Immunotherapy for head and neck squamous cell carcinoma

Regulatory mechanisms of PD-1/PD-L1 in cancers

Immune evasion contributes to cancer growth and progression. Cancer cells have the ability to activate different immune checkpoint pathways that harbor immunosuppressive functions. The programmed death protein 1 (PD-1) and programmed cell death ligands (PD-Ls) are considered to be the major immune checkpoint molecules. The interaction of PD-1 and PD-L1 negatively regulates adaptive immune response mainly by inhibiting the activity of effector T cells while enhancing the function of immunosuppressive regulatory T cells (Tregs), largely contributing to the maintenance of immune homeostasis that prevents dysregulated immunity and harmful immune responses. However, cancer cells exploit the PD-1/PD-L1 axis to cause immune escape in cancer development and progression. Blockade of PD-1/PD-L1 by neutralizing antibodies restores T cells activity and enhances anti-tumor immunity, achieving remarkable success in cancer therapy. Therefore, the regulatory mechanisms of PD-1/PD-L1 in cancers have attracted an increasing attention. This article aims to provide a comprehensive review of the roles of the PD-1/PD-L1 signaling in human autoimmune diseases and cancers. We summarize all aspects of regulatory mechanisms underlying the expression and activity of PD-1 and PD-L1 in cancers, including genetic, epigenetic, post-transcriptional and post-translational regulatory mechanisms. In addition, we further summarize the progress in clinical research on the antitumor effects of targeting PD-1/PD-L1 antibodies alone and in combination with other therapeutic approaches, providing new strategies for finding new tumor markers and developing combined therapeutic approaches.

Immuno-oncology in head and neck squamous cell carcinoma - a narrative review

Immuno-oncology studies the immune system in cancer. In recent decades, immunotherapy has shown a good response to the treatment of various locally advanced and metastatic cancers. The main mechanisms of action include stimulation of the patient's own immune system to enhance immune responses acting in tumor escape pathways. This review examined the literature related to immune system mechanisms in head and neck squamous cell carcinoma (HNSCC) and their application in immunotherapy using biomarkers. The PUBMED, LILACS, MEDLINE, WHOLIS, and SCIELO databases were searched using the terms squamous cell carcinoma, head and neck, immuno-oncology, immunotherapy, and immunology. The main drugs currently available for clinical use in patients diagnosed with HNSCC include pembrolizumab and nivolumab, both classified as check-point inhibitors. These immunobiological agents improve patient survival and quality of life. Many authors and clinical trials point out that the recommendation of these agents is linked to the dose of PD-L1 (ligand expressed primarily by tumor cells), which proved to be an unreliable biomarker in the patient selection. Recommendation of immunotherapy depends on reliable biomarkers that must be identified in order to achieve good therapeutic results.

The expression pattern of Immune checkpoints after chemo/radiotherapy in the tumor microenvironment

As a disease with the highest disease-associated burden worldwide, cancer has been the main subject of a considerable proportion of medical research in recent years, intending to find more effective therapeutic approaches with fewer side effects. Combining conventional methods with newer biologically based treatments such as immunotherapy can be a promising approach to treating different tumors. The concept of "cancer immunoediting" that occurs in the field of the tumor microenvironment (TME) is the aspect of cancer therapy that has not been at the center of attention. One group of the role players of the so-called immunoediting process are the immune checkpoint molecules that exert either co-stimulatory or co-inhibitory effects in the anti-tumor immunity of the host. It involves alterations in a wide variety of immunologic pathways. Recent studies have proven that conventional cancer therapies, such as chemotherapy, radiotherapy, or a combination of them, i.e., chemoradiotherapy, alter the "immune compartment" of the TME. The mentioned changes encompass a wide range of variations, including the changes in the density and immunologic type of the tumor-infiltrating lymphocytes (TILs) and the alterations in the expression patterns of the different immune checkpoints. These rearrangements can have either anti-tumor immunity empowering or immune attenuating sequels. Thus, recognizing the consequences of various chemo(radio)therapeutic regimens in the TME seems to be of great significance in the evolution of therapeutic approaches. Therefore, the present review intends to summarize how chemo(radio)therapy affects the TME and specifically some of the most important, well-known immune checkpoints' expressions according to the recent studies in this field.

