Long term cardiac outcomes and anthracycline exposure in breast cancer survivors: A retrospective cohort data linkage and competing risks analysis.

553Background: Anthracycline chemotherapy is used frequently in adjuvant breast cancer treatment but there is clinical trial evidence of cardiac toxicity. Attempts to quantify this risk in routine care have been limited by follow up time & confounding factors. The aim of this project was to exploit rich Scottish NHS datasets for this purpose. Methods: Patients treated surgically for stage I-III invasive breast cancer between 2000 & 2010 were identified from a local cancer database (Edinburgh Cancer Centre). Outcomes were captured by linkage to the Scottish Morbidity & death Records. Follow-up was until March 2016. The primary outcome was a cardiac event or cardiac death, identified from coding. Analysis used the Latouche approach (estimating cause-specific hazards & sub-distribution hazards) for the primary outcome & the competing risks of death from breast cancer & death from other causes. Results were adjusted for age, deprivation (SIMD), co-morbidity (Charlson), year of diagnosis, side of radiotherapy,...