BACKGROUND: Previous studies have shown that breast cancer survival decreases with increasing age among older patients who participate in trials. However, trial participants differ from patients in the general population. Therefore, the aim of this study was to evaluate the association between age and breast cancer outcome in an unselected group of older breast cancer patients.

METHODS: We included all older (65 years and older) consecutive breast cancer patients, diagnosed between 1997 and 2004 from a geographically defined area in the Netherlands. Primary outcome was relative survival and the secondary endpoint was breast cancer recurrence. These outcomes were compared between two age-categories (65-74 years and ≥75 years).

RESULTS: Five-year relative survival was 91.9% in patients aged 65-74 years, and 84.3% in patients aged ≥75 years. This corresponded with a higher excess risk of death in patients aged ≥75 years as compared to patients aged 65-74 years (multivariable relative excess risk of death: 1.73 (95% CI 1.20-2.49)). The risks of locoregional recurrence, distant recurrence and contralateral breast cancer were similar in both age-categories.

CONCLUSIONS: Breast cancer survival deteriorates with increasing age among unselected older breast cancer patients. Of note, this was not accompanied by an increased risk of recurrence. This study shows that not only in relatively healthy patients who participate in a trial, but in all older breast cancer patients, outcome deteriorates with increasing age. These findings urge the need for age-specific breast cancer studies, in order to obtain evidence-based medicine in this large and heterogeneous group of patients.