassing a total of 15 regulators. Drawing upon the expression levels of prognostic m6A-regulated lncRNAs, two distinct lncRNA clusters were identified. Further analysis revealed differentially expressed lncRNAs between these clusters. In addition to studying the expression of lncRNAs, the researchers also examined the distribution of clinical characteristics and the tumor microenvironment (TME) in relation to the identified lncRNA clusters. This provided valuable insights into potential associations between lncRNA expression patterns and the clinical features of LSCC. Through the establishment of a risk model associated with lncRNAs, we were able to further investigate their clinical features, prognosis, and immune status. Additionally, we conducted a separate analysis of LINC00528, a lncRNA associated with smoking, examining its expression, overall survival time, correlated mRNAs, and conducting enrichment of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), as well as determining the sensitivity of related drugs. RT-qPCR results also indicated an increase in LINC00528 expression among smoking LSCC patients. The findings suggest that a high expression level of LINC00528 in LSCC patients may lead to a more favorable prognosis, providing new insights for the management and treatment of LSCC patients, particularly those with high expression of LINC00528. Overall, this research sheds light on the prognostic impact of m6A-regulated lncRNAs in LSCC. The implications of these findings for the advancement of innovative therapeutic approaches for LSCC patients are noteworthy.

Immune-scoring in head and neck squamous cell carcinoma: a scoping review

INTRODUCTION

Head and neck squamous cell carcinomas (HNSCCs) have an increasing incidence, high recurrence, and an overall unfavorable prognosis despite numerous treatment options. The distinct immune landscape of HNSCC suggests a potential for immune-related biomarkers to aid classification and treatment planning.

AREAS COVERED

Immunoscore, a multiplex measure of tumor-infiltrating immune cells, is currently approved in colorectal carcinoma and is under investigation in various other cancer types. Recent studies have tried to implement the immunoscore and other novel immune cell-based scoring systems in HNSCC as predictors of survival. This study provides an overview of tumor-infiltrating immune cells and their prognostic significance, as well as a comparative summary of studies introducing an immunoscore in HNSCC.

EXPERT OPINION

With sufficient insight of the current literature, future studies could lead to the definition and validation of a new immune-based classification system for HNSCC. Such a classification strategy could be the basis for patient selection and, thus, optimize treatment outcomes and reduce unwanted complications. The heterogeneity of HNSCC subtypes, as well as the intratumoral variability of immune infiltrates, should be accounted for in the immunoscore.

Application of single-cell RNA sequencing in head and neck squamous cell carcinoma

Single-cell RNA sequencing has been broadly applied to head and neck squamous cell carcinoma (HNSCC) for characterizing the heterogeneity and genomic mutations of HNSCC benefiting from the advantage of single-cell resolution. We summarized most of the current studies and aimed to explore their research methods and ideas, as well as how to transform them into clinical applications. Through single-cell RNA sequencing, we found the differences in tumor cells' expression programs and differentiation tracks. The studies of immune microenvironment allowed us to distinguish immune cell subpopulations, the extensive expression of immune checkpoints, and the complex crosstalk network between immune cells and non-immune cells. For cancer-associated fibroblasts (CAFs), single-cell RNA sequencing had made an irreplaceable contribution to the exploration of their differentiation status, specific CAFs markers, and the interaction with tumor cells and immune cells. In addition, we demonstrated in detail how single-cell RNA sequencing explored the HNSCC epithelial-to-mesenchymal transition (EMT) model and the mechanism of drug resistance, as well as its clinical value.

The Immune Cells in the Development of Oral Squamous Cell Carcinoma

A still unresolved issue surrounding tumor formation concerns the role that the immune system plays in preventing the formation and progression of neoplasia, including oral squamous cell carcinoma (OSCC). Antitumor immunity has historically been seen as a critical barrier for cancer cells to develop, grow and spread, and this can be modulated using immunotherapies to achieve antitumor clinical responses. However, it has recently become clear that tumor-associated immunity, particularly the inflammatory microenvironment, has the paradoxical effect of enhancing tumorigenesis and progression. In this review, we discuss the multifaceted function of infiltrating immune cells in suppressing or promoting premalignancy and cancer. In particular, we report on the evidence supporting a role for T lymphocytes, dendritic cells, macrophages, and neutrophils in the development and progression of oral potentially malignant disorders (OPMD) and OSCC. We also draw attention to the clinical relevance of immune cell phenotypes and associated molecules for use as biomarkers and to the translatability of current research findings to improve classification systems and precision medicine in patients with OSCC.

Tumor-derived GDF-15 blocks LFA-1 dependent T cell recruitment and suppresses responses to anti-PD-1 treatment

Immune checkpoint blockade therapy is beneficial and even curative for some cancer patients. However, the majority don't respond to immune therapy. Across different tumor types, pre-existing T cell infiltrates predict response to checkpoint-based immunotherapy. Based on in vitro pharmacological studies, mouse models and analyses of human melanoma patients, we show that the cytokine GDF-15 impairs LFA-1/β2-integrin-mediated adhesion of T cells to activated endothelial cells, which is a pre-requisite of T cell extravasation. In melanoma patients, GDF-15 serum levels strongly correlate with failure of PD-1-based immune checkpoint blockade therapy. Neutralization of GDF-15 improves both T cell trafficking and therapy efficiency in murine tumor models. Thus GDF-15, beside its known role in cancer-related anorexia and cachexia, emerges as a regulator of T cell extravasation into the tumor microenvironment, which provides an even stronger rationale for therapeutic anti-GDF-15 antibody development.

The Histological Background of Recurrence in Laryngeal Squamous Cell Carcinoma: An Insight into the Modifications of Tumor Microenvironment

Recurrent laryngeal carcinoma presents differences from the primary tumor that largely depend on the treatment. In this article, we review the histologic and molecular treatment-induced changes that may affect the diagnosis of recurrent laryngeal carcinoma, the assessment of predictive markers, and the response to treatment with immune checkpoint inhibitors. Radiotherapy induces profound modifications that are strictly related to necrosis of different tissue components, fibrosis, and damage of the tumor vessels. Postradiotherapy recurrent/persistent laryngeal squamous cell carcinoma typically presents a discohesive growth pattern within a fibrotic background associated with significant changes of the tumor immune microenvironment, with both important immunosuppressive and immunostimulatory effects. Overall, the increase of immunoregulatory cells and immune checkpoints such as CTLA-4, TIM-3, PD-1, and PD-L1 induced by radiotherapy and chemotherapy strongly supports the use of immune checkpoint inhibitors in recurrent/persistent laryngeal carcinoma. Future studies aiming to identify predictive factors of the response to immune checkpoint inhibitors should consider such treatment-induced modifications.

The Tumor-Specific Immune Landscape in HPV+ Head and Neck Cancer

Human papillomaviruses (HPVs) are the causative agent of several anogenital cancers as well as head and neck cancers, with HPV+ head and neck squamous cell carcinoma (HNSCC) becoming a rapidly growing public health issue in the Western world. Due its viral etiology and potentially its subanatomical location, HPV+ HNSCC exhibits an immune microenvironment which is more inflamed and thus distinct from HPV-negative HNSCC. Notably, the antigenic landscape in most HPV+ HNSCC tumors extends beyond the classical HPV oncoproteins E6/7 and is extensively targeted by both the humoral and cellular arms of the adaptive immune system. Here, we provide a comprehensive overview of HPV-specific immune responses in patients with HPV+ HNSCC. We highlight the localization, antigen specificity, and differentiation states of humoral and cellular immune responses, and discuss their similarities and differences. Finally, we review currently pursued immunotherapeutic treatment modalities that attempt to harness HPV-specific immune responses for improving clinical outcomes in patients with HPV+ HNSCC.

