Primary endocrine therapy as a treatment for older women with operable breast cancer – a comparison of randomised controlled trial and cohort study findings

Introduction: One third of all breast cancers occur in women over the age of 70. Primary endocrine therapy (PET) is used in some women to minimise morbidity in a population with higher rates of comorbidity and frailty. In the UK up to 40% of women over 70 are treated with PET although there is a high rate of variability of practice between centres reflecting a lack of guidance about case selection. Methods: A systematic review of the literature was performed to try and establish if this form of treatment is still valid in modern breast practice. Results: Six randomised controlled trials (RCTs) and 31 non-randomised studies were deemed eligible. Available data demonstrate an advantage for surgery over PET in terms of disease control and a likely survival benefit in patients with a predicted life expectancy of five years or more. Patients treated only with aromatase inhibitors (AIs) had superior rates of disease control when compared to Tamoxifen. Conclusions: Guidelines to aid selection are needed but PET should be reserved for patients with reduced predicted life expectancy (e.g. less than five years), with AIs being preferable over Tamoxifen