Immunological Phenotypes of Premalignant Oral Lesions and the Immune Shifts with the Development of Head and Neck Cancer

Review Article

Austin J Otolaryngol. 2014;1(2): 7.

Immunological Phenotypes of Premalignant Oral Lesions and the Immune Shifts with the Development of Head and Neck Cancer

Young MRI*

Research Service, Ralph H. Johnson VA Medical Center, USA and Department of Otolaryngology, Head and Neck Surgery, Medical University of South Carolina, USA

*Corresponding author: Young MRI, Research Service (151), Ralph H. Johnson VA Medical Center, 109 Bee Street, Charleston, SC 29401, USA

Received: July 25, 2014; Accepted: September 11, 2014; Published: September 15, 2014

Abstract

Compared to other cancer types, squamous cell carcinomas of the head and neck (HNSCC) have been understudied.Studies in other cancer types have demonstrated immunological changes that occur with the development of cancer.However, few studies have looked at the immune changes that occur in premalignant lesions.HNSCC is often preceded by the appearance of premalignant oral lesions.However, information about the immune shifts that occur as a result of the premalignant oral lesions and following progression to HNSCC is sparse.This review aims to pull together studies with patients and animal models to summarize the multiplicities of immune activities that are associated with premalignant oral lesions and HSNCC.In general, the immune phenotype in premalignant oral lesions and regional lymph nodes is inflammatory and activated.However, development of HNSCC results in a shift to an immune inhibitory environment.

Keywords: Cytokines, Head and neck cancer, HNSCC, Immune, Inflammation, Oral cancer, Premalignant oral lesions

Overview of the Immune Influences on Premalignant Oral Lesions and Their Progression to Cancer

Despite advances in diagnosis and treatment, the 5-year survival rates for patients with head and neck squamous cell carcinoma (HNSCC) have not improved over 60% [1]. HNSCC is a highly aggressive disease that develops from the oral epithelium and its appearance is often preceded by premalignant oral lesions, most commonly leukoplakias [2]. Even with advanced treatments for premalignant oral lesions, about 30% progress to cancer [3]. Persistent infection with high-risk human Papillomaviruses (HPV) is associated with increased risk of oral cancer.Also associated with risk for HNSCC are alcohol consumption and tobacco.Each of these contributors to the development of epithelial dysplasia and progression to cancer are immune modulatory and complicate the immunological phenotype of oral tissues that are progressing to cancer [4-6].

The multifaceted aspects of the immune system have placed it into opposing roles in the development and progression of cancer (Table 1). On one hand, immune activation, and in particular inflammation, is considered to be among the contributors of cancer onset.Examples of this include associations between cancer and inflammation associated with obesity, inflammatory bowel disease and even oral irritation[7-11]. On the other hand, immune activation can also repress tumor development, as demonstrated through clinical immunotherapeutic trials using various iterations of cancer vaccines or other immune modulatory approaches.Immune protection against cancer is also demonstrated by the increased cancer development in immune compromised individuals such as the increased incidence of non-AIDS-defining cancers in patients with HIV infection [12-14]. These opposing capabilities of the immune system to promote or protect against cancer raise the question of its role in the development of oral lesions and progression to cancer.The answer to this question is highly fragmented, although there are more fragments that can be assembled to understand the immune status in overt HNSCC, as compared to the absence of information pertaining to the impact of the immune milieu on premalignant oral lesions.