Immunological treatment options for locoregionally advanced head and neck squamous cell carcinoma

The cancer-testis antigen, sperm protein 17, a new biomarker and immunological target in head and neck squamous cell carcinoma

Head and Neck Squamous Cell Carcinoma is a deadly and locally aggressive malignancy that frequently portends a poor prognosis. Since current treatment modalities including surgery, chemotherapy and radiation are heavily debilitating and often result in recurrence intense efforts have been put into the development of novel less toxic and more lasting treatment strategies. Recently, immunotherapy has been proposed as a promising alternative that could potentially meet these requirements.

SP17 is a validated cancer-testis antigen in multiple myeloma, ovarian cancer and non-small cell lung cancer. We aim at studying SP17 expression in HNSCC and its immunogenicity as a possible future target for HNSCC therapeutic vaccines.

SP17 expression was evaluated in tissue specimens of HNSCC patients and controls. Moreover, SP17 immunogenicity was studied by generating autologous dendritic cells in vitro from the peripheral blood mononucleated cells of HNSCC patients and testing their ability to induce SP17 specific cytotoxic lymphocytes capable of killing autologous tumor cells in vitro. SP17specific immune responses were also evaluated in HNSCC patients as circulating anti-SP17 autoantibodies.

SP17 was expressed in HNSCC tissues of HNSCC patients. Autologous dendritic cells pulsed with SP17 antigen induced powerful SP17 MHC class-I restricted, perforin-dependent, cytotoxic T-cells capable of efficiently killing autologous tumor cells in vitro. SP17-specific autoantibodies were detectable in the serum of HNSCC patients irrespective of tumor site or TNM stage.

In conclusion, SP17 is an ideal immunotherapeutic target for HNSCC and a potential serological biomarker of the disease.

Primary intraosseous squamous cell carcinoma arising in dentigerous cyst: Report of 2 cases and review of the literature

Dentigerous cysts are one of the most common odontogenic cysts of the oral cavity. Odontogenic cysts can give rise to a variety of neoplasms. Carcinoma arising in a dentigerous cyst is extremely rare, with a review of literature showing near 30 cases. The present report describes 2 cases of primary intraosseous squamous cell carcinoma originated from a dentigerous cyst. The first one refers to a 57-year old female with a persistent lesion in the left retromolarregion and diagnosed with squamous cell carcinoma originated fromthe incomplete excision of the lower third molar follicle during its surgical extraction. The second case describes the case of an 18-year old male with an impacted upper canine with previous history of infection and swelling of the oral cavity. The histopathological study revealed the malignization of the follicle surrounding the dental crown. These two cases confirmed the importance of the histopathological study of all the tissue samples obtained from surgical procedures. Although the development of a malignant lesion from a dentigerous cyst is rare and its clinical-radiological features are apparently innocuous, this entity should be considered as a differential diagnosis.

Key words:Dentigerous cyst, odontogenic cyst, squamous cell carcinoma, primary intraosseous squamous cell carcinoma, odontogenic carcinoma.

Emerging drugs for head and neck cancer

INTRODUCTION

Despite improvements in treatment, survival rates of head and neck squamous cell carcinoma (HNSCC) are stagnant. The existing chemotherapeutic agents are non-selective and associated with toxicities. Combinations of the only the US FDA-approved epidermal growth factor receptor (EGFR)-targeted agent, cetuximab, with chemotherapy or radiation improves overall survival. However, the response rates to cetuximab are modest. Thus, there is an urgent need for new agents that can be safely integrated into current treatment regimens to improve outcome.

AREAS COVERED

Current EGFR-targeted drugs under clinical development include mAbs and tyrosine kinase inhibitors. The modest efficacy of these drugs implicates intrinsic or acquired resistance. Novel molecular agents inhibiting alternative targets to overcome anti-EGFR resistance in HNSCC are under investigation. Gene therapy and immunotherapy are also promising strategies to improve efficacy and reduce toxicity.

EXPERT OPINION

To date, only six drugs have been FDA-approved for the treatment of head and neck cancer. Cetuximab is the only approved molecular targeting agent for HNSCC and despite ubiquitous expression of EGFR in HNSCC tumors, clinical responses are limited. Genetic and epigenetic characterization of HNSCC tumors, coupled with improved preclinical models, should facilitate the development of more effective drugs.