Improving head and neck cancer therapies by immunomodulation of the tumour microenvironment

Targeted immunotherapy has improved patient survival in head and neck squamous cell carcinoma (HNSCC), but less than 20% of patients produce a durable response to these treatments. Thus, new immunotherapies that consider all key players of the complex HNSCC tumour microenvironment (TME) are necessary to further enhance tumour-specific T cell responses in patients. HNSCC is an ideal tumour type in which to evaluate immune and non-immune cell differences because of two distinct TME aetiologies (human papillomavirus (HPV)-positive and HPV-negative disease), multiple anatomic sites for tumour growth, and clear distinctions between patients with locally advanced disease and those with recurrent and/or metastatic disease. Recent technological and scientific advancements have provided a more complete picture of all cellular constituents within this complex TME and have evaluated the interplay of both immune and non-immune cells within HNSCC. Here, we include a comprehensive analysis of the complete ecosystem of the HNSCC TME, performed utilizing data-rich resources such as The Cancer Genome Atlas, and cutting-edge techniques, such as single-cell RNA sequencing, high-dimensional flow cytometry and spatial multispectral imaging, to generate improved treatment strategies for this diverse disease.

Canine melanoma: A review of diagnostics and comparative mechanisms of disease and immunotolerance in the era of the immunotherapies

Melanomas in humans and dogs are highly malignant and resistant to therapy. Since the first development of immunotherapies, interest in how the immune system interacts within the tumor microenvironment and plays a role in tumor development, progression, or remission has increased. Of major importance are tumor-infiltrating lymphocytes (TILs) where distribution and cell frequencies correlate with survival and therapeutic outcomes. Additionally, efforts have been made to identify subsets of TILs populations that can contribute to a tumor-promoting or tumor-inhibiting environment, such as the case with T regulatory cells versus CD8 T cells. Furthermore, cancerous cells have the capacity to express certain inhibitory checkpoint molecules, including CTLA-4, PD-L1, PD-L2, that can suppress the immune system, a property associated with poor prognosis, a high rate of recurrence, and metastasis. Comparative oncology brings insights to comprehend the mechanisms of tumorigenesis and immunotolerance in humans and dogs, contributing to the development of new therapeutic agents that can modulate the immune response against the tumor. Therapies that target signaling pathways such as mTOR and MEK/ERK that are upregulated in cancer, or immunotherapies with different approaches such as CAR-T cells engineered for specific tumor-associated antigens, DNA vaccines using human tyrosinase or CGSP-4 antigen, anti-PD-1 or -PD-L1 monoclonal antibodies that intercept their binding inhibiting the suppression of the T cells, and lymphokine-activated killer cells are already in development for treating canine tumors. This review provides concise and recent information about diagnosis, comparative mechanisms of tumor development and progression, and the current status of immunotherapies directed toward canine melanoma.

FAM3D as a Prognostic Indicator of Head and Neck Squamous Cell Carcinoma Is Associated with Immune Infiltration

Background

Globally, head and neck squamous cell carcinoma (HNSCC) is a common malignant tumor with high morbidity and mortality. Hence, it is important to find effective biomarkers for the diagnosis and prediction of the prognosis of patients with HNSCC. FAM3D had been proven to be vital in other cancers. However, its predictive and therapeutic value in HNSCC is unclear. Therefore, it is valuable to explore the association between the expression level of FAM3D and its impacts on the prognosis and tumor microenvironment in HNSCC.

Methods

The Cancer Genome Atlas (TCGA) dataset, Genotype-Tissue Expression (GTEx) dataset, the Clinical Proteomic Tumor Analysis Consortium (CPTAC) dataset, and The Human Protein Atlas (THPA) website were used to assess HNSCC expressions in tumor and nontumor tissues. Then, we further conducted immunohistochemistry experiment as internal cohort to validate the same results. The Cox regression analysis, Kaplan-Meier analysis, and nomograms were performed to find the predictive prognostic value of FAM3D in HNSCC patients and its relationship with the clinicopathological features in HNSCC. The Gene Expression Omnibus (GEO) dataset was utilized to externally verify the prognosis value of FAM3D in HNSCC. Gene Set Enrichment Analysis (GESA) was applied to search the molecular and biological functions of FAM3D. The association between FAM3D and immune cell infiltration was investigated with the Tumor Immune Estimating Resource, version 2 (TIMER2). The relationships between FAM3D expression and tumor microenvironment (TME) scores, immune checkpoints, and antitumor compound half-maximal inhibitory concentration predictions were also explored.

Results

In different datasets, FAM3D mRNA and protein levels were all significantly lower in HNSCC tissues than in normal tissues, and they were strongly inversely associated with tumor grade, stage, lymph node metastasis, and T stage. Patients with high-FAM3D-expression displayed better prognosis than those with low-FAM3D-expression. FAM3D was also determined to be a suitable biomarker for predicting the prognosis of patients with HNSCC. This was externally validated in the GEO dataset. As for gene and protein level, the functional and pathway research results of FAM3D indicated that it was enriched in alteration of immune-related pathways in HNSCC. The low-expression group had higher stromal and ESTIMATE scores by convention than the high-expression group. FAM3D expression were found to be positively correlated with immune infiltrating cells, such as cancer-associated fibroblasts, myeloid-derived suppressor cells, macrophage cells, T cell CD8+ cells, regulatory T cells, and T cell follicular helper cells. FAM3D's relationships with immune checkpoints and sensitivity to antitumor drugs were also investigated.

Conclusion

Our study explored the impact of FAM3D as a favorable prognostic marker for HNSCC on the tumor immune microenvironment from multiple perspectives. The results may provide new insights into HNSCC-targeted immunotherapy.

Prognostic value of CD103+ tumor-infiltrating lymphocytes and programmed death ligand-1 (PD-L1) combined positive score in recurrent laryngeal squamous cell carcinoma

OBJECTIVES

In an evolving era of immunotherapeutic options for persistent or recurrent laryngeal squamous cell carcinoma (LSCC), there is a need for improved biomarkers of treatment response and survival to inform optimal treatment selection and prognostication. Herein, our primary objective was to explore correlations between tumor infiltrating lymphocytes (TILs) and PD-L1 Combined Positive Score (CPS). Secondarily, we sought to explore their combined association with survival outcomes in patients with persistent or recurrent LSCC treated with salvage surgery.

MATERIALS AND METHODS

This was a retrospective cohort study at a single academic medical center. Immunohistochemistry staining for TILs and PD-L1 was performed on a tissue microarray of persistent or recurrent LSCC pathologic specimens. Correlations between TIL subsets and PD-L1 CPS were examined using Pearson's correlation coefficient and survival outcomes were analyzed with the Kaplan-Meier method and log-rank tests.

RESULTS

Only CD103+ TILs showed a statistically significant, weakly-positive correlation with PD-L1 CPS (r2 = 0.264, p < 0.015). No other TIL subsets correlated with PD-L1 CPS in our cohort. The most favorable survival outcomes were seen in patients with pathologic N0 tumors showing high CD103+ TILs and/or high PD-L1 CPS staining.

CONCLUSION

Among patients with persistent or recurrent LSCC, CD103+ TILs only modestly correlated with PD-L1 CPS. A combined biomarker score incorporating CD103+ TILs and PD-L1 CPS greatly enhanced survival discrimination. This model may have additional utility in predicting the clinical benefit of immunotherapies in persistent or recurrent LSCC in the future.

PD1+CD8+ Cells Are an Independent Prognostic Marker in Patients with Head and Neck Cancer

Head and neck squamous cell carcinomas (HNSCCs) belong to a group of diverse tumors, which can be induced by infection with human papillomavirus (HPV) or tobacco and alcohol consumption. The viral etiology of HNSCC relates to better clinical outcomes reflecting a different immune system response. Here, we retrospectively analyzed 97 tissue samples from oral and oropharyngeal carcinomas associated and non-associated with HPV infection using multispectral fluorescent immunohistochemistry. To evaluate the immune cell infiltration in tumor and stroma compartments, we designed four panels of four to five antibodies. We detected more T lymphocytes in the stroma, compared to the tumor parenchyma. In HPV positive (HPV+) in comparison to HPV negative (HPV−) tumors, higher counts of CD3+CD4+, CD3+CD8+, PD1+CD4+, PD1+CD8+ T cells, and ICOS− Treg cells were detected while more ICOS+ Treg cells and CTLA4+CD4+ T cells were observed in HPV− than in HPV+ tumors. The results of the univariate and multivariate analyses confirmed the predominant impact of HPV status on prognosis. More importantly, the number of CD8+PD-1+ T cells was identified as an independent factor, influencing the overall and/or disease-specific survival of patients with oral cavity or oropharyngeal carcinomas.

