Temporal changes in loss of life expectancy due to cancer in Australia: a flexible parametric approach

PURPOSE: To evaluate changes in cancer mortality burden over time by assessing temporal trends in life expectation for Australian residents diagnosed with cancer. METHODS: The study cohort consisted of all people diagnosed with cancer in the period 1990-2000 and aged 15-89 years (n = 1,275,978), with mortality follow-up to 31 December 2010. Flexible parametric survival models incorporating background age-sex-year-specific population mortality rates were applied to generate the observed survival curves for all cancers combined and selected major cancer types. Predicted values of loss of life expectancy (LOLE) in years were generated and then averaged across calendar year and age group (15-49, 50-69 and 70-89 years) or spread of disease (localized, regional, distant, unknown). RESULTS: The greatest LOLE burden was for lung cancer (14.3 years per diagnosis) and lowest for melanoma (2.5 years). There was a significant decrease in LOLE over time (-0.13 LOLE per year) for all cancers combined. Decreases were also observed for female breast cancer (-0.21), prostate cancer (-0.17), colorectal cancer (-0.08), melanoma (-0.07) and stomach cancer (-0.02), with slight increases for lung cancer (+0.04). When restricted to the sub-cohort from New South Wales with spread of disease information, these decreases in LOLE were primarily among cancers categorized as localized or regional spread at diagnosis. CONCLUSIONS: In Australia, persons diagnosed with cancer have a steadily improving outlook that exceeds that expected by general improvement in population life expectancy. The overall improvement is observed in persons with localized or regional cancers but not in those with advanced cancers, findings which encourage earlier diagnosis.