How patients with an intact immune system develop head and neck cancer

A comprehensive and longitudinal evaluation of the different populations of lymphoid and myeloid cells in the peripheral blood of patients treated with chemoradiotherapy for head and neck cancer

BACKGROUND

Immunotherapy provided significant survival benefits for recurrent and metastatic patients with head and neck cancer. These improvements could not be reproduced in patients treated with curative-intent chemoradiotherapy (CRT) and the optimal radio-immunotherapy (RIT) concepts have yet to be designed. Exploration and analysis of the pre-therapeutic immune status of these patients and the changes occurring during the treatment course could be crucial in rationally designing future combined treatments.

METHODS

Blood samples were collected from a cohort of 25 head and neck cancer patients treated with curative-intended (C)-RT prior to therapy, after the first week of treatment, and three months after treatment completion. Peripheral blood mononuclear cells (PBMCs) or all nucleated blood cells were isolated and analyzed via flow cytometry.

RESULTS

At baseline, patients showed reduced monocyte and lymphocyte counts compared to healthy individuals. Although overall CD8+ T-cell frequencies were reduced, the proportion of memory subsets were increased in patients. Radiotherapy (RT) treatment led to a further increase in CD8+ effector memory T-cells. Among myeloid populations, tumor-promoting subsets became less abundant after RT, in favor of pro-inflammatory cells.

CONCLUSION

The present study prospectively demonstrated a complex interplay and distinct longitudinal changes in the composition of lymphocytic and myeloid populations during curative (C)-RT of head and neck cancer. Further validation of this method in a larger cohort could allow for better treatment guidance and tailored incorporation of immunotherapies (IT) in the future.

Immune escape of head and neck cancer mediated by the impaired MHC-I antigen presentation pathway

Tumor immune evasion is a hallmark of Head and Neck Cancers. The advent of immune checkpoint inhibitors (ICIs) in the first-line setting has transformed the management of these tumors. Unfortunately, the response rate of Head and Neck Squamous Cell Carcinomas (HNSCC) to ICIs is below 15%, regardless of the human papillomavirus (HPV) status, which might be partially related with impaired antigen presentation machinery (APM). Mechanistically, HNSCC cells are usually defective in the expression of MHC-I associated APM, while this transcriptional pathway is critical for the activation of tumor-killing effector T-cells. To specifically illuminate the phenomenon and seek for therapeutic strategies, this review summarizes the most recently identified role of genetic and functional dysregulation of the MHC-I pathway, specifically through changes at the genetic, epigenetic, post-transcriptional, and post-translational levels, which substantially contributes to HNSCC immune escape and ICI resistance. Several treatment modalities can be potentially exploited to restore APM signaling in tumors, which improves anti-tumor immunity through the activation of interferons, vaccines or rimantadine against HPV and the inhibition of EGFR, SHP-2, PI3K and MEK. Additionally, the combinatorial use of radiotherapy or cytotoxic agents with ICIs can synergize to potentiate APM signaling. Future directions would include further dissection of MHC-I related APM signaling in HNSCC and whether reversing this inhibition in combination with ICIs would elicit a more robust immune response leading to improved response rates in HNSCC. Therapeutic approaches to restore the MHC-I antigen presentation machinery in Head and Neck Cancer. (Red color texts represent the according strategies and the outcomes).

Immune Escape Strategies in Head and Neck Cancer: Evade, Resist, Inhibit, Recruit

Head and neck cancers (HNCs) arise from the mucosal lining of the aerodigestive tract and are often associated with alcohol use, tobacco use, and/or human papillomavirus (HPV) infection. Over 600,000 new cases of HNC are diagnosed each year, making it the sixth most common cancer worldwide. Historically, treatments have included surgery, radiation, and chemotherapy, and while these treatments are still the backbone of current therapy, several immunotherapies have recently been approved by the Food and Drug Administration (FDA) for use in HNC. The role of the immune system in tumorigenesis and cancer progression has been explored since the early 20th century, eventually coalescing into the current three-phase model of cancer immunoediting. During each of the three phases-elimination, equilibrium, and escape-cancer cells develop and utilize multiple strategies to either reach or remain in the final phase, escape, at which point the tumor is able to grow and metastasize with little to no detrimental interference from the immune system. In this review, we summarize the many strategies used by HNC to escape the immune system, which include ways to evade immune detection, resist immune cell attacks, inhibit immune cell functions, and recruit pro-tumor immune cells.

