Licensing of anastrozole for primary prevention of breast cancer

The national multi-agency Medicines Repurposing Programme successfully secured a MHRA licence variation for anastrozole on 6 November 2023. Anastrozole’s marketing authorisation now includes a new indication of primary prevention of breast cancer in postmenopausal women at moderate or high risk. The new indication mirrors the pre-existing NICE guideline recommendation. The licence variation has been secured to provide more confidence in the use of the medicine in this preventative indication and support more equitable uptake.

The following information may assist local clinical leaders in managing any associated queries about local pathways. The responsible commissioners are ICBs.

Anastrozole reduces the incidence of breast cancer in post-menopausal women at increased risk of the disease by almost 50% (IBIS-II). About 4% of women aged 50-69 (289,000 women in England) are at moderate or high risk, and hence potentially eligible for anastrozole (based on clinical advice and Evans et al. 2014). While not all will choose to take anastrozole, NHS England modelling estimates that if 25% do, around 2,000 cases of breast cancer could potentially be prevented while saving the NHS around £15 million in treatment costs.

The NICE guideline on familial breast cancer has recommended anastrozole off-label since 2017. The NICE guideline has been updated to reflect that anastrozole is now licensed for prevention. The updated summary of product characteristics for anastrozole is available.

If a patient contacts primary care, the NICE guideline recommends that primary care professionals should offer to refer potentially eligible patients to secondary care. The referral criteria are in sections 1.3.3 to 1.3.6. Risk reduction and treatment strategies are in section 7. The first prescription is likely to be in secondary care. If there is prior agreement from primary care, continued prescribing may be from primary care.

Information for patients has been produced by NICE and, separately, Breast Cancer Now (Family history: assessing your breast cancer risk; Family history: managing your risk; Anastrozole; Tamoxifen). The NICE patient decision aids have been updated to include the most recent trial data on anastrozole for prevention.

Local decision-makers may find it helpful to consider the Greater Manchester Cancer Alliance Risk Reducing Endocrine Therapy Toolkit. The Greater Manchester treatment algorithm goes into more detail than the NICE guideline in some areas. Any deviations from the NICE guideline should be considered carefully before being adopted into local policies.

NHS England (formerly Health Education England) has produced an e-learning for healthcare module on breast cancer primary prevention education. This will be updated to reflect the licence variation for anastrozole.