14 March 2022
The preventive management of breast cancer often involves endocrine targeted treatments including tamoxifen and aromatase inhibitors. These have shown to lead to fewer diagnosis of estrogen receptor-positive breast cancers but have not consistently demonstrated reduced mortality related to breast cancer. The following paper to be commented is a review of the evidence of different treatments to reduce risk of future breast cancer . A meta-analysis of four randomised prevention trials has shown that tamoxifen reduced the 10 year cumulative incidence of invasive breast cancers by 33% . However, there was no beneficial effect on mortality demonstrated. Interventions such as magnetic resonance imaging screening and risk reduction bilateral mastectomy have shown to be effective interventions. Despite this, in the Women’s Health Initiative (WHI) randomized, controlled trial, ER-positive, PR-negative cancers were statistically significantly reduced in the group given conjugated equine estrogen and also deaths from breast cancer were reduced by 40% . This finding has not been demonstrated for any other pharmacological intervention. This information needs to be widely disseminated to clinicians.