Evaluation of CD4+ tumor-infiltrating lymphocyte association with some clinicopathological indices of oral squamous cell carcinoma

BACKGROUND

The delayed diagnosis of oral squamous cell carcinoma (OSCC) affects therapeutic and prognostic strategies, and provides regional recurrence or distant metastasis. The tumor-infiltrating lymphocytes (TILs) are known as a critical diagnostic biomarker in antitumor immune response. We evaluated the association between CD4⁺ T-lymphocyte marker, some clinicopathological indices, and the impact of TILs on the stage and grade of OSCC.

MATERIALS AND METHODS

In this cross-sectional study, 37 OSCC specimens including 16 early and 21 advanced stages (categorized base-on recent clinical oncology references) and their related healthy surgical margin (as internal control group) were collected. Obtained histochemical data were analyzed by SPSS V.23 software. The expression of CD4⁺ marker in tumor microenvironment (TME) was compared by nonparametric Mann-Whitney and Kruskal-Wallis as well as Fisher's exact tests. P < 0.05 was remarked statistically significant.

RESULTS

The low-grade patients represented more CD4⁺ TIL that was statistically significant (P = 0.011). However, there was no statistically significant difference in CD4⁺ TIL between various stages (P = 0.404), tumor size, and lymph node involvement (P > 0.05). Moreover, there was no significant relation between TIL infiltration, age, and tumor localization (P > 0.05), however CD4⁺ expression in women was more than men (P = 0.008). The CD4⁺ T-lymphocyte infiltration in TME was more significant than healthy surgical margin (P < 0.001). There was a statistically significant difference between healthy surgical margin and different grades and stages of OSCCs that lower grades demonstrated more CD4⁺ TIL infiltration (P < 0.001).

CONCLUSION

The CD4⁺ T-lymphocytes may play important role in differentiation and maturity of epithelial cell, tumorigenesis, and progression of OSCC.

Divergent outcomes of anti-PD-L1 treatment coupled with host-intrinsic differences in TCR repertoire and distinct T cell activation states in responding versus non-responding tumors

Differential responses to immune checkpoint inhibitors (ICI) may be attributed to tumor-intrinsic factors or environmental cues; however, these mechanisms cannot fully explain the variable ICI responses in different individuals. Here, we investigate the potential contribution of immunological heterogeneity with a focus on differences in T-cell receptor (TCR) repertoire to ICI responses, which has not been defined previously. To reveal additional factors underlying heterogeneous responses to ICI, we employed a squamous cell carcinoma (SCC) mouse model in which tumor-bearing recipients unambiguously diverged into responders (R) or non-responders (NR) upon anti-PD-L1 treatment. Treatment efficacy absolutely required CD8 T-cells and correlated positively with effector functions of CD8 tumor-infiltrating lymphocytes (TILs). We showed that TCR repertoires exhibited a similar magnitude of clonal expansion in R vs. NR CD8 TILs. However, the top expanded TCR clonotypes appeared to be mutually exclusive between R and NR CD8 TILs, which also occurred in a recipient-specific manner, demonstrating preferential expansion of distinct TCR clonotypes against the same SCC tumor. Unexpectedly, R vs. NR CD8 TILs reached all activation clusters and did not exhibit substantial global differences in transcriptomes. By linking single-cell transcriptomic data with unique TCR clonotypes, CD8 TILs harboring top TCR clonotypes were found to occupy distinct activation clusters and upregulate genes favoring anti-tumor immunity to different extents in R vs. NR. We conclude that stochastic differences in CD8 TIL TCR repertoire and distinct activation states of top TCR clonotypes may contribute to differential anti-PD-L1 responses. Our study suggests that host-intrinsic immunological heterogeneity may offer a new explanation for differential ICI responses in different individuals, which could impact on strategies for personalized cancer immunotherapy.

Immune Cells in Head-and-Neck Tumor Microenvironments

Head-and-neck cancers constitute a heterogeneous group of aggressive tumors with high incidence and low survival rates, collectively being the sixth most prevalent cancer type globally. About 90% of head-and-neck cancers are classified as squamous cell carcinomas (HNSCC). The innate and adaptive immune systems, indispensable for anti-cancer immune surveillance, largely define the rates of HNSCC emergence and progression. HNSCC microenvironments harbor multiple cell types that infiltrate the tumors and interact both with tumor cells and among themselves. Gradually, tumor cells learn to manipulate the immune system, either by adapting their own immunogenicity or through the release of immunosuppressive molecules. These interactions continuously evolve and shape the tumor microenvironment, both structurally and functionally, facilitating angiogenesis, proliferation and metastasis. Our understanding of this evolution is directly related to success in the development of advanced therapies. This review focuses on the key mechanisms that rule HNSCC infiltration, featuring particular immune cell types and their roles in the pathogenesis. A close focus on the tumor-immunity interactions will help identify new immunotherapeutic targets in patients with HNSCC.

Immunoscore Combining CD8, FoxP3, and CD68-Positive Cells Density and Distribution Predicts the Prognosis of Head and Neck Cancer Patients

We assessed immune cell infiltrates to develop an immunoscore for prognosis and to investigate its correlation with the clinical data of patients with head and neck cancer. CD8, FoxP3, and CD68 markers were evaluated by immunohistochemistry in 258 carcinoma samples and positive cells were counted in stromal and intra-tumoral compartments. The RStudio software was used to assess optimal cut-offs to divide the population according to survival while the prognostic value was established by using Kaplan–Meier curves and Cox regression models for each immune marker alone and in combination. We found with univariate analysis that the infiltration of immune cells in both compartments was predictive for recurrence-free survival and overall survival. Multivariate analysis revealed that CD8+ density was an independent prognostic marker. Additionally, the combination of CD8, FoxP3, and CD68 in an immunoscore provided a significant association with overall survival (p = 0.002, HR = 9.87). Such an immunoscore stayed significant (p = 0.018, HR = 11.17) in a multivariate analysis in comparison to tumor stage and histological grade, which had lower prognostic values. Altogether, our analysis indicated that CD8, FoxP3, and CD68 immunoscore was a strong, independent, and significant prognostic marker that could be introduced into the landscape of current tools to improve the clinical management of head and neck cancer patients.

Effect of kangai injection combined with platinum-based chemotherapy on the immune function of patients with advanced non-small-cell lung cancer: A meta-analysis

BACKGROUND

Kangai injection (KAI) is a well-known Chinese patent medicine applied for several different types of cancers in the clinic as an auxiliary therapeutic approach, which is refined from three herbal extracts (Astragalus, Ginseng and Matrine).

PURPOSE

To systematically evaluate the effect of combination treatment of platinum-based chemotherapy and KAI on patients with advanced non-small-cell lung cancer (NSCLC).

STUDY DESIGN

A meta-analysis of randomized clinical trials.

MATERIALS AND METHODS

The randomized controlled trials (RCTs) about stage Ⅲ-Ⅳ NSCLC using KAI combined platinum-based chemotherapy were electronically retrieved from eight electronic databases up to July 2021. We applied RevMan 5.4, Stata 16.0, TSA 0.9.5.10 Beta and GRADE Pro-GDT to evaluate the quality of the included RCTs and perform the meta-analysis.

RESULTS

19 RCTs were included, consisting a total sample size of 1,389 cases. Meta-analysis revealed that compared with chemotherapy alone, KAI combined with platinum-based chemotherapy was associated with significantly higher objective response rate (ORR) [RR = 1.36, 95%CI (1.21,1.54), p< 0.00001], higher disease control rate (DCR) [RR = 1.15, 95%CI (1.09,1.21), p< 0.00001], greater Karnofsky performance status (KPS) [RR = 1.75, 95%CI (1.41,2.18), p< 0.00001], lower white blood cell toxicity [RR = 0.67, 95%CI (0.55,0.82), p = 0.0001], lower platelet toxicity [RR = 0.60, 95%CI (0.47,0.75), P  < 0.0001], and lower incidence of vomiting [RR = 0.66, 95%CI (0.57,0.76), p< 0.00001]. In terms of the immune function, KAI united with chemotherapy significantly raised the ratio of CD3⁺ cells [MD = 10.65, 95%CI (8.21,13.09), p< 0.00001], CD4⁺ cells [MD = 7.67, 95%CI (6.31,9.03), p< 0.00001], NK cells [MD = 4.97, 95%CI (3.03,6.92), p< 0.00001], and CD4⁺/ CD8⁺ [MD = 0.32, 95%CI (0.19,0.45), p< 0.00001], and decreased the percentage of CD8⁺ cells [MD = -5.56, 95%CI (-7.51,-3.61), p< 0.00001].

