Differentials in survival for childhood cancer in Australia by remoteness of residence and area disadvantage.

BACKGROUND It is not known whether improvements in cancer survival over recent decades have benefited children from different geographic locations equally. This is the first study to produce national survival estimates for childhood cancer in Australia by remoteness of residence and area-based socioeconomic status. METHODS The study utilized population-based data from the Australian Paediatric Cancer Registry for children diagnosed with cancer from 1996 onward who were at risk of mortality between January 2001 and December 2006 (n = 6,289). Remoteness was specified according to the Australian Standard Geographical Classification Remoteness Areas, whereas an index of area disadvantage was obtained from census information. Five-year relative survival estimates were produced by the period method for all cancers and the most common diagnostic groups, with corresponding age-sex adjusted mortality hazard ratios calculated using Poisson regression. RESULTS Overall, children with cancer from remote/very remote areas had a significantly lower survival rate than their counterparts in major cities (HR = 1.55, 95% CI = 1.08-2.23). Survival was also lower for children with leukemia living in inner regional (HR = 1.52, 95% CI = 1.11-2.08) or outer regional areas (HR = 1.53, 95% CI = 1.03-2.28). There was weak evidence (P(grad) = 0.051) of a trend toward poorer survival by greater area disadvantage for all childhood cancers. CONCLUSIONS Some variation in prognosis by place of residence was present for children with cancer in Australia, particularly among leukemia patients. IMPACT Treatment, clinical or area-related factors that contribute to these survival differentials need to be identified.