Expanding mastectomy access could prevent more breast cancer cases

More women at higher risk of breast cancer should be offered a mastectomy, according to a new study led by researchers at the London School of Hygiene & Tropical Medicine (LSHTM) and Queen Mary, University of London.

A new economic modelling analysis found the surgical technique was a cost-effective way of reducing the likelihood of developing breast cancer when compared to breast screening and medication. It's hoped the findings could lead to changes in medical guidelines for offering mastectomies.

To identify the risk of women developing breast cancer, clinicians combine genetic and medical data to create personalised risk prediction models. Depending on their risk, clinicians will offer a range of treatment options including: mammograms, MRI screening, surgery, and medication.

Current guidelines recommend risk-reducing mastectomy (RRM) for women at high risk but in practice, this surgery is only offered to those carrying faults in genes that are known to increase the likelihood they will develop the disease (BRCA1/ BRCA2/ PALB2 PV).

Dr Rosa Legood at LSHTM and Professor Ranjit Manchanda at Queen Mary worked with colleagues from Manchester University and Peking University to create a new economic evaluation model to determine the level of risk at which RRM is the most cost-effective treatment.

Results from their model, published in JAMA Oncology, indicated that mastectomy was a cost-effective treatment for women aged 30 or above who have a one in three chance (35% risk) or greater of getting breast cancer in their lifetime This suggests there is scope to offer RRMs beyond those carrying the specific BRCA1/ BRCA2/ PALB2 genetic mutations.

Using data from women aged between 30 and 60 years, results from their simulations showed that offering RRM to women in this cohort could potentially prevent 6,500 of the 58,500 cases of breast cancer that are diagnosed every year in the UK.

Undergoing risk reducing mastectomy (RRM) is cost-effective for women 30-55 years old with a lifetime breast cancer risk of 35% or more.

These results can support additional management options for personalised breast cancer risk prediction, enabling more women at increased risk to access prevention. Offering RRM could both save lives by preventing cancers and provide good value for money for the NHS."

Dr. Rosa Legood, Associate Professor at LSHTM

Professor Ranjit Manchanda, Professor of Gynaecological Oncology at Queen Mary, said: "For the first time, we define the risk at which we should offer RRM. Our results could have significant clinical implications to expand access to mastectomy beyond those patients with known genetic susceptibility in high penetrance genes- BRCA1/ BRCA2/ PALB2 - who are traditionally offered this.

"This could potentially prevent ~6,500 breast cancer cases annually in UK women. We recommend that more research is carried out to evaluate the acceptability, uptake, and long-term outcomes of RRM among this group".

For their model, the researchers used guidelines from the National Institute for Health and Care Excellence (NICE) to determine whether a treatment is considered cost-effective. NICE deems a treatment cost effective if it typically brings one additional year of health for no more than £20,000-£30,000 per patient (known as the 'willingness to pay' threshold). The researchers' model used a threshold of £30,000/Quality Adjusted Life Year.

The study used data from women aged 30-60 years old with varying lifetime breast cancer risks between 17% and 50%, and who were either undergoing RRM or receiving screening with medical prevention according to currently used predictive models.

The authors acknowledged limitations in their research including the lack of data on the level of risk reduction from RRM for non BRCA women at increased risk, and the lack of long-term data on the quality-of-life implications of RRM.