Geographic variation in surgery rates among older patients with early (ER positive HER2 negative) breast cancer: Influence of cardiovascular disease and comorbidities: A national registry dataset analysis

INTRODUCTION: Women over 70 years of age with operable oestrogen receptor positive (ER positive) breast cancer have worse survival outcomes than younger women. Primary surgery is the optimal treatment with primary endocrine therapy reserved for patients who are unfit or who have multiple co-morbidities. Inferior outcomes in this patient population might be explained by underuse of surgery, the rates of which vary considerably between geographical regions in the UK. We determined the rates of surgery versus primary endocrine therapy in a cohort of women aged over 70 in England, with potentially curable ER positive breast cancer, according to the presence of pre-existing cardiovascular disease (CVD), comorbidities, social deprivation, and by geographical location. MATERIALS AND METHODS: 33,235 women aged 70 years or older with stage I to III ER positive breast cancer from the 20 regional NHS Cancers Alliances in England were identified from the cancer registry. Linked hospital records were used to identify patient demographics, tumour and treatment characteristics, resection rates, CVD prevalence and other co-morbidities. RESULTS: 25,800 (77.6 %) patients underwent surgery, 6787 (20.4 %) patients received primary endocrine therapy alone, 648 (2 %) patients received no treatment. Both CVD and surgery prevalence varied by geographical location. After adjustment for case mix the differences between Cancer Alliances attenuated and no longer reached statistical significance. CONCLUSIONS: We found regional differences in rates of surgery in patients with breast cancer across different centres. After adjustments, the variation is largely attributable to case mix. Under recording of endocrine therapy data in secondary care limits full interpretation.