Geographic remoteness and risk of advanced colorectal cancer at diagnosis in Queensland: a multilevel study

BACKGROUND: We examine the relationships between geographic remoteness, area disadvantage and risk of advanced colorectal cancer. METHODS: Multilevel models were used to assess the area- and individual-level contributions to the risk of advanced disease among people aged 20-79 years diagnosed with colorectal cancer in Queensland, Australia between 1997 and 2007 (n=18,561). RESULTS: Multilevel analysis showed that colorectal cancer patients living in inner regional (OR=1.09, 1.01-1.19) and outer regional (OR=1.11, 1.01-1.22) areas were significantly more likely to be diagnosed with advanced cancer than those in major cities (P=0.045) after adjusting for individual-level variables. The best-fitting final model did not include area disadvantage. Stratified analysis suggested this remoteness effect was limited to people diagnosed with colon cancer (P=0.048) and not significant for rectal cancer patients (P=0.873). CONCLUSION: Given the relationship between stage and survival outcomes, it is imperative that the reasons for these rurality inequities in advanced disease be identified and addressed.