Myeloid-Derived Suppressor Cells in Solid Tumors

Myeloid-derived suppressor cells (MDSCs) are one of the main suppressive cell population of the immune system. They play a pivotal role in the establishment of the tumor microenvironment (TME). In the context of cancers or other pathological conditions, MDSCs can differentiate, expand, and migrate in large quantities during circulation, inhibiting the cytotoxic functions of T cells and NK cells. This process is regulated by ROS, iNOS/NO, arginase-1, and multiple soluble cytokines. The definition of MDSCs and their phenotypes in humans are not as well represented as in other organisms such as mice, owing to the absence of the cognate molecule. However, a comprehensive understanding of the differences between different species and subsets will be beneficial for clarifying the immunosuppressive properties and potential clinical values of these cells during tumor progression. Recently, experimental evidence and clinical investigations have demonstrated that MDSCs have a close relationship with poor prognosis and drug resistance, which is considered to be a leading marker for practical applications and therapeutic methods. In this review, we summarize the remarkable position of MDSCs in solid tumors, explain their classifications in different models, and introduce new treatment approaches to target MDSCs to better understand the advancement of new approaches to cancer treatment.

Expression and clinicopathological significance of Foxp3 and VISTA in cervical cancer

OBJECTIVE

To detect the expression differences of Foxp3 and VISTA in chronic cervical inflammation, cervical intraepithelial neoplasia, and cervical cancer, and to explore the role of Foxp3 and VISTA in the development of cervical cancer and the effect of Foxp3 and VISTA on the prognosis of cervical cancer, to provide a theoretical basis for clinical immunotherapy of cervical cancer.

METHODS

We collected 130 paraffin specimens of cervical tissue, which included 70 cases of cervical cancer tissue, 40 cases of cervical intraepithelial neoplasia tissues and 20 cases of chronic cervicitis. The expression of Foxp3 and VISTA in each group was detected, and the study was conducted based on the clinicopathological characteristics of the patients. The patients were followed up and the prognosis was statistically analyzed.

RESULT

1. The expression of Foxp3 and VISTA was statistically different between the cervical cancer group and other groups. 2. Expressions of Foxp3 and VISTA were significantly correlated. 3. In 70 cases of cervical cancer, the expression of Foxp3 and VISTA was related to the clinical stage. 4. The 3-year survival rate of 70 patients with cervical cancer was 72.9%, and there were no factors affecting 3-year OS found. The expression of Foxp3 and VISTA was significantly correlated with the prognosis of cervical cancer. Foxp3 and VISTA double positive expression group had the worst prognosis.

CONCLUSION

1. In cervical cancer, the expression of Foxp3 and VISTA was significantly higher than that of cervical intraepithelial neoplasia and chronic cervicitis, which suggested that they were closely related to the occurrence and growth of cervical cancer. 2. The expression of Foxp3 and VISTA was significantly related. 3. The positive expression of Foxp3 and VISTA could be used as independent prognostic factors for cervical cancer prognosis providing a strong basis for cervical cancer immunotherapy.

A Case of Metastatic Pancreatic Adenocarcinoma in Complete Remission Using Chemotherapy and Immunotherapy

Among the various types of cancer, pancreatic cancer is considered to have a particularly grim prognosis. Treatment includes surgery, chemotherapy, or both. While the role of immunotherapy is well-studied in many types of cancer, such is not the case with pancreatic cancer.

