Abstract
BACKGROUND: Around 60% of women ≥ 80 years old, in the UK do not have surgery for their breast cancer (vs<10% of younger age groups). The extent to which this difference can be accounted for by co-morbidity has not been established. METHODS: A Cancer Registry/Hospital Episode Statistics-linked data set identified women aged ≥ 65 years diagnosed with invasive breast cancer (between 1 April 1997 and 31 March 2005) in two regions of the UK (n=23038). Receipt of surgery by age was investigated using logistic regression, adjusting for co-morbidity and other patient, tumour and treatment factors. RESULTS: Overall, 72% of older women received surgery, varying from 86% of 65-69-year olds to 34% of women aged ≥ 85 years. The proportion receiving surgery fell with increasing co-morbidity (Charlson score 0=73%, score 1=66%, score 2+=49%). However, after adjustment for co-morbidity, older age still predicts lack of surgery. Compared with 65-69-year olds, the odds of surgery decreased from 0.74 (95% CI: 0.66-0.83) for 70-74-year olds to 0.13 (95% CI: 0.11-0.14) for women aged ≥ 85 years. CONCLUSION: Although co-morbidity is associated with a reduced likelihood of surgery, it does not explain the shortfall in surgery amongst older women in the UK. Routine data on co-morbidity enables fairer comparison of treatment across population groups but needs to be more complete.