Decoding the influence of the immune system and immunotherapy targets on carcinomas: A hidden prism in oral cancer therapy

In recent decades, understanding tumorigenesis and the complex interaction between the host and the immune system has been the pillar for significant advances in anticancer therapy. Conventional anticancer therapy (e.g., cut, burn, and cytotoxic drugs) involves multiple targeting of tumor cells. However, the tumor tissue microenvironment can present a dysregulated, stimulating, or subverted immune response which, in turn, reveals pro-tumor activities favoring tumor expansion and progression. Recently, new potential targets have been identified based on immunomodulatory therapies, which are crafted to re-establish the host anti-tumoral immune response. Clinicians should fully understand the intricate interactions between carcinogens, the tumor milieu, the immune system, and traditional anticancer therapies in order to progress and to overcome the refractory/recurrent challenges and morbidity of the disease. Thus, in this article, we highlight the complex milieu of the oral cancer immune response, pointing out potential therapeutic immunotargets for oral squamous cell carcinomas. The impact of traditional anticancer therapy on the immune system is also outlined.

Oxidative Stress in Cancer Immunotherapy: Molecular Mechanisms and Potential Applications

Immunotherapy is an effective treatment option that revolutionizes the management of various cancers. Nevertheless, only a subset of patients receiving immunotherapy exhibit durable responses. Recently, numerous studies have shown that oxidative stress induced by reactive oxygen species (ROS) plays essential regulatory roles in the tumor immune response, thus regulating immunotherapeutic effects. Specifically, studies have revealed key roles of ROS in promoting the release of tumor-associated antigens, manipulating antigen presentation and recognition, regulating immune cell phenotypic differentiation, increasing immune cell tumor infiltration, preventing immune escape and diminishing immune suppression. In the present study, we briefly summarize the main classes of cancer immunotherapeutic strategies and discuss the interplay between oxidative stress and anticancer immunity, with an emphasis on the molecular mechanisms underlying the oxidative stress-regulated treatment response to cancer immunotherapy. Moreover, we highlight the therapeutic opportunities of manipulating oxidative stress to improve the antitumor immune response, which may improve the clinical outcome.

Comprehensive gene cluster analysis of head and neck squamous cell carcinoma TCGA RNA-seq data defines B cell immunity-related genes as a robust survival predictor

BACKGROUND

The authors aimed to define novel gene expression signatures that are associated with patients' survival with head and neck squamous cell carcinoma (HNSCC).

METHODS

TCGA RNA-seq data were used for gene expression clusters extraction from 499 tumor samples by the "EPIG" method. Tumor samples were then partitioned into lower and higher than median level groups for survival relevant analysis by Kaplan-Meier estimator.

RESULTS

We found that two gene clusters (_1, _2) are favorably, while two (_3, _4) are unfavorably, associated with patients' survival with HNSCC. Notably, most genes on the top lists of cluster_2 are associated with B cells. A gene expression signature with combined genes from cluster_2 and _4 was further determined to be associated with HNSCC survival rate.

CONCLUSION

Our work strongly supported a favorable role of B cells in patients' survival with HNSCC and identified a novel coexpressed gene signature as prognostic biomarker for patients' survival with HNSCC estimation.

Expression level of PD-L1 is involved in ALDH1A1-mediated poor prognosis in patients with head and neck squamous cell carcinoma

OBJECTIVE

To evaluate the expression levels of ALDH1A1, PDL1, and PDL2 in head and neck squamous cell carcinoma (HNSCC) patients, and explore their clinical relevance in prognosis of patients with HNSCC.

METHODS

Immunohistochemistry of ALDH1A1 and PD-L1/PD-L2 in 85 primary HNSCC patients was carried out. The expression level of PD-L2 was assessed with the modified Moratin's immune response scoring (IRS) system. tumor proportion score (TPS) was defined as the percentage of viable tumor cells showing partial or complete membrane staining at any intensity. The chi-square test and Fisher's exact test were used to analyze the associations between ALDH1A1 expression and clinicopathological features. The Spearman's correlation was applied to analyze the correlation of ALDH1A1 expression with PD-L1/PD-L2 expression.