A 49-year-old female presented to the oncology clinic following a biopsy of a pancreatic mass. CT-guided needle biopsy of the mass demonstrated moderately differentiated pancreatic adenocarcinoma. Positive emission tomography-computed tomography (PET-CT) revealed metastases to the liver. She was started on chemotherapy with FOLFIRINOX (leucovorin calcium, 5-fluorouracil, irinotecan hydrochloride, oxaliplatin) and demonstrated over 60% reduction in the size of liver metastases within three months. PET-CT four months after initiation of chemotherapy revealed no focal avid fluorodeoxyglucose (FDG) uptake in the liver, and the pancreatic body mass was stable in size at 3.0 cm with stable standardized uptake value (SUV) max at 2.4, only slightly elevated from 1.9 on the previous scan. Further treatment with chemotherapy was halted after 18 cycles due to side effects. With the patient’s tumor being epidermal growth factor receptor (EGFR) negative, mismatch repair (MMR) negative, 3% tumor cells PD-L1 positive with 10% tumor-associated immune cells positive, treatment with pembrolizumab was started. Follow-up PET-CTs over the next several months confirmed the patient was in complete remission from metastatic pancreatic cancer. At the time of the report, the patient had a durable response of three years.

We report a rare case of complete remission of metastatic pancreatic adenocarcinoma treated with chemotherapy, followed by immunotherapy. With emerging targets for modification of tumor microenvironment, immunotherapy must be further explored in the treatment of pancreatic cancer.

Immune Checkpoints and CAR-T Cells: The Pioneers in Future Cancer Therapies?

Although the ever-increasing number of cancer patients pose substantial challenges worldwide, finding a treatment with the highest response rate and the lowest number of side effects is still undergoing research. Compared to chemotherapy, the relatively low side effects of cancer immunotherapy have provided ample opportunity for immunotherapy to become a promising approach for patients with malignancy. However, the clinical translation of immune-based therapies requires robust anti-tumoral immune responses. Immune checkpoints have substantial roles in the induction of an immunosuppressive tumor microenvironment and tolerance against tumor antigens. Identifying and targeting these inhibitory axes, which can be established between tumor cells and tumor-infiltrating lymphocytes, can facilitate the development of anti-tumoral immune responses. Bispecific T-cell engagers, which can attract lymphocytes to the tumor microenvironment, have also paved the road for immunological-based tumor elimination. The development of CAR-T cells and their gene editing have brought ample opportunity to recognize tumor antigens, independent from immune checkpoints and the major histocompatibility complex (MHC). Indeed, there have been remarkable advances in developing various CAR-T cells to target tumoral cells. Knockout of immune checkpoints via gene editing in CAR-T cells might be designated for a breakthrough for patients with malignancy. In the midst of this fast progress in cancer immunotherapies, there is a need to provide up-to-date information regarding immune checkpoints, bispecific T-cell engagers, and CAR-T cells. Therefore, this review aims to provide recent findings of immune checkpoints, bispecific T-cell engagers, and CAR-T cells in cancer immunotherapy and discuss the pertained clinical trials.

ERH overexpression is associated with decreased cell migration and invasion and a good prognosis in gastric cancer

Background

The enhancer of rudimentary homolog (ERH) protein is implicated in transcriptional regulation, cell cycle progression, and malignancy. We previously conducted a proteomics analysis using gastric cancer (GC) tissues and identified ERH as a biomarker candidate. The aim of this study was to investigate whether ERH may be useful as a prognostic marker for GC.

Methods

Surgically resected GC tissue specimens were obtained from 327 patients who underwent gastrectomy at Gyeongsang National University Hospital. Immunohistochemistry (IHC) was used to validate ERH as a prognostic marker in these tissues. SNU601 and MKN74 cells with siRNA-mediated knockdown of ERH expression and ERH-overexpressing SNU601 and MKN74 knock-in cells were used for analysis of ERH function.

Results

ERH was overexpressed in stomach cancer tissues compared with normal tissues according to proteomics analysis (n=29, P<0.01) of patient samples. Based on IHC, patients with tumors overexpressing ERH had lower T stage and lower TNM stage classifications, lower cancer recurrence rates and longer survival times than did patients with tumors showing low expression of ERH (P=0.04). In vitro, forced expression of ERH significantly decreased GC cell migration and invasion, and depletion of ERH triggered GC cell migration and invasion but had no effect on proliferation in vitro.

