Head and neck cancer
More than 3,800 new cases of head and neck cancer are diagnosed in Australia (70% men, 30% women) each year. These cancers are of increasing concern because the five year survival rate is just nine per cent as diagnosis does not occur until the cancer is advanced. Head and neck cancer occurs when malignant tumours grow in any of the tissue in the head or neck. Types of head and neck cancer include mouth or oral cancer; salivary gland cancer; pharyngeal cancer; laryngeal cancer; and nasal cancer or paranasal sinus cancer.
Causes of head and neck cancers
The human papillomavirus (HPV), a common sexually transmitted disease, is associated with the development of some head and neck cancers, particularly in the upper throat and back of the tongue.
Major causes include smoking and alcohol consumption as well as sun exposure, radiation, inhalation of asbestos or wood or nickel dust; or poor oral hygiene.
Risk factors include smoking and excessive alcohol consumption. People who smoke one pack of cigarettes a day are six times more likely than non-smokers to get cancer of the head or neck. Those who also have two alcoholic drinks a day increase their risk 20-fold.
Head and neck cancers are treated differently depending on their location and size. Surgery, radiotherapy or chemotherapy, or a combination of these treatments, are used to treat the cancer.
Head and neck cancer research at the Perkins
Our head and neck research focuses on assessing the impact of microRNAs on cancer growth and proliferation. RNAs are involved in almost all aspects of human development and disease and microRNAs are one form of small RNAs. In 2006, a team of Perkins researchers discovered that one particular microRNA (miR-7) can reduce the growth of some cancer cells, as well as killing off others, particularly in cancers of the brain, head and neck. Following this discovery, the team formed a company dedicated to commercialising miR-7 and undertaking extensive pre-clinical testing. Since the initial discovery we’ve identified key functional roles for a number of miRNAs in these tumours and uncovered several new members of a complex network of RNA-binding nuclear receptor hormone coregulators. It is anticipated that our discoveries will assist in the development of effective treatments for these poor-prognosis cancers. Our researchers made steps towards achieving the goal of therapeutic translation when they conducted an in vitro study to explore a potential synergy between miR-7, and erlotinib, a drug currently used to treat head and neck cancers. Erlotinib is used in the treatment of head and neck cancers, but is often not very effective, with only 20 to 30% of patients deriving much benefit from the drug. The responses are typically short and tumours often build up resistance to erlotinib quite quickly. Perkins studies have found that when erlotinib is combined with the anti-cancer miR-7, its effectiveness increased. miR-7 acts as a tumour suppressor by inhibiting the epidermal growth factor receptor (EFGR). It is more effective due to it targeting several members of the EFGR pathway, hitting at multiple levels simultaneously, so cancer cells are less likely to survive. Current drugs often block the cancer cells at one level.