Case mix does not fully explain variation in rates of non-surgical treatment of older women with operable breast cancer

Introduction: The use of primary endocrine therapy (PET) as an alternative to surgery for older women with operable breast cancer varies widely in the UK. Whilst this may be appropriate for frailer patients, for some it may result in treatment failure, contributing to the poor outcomes seen in women over 70. It has been suggested that case mix may partly explain this variation in practice.