Conclusions

The findings from the present study show that ERH is associated with decreased cancer cell migration and invasion, suggesting that overexpression of ERH may serve as a marker of good prognosis for patients with GC.

Sensitization of head and neck squamous cell carcinoma to apoptosis by combinational SMAC mimetic and Fas ligand-Fc treatment in vitro

This study aimed to investigate the in vitro efficacy of three different SMAC mimetics for pro-apoptotic sensitization of HNSCC cells. We evaluated BV-6 in comparison to Birinapant and LCL161, for which pro-apoptotic sensitization effects have been demonstrated. Concentration-dependent response was measured for BV-6 in each cell line with an average IC₅₀ value 8-fold lower than of aforementioned SMAC mimetics. Combination treatment of FasL (log2) and BV-6 (IC₁₀) showed highly significant cell count reductions even in the lowest applied concentration in five cell lines (PCI-1: p = 0.0002, PCI-13: p = 0.0002, Detroit 562: p: p < 0.0001, FaDu: p < 0.0001, SCC-25: p = 0.0047). Synergistic effects (y < 1) were evident in eight out of 10 cell lines (PCI-1, PCI-9, PCI-13, PCI-68, Detroit 562, FaDu, SCC-25 and HaCaT). Annexin V assays revealed in nine cell lines very highly significant (p < 0.001) pro-apoptotic effects of BV-6. Western blots showed a heterogeneous IAP expression following SMAC mimetic treatment. Except for two cell lines, at least the cellular inhibitor of apoptosis protein 1 (cIAP1) was degraded in response to BV-6. For prospective targeted HNSCC therapy, this study identifies SMAC mimetics, particularly BV-6 as the compound with the highest pro-apoptotic potency, as promising antitumor agents.

Novel immune checkpoint targets: moving beyond PD-1 and CTLA-4

The emergence of immune checkpoint inhibitors (ICIs), mainly including anti-programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) and anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) monoclonal antibodies (mAbs), has shaped therapeutic landscape of some type of cancers. Despite some ICIs have manifested compelling clinical effectiveness in certain tumor types, the majority of patients still showed de novo or adaptive resistance. At present, the overall efficiency of immune checkpoint therapy remains unsatisfactory. Exploring additional immune checkpoint molecules is a hot research topic. Recent studies have identified several new immune checkpoint targets, like lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin and mucin-domain containing-3 (TIM-3), T cell immunoglobulin and ITIM domain (TIGIT), V-domain Ig suppressor of T cell activation (VISTA), and so on. The investigations about these molecules have generated promising results in preclinical studies and/or clinical trials. In this review, we discussed the structure and expression of these newly-characterized immune checkpoints molecules, presented the current progress and understanding of them. Moreover, we summarized the clinical data pertinent to these recent immune checkpoint molecules as well as their application prospects.

Treatment of a stage III rima glottidis patient with the oncolytic virus Rigvir: A retrospective case report

RATIONALE

Of all the parts of the larynx, the glottis has the highest frequency of cancer. With disease progression, the vocal cord movement is affected and for advanced stages its anatomical and functional preservation is rarely achievable, if at all.

PATIENT CONCERNS

Here we describe a 72-year-old patient who presented with hoarseness for a year and was only able to whisper.

DIAGNOSIS

A computed tomography (CT) scan of the vocal cords (without contrast) showed higher density tissue. Histological examination disclosed a well-differentiated verrucous squamous cell carcinoma of the glottis.

INTERVENTIONS

The patient was treated with the oncolytic ECHO-7 virus Rigvir without any of the standard treatments.

OUTCOMES

As shown by CT scans, the patient has been stabilized, and the laryngeal functions are preserved with the virotherapy still ongoing. The patient was diagnosed over 4.2 years ago.

LESSONS

Considering the present patient being treated with Rigvir without any standard treatment, the results suggest that Rigvir therapy could be a possible treatment for glottic cancer.

