Age at diagnosis in relation to XXXX : a cohort study.

@entity1 @entity0
BACKGROUND: Age is an important risk factor for @entity0 , but previous data has been contradictory on whether @entity1 age at diagnosis is also related to @entity0 survival. The present study evaluates age at diagnosis as a prognostic factor for @entity0 on a large cohort of @entity1 at a single institution. METHODS: All 4,453 @entity1 diagnosed with @entity0 in Malm   University Hospital, Sweden between 1961 and 1991 were followed up on for 10  years with regards to @entity0 -specific mortality (BCSM) in different age groups. Corresponding relative risks (RR), with 95% confidence intervals, were obtained using Cox's proportional hazards analysis. All analyses were adjusted for potential confounders and stratified for axillary lymph node involvement (ALNI) and diagnostic period. RESULTS: As compared to @entity1 aged 40 to 49  years, those who were aged under 40 (RR: 1.40; 95% CI: 1.04 to 1.88) and 80 or more years (RR: 1.80; 95% CI: 1.45 to 2.25) had a statistically significant higher 10-year mortality rate. When adjusted for potential confounders, including stage at diagnosis, the associations only remained statistically significant for @entity1 aged 80  years or more. In the analyses stratified on ALNI, ALNI-negative @entity1 under 40  years had a statistically significant higher five-year mortality rate (RR: 2.65; 95% CI: 1.23 to 5.70). In the analyses stratified on diagnostic period, the positive association between @entity1 aged under 40 or aged 80 or more years and high BCSM rate remained, with statistically significant results for @entity1 aged 80  years or more in all periods. CONCLUSIONS: @entity1 under 40  years of age had a poor prognosis, and this association was strongest among young @entity1 with axillary lymph node negative @entity0 . An age of 80  years or more was a prognostic factor for poor survival, independent of stage at diagnosis and diagnostic period.
