Oral cancer in Western Australia is on the rise with trends showing a regional-urban divide, two recent studies contend.
The research drew on de-identified data provided by the Western Australian Cancer Registry from 1982 to 2009 for incidences of oropharyngeal cancer, affecting the pharynx (throat), tongue and major salivary glands/parotid.
Over the 27-year testing period, 2801 cases were reported in WA, with three-quarters of those afflicted being male, and rural and remote areas hardest hit.
“The age-standardised rates for pharyngeal cancers were statistically significantly higher among rural and remote WA residents than urban dwellers,” UWA Professor Estie Kruger says.
“Rates were also higher in rural areas for tongue and parotid gland cancers, but were not significantly higher.
“Reasons for this divide might include the higher exposure to risk factors for oral cancer among those outside city centres, and indicates the need for a common-risk factor approach when attempting to improve country health in WA.”
Risk factors include tobacco and alcohol use, which have been linked in particular to cancer of the pharynx.
While smoking has steadily decreased in Australia, researchers note Australians living outside major cities are more likely to be smokers and drink alcohol in hazardous quantities.
In addition, remote and rural dwellers face practical hurdles to diagnosis and treatment, with cancer centres located primarily in city centres, making access to services more difficult.
Over the testing period, cancer of the pharynx was the most prevalent form of the disease, increasing from 1.6 to 3.5 (per 100,000 persons) from 1982 to 2009.
Cancer of the tongue ranked second, increasing from 1.8 to 2.9 (per 100,000 persons), far exceeding national rates.
Overall, all forms of oropharyngeal cancer increased.
Prof Kruger says this upward trend is projected to continue over the next 15 years for pharynx and tongue cancers, due in part to an ageing population, with cancer being an age-related disease.
It also reflects more current trends, with researchers constructing their projections using both a traditional linear method and an estimated weighted moving average (EWMA) that places greater weight on more recent data.
Prof Kruger says her team’s research fundamentally shows a rural-urban difference for oral cancer and offers important information for policy planners.
“Our hope is that these predictions, based on long-term incidence figures over 27 years, will prompt efficient planning in terms of future resource requirements to manage the disease burden,” Prof Kruger says.