Abstract
Oral squamous cell carcinoma (OSCC) is one of the leading presentations of head and neck cancer (HNC). The first part of this review will describe the highlights of the oral microbiome in health and normal development while demonstrating how both the oral and gut microbiome can map OSCC development, progression, treatment and the potential side effects associated with its management. We then scope the dynamics of the various microorganisms of the oral cavity, including bacteria, mycoplasma, fungi, archaea and viruses, and describe the characteristic roles they may play in OSCC development. We also highlight how the human immunodeficiency viruses (HIV) may impinge on the host microbiome and increase the burden of oral premalignant lesions and OSCC in patients with HIV. Finally, we summarise current insights into the microbiome–treatment axis pertaining to OSCC, and show how the microbiome is affected by radiotherapy, chemotherapy, immunotherapy and also how these therapies are affected by the state of the microbiome, potentially determining the success or failure of some of these treatments.
Highlights
In the Global Cancer report 2018, head and neck cancer is thought to be the eighth most commonly occurring cancer in the world [1], with oral squamous cell carcinoma being the most common presentation
Since periodontal disease is a microbial disease, this sets the tone for the question: what is the role of microorganisms in the aetiology of oral squamous cell carcinoma? This review sets out to answer this question, delving into how both the oral and gut microbiome may sculpt, in many ways, the outcome of an oral squamous cell carcinoma from start to finish
Rare species to inhabit the oral cavity, such as Bacteroides fragilis [77], previously unnamed bacteria such as Actinomyces and Streptococcus [70,78] and the environmental species Dietzia psychralcaliphila and Gordonia sputi, have all been identified from Oral squamous cell carcinoma (OSCC) samples [68]. Some of these species have been researched in more detail, such as Fusobacterium nucleatum and Porphyromonas gingivalis, which will be discussed in more detail; most have not been pondered in relation to both their singleton and polymicrobial roles in the OSCC-associated microbiome
Summary
In the Global Cancer report 2018, head and neck cancer is thought to be the eighth most commonly occurring cancer in the world [1], with oral squamous cell carcinoma being the most common presentation. On that latter note, chronic inflammation is thought to be the cause of one in four cancers [6] How this may relate to the aetiopathogenesis of oral squamous cell carcinoma is an important undertaking. Compelling evidence exists for the association of chronic periodontal disease and the development of head and neck cancer in general and oral squamous cell carcinoma . For every millimetre of alveolar bone loss, a four-fold increased risk of developing squamous cell carcinoma of the head and neck cancer unfolds. Those with periodontal disease are thought to be at greater risk of poorly differentiated cancers [7,8]. Since periodontal disease is a microbial disease, this sets the tone for the question: what is the role of microorganisms in the aetiology of oral squamous cell carcinoma? This review sets out to answer this question, delving into how both the oral and gut microbiome may sculpt, in many ways, the outcome of an oral squamous cell carcinoma from start to finish
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