The immune system and head and neck squamous cell carcinoma: from carcinogenesis to new therapeutic opportunities

Head and neck squamous cell carcinomas (HNSCCs) exhibit complex interactions with the host immune system that may simultaneously explain resistance to various therapeutic modalities and that may also provide opportunities for therapeutic intervention. Discoveries in immunologic research over the last decade have led to an increased understanding of these interactions as well as the development of a multitude of investigational immunotherapies. Here, we describe the interaction between HNSCC and the immune system, including a discussion of immune cells involved with tumor carcinogenesis and the role of immune-modulating factors derived from tumors. We also describe the current immunotherapeutic approaches being investigated for HNSCC, including a discussion of the successes and limitations. With this review, we hope to present HNSCC as a model to guide future research in cancer immunology.

Immune alterations and immunotherapy prospects in head and neck cancer

INTRODUCTION

Several literature sources have suggested that subjects with head and neck squamous cell carcinoma (HNSCC) display significant abnormalities of immunocompetent cells and cytokine secretion. Serious side effects and only a limited success with traditional therapies in HNSCC dictate the need for newer therapies.

AREAS COVERED

This article comprehensively reviews the immune system alterations in HNSCC and the rationale behind various experimental immunotherapies, aiming at keeping this disease under control. Relevant publications were identified through the PubMed database search. The ongoing clinical trials regarding experimental immunotherapy agents in HNSCC were accessed at www.clinicaltrials.gov . The obtained information was thoroughly analyzed and systematized.

EXPERT OPINION

Important and severe immune defects including T-cell dysfunction, cytokine alterations and antigen presentation defects are present in patients with HNSCC. In addition, tumor microenvironment was shown to play a critical role in the HNSCC progression. These discoveries have triggered a growing interest in immunotherapy as a potential treatment strategy for HNSCC. Effective immunotherapy could avoid the toxic side effects plaguing the current management of HNSCC. It is also hoped that immunotherapy will have long-lasting effects due to induction of immunologic memory. Promising directions include nonspecific immune stimulation, targeting specific HNSCC tumor antigens and therapeutic vaccines among others. These new agents may expand the existing therapy options for HNSCC in future.

Exploring dendritic cell based vaccines targeting survivin for the treatment of head and neck cancer patients

Background

New treatment modalities are needed for the treatment of cancers of the head and neck region (HNSCC). Survivin is important for the survival and proliferation of tumor cells and may therefore provide a target for immunotherapy. Here we focused on the ex vivo presence and in vitro induction of survivin specific T cells.

Methods

Tetramer staining and ELIspot assays were used to document the presence of survivin specific T cells in patient derived material, and to monitor the presence and persistence of survivin specific T cells after repeated in vitro stimulation with autologous dendritic cells.

Results

Ex vivo analysis showed the presence of survivin-specific T cells in the peripheral blood (by tetramer analysis) and in the draining lymph node (by ELIspot analysis) in a HNSCC and a locally advanced breast cancer patient respectively. However, we were unable to maintain isolated survivin specific T cells for prolonged periods of time. For the in vitro generation of survivin specific T cells, monocyte derived DC were electroporated with mRNA encoding full length survivin or a survivin mini-gene together with either IL21 or IL12 mRNA. Western blotting and immunohistochemical staining of dendritic cell cytospin preparations confirmed translation of the full length survivin protein. After repeated stimulation we observed an increase, followed by a decrease, of the number of survivin specific T cells. FACS sorted or limiting dilution cloned survivin specific T cells could not be maintained on feeder mix for prolonged periods of time. Protein expression analysis subsequently showed that activated, but not resting T cells contain survivin protein.

Conclusions

Here we have shown that survivin specific T cells can be detected ex vivo in patient derived material. Furthermore, survivin specific T cells can be induced in vitro using autologous dendritic cells with enforced expression of survivin and cytokines. However, we were unable to maintain enriched or cloned survivin specific T cells for prolonged periods of time. Endogenous expression of survivin in activated T cells and subsequent fratricide killing might explain our in vitro observations. We therefore conclude that survivin, although it is a universal tumor antigen, might not be the ideal target for immunotherapeutic strategies for the treatment of cancer of the head and neck.

Immunotherapy for head and neck cancer patients: shifting the balance

Head and neck squamous cell carcinoma is the sixth most common cancer in the western world. Over the last few decades little improvement has been made to increase the relatively low 5-year survival rate. This calls for novel and improved therapies. Here, we describe opportunities in immunotherapy for head and neck cancer patients and hurdles yet to be overcome. Viruses are involved in a subset of head and neck squamous cell carcinoma cases. The incidence of HPV-related head and neck cancer is increasing and is a distinctly different disease from other head and neck carcinomas. Virus-induced tumors express viral antigens that are good targets for immunotherapeutic treatment options. The type of immunotherapeutic treatment, either active or passive, should be selected depending on the HPV status of the tumor and the immune status of the patient.