CONCLUSIONS

This meta-analysis identified that the combination treatment of KAI and platinum-based chemotherapy was more beneficial to patients with advanced NSCLC when compared to chemotherapy alone, which could significantly improve the clinical efficacy, enhance the immune function, and reduce chemotherapy toxicity. Our study provides a theoretical basis and treatment guidance for patients with NSCLC.

Temporal Bone Squamous Cell Carcinoma: Molecular Markers Involved in Carcinogenesis, Behavior, and Prognosis: A Systematic Review

Temporal bone squamous cell carcinoma (TBSCC) is an uncommon malignancy with a poor prognosis in advanced cases. The dismal outcome of advanced TBSSC cases is largely due to the cancer’s local aggressiveness and the complex anatomy of this region, as well as to persistent pitfalls in diagnosis and treatment. Molecular changes occur in malignancies before any morphological changes become visible, and are responsible for the disease’s clinical behavior. The main purpose of this critical systematic review is to assess the level of knowledge on the molecular markers involved in the biology, behavior, and prognosis of TBSCC. A search (updated to March 2022) was run in PubMed, Scopus, and Web of Science electronic databases without publication date limits for studies investigating molecular markers in cohorts of patients with primary TBSCC. The search terms used were: “temporal bone” OR “external auditory canal” OR “ear”, AND “cancer” OR “carcinoma” OR “malignancy”. We preliminarily decided not to consider series with less than five cases. Twenty-four case series of TBSCC were found in which different analytical techniques had been used to study the role of several biomarkers. In conclusion, only very limited information on the prognostic role of molecular markers in TBSCC are currently available; prospective, multi-institutional, international prognostic studies should be planned to identify the molecular markers involved in the clinical behavior and prognosis of TBSCC. A further, more ambitious goal would be to find targets for therapeutic agents able to improve disease-specific survival in patients with advanced TBSCC.

A loss-of-function polymorphism in ATG16L1 compromises therapeutic outcome in head and neck carcinoma patients

The anticancer immune response is shaped by immunogenic cell stress and death pathways. Thus, cancer cells can release danger-associated molecular patterns that act on pattern recognition receptors expressed by dendritic cells and their precursors to elicit an antitumor immune response. Here, we investigated the impact of single nucleotide polymorphisms (SNPs) in genes affecting this cancer-immunity dialogue in the context of head and neck squamous cell carcinoma (HNSCC). We observed that homozygosity for a loss-of-function SNP (rs2241880, leading to the substitution of a threonine residue in position 300 by an alanine) affecting autophagy related 16 like 1 (ATG16L1) is coupled to poor progression-free survival in platinum-treated HNSCC patients. This result was obtained on a cohort of patients enrolled at the Gustave Roussy Cancer Campus and was validated on an independent cohort of The Cancer Genome Atlas (TCGA). Homozygosity in rs2241880 is well known to predispose to Crohn’s disease, and epidemiological associations between Crohn’s disease and HNSCC have been reported at the levels of cancer incidence and prognosis. We speculate that rs2241880 might be partially responsible for this association.

NOTCH1 Intracellular Domain and the Tumor Microenvironment as Prognostic Markers in HNSCC

Simple Summary

In the head and neck, a large proportion of squamous cell carcinoma demonstrate a mutation of the NOTCH1 gene. The aim of this project was to investigate the role of NOTCH1 and immunological characteristics and highlight a potential rationale for therapy. We found that a high expression of NOTCH1 intracellular domain in these patients is associated with reduced overall survival. In vitro experiments additionally showed a reduction of migration and proliferation of cancer cells when NOTCH1 was knocked down. NOTCH1 is, therefore, most likely involved in migration and proliferation of head and neck squamous cell carcinoma and is a prognostic marker in these patients.

Abstract

(1) Background: NOTCH1 is the second most common mutated gene in whole-exome sequencing of HNSCC. The aim of this project was to gain further insight into the relevance of NOTCH1 in HNSCC, potentially establishing NOTCH1 as a prognostic marker or therapeutic target; (2) Methods: NOTCH1 was silenced via RNA interference in six HNSCC cell lines and the impact was evaluated in migration and proliferation assays. Subsequently, the protein expression of NOTCH1 intracellular domain (NICD) and NOTCH1 mRNA expression were examined in 70 oropharyngeal squamous cell cancer tissue samples. Lastly, the NICD expression was compared with the local infiltration of lymphocytes, measured with the immunoscore; (3) Results: Knockdown of NOTCH1 decreased migration and proliferation. A high NICD expression was associated with lower OS. A high immunoscore resulted in significantly better OS. NICD expression was independent of the immunoscore and as a whole differentiated three distinct prognostic groups; (4) Conclusions: These data suggest that NOTCH1 is involved in migration and proliferation of HNSCC cell lines. In vivo, NICD expression was associated with overall survival and could, therefore, be used as a prognostic marker. NICD expression differs from NOTCH1 mRNA levels, potentially explaining the previously suggested bimodal role as an oncogene and tumor suppressor in HNSCC.

Ulinastatin combined with glutamine improves liver function and inflammatory response in patients with severe acute pancreatitis

OBJECTIVE

To explore whether ulinastatin combined with glutamine (Gln) can improve the liver function and inflammation in patients with severe acute pancreatitis (SAP).

METHODS

Altogether 78 patients with SAP treated in Tangshan Workers' Hospital were retrospectively enrolled and divided into the control group (CG, n=35, conventional treatment plus ulinastatin) and the research group (RG, n=43, additional Gln on the basis of treatment in the CG) according to the treatment regimen. The improvement of clinical symptoms after treatment was observed in both groups. The levels of IgM, IgA and IgG were tested by ELISA. The Acute Physiology and Chronic Health Evaluation (APACHE) II scores were utilized to evaluate the changes of the patients' condition before and after treatment, and the Balthazar CT score was used to assess the changes of the lesions. The changes of inflammatory cytokines were determined via Enzyme linked immunosorbent assay (ELISA). The liver function and amylase indexes of both groups were measured.

RESULTS

Patients in the RG experienced faster improvement in bloating and abdominal pain, first defecation, and bowel sound recovery than the CG (all P<0.05). After treatment, IgM, IgA and IgG in the RG were higher than those in the CG (all P<0.05). Besides, the RG exhibited markedly lower interleukin-6 (IL6), IL, tumor necrosis factor α (TNF-α), and high-sensitivity C-reactive protein (hs-CRP) levels than the CG after treatment (all P<0.05). After treatment, the indexes of liver function and amylase in both groups were decreased, and those in the RG were lower than those in the CG (all P<0.05).

CONCLUSION

Ulinastatin in combination with glutamine is effective in treating severe pancreatitis, which efficiently reduces inflammation in patients and facilitates the recovery of immune, metabolic, and liver functions, and therefore it has a high clinical application value.

T cell subtype profiling measures exhaustion and predicts anti-PD-1 response

Anti-PD-1 therapy can provide long, durable benefit to a fraction of patients. The on-label PD-L1 test, however, does not accurately predict response. To build a better biomarker, we created a method called T Cell Subtype Profiling (TCSP) that characterizes the abundance of T cell subtypes (TCSs) in FFPE specimens using five RNA models. These TCS RNA models are created using functional methods, and robustly discriminate between naïve, activated, exhausted, effector memory, and central memory TCSs, without the reliance on non-specific, classical markers. TCSP is analytically valid and corroborates associations between TCSs and clinical outcomes. Multianalyte biomarkers based on TCS estimates predicted response to anti-PD-1 therapy in three different cancers and outperformed the indicated PD-L1 test, as well as Tumor Mutational Burden. Given the utility of TCSP, we investigated the abundance of TCSs in TCGA cancers and created a portal to enable researchers to discover other TCSP-based biomarkers.