RESULTS

kaplan-Meier analysis showed that the expression levels of ALDH1A1 and PD-L1/PD-L2 were inversely associated with recurrence-free survival (RFS; P = 0.001, 0.014, and 0.023, respectively). Moreover, expression levels of ALDH1A1 and PD-L1 were correlated with poor overall survival (OS; P = 0.002 and 0.039, respectively). Furthermore, multivariate logistics regression analyses demonstrated that expression level of ALDH1A1 was independently associated with shorter RFS (P = 0.013) and poorer OS (P = 0.014) in HNSCC patients, and the expression level of PD-L2 was only negatively associated with RFS (P = 0.041), rather than PD-L1. Spearman's correlation analysis unveiled that expression levels of PD-L1 and PD-L2 were positively correlated with ALDH1A1 expression in HNSCC patients (P = 0.000 and 0.015, respectively). Especially, the patients with expression levels of ALDH1A1 and PD-L1 had the worst prognosis.

CONCLUSIONS

Our results indicated that ALDH1A1 is an independent prognostic factor in patients with HNSCC, and the expression level of PDL-1 may be involved in ALDH1A1-mediated poor prognosis in patients with HNSCC.

Tumor control via targeting PD-L1 with chimeric antigen receptor modified NK cells

Failed T cell-based immunotherapies in the presence of genomic alterations in antigen presentations pathways may be overcome by NK cell-based immunotherapy. This approach may still be limited by the presence of immunosuppressive myeloid populations. Here, we demonstrate that NK cells (haNKs) engineered to express a PD-L1 chimeric antigen receptor (CAR) haNKs killed a panel of human and murine head and neck cancer cells at low effector-to-target ratios in a PD-L1-dependent fashion. Treatment of syngeneic tumors resulted in CD8 and PD-L1-dependent tumor rejection or growth inhibition and a reduction in myeloid cells endogenously expressing high levels of PD-L1. Treatment of xenograft tumors resulted in PD-L1-dependent tumor growth inhibition. PD-L1 CAR haNKs reduced levels of macrophages and other myeloid cells endogenously expressing high PD-L1 in peripheral blood from patients with head and neck cancer. The clinical study of PD-L1 CAR haNKs is warranted.

Mechanisms of resistance to T cell-based immunotherapy in head and neck cancer

BACKGROUND

Most current approved or investigational immunotherapeutic approaches for head and neck squamous cell carcinoma are aimed at activating T cells. The majority of patients receiving such immunotherapy do not demonstrate durable tumor remission.

METHODS

Original articles covering tumor heterogeneity, immunoediting, immune escape, and local tumor immunosuppression were reviewed.

RESULTS

In the face of immune pressure, subclones susceptible to T cell killing are eliminated, leaving behind resistant tumor clones in a process known as immunoediting. Such subclones of tumor cells that are resistant to T cell killing may remain sensitive to natural killer (NK) cell detection and elimination, suggesting that patients harboring such tumors may benefit from combination of T and NK cell-based immunotherapy. Even in the setting of optimal immunotherapy, the immunosuppressive tumor microenvironment may arrogate effector immune responses through a number of distinct mechanisms.

CONCLUSIONS

Highly effective immunotherapy will likely require multimodality approaches targeting independent mechanisms of immune activation.

Impact of HPV Infection on the Immune System in Oropharyngeal and Non-Oropharyngeal Squamous Cell Carcinoma: A Systematic Review

Objectives: To review the current knowledge regarding the involvement of human papilloma virus (HPV) infection and the immune system in the development of head and neck squamous cell carcinoma (HNSCC). Methods: An electronic literature search was conducted to identify articles published between 1990 and 2019 pertaining to tumor-infiltrating immune cells (TICs) in HNSCC using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Issues of clinical relevance, including tumor location, the number of tumor samples, the inclusion of additional specimens (dysplastic or normal mucosa), tumor size, methods used for HPV detection, relationship between antigen expression and patient characteristics (age, gender, smoking, alcohol consumption, etc.), and prognostic data (overall survival (OS) and recurrence-free survival (RFS)) were assessed by four blinded investigators. Results: The search identified 335 relevant studies, of which 41 met the inclusion criteria. Of these, 7 studies focused on the peripheral blood immune cell concentration in patients with HNSCC according to HPV status, and 36 studies investigated TICs in the intraepithelial and/or stromal compartment(s) according to HPV status. The immune cells studied were CD8+ T cells (N = 19), CD4+ T cells (N = 7), regulatory T cells (Tregs, N = 15), macrophages (N = 13), myeloid-derived suppressor cells (MDSCs, N = 4), and Langerhans cells (LCs, N = 2). Conclusions: Irrespective of tumor location, CD8+ and CD4+ T cells appear to play a key role in the development of HPV−related HNSCC, and their infiltration is likely associated with a significant impact on OS and RFS. To date, the roles and prognostic value of Tregs, macrophages, DCs and MDSCs remain unclear.