Cancer drug development: The missing links

IMPACT STATEMENT

The success rate for cancer drugs which enter into phase 1 clinical trials is utterly less. Why the vast majority of drugs fail is not understood but suggests that pre-clinical studies are not adequate for human diseases. In 1975, as per the Tufts Center for the Study of Drug Development, pharmaceutical industries expended 100 million dollars for research and development of the average FDA approved drug. By 2005, this figure had more than quadrupled, to $1.3 billion. In order to recover their high and risky investment cost, pharmaceutical companies charge more for their products. However, there exists no correlation between drug development cost and actual sale of the drug. This high drug development cost could be due to the reason that all patients might not respond to the drug. Hence, a given drug has to be tested in large number of patients to show drug benefits and obtain significant results.

Machine Learning Identifies Stemness Features Associated with Oncogenic Dedifferentiation

Cancer progression involves the gradual loss of a differentiated phenotype and acquisition of progenitor and stem-cell-like features. Here, we provide novel stemness indices for assessing the degree of oncogenic dedifferentiation. We used an innovative one-class logistic regression (OCLR) machine-learning algorithm to extract transcriptomic and epigenetic feature sets derived from non-transformed pluripotent stem cells and their differentiated progeny. Using OCLR, we were able to identify previously undiscovered biological mechanisms associated with the dedifferentiated oncogenic state. Analyses of the tumor microenvironment revealed unanticipated correlation of cancer stemness with immune checkpoint expression and infiltrating immune cells. We found that the dedifferentiated oncogenic phenotype was generally most prominent in metastatic tumors. Application of our stemness indices to single-cell data revealed patterns of intra-tumor molecular heterogeneity. Finally, the indices allowed for the identification of novel targets and possible targeted therapies aimed at tumor differentiation.

Monoclonal Antibodies for the Treatment of Multiple Myeloma: An Update

The past two decades have seen a revolution in multiple myeloma (MM) therapy with the introduction of several small molecules, mostly orally effective, whose mechanisms are based on proteasome inhibition, histone deacetylase (HDAC) blockade, and immunomodulation. Immunotherapeutic approaches to MM treatment using monoclonal antibodies (mAbs), while long in development, began to reap success with the identification of CD38 and SLAMF7 as suitable targets for development, culminating in the 2015 Food and Drug Administration (FDA) approval of daratumumab and elotuzumab, respectively. This review highlights additional mAbs now in the developmental pipeline. Isatuximab, another anti-CD38 mAb, currently is under study in four phase III trials and may offer certain advantages over daratumumab. Several antibody-drug conjugates (ADCs) in the early stages of development are described, including JNJ-63723283, which has attained FDA breakthrough status for MM. Other mAbs described in this review include denosumab, recently approved for myeloma-associated bone loss, and checkpoint inhibitors, although the future status of the latter combined with immunomodulators has been clouded by unacceptably high death rates that caused the FDA to issue clinical holds on several of these trials. Also highlighted are the therapies based on the B Cell Maturation Antigen (BCMA), another very promising target for anti-myeloma development.

The Role of Immunotherapy and Radiation Therapy in Tumor Chemosensitivity in Advanced Head and Neck Cancer

BACKGROUND Cancer is the second leading cause of death internationally, resulting in millions of deaths each year. While treatment in the past has heavily relied on surgery and radiotherapy, chemotherapy and immunotherapy are being increasingly utilized depending on disease presentation. CASE REPORT A 56-year-old male presented to the Emergency Department with a 3-week history of a rapidly enlarging left supraclavicular neck mass. Computed tomography scan revealed a 12×13 cm mass extending from the angle of the mandible to the supraclavicular area. A biopsy confirmed advanced stage squamous cell carcinoma of the head and neck. The patient was started on a chemotherapy regimen of docetaxel, cisplatin, and 5-fluorouracil (TCF). The tumor progressed through chemotherapy, which was switched to cetuximab; however, this therapy was discontinued after an anaphylactic reaction. Palliative radiation treatment was begun along with pembrolizumab. Pembrolizumab was continued, and after 9 cycles, the patient's cancer was almost in complete remission. Three months later, disease progression was once again noted with pembrolizumab treatment, which was subsequently discontinued. The patient was started on paclitaxel and carboplatin chemotherapy regimen as a last resort, despite failure of prior TCF treatment, and the patient responded, this time with complete remission in 4 months. CONCLUSIONS This case demonstrates a unique outcome in which a patient who previously was resistant to chemotherapy, later responded to chemotherapy after a trial of radiation therapy and immunotherapy. Immunotherapy may have a synergistic effect with radiation therapy and play a role in tumor sensitivity to chemotherapy in head and neck cancer treatment.