Antiviral Responses in Cancer: Boosting Antitumor Immunity Through Activation of Interferon Pathway in the Tumor Microenvironment

In recent years, it became apparent that cancers either associated with viral infections or aberrantly expressing endogenous retroviral elements (EREs) are more immunogenic, exhibiting an intense intra-tumor immune cell infiltration characterized by a robust cytolytic apparatus. On the other hand, epigenetic regulation of EREs is crucial to maintain steady-state conditions and cell homeostasis. In line with this, epigenetic disruptions within steady-state cells can lead to cancer development and trigger the release of EREs into the cytoplasmic compartment. As such, detection of viral molecules by intracellular innate immune sensors leads to the production of type I and type III interferons that act to induce an antiviral state, thus restraining viral replication. This knowledge has recently gained momentum due to the possibility of triggering intratumoral activation of interferon responses, which could be used as an adjuvant to elicit strong anti-tumor immune responses that ultimately lead to a cascade of cytokine production. Accordingly, several therapeutic approaches are currently being tested using this rationale to improve responses to cancer immunotherapies. In this review, we discuss the immune mechanisms operating in viral infections, show evidence that exogenous viruses and endogenous retroviruses in cancer may enhance tumor immunogenicity, dissect the epigenetic control of EREs, and point to interferon pathway activation in the tumor milieu as a promising molecular predictive marker and immunotherapy target. Finally, we briefly discuss current strategies to modulate these responses within tumor tissues, including the clinical use of innate immune receptor agonists and DNA demethylating agents.

CCR4 is a prognostic biomarker and correlated with immune infiltrates in head and neck squamous cell carcinoma

Background

Increased evidence has indicated that the tumour microenvironment plays an essential in the development, treatment and prognosis of head and neck squamous cell carcinoma (HNSC). Recent studies have indicated CC chemokine receptor 4 (CCR4) plays an essential role in tumor invasion and other adverse biological behavior. This study used data from the Cancer Genome Atlas (TCGA) database to explore the role of CCR4 in HNSC and its clinical significance.

Methods

The gene expression and clinical data of HNSC patients in the TCGA database were extracted. Gene Expression Profiling Interactive Analysis (GEPIA) was used to analyze the expression of CCR4 in tumor and non-tumor tissue. Kaplan-Meier survival analysis was used to analyze the relationship between CCR4 expression and overall survival rate (OS), disease-specific survival (DSS), and progression-free interval (PFI) in HNSC. A logistic regression model was used to analyze the relationships between various clinical factors and CCR4 expression. Gene Set Enrichment Analysis (GSEA) was used to explore the potential role of CCR4 in HNSC. Additionally, we explored the relationship between CCR4 and immune infiltration.

Results

The expression of CCR4 in HNSC was not significantly different from that in normal tissue. The expression level of CCR4 in wild-type TP53 was higher than that in mutant TP53. Cox regression analysis showed the expression level of CCR4 was related to the patient's tumor grade and Tumor-Node-Metastasis (TNM) stage. CCR4 expression level is an independent prognostic factor. CCR4 is positively correlated with immune infiltration and immune checkpoints expression levels. The results of GSEA revealed that the high CCR4 expression group genes were enriched in allograft rejection, inflammatory response, IL-6/JAK/STAT3 signaling, interferon gamma response, and KRAS signaling up. Low CCR4 expression group genes were enriched in oxidative phosphorylation, MYC targets v1, DNA repair, reactive oxygen species pathway, and P53 pathway. Further, our study indicated CCR4 can also predict the prognosis of radiotherapy patients.

Conclusions

Our study found that CCR4 was a prognostic marker related to HNSC immune infiltration, and patients with high expression of CCR4 had a better prognosis.

Recent progress of biomarkers in oral cancers

Oral cancers are the seventh most common cancer globally. While progresses in oral cancer treatment have been made, not all patients respond to these therapies in the same way. To overcome this difficulty, numerous studies have been devoted to identifying biomarkers, which enable early identification of patients who may benefit from a particular treatment modality or at risk for poor prognosis. Biomarkers are protein molecules, gene expression, DNA variants, or metabolites that are derived from tumors, adjacent normal tissue or bodily fluids, which can be acquired before treatment and during follow-up, thus extending their use to the evaluation of cancer progression and prediction of treatment outcome. In this review, we employed a basic significance level (<0.05) as the minimal requirement for candidate biomarkers. Effect sizes of the biomarkers in terms of odds ratio, hazard ratio, and area under the receiver operating characteristic curves were subsequently used to evaluate the potential of their clinical use. We identified the CCND1 from the tumor, human papillomavirus, HSP70, and IL-17 from the peripheral blood, and high density of CD45RO+ tumor-infiltrating lymphocytes as the clinically relevant biomarkers for oral cancers.

Assessment of Immune Cell Populations in Tumor Tissue and Peripheral Blood Samples from Head and Neck Squamous Cell Carcinoma Patients

Head and neck squamous cell carcinoma (HNSCC) is a common type of cancer worldwide. Strong connections have been revealed between immune cells and the pathogenesis of HNSCC. Important differences regarding the levels of immune cell subpopulations in both peripheral circulation and tumor microenvironment were emphasized, with some of them having prognostic significance. In our study, we performed an analysis of immune changes in the tumor tissue and the peripheral blood of untreated HNSCC patients, investigating the proportions of different immune cell populations in these two compartments. The local infiltrating lymphocytes were mainly cytotoxic T cells (CD8⁺). We have also revealed an increased level of B lymphocytes (CD19⁺) in the tumor microenvironment. In peripheral blood, the most important lymphocyte subtype was represented by the helper T lymphocytes (CD4⁺). We also found an increased proportion of circulating NK cells (CD56⁺). Our results showed significant differences between all investigated lymphocyte subtypes in the peripheral blood and the tumor tissue of untreated HNSCC patients, suggesting that the local and systemic expressions of antitumor immune responses are different and that investigation of immune cell proportions in peripheral circulation has different cues that do not reflect the immune infiltrate pattern within the tumor microenvironment. Further studies are necessary to unveil the complex interplay involving local and systemic events in the immune system's fight against cancer.

Exacerbation of cancer pain after administering immune checkpoint inhibitor in a patient taking opioids: A case report

WHAT IS KNOWN AND OBJECTIVE

Clinical cases of attenuation of opioid analgesic effect by administration of immune checkpoint inhibitors has not been reported. We present a case of head and neck cancer under pain management with opioids, in which cancer pain was exacerbated after administration of nivolumab.

CASE SUMMARY

A male patient with head and neck cancer was hospitalized for the second-line treatment of nivolumab. He had complained of head and neck pain after admission, but the pain was especially worse after nivolumab administration. The dose of opioids was eventually increased by approximately 320% (morphine equivalent dose) compared to before administering nivolumab.

WHAT IS NEW AND CONCLUSION

When administering immune checkpoint inhibitors such as nivolumab in clinical practice, the possibility of attenuation of opioid analgesic effect should be considered.

Characterization of immune cell infiltrate in tumor stroma and epithelial compartments in oral squamous cell carcinomas of Sudanese patients

BACKGROUND

Tumor immune infiltrate has been explored in oral squamous cell carcinoma (OSCC), but studies on simultaneous characterization of multiple immune cell subtypes separately in stromal and intraepithelial tumor compartments are limited.

OBJECTIVES

We aimed to investigate the immune cell infiltrate in OSCC by using immunohistochemistry (IHC) for a panel of inflammatory cells in stromal and epithelial tumor compartments for a better characterization of the tumors.

METHODS

Thirty-six OSCC lesions and nine normal oral mucosa (NOM) samples from patients attending Khartoum Dental Teaching Hospital, Sudan were investigated for presence of tumor infiltrating lymphocytes, tumor-associated macrophages, tumor-associated neutrophils, and PD-L1 positive cells in the inflammatory infiltrate by single and double IHC. Digital quantitative analysis (Aperio Technologies Inc.) was performed separately for stromal and epithelial compartments.

RESULTS

OSCC cases displayed a higher inflammatory infiltrate in the associated stroma, but not in the epithelial compartment when compared to NOM. The immunosuppressive type of inflammatory infiltrate, that is, T regulatory cells (FoxP3⁺ cells) was identified to be significantly higher in the epithelial compartment of tumors with advanced clinical state. An immunoscore developed by combining intraepithelial FoxP3⁺ and CD4⁺ cells was found significantly higher in lesions from elderly patients, localized at toombak dipping-related sites, poorly differentiated OSCCs, or with loco-regional lymph node spreading.

