1375 - Improved survival of older patients with advanced breast cancer due to an increase in systemic treatments – a population-based study

Background

The number of older patients with breast cancer is rapidly increasing. A previous study showed that in the Netherlands, between 1990 and 2005, survival of older patients with breast cancer did not improve in contrast to younger patients. In recent years, scientific evidence in the older age group has increased and specific guidelines for older women with breast cancer have been developed. The aim of this study was to assess recent survival outcomes of older patients with breast cancer compared to younger patients.

Methods

All patients with stage I-IV breast cancer between 2000 and 2017 were included from the Netherlands cancer registry. We assessed changes in treatments over time using logistic regression models. We calculated the changes in relative survival as proxy for breast cancer mortality, stratified by age and stage.

Results

We included 239,992 patients. Relative survival improved over time for patients in the youngest age-group for all stages. In patients aged 65-75 years, relative survival adjusted for tumour characteristics did not improve in stage I-II but did improve in stage III (RER 0.98, 95% C.I. 0.96-1.00, p = 0.046). Concurrently, was prescribed in an increasing proportion of patients aged 65-75 years (33.6% in 2000 to 52.7, p < 0.001). In patients aged 75 years or older, relative survival did not improve in patients with stage I/II or stage III disease, nor did treatment strategies change.

Conclusions

This study shows that over time, the relative survival of patients aged 65-75 years with advanced breast cancer has improved, and concurrently, prescription of systemic treatment increased. These data suggest that older patients with advanced breast cancer do benefit from adjuvant systemic treatment. In order to further improve survival of patients >75 as well, future studies should focus on individualizing treatments based on concomitant comorbidity, geriatric parameters and the risk toxicity of treatments.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Leiden University Medical Center, Department of Medical Oncology, Geriatric Oncology Research Group.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.