Effect of age at diagnosis of breast cancer on the patterns and risk of mortality from all causes: A population-based study in Australia

Aims This retrospective, population-based study investigated the patterns and risks of mortality from breast cancer, other cancers and non-cancer causes according to the age at diagnosis of breast cancer. Methods Mortality was assessed in all Australian women (n=179653) aged 3079 years who were diagnosed with breast cancer between 1982 and 2004 and who survived a minimum of 1year. The mean follow up was 6.3years (range 023years). Results Before December 2005, 52934 women had died (34459 of breast cancer, 5019 of other cancers and 13456 of non-cancer causes). There was an inverse age-related relative risk of mortality (calculated as the standardized mortality ratio [SMR]) from breast cancer (linear trend across age P<0.01). For breast cancer survivors the age-adjusted SMR was 0.99 for other cancers and 0.81(P<0.01) for non-cancer causes in comparison with the general population. The SMR for other cancers and non-cancer causes was highest in the 3039-year-old age group (2.13, P<0.01 and 2.15, P<0.01, respectively), and progressively decreased with increasing age, with the 7079-year-old age group having significantly reduced SMR (0.95, P<0.05, and 0.78, P<0.01, respectively, compared with the age-matched general population). Conclusion There was an inverse age-related relative risk of death from breast cancer, other cancers and non-cancer causes. These findings suggest that younger Australian women require long-term health surveillance and that older women with limited comorbidities require optimal treatment of their breast cancer.