CONCLUSIONS

Despite heavy immune cell infiltration in tumor-associated stroma, the majority of OSCCs in this cohort displayed a low intraepithelial immune infiltration. An immunoscore based on combined CD4 and FoxP3 intraepithelial expression may serve as an indicator of advanced tumor progression and should be further investigated for its use as potential prognostic biomarker in OSCC.

CXCL10 Produced by HPV-Positive Cervical Cancer Cells Stimulates Exosomal PDL1 Expression by Fibroblasts via CXCR3 and JAK-STAT Pathways

Persistent infection with human papillomavirus (HPV) and immune surveillance failure may be the initiating factors for the carcinogenesis of cervical squamous cell carcinoma (CSCC). HPV infection might affect the innate immune pathway of cervical epithelial cells that constitute the “microenvironment” for tumor cells. Programmed death-ligand 1 (PD-L1) has been reported to be an immunosuppressor that helps cancer cells escape the actions of T cells. In the present study, CXCL10 was substantially upregulated both in cervical tissues of HPV infected patients with cervical intraepithelial neoplasia (CIN) or CSCC, as well as in HPV16 E6/E7 transgenic murine cervix. The HPV-positive (HPV+) cervical cancer cell lines SiHa and Caski secreted increased levels of CXCL10 compared to human foreskin fibroblasts (HFF-1), and its receptor CXCR3 was overexpressed in HFF-1. After co-culture with SiHa or Caski, the JAK-STAT signaling pathway and exosomal PD-L1 expression were both upregulated in HFF-1. Recombinant human CXCL10 induced JAK-STAT and PD-L1, while the CXCL10-CXCR3 and JAK-STAT inhibitors AMG487 or ruxolitinib reduced the expression of PD-L1 in HFF-1 cells. Furthermore, the upregulated expression of PD-L1 was verified in HPV+ but not HPV-negative (HPV-) patients with cervical cancers by analysis of tissue microarray cores in 25 cervical lesion patients (P < 0.05). The results indicate that HPV infection can induce cervical cancer cells to secrete CXCL10, which binds to CXCR3 in the surrounding fibroblast cells,leading to JAK-STAT pathway activation and the subsequent upregulated expression of exosomal PD-L1. These mechanisms may help HPV to escape immune response attack, leading to carcinogenesis.

Cancer-specific immune evasion and substantial heterogeneity within cancer types provide evidence for personalized immunotherapy

The immune response against cancer is orchestrated by various parameters and site-dependent specificities have been poorly investigated. In our analyses of ten different cancer types, we describe elevated infiltration by regulatory T cells as the most common feature, while other lymphocyte subsets and also expression of immune-regulatory molecules on tumor-infiltrating lymphocytes showed site-specific variation. Multiparametric analyses of these data identified similarities of renal and liver or lung with head and neck cancer. Co-expression of immune-inhibitory ligands on tumor cells was most frequent in colorectal, lung and ovarian cancer. Genes related to antigen presentation were frequently dysregulated in liver and lung cancer. Expression of co-inhibitory molecules on tumor-infiltrating T cells accumulated in advanced stages while T-cell abundance was related to enhanced expression of genes related to antigen presentation. Our results promote evaluation of cancer-specific or even personalized immunotherapeutic combinations to overcome primary or secondary resistance as major limitation of immune-checkpoint inhibition.

The relationship between the expression of soluble programmed cell death-1 and cancer pain: A protocol for systematic review and meta analysis

BACKGROUND

The immune checkpoint programmed cell death-1 (PD-1) plays a critical role in immune regulation. Recent studies have demonstrated functional PD-1 expression in peripheral sensory neurons, which contributes to neuronal excitability, pain, and opioid analgesia. However, the relationship between the expression of soluble programmed cell death-1(sPD-1) and cancer pain is controversial. The purpose of this study was to evaluate the relationship between sPD-1 expression level and cancer pain through meta-analysis.

METHODS

Studies were selected from Pubmed, Web of science, Embase, Google Scholar, and Chinese National Knowledge Infrastructure, and the Chinese Biomedical Literature Database based on inclusion and exclusion criteria. The standard mean difference (SMD) and 95% confidence interval (CI) were calculated using the random-effect model or fixed-effect model to assess the association between sPD-1 expression level and cancer pain. All analyses were performed with the Stata 14 software.

RESULTS

This review will be disseminated in print by peer-review.

CONCLUSION

The results of this study will help us to determine whether the expression level of sPD-1 is related to cancer pain.

ETHICS AND DISSEMINATION

The private information from individuals will not be published. This systematic review also should not endanger participant rights. Ethical approval is not available. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/WDPUY.

Machine-Learning-Based Evaluation of Intratumoral Heterogeneity and Tumor-Stroma Interface for Clinical Guidance

Assessment of intratumoral heterogeneity and tumor-host interaction within the tumor microenvironment is becoming increasingly important for innovative cancer therapy decisions because of the unique information it can generate about the state of the disease. However, its assessment and quantification are limited by ambiguous definitions of the tumor-host interface and by human cognitive capacity in current pathology practice. Advances in machine learning and artificial intelligence have opened the field of digital pathology to novel tissue image analytics and feature extraction for generation of high-capacity computational disease management models. A particular benefit is expected from machine-learning applications that can perform extraction and quantification of subvisual features of both intratumoral heterogeneity and tumor microenvironment aspects. These methods generate information about cancer cell subpopulation heterogeneity, potential tumor-host interactions, and tissue microarchitecture, derived from morphologically resolved content using both explicit and implicit features. Several studies have achieved promising diagnostic, prognostic, and predictive artificial intelligence models that often outperform current clinical and pathology criteria. However, further effort is needed for clinical adoption of such methods through development of standardizable high-capacity workflows and proper validation studies.

A prognostic value of CD45RA+, CD45RO+, CCL20+ and CCR6+ expressing cells as 'immunoscore' to predict cervical cancer induced by HPV

The interplay between cervical cancer (CC) and immune cells, mainly intratumoral lymphocytes, has a pivotal role in carcinogenesis. In this context, we evaluated the distribution of CD45RA⁺ and CD45RO⁺ cells as well as CCR6⁺ and CCL20⁺ cells in intraepithelial (IE) and marginal stroma (MS) areas from cervical intraepithelial neoplasia (CIN) I-III, and CC as 'immunoscore' for HPV-induced CC outcome. We observed increased CD45RA⁺ and CD45RO⁺ cells distribution in IE and MS areas in the CC group compared to CIN groups and healthy volunteers. Interestingly, there is a remarkable reduction of CCL20⁺ expressing cells distribution according to lesion severity. The CC group had a significant decrease in CCL20⁺ and CCR6⁺-expressing cells distribution in both IE and MS areas compared to all groups. Using the 'immunoscore' model, we observed an increased number of women presenting high CD45RA⁺/CD45RO⁺ and low CCL20⁺/CCR6⁺ 'immunoscore' in the CC group. Our results suggested a pattern in cervical inflammatory process with increasing CD45RA⁺/CD45RO⁺, and decreasing CCL20⁺/CCR6⁺ expression in accordance with CIN severity. Taken together, these markers could be evaluated as 'immunoscore' predictors to CC response. A more comprehensive analysis of longitudinal studies should be conducted to associate CD45RA⁺/CD45RO⁺ and CCL20⁺/CCR6⁺ 'immunoscore' to CC progression and validate its value as a prognosis method.

