Objective: To examine the association between residential remoteness and stage of cancer at diagnosis, treatment uptake, and survival within the Australian Indigenous population.
Design: Systematic review and matched retrospective cohort study.
Participants: Systematic review: published papers that included a comparison of cancer stage at diagnosis, treatment uptake, mortality and/or survival for Indigenous people across remoteness categories were identified (n = 181). Fifteen papers (13 studies) were included in the review. Original analyses: new analyses were conducted using data from the Queensland Indigenous Cancer Study (QICS) comparing cancer stage at diagnosis, treatment uptake, and survival for Indigenous cancer patients living in rural/remote areas (n = 627, 66%) and urban areas (n = 329, 34%).
Main Outcome Measures: Systematic review: Papers were included if there were related to stage of disease at diagnosis, treatment, mortality and survival of cancer. Restrictions were not placed on the outcome measures reported (e.g. standardised mortality ratios versus crude mortality rates). Original analyses: Odds ratios (OR, 95%CI) were used to compare stage of disease and treatment uptake between the two remoteness groups. Treatment uptake (treated/not treated) was analysed using logistic regression analysis. Survival was analysed using Cox proportional hazards regression. The final multivariate models included stage of cancer at diagnosis and area-level socioeconomic status (SEIFA).
Results: Existing evidence of variation in cancer outcomes for Indigenous people in remote compared with metropolitan areas is limited. While no previous studies have reported on differences in cancer stage and treatment uptake by remoteness within the Indigenous population, the available evidence suggests Indigenous cancer patients are less likely to survive their cancer the further they live from urban centres. New analysis of QICS data indicates that Indigenous cancer patients in rural/remote Queensland were less likely to be diagnosed with localised disease and less likely to receive treatment for their cancer compared to their urban counterparts.
Conclusion: More research is needed to fully understand geographic differentials in cancer outcomes within the Indigenous population. Knowing how geographical location interacts with Indigenous status can help to identify ways of improving cancer outcomes for Indigenous Australians.