Effect of age at diagnosis of breast cancer on the patterns and risk of mortality from all causes: a population-based study in Australia.
OBJECTIVE
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 = 179,653) aged 30-79 years who were diagnosed with breast cancer between 1982 and 2004 and who survived a minimum of 1 year. The mean follow up was 6.3 years (range 0-23 years).


RESULTS
Before December 2005, 52,934 women had died (34,459 of breast cancer, 5019 of other cancers and 13,456 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 30-39-year-old age group (2.13, P < 0.01 and 2.15, P < 0.01, respectively), and progressively decreased with increasing age, with the 70-79-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).


CONCLUSIONS
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.
Queensland Institute of Medical Research, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia. geoffbe@qimr.edu.au
Geoffrey Francis
GF
Beadle
Nicole Jean
NJ
McCarthy
Peter David
PD
Baade
D000328:Adult; D000367:Age Factors; D000368:Aged; D001315:Australia / Q000453:epidemiology; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000401:mortality*; D002423:Cause of Death; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate; D017741:Survivors