Geographic variations in stage at diagnosis and survival for colorectal cancer in Australia: A systematic review

Introduction: Australia has one of the highest incidence rates of colorectal cancer (CRC) in the world. Residents in rural areas of Australia experience disadvantage in health care and outcomes. This review investigates whether patients with CRC in rural areas demonstrate poorer survival and more advanced stages of disease at diagnosis. Methods: Systematic review of peer-reviewed articles and grey literature. Studies were included if they provided data on survival or stage of disease at diagnosis across multiple geographical locations; focused on CRC patients; and were conducted in Australia. Results: Twenty-six articles met inclusion criteria. Twenty-three studies examined survival, while five studies investigated stage at diagnosis. The evidence suggests that non-metropolitan patients are less likely to survive CRC for five years compared to patients living in metropolitan areas, yet there was limited evidence to suggest geographical disparity in stage of diagnosis. Conclusions: While five-year survival disparities are apparent, these patterns appear to vary as a function of specific region and health jurisdiction, cancer type and year/s of data collection. Future research should examine current data using consistent and robust methods of reporting survival and classifying geographical location. The impact of population-level screening programmes on survival and stage at diagnosis also needs to be thoroughly explored.