Three distinct genomic subtypes of head and neck squamous cell carcinoma associated with clinical outcomes

OBJECTIVES

Heterogeneity of head and neck squamous cell carcinomas (HNSCCs) results in unpredictable outcomes for patients with similar stages of cancer. Beyond the role of human papilloma virus (HPV), no validated molecular marker of HNSCCs has been established. Thus, clinically relevant molecular subtypes are needed to optimize HNSCC therapy. The purpose of this study was to identify subtypes of HNSCC that have distinct biological characteristics associated with clinical outcomes and to characterize genomic alterations that best reflect the biological and clinical characteristics of each subtype.

MATERIALS AND METHODS

We analyzed gene expression profiling data from pan-SCC tissues including cervical SCC, esophageal SCC, lung SCC, and HNSCC (n = 1346) to assess the similarities and differences among SCCs and to identify molecular subtypes of HNSCC associated with prognosis. Subtype-specific gene expression signatures were identified and used to construct predictive models. The association of the subtypes with prognosis was validated in two independent cohorts of patients.

RESULTS

Pan-SCC analysis identified three novel subtypes of HNSCC. Subtype 1 had the best prognosis and was similar to cervical SCC, whereas subtype 3 had the worst prognosis and was similar to lung SCC. Subtype 2 had a moderate prognosis. The 600-gene signature associated with the three subtypes significantly predicted prognosis in two independent validation cohorts. These three subtypes also were associated with potential benefit of immunotherapy.

CONCLUSION

We identified three clinically relevant HNSCC molecular subtypes. Independent prospective studies to assess the clinical utility of the subtypes and associated gene signature are warranted.

Is pulmonary metastasectomy beneficial in head and neck squamous cell carcinoma? A review of literature

Metastatic head and neck squamous cell carcinoma (HNSCC) has traditionally carried a dismal prognosis; however with advances in care, it has been shown that pulmonary metastasectomy is a viable therapeutic option in selected patients, palliating symptoms and improving survival. With the increasing incidence of human papilloma virus-related HNSCC and better availability of minimal access surgery, there is a need to better understand the role of pulmonary metastasectomy in the treatment of HNSCC. This article summarizes the literature on indications, results, surgical options and approaches, clinical dilemmas, and controversies associated with pulmonary metastasectomy in HNSCC, to identify suitable candidates and optimize outcomes.

lncRNA in HNSCC: challenges and potential

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cause of cancer mortality in the world. Some progress has been made in the therapy of HNSCC, however treatment remains unsatisfactory. Recent studies have shown that different types of long non-coding RNAs (lncRNAs) are dysregulated in HNSCC and correlate with tumor progression, lymph node metastasis, clinical stage and poor prognosis. lncRNAs are a class of functional RNA molecules that can not be translated into proteins but can modulate the activity of transcription factors or regulate changes in chromatin structure. The lncRNAs might have potential of biomarker in HNSCC diagnosis, prognosis, prediction and targeted treatment. In this review we describe the potential role of lncRNAs as new biomarkers and discuss their features including source of origin, extraction methods, stability, detection methods and data normalization and potential function as biomarkers in HNSCC.

