Human Papilloma Virus and Cancer
Traditional lifestyle risk factors for head and neck cancer (HNC) are smoking and alcohol. However, in recent years, a new entity of Human Papilloma Virus (HPV)-associated oropharyngeal squamous cell cancer (OSCC) has emerged, wherein ~60% of these tumours harbour the HPV genome, curiously associated with a significantly superior clinical outcome, compared to their HPV-negative counterparts. The incidence of oropharyngeal cancer (OPC) has also been increasing over the last two decades for unknown reasons, despite the reduction in other head and neck squamous cell cancers (HNSCCs) in this same period. Patients with HPV-positive OPC are clinically distinct from their HPV-negative counterparts, being younger at age of presentation, less inclined to be heavy smokers or drinkers, and are highly curable with ionizing radiation with or without chemotherapy, despite often presenting with locoregionally advanced disease.
The molecular mechanisms underlying HPV tumorigenesis are well understood, with its two major oncogenes E6 and E7, inactivating p53 and pRb, respectively. However, the mechanisms underlying the significantly greater sensitivity of HPV-positive OPC to radiation therapy (or chemo-radiotherapy) remains unclear. Thus, the Liu lab is currently trying to elucidate the molecular differences between HPV-positive HNSCCs and their HPV-negative counterparts, as well the mechanisms by which they are associated with superior clinical outcome.
Actuarial Kaplan-Meier graph for disease-free survival (DFS) as a function of HPV-16 E6 mRNA.
Representative Publications:
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