Immuno-Oncological Biomarkers for Squamous Cell Cancer of the Head and Neck: Current State of the Art and Future Perspectives

The era of immune checkpoint inhibitors has altered the therapeutic landscape in squamous cell cancer of the head and neck (SCCHN). Our knowledge about the tumor microenvironment has fueled the research in SCCHN, leading to several well-known and less-known prognostic and predictive biomarkers. The clinical staging, p16/HPV status, and PD-L1 expression are currently the main tools for assessing the patients' diagnosis and prognosis. However, several novel biomarkers have been thoroughly investigated, some reaching actual significant clinical contributions. The untangling of the immune infiltrate with the subtyping of tissue-associated tumor infiltrating lymphocytes, tumor-associated macrophages, and circulating blood-based biomarkers are an interesting avenue to be further explored and prospectively assessed. Although PD-L1 expression remains the most important response predictor for immune checkpoint inhibitors, several flaws impede proper assessment such as technical issues, different scoring protocol, and intra-, inter-, and temporal heterogeneity. In addition, the construction of an immune-related gene panel has been proposed as a prognostic and predictive stratification but lacks consensus. Recently, the role of microbioma have also been explored regarding its systemic and antitumor immunity. This review gives a comprehensive overview of the aforementioned topics in SCCHN. To this end, the integration of these clinically advantageous biomarkers via construction of an immunogram or nomogram could be an invaluable tool for SCCHN in future prospects.

Soluble Sema4D in Plasma of Head and Neck Squamous Cell Carcinoma Patients Is Associated With Underlying Non-Inflamed Tumor Profile

Semaphorin 4D (Sema4D) is a glycoprotein that is expressed by several tumors and immune cells. It can function as a membrane bound protein or as a cleaved soluble protein (sSema4D). We sought to investigate the translational potential of plasma sSema4D as an immune marker in plasma of patients with head and neck squamous cell carcinoma (HNSCC). Paired peripheral blood and tumor tissue samples of 104 patients with HNSCC were collected at the same time point to allow for real time analysis. Scoring of the histological inflammatory subtype (HIS) was carried out using Sema4D immunohistochemistry on the tumor tissue. sSema4D was detected in plasma using direct ELISA assay. Defining elevated sSema4D as values above the 95^th percentile in healthy controls, our data showed that sSema4D levels in plasma were elevated in 25.0% (95% CI, 16.7–34.9%) of the patients with HNSCC and showed significant association with HIS immune excluded (HIS-IE) (p = 0.007), Sema4D^+ve tumor cells (TCs) (p = 0.018) and PD-L1^+ve immune cells (ICs) (p = 0.038). A multi-variable logistic regression analysis showed that HIS was significantly (P = 0.004) associated with elevated sSema4D, an association not explained by available patient-level factors. Using the IO-360 nanoString platform, differential gene expression (DGE) analysis of 10 HNSCC tumor tissues showed that patients with high sSema4D in plasma (HsS4D) clustered as IFN-γ negative tumor immune signature and were mostly HIS-IE. The IC type in the HsS4D paired tumor tissue was predominantly myeloid, while the lymphoid compartment was higher in the low sSema4D (LsS4D). The Wnt signaling pathway was upregulated in the HsS4D group. Further analysis using the IO-360, 770 gene set, showed significant non-inflamed profile of the HsS4D tumors compared to the LsS4D. In conclusion, our data reveals an association between sSema4D and the histological inflammatory subtype.

CD4+ and CD8+ T cells in sentinel nodes exhibit distinct pattern of PD-1, CD69, and HLA-DR expression compared to tumor tissue in oral squamous cell carcinoma

Anticancer immunotherapies have revolutionized cancer management, yet the effect of systemic anti-programmed cell death protein 1 (PD-1) treatment is predominantly studied in tumor-infiltrating lymphocytes (TILs). Its impact on PD-1 expressing cells in tumor-draining lymph nodes (TDLNs) is not well understood and yet to be explored. Thus, further research aiming for better understanding of the PD-1 pathway not only in tumor tissue but also in TDLNs is warranted. In this study, we investigated the expression of PD-1, CD69, and HLA-DR on CD4+ and CD8+ T cells by flow cytometry analysis of peripheral blood mononuclear cells (PBMCs), TDLNs, and tumor samples from patients with oral squamous cell carcinoma (OSCC). Our data showed that both helper and cytotoxic T lymphocytes in OSCC tissue were highly activated and expressed high level of PD-1 (over 70% positivity). Lymphocytes in TDLNs and peripheral blood expressed significantly lower levels of PD-1 and other activation markers compared to TILs. Moreover, we demonstrated that a significant fraction of PD-1 negative TILs expressed high levels of human leukocyte antigen - DR isotype and CD69. In contrast, PD-1 negative cells in TDLNs and PBMCs scarcely expressed the aforementioned activation markers. Furthermore, we proved that patients with a high percentage of CD3+ PD-1+ cells in tumor-draining lymph nodes had significantly lower disease-free and overall survival rates (log-rank test P = .0272 and P = .0276, respectively). Taken together, we proved that flow cytometry of lymph nodes in OSCC is feasible and may be used to investigate whether PD-1 levels in TDLNs correspond with survival and potentially with response to anti-PD-1 therapy. Such knowledge may ultimately help guide anti-PD-1 treatment.

Comprehensive analysis of chronic rodent inhalation toxicity studies for methyl acrylate with attention to test conditions exceeding a maximum tolerated concentration

MA is a chemical intermediate, manufactured and processed within closed systems. While so far available subacute to chronic inhalation toxicity studies performed in compliance with OECD TG principles gave no indication of any carcinogenic potential for MA, a recent 2-year inhalation study with F344/DuCrlCrlj rats published in 2017 by the JBRC showed a statistically significant increase of squamous cell carcinoma in the nasal cavity of male rats at the highest tested concentration of 160 ppm. However, the results of the different studies in total indicate that this high concentration exceeded the MTC. As MA has a low potential for genotoxic and mutagenic activity, the increased tumour incidence can be attributed to a non-genotoxic mechanism, namely to a strong inflammatory response observed in this study. Together with mechanistic and epidemiologic data for other compounds related to nasal carcinogenesis via this mode of action, it can be concluded that the relevance of this increased tumour incidence in male rats for humans is questionable. Also, a long-term exposure to higher concentrations of MA is highly unlikely to be reached in the environment or at workplaces. Therefore, a risk for humans including cancer hazard is considered implausible.

Characteristics of B lymphocyte infiltration in HPV+ head and neck squamous cell carcinoma

Human papillomavirus (HPV) is an important etiological factor of head and neck squamous cell carcinoma (HNSCC). HPV⁺ HNSCC patients usually have a better prognosis, which probably results from the higher infiltration of B lymphocytes. This study was purposed to detect the infiltration of B lymphocyte subsets and the correlation between B lymphocyte subsets and the prognosis in HPV‐related HNSCC. In this study, 124 HPV⁺ and 513 HPV⁻ HNSCC samples were obtained from the Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA) database for transcriptomic analysis. Infiltration of B lymphocytes subsets was detected with 7 HPV⁺ HNSCC and 13 HPV⁻ HNSCC tissues through immunohistochemistry and immunofluorescence. One HPV⁻ HNSCC sample was detected with single‐cell sequencing for chemokine analysis. In the results, the infiltration of plasma cells (CD19⁺CD38⁺) and memory B cells (MS4A1⁺CD27⁺) was higher in HPV⁺ HNSCC samples. High infiltration of plasma cells and memory B cells was related to a better prognosis. High density of B lymphocytes was positively correlated with high CXCL13 production mainly from CD4⁺ T lymphocytes in HNSCC. These results indicated that a high density of plasma cells and memory B cells could predict excellent prognosis. CD4⁺ T lymphocytes might affect B lymphocytes and their subsets through the CXCL13/CXCR5 axis in HNSCC.

Neoadjuvant immunotherapy in resectable head and neck cancer: oral cavity carcinoma as a potential research model

Squamous cell carcinoma of oral cavity (OCSCC) accounts for approximately 25% of cases of head and neck squamous cell carcinoma (HNSCC). Tobacco and alcohol consumption are the main risk factors for both cancers. Surgical resection, combined with adjuvant radiotherapy or radiochemotherapy in patients with high risk of relapse, is the key element in management in the initial stages. However, despite the availability of aggressive multidisciplinary treatments, advanced resectable OCSCC carries poor prognosis; only half of the patients are disease-free 5 years after the surgery. Immunotherapy based on the use of immune checkpoint inhibitors has been proven to be effective in a wide variety of tumours, including recurrent and metastatic HNSCC. These positive results resulted in investigations into its effectiveness in earlier stages of the disease with OCSCC emerging as an interesting research model because of the accessible location of the tumours. This article reviews the potential advantages of emerging immunotherapeutic agents [mainly monoclonal antibodies against programmed cell death-1 (PD-1) immune checkpoint inhibitors] as neoadjuvant treatment for OCSCC at locoregional stages as well as the ongoing clinical trials, challenges in evaluating tumour response, and possible predictive biomarkers of response with highlights regarding the role of oral microbiota as modulators of immune response. The efficacy and safety of anti-PD-1 drugs in these patients have been proven in preliminary trials. If there is a decrease in the relapse rate and an improvement in the overall survival after surgical resection in ongoing trials, preoperative immunotherapy may be established as a treatment option for patients with early stages of the disease.