Blockade of PD-1 effectively inhibits in vivo malignant transformation of oral mucosa

Curbing PD-1 immunosuppressive signaling represents an effective immune awakening or immune-reactivation approach for tumor eradication for many cancers. Yet, the potential involvement of this critical PD-1 immunosuppressive signaling in de novo malignant transformation of epithelial cells to pre-cancerous or cancerous lesions is largely unknown. In this study, we demonstrate that PD-1 signaling is critically involved in de novo malignant transformation of oral mucosa upon carcinogen exposure in vivo. Our findings revealed that 4NQO-treated mice had almost double the numbers of PD-1-positive CD4⁺ cells and PD-1-positive CD8⁺ cells in peripheral blood lymphocytes as well as elevated PD-1 expression in tumor infiltrating lymphocytes (when compared to that of control-treated mice), strongly supportive of a general immune-suppression induced by carcinogen challenges in vivo. Importantly, inhibition of PD-1 signaling during the carcinogenesis process (immediately after 4NQO challenge) significantly reduced and delayed de novo formation of both pre-cancerous and cancerous lesions in vivo, in conjunction with effective PD-1 down-modulation in the tumor infiltrating leukocyte and peripheral lymph organs. Lastly, reduction of carcinogen-induced lesions upon PD-1 mAb treatment in vivo was accompanied by reduction of potent immunosuppressive myeloid-derived suppressor cells (MDSCs), and increase in "activated" T cell accumulations in the lesion-microenvironment (127% increase) and peripheral lymph nodes (25% increase). These data support PD-1 blockade as a new approach to enhance the efficacy of T-cell immunotherapy and reduce canceration rate in premalignant lesions.

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

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

Hepatocyte Growth Factor/c-Met Signaling in Head and Neck Cancer and Implications for Treatment

Aberrant signaling of the hepatocyte growth factor (HGF)/c-Met pathway has been identified as a promoter of tumorigenesis in several tumor types including head and neck squamous cell carcinoma (HNSCC). Despite a relatively low c-Met mutation frequency, overexpression of HGF and its receptor c-Met has been observed in more than 80% of HNSCC tumors, with preclinical and clinical studies linking overexpression with cellular proliferation, invasion, migration, and poor prognosis. c-Met is activated by HGF through a paracrine mechanism to promote cellular morphogenesis enabling cells to acquire mesenchymal phenotypes in part through the epithelial-mesenchymal transition, contributing to metastasis. The HGF/c-Met pathway may also act as a resistance mechanism against epidermal growth factor receptor (EGFR) inhibition in advanced HNSCC. Furthermore, with the identification of a biologically distinct subset of HNSCC tumors acquired from human papillomavirus (HPV) infection that generally portends a good prognosis, high expression of HGF or c-Met in HPV-negative tumors has been associated with worse prognosis. Dysregulated HGF/c-Met signaling results in an aggressive HNSCC phenotype which has led to clinical investigations for targeted inhibition of this pathway. In this review, HGF/c-Met signaling, pathway alterations, associations with clinical outcomes, and preclinical and clinical therapeutic strategies for targeting HGF/c-Met signaling in HNSCC are discussed.

Application of the Immunoscore as prognostic tool for hepatocellular carcinoma

To date, the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) tumor, nodes, metastasis (TNM) classification represents the standard system for evaluation of prognosis in solid tumors. However, the clinical outcome can be significantly different in patients with the same TNM stage. Therefore, many efforts have been made aiming to define new prognostic parameters.

Indeed, analyses conducted in large cohorts of colorectal cancer patients emphasized the prognostic value of tumor-infiltrating lymphocytes, leading to the development of a prognostic score referred to as “Immunoscore”.

In this commentary, we recapitulate the study by Gabrielson and colleagues, recently published in Cancer Immunology Research, addressing the role of intratumoral CD3⁺ and CD8⁺ T cells as well as as prognostic markers for hepatocellular carcinoma.

The authors demonstrate that Immunoscore represents a valuable prognostic marker in patients with hepatocellular carcinoma who have undergone primary tumor resection, supporting its application in a tumor setting other than colorectal cancer.