Spatial disparities in incidence and survival of liver cancer in Australia, 2010-2019

Liver cancer incidence rates are increasing, and survival rates remain among the lowest of all cancers in Australia. Geographic inequalities in incidence and survival have been partially attributed to access and socioeconomic barriers; however previous reports have been based on coarse, typically heterogenous geographic factors and so were unable to detect variation at a finer resolution. This study investigates high resolution spatial patterns of incidence and survival rates of liver cancer across Australia.

Liver cancer data were extracted from all Australian state and territory cancer registries (aged 15 and over). Incidence and 5-year relative survival spatial patterns (2010-2019) at the small-area level were modelled using Bayesian spatial Leroux models and spatial heterogeneity tested using the maximised excess events test.

The age-standardized (Aust 2001) incidence rate was 9.4 cases per 100,000 person-years, with higher rates among males than females. Strong evidence of spatial variation in the incidence and survival of liver cancer was found at the small area level (p < 0.001). Compared to the national average, many areas in Australia's north and centre showed higher incidence, as well as some areas in most state and territory capitals. Generally, survival rates were poorer than the Australian average outside major cities; however, some city areas also had poorer survival.

The spatial patterns of incidence of liver cancer reflect the geographic distribution of the priority populations in state capitals of people born overseas in hepatitis B endemic regions and First Nations Australians in the northern and central regions. Our findings highlight the need for targeted, place-based interventions to reduce the prevalence of modifiable risk factors for liver cancer in Australia. Before these evidence-based interventions can be developed, a greater understanding of what area and individual-level factors are contributing to these spatial survival disparities is required.