Prediction of Response in Head and Neck Tumor: Focus on Main Hot Topics in Research

Radiation therapy is a cornerstone in the treatment of head and neck cancer patients; actually, their management is based on clinical and radiological staging with all patients at the same stage treated in the same way. Recently the increasing knowledge in molecular characterization of head and neck cancer opens the way for a more tailored treatment. Patient outcomes could be improved by a personalized radiotherapy beyond technological and anatomical precision. Several tumor markers are under evaluation to understand their possible prognostic or predictive value. In this paper we discuss those markers specific for evaluate response to radiation therapy in head and neck cancer for a shift toward a biological personalization of radiotherapy.

Differences in TCR repertoire and T cell activation underlie the divergent outcomes of antitumor immune responses in tumor-eradicating versus tumor-progressing hosts

Background

Antitumor immunity is highly heterogeneous between individuals; however, underlying mechanisms remain elusive, despite their potential to improve personalized cancer immunotherapy. Head and neck squamous cell carcinomas (HNSCCs) vary significantly in immune infiltration and therapeutic responses between patients, demanding a mouse model with appropriate heterogeneity to investigate mechanistic differences.

Methods

We developed a unique HNSCC mouse model to investigate underlying mechanisms of heterogeneous antitumor immunity. This model system may provide a better control for tumor-intrinsic and host-genetic variables, thereby uncovering the contribution of the adaptive immunity to tumor eradication. We employed single-cell T-cell receptor (TCR) sequencing coupled with single-cell RNA sequencing to identify the difference in TCR repertoire of CD8 tumor-infiltrating lymphocytes (TILs) and the unique activation states linked with different TCR clonotypes.

Results

We discovered that genetically identical wild-type recipient mice responded heterogeneously to the same squamous cell carcinoma tumors orthotopically transplanted into the buccal mucosa. While tumors initially grew in 100% of recipients and most developed aggressive tumors, ~25% of recipients reproducibly eradicated tumors without intervention. Heterogeneous antitumor responses were dependent on CD8 T cells. Consistently, CD8 TILs in regressing tumors were significantly increased and more activated. Single-cell TCR-sequencing revealed that CD8 TILs from both growing and regressing tumors displayed evidence of clonal expansion compared with splenic controls. However, top TCR clonotypes and TCR specificity groups appear to be mutually exclusive between regressing and growing TILs. Furthermore, many TCRα/TCRβ sequences only occur in one recipient. By coupling single-cell transcriptomic analysis with unique TCR clonotypes, we found that top TCR clonotypes clustered in distinct activation states in regressing versus growing TILs. Intriguingly, the few TCR clonotypes shared between regressors and progressors differed greatly in their activation states, suggesting a more dominant influence from tumor microenvironment than TCR itself on T cell activation status.

Conclusions

We reveal that intrinsic differences in the TCR repertoire of TILs and their different transcriptional trajectories may underlie the heterogeneous antitumor immune responses in different hosts. We suggest that antitumor immune responses are highly individualized and different hosts employ different TCR specificities against the same tumors, which may have important implications for developing personalized cancer immunotherapy.

Biotherapeutic Antibodies for the Treatment of Head and Neck Cancer: Current Approaches and Future Considerations of Photothermal Therapies

Head and neck cancer (HNC) is a heterogeneous disease that includes a variety of tumors originating in the hypopharynx, oropharynx, lip, oral cavity, nasopharynx, or larynx. HNC is the sixth most common malignancy worldwide and affects thousands of people in terms of incidence and mortality. Various factors can trigger the development of the disease such as smoking, alcohol consumption, and repetitive viral infections. HNC is currently treated by single or multimodality approaches, which are based on surgery, radiotherapy, chemotherapy, and biotherapeutic antibodies. The latter approach will be the focus of this article. There are currently three approved antibodies against HNCs (cetuximab, nivolumab, and pembrolizumab), and 48 antibodies under development. The majority of these antibodies are of humanized (23 antibodies) or human (19 antibodies) origins, and subclass IgG1 represents a total of 32 antibodies. In addition, three antibody drug conjugates (ADCs: telisotuzumab-vedotin, indatuximab-ravtansine, and W0101) and two bispecific antibodies (GBR 1372 and ABL001) have been under development. Despite the remarkable success of antibodies in treating different tumors, success was limited in HNCs. This limitation is attributed to efficacy, resistance, and the appearance of various side effects. However, the efficacy of these antibodies could be enhanced through conjugation to gold nanoparticles (GNPs). These conjugates combine the high specificity of antibodies with unique spectral properties of GNPs to generate a treatment approach known as photothermal therapy. This approach can provide promising outcomes due to the ability of GNPs to convert light into heat, which can specifically destroy cancer cells and treat HNC in an effective manner.

Inhibition of TRPV1 by SHP-1 in nociceptive primary sensory neurons is critical in PD-L1 analgesia

Recently programmed death-ligand 1 (PD-L1) receptor PD-1 was found in dorsal root ganglion (DRG) neurons, and PD-L1 activates PD-1 to inhibit inflammatory and neuropathic pain by modulating neuronal excitability. However, the downstream signaling of PD-1 in sensory neurons remains unclear. Here, we show that PD-L1 activated Src homology 2 domain-containing tyrosine phosphatase-1 (SHP-1) to downregulate transient receptor potential vanilloid 1 (TRPV1) in DRG neurons and inhibit bone cancer pain in mice. Local injection of PD-L1 produced analgesia. PD-1 in DRG neurons colocalized with TRPV1 and SHP-1. PD-L1 induced the phosphorylation of SHP-1 in DRG TRPV1 neurons and inhibited TRPV1 currents. Loss of TRPV1 in mice abolished bone cancer–induced thermal hyperalgesia and PD-L1 analgesia. Conditioned deletion of SHP-1 in Na_V1.8⁺ neurons aggravated bone cancer pain and diminished the inhibition of PD-L1 on TRPV1 currents and pain. Together, our findings suggest that PD-L1/PD-1 signaling suppresses bone cancer pain via inhibition of TRPV1 activity. Our results also suggest that SHP-1 in sensory neurons is an endogenous pain inhibitor and delays the development of bone cancer pain via suppressing TRPV1 function.

PD-L1/PD-1 signaling suppresses TRPV1 activity and alleviates pain-like behaviors via phosphorylation of SHP-1 in nociceptive primary sensory neurons in a mouse bone cancer model.

Exploration of Feasible Immune Biomarkers for Immune Checkpoint Inhibitors in Head and Neck Squamous Cell Carcinoma Treatment in Real World Clinical Practice

Recurrent locally advanced or metastatic head and neck squamous cell carcinoma (HNSCC) is associated with dismal prognosis because of its highly invasive behavior and resistance to conventional intensive chemotherapy. The combination of targeted therapy and conventional chemotherapy has significantly improved clinical outcomes. In recent years, the development of immunotherapies, such as immune checkpoint inhibitors (ICIs), has further increased treatment responses and prolonged survival. However, the limited response rate, risk of immunotherapy-related adverse effects and high cost of immunotherapy make the identification of predictive markers to optimize treatment efficacy a critical issue. Biomarkers are biological molecules that have been widely utilized to predict treatment response to certain treatments and clinical outcomes or to detect disease. An ideal biomarker should exhibit good predictive ability, which can guide healthcare professionals to achieve optimal treatment goals and bring clinical benefit to patients. In this review, we summarized the results of recent and important studies focused on HNSCC ICI immunotherapy and discussed potential biomarkers including their strengths and limitations, aiming to gain more insight into HNSCC immunotherapy in real world clinical practice.