A joint study by the University of Cambridge and the Institute of Cancer Research (ICR), London, has found that NICE GP-referral criteria miss up to 95% of women under 50 in England who go on to develop breast cancer within the next 10 years. The research, published in the British Journal of Cancer on 4 August 2026, compared the existing NICE guidelines with a new multifactorial risk assessment system called Boadicea, developed by the University of Cambridge and funded by Cancer Research UK.

NICE (the National Institute for Health and Care Excellence) sets the guidelines that GPs in England use to decide which patients warrant further investigation. The NICE criteria also miss up to 95% of women aged under 50 with a higher-than-average risk of breast cancer. A key driver of this gap is the guidelines' reliance on family history as a primary screening criterion. According to the study, 73% of women under 50 who develop breast cancer within 10 years have no family history of the disease (The Guardian).

Boadicea assesses additional risk factors beyond family history, including reproductive history, lifestyle, and genetics. Think of the NICE criteria as a single-question filter — "Does breast cancer run in your family?" — while Boadicea runs the same women through a multi-layered sieve that weighs several variables at once. The system identified eight times as many women in the under-50 age group who would develop breast cancer compared with the current NICE criteria. The ICR concurrently published its own news release announcing the findings (ICR).

Dr Juliet Usher-Smith of the University of Cambridge, a named author of the study, called for a review of the NICE criteria. She stated that the current NICE criteria used in general practice are missing up to 95% of women under 50 who will go on to develop breast cancer. Prof Montserrat García-Closas of the ICR, also a named author, noted a trade-off between the ease of implementing NICE criteria and the burden of full risk assessment including genetic testing.

Breast Cancer Now, which supported the study, said the research must be considered as part of the current review of NICE's family history guidelines. Dr Simon Vincent, chief scientific officer at Breast Cancer Now, said new ways to identify women at increased risk could help prevent some breast cancers or detect them earlier.

The Broader Context

These findings surface amid ongoing efforts to integrate multifactorial risk assessment into general practice. The CanRisk-GP protocol, described by F Stutzin Donoso and colleagues in 2025, is a feasibility study of incorporating proactive multifactorial breast cancer risk assessment in primary care. That study will provide evidence on whether offering cancer risk assessment including polygenic scores (PGS) in general practice is feasible and acceptable to women. Polygenic scores combine the small effects of many genetic variants into a single number estimating a person's inherited risk.

Prior research has mapped systemic friction in referral pathways. A 2024 study by JA Usher-Smith titled "Patterns of referrals to regional clinical genetics services" reviewed hospital records of GP referrals for women aged 18-49 years suspected to be at above-population level risk for breast cancer. A separate 2024 study by Usher-Smith found that in one randomised controlled trial, an intervention improved the proportion of genetic referrals that met referral guidelines for breast cancer, with an odds ratio of 4.5 and a 95% CI of 1.6 to 13.1. A 2024 study by S Hindmarch noted that NICE guidance recommends enhanced screening and prevention for women at increased breast cancer risk, and aimed to map current risk assessment practice.

National guidelines recommend English women aged 30-49 years with moderate or high risk of breast cancer be offered screening and prevention interventions, according to a 2026 study by R Dennison at the University of Cambridge titled "Priorities for breast cancer risk assessment in UK women." A 2018 study by LA Littlejohn assessing the effectiveness of NICE criteria for stratifying breast cancer risk found that UK NICE guidelines use family history to stratify women by 10-year risk of breast cancer from age 40.

The stakes for earlier identification are quantifiable. According to the Breast Cancer Research Foundation, a US woman aged 30 has a 0.49% risk of developing breast cancer over the next 10 years, while a woman aged 50 has a 2.40% risk over the next 10 years. Earlier ICR research from 2014, published in a news release titled "Genetic testing could improve breast cancer prevention," reported that screening women for a wide range of known genetic risk factors could improve strategies for breast cancer prevention.

The broader context here is one of slow but real momentum toward personalised risk assessment in routine primary care. The Boadicea findings, combined with the forthcoming CanRisk-GP results, may pressure NICE to move beyond a family-history-only gatekeeping model. Whether general practice can absorb the added workload of full multifactorial assessment, including genetic testing, is a question the feasibility studies are designed to answer. The trade-off that Prof García-Closas identified between simplicity and thoroughness is likely to sit at the centre of any guideline revision.