Guidance

Protocols for the surveillance of women at higher risk of developing breast cancer

Updated 16 August 2023

Applies to England

The national cancer strategy requires the NHS breast screening programme (BSP) to manage the surveillance of women at very high risk of developing breast cancer to national standards across England.

This guidance is aimed at BSP providers, commissioners, organisations and individuals who refer women into the very high-risk programme. These organisations include genetics services, oncology services and the breast screening after radiotherapy dataset (BARD).

Women at very high risk eligible for screening in the NHS BSP are a subset of the high-risk group defined by the National Institute for Health and Care Excellence (NICE).

The NHS BSP screens very high risk women with digital X-ray mammography and/or magnetic resonance imaging (MRI) according to the frequencies published in this guidance.

The national breast screening system (NBSS) manages the invitation process and records all outcomes for women screened through the very high risk programme. Breast screening services should not use NBSS for the management of family history women identified to be outside the NHS BSP very high risk programme.

This revised guidance is applicable to all new referrals of women at very high risk (VHR) of breast cancer from September 2020. Women already participating in the VHR programme prior to this date can continue to be screened on their existing protocols until their 71st birthday.

Revisions to previous guidance

This guidance has been revised specifically to clarify the following points:

• which cohort of women is entitled to very high risk screening following radiotherapy to sites involving breast tissue (formerly referred to as ‘supra-diaphragmatic radiotherapy’)
• the breast density review process
• the interval to next screening appointment following a short term recall episode
• screening during pregnancy and lactation
• screening transgender and non-binary people

Accessing very high risk screening

Referrals into the NHS BSP should be through:

• a genetics service by a consultant clinical geneticist, genetic counsellor or an appropriately trained individual nominated by them
• the treating clinician (surgeon or oncologist) - for cancer patients found to carry a genetic mutation that meets the eligibility criteria for very high risk screening
• BARD - for women who received radiotherapy to sites involving breast tissue during treatment for lymphoma and non-lymphomas (where appropriate)

Oncologists wishing to refer women who received radiotherapy to sites involving breast tissue for cancers other than lymphoma, are advised to complete a BARD non-lymphoma patient referral-form and send to BARD on chn-tr.bard@nhs.net to confirm eligibility for very high risk screening, and subsequent referral if appropriate.

Referrers should make sure that all women referred meet the criteria for very high risk screening within the NHS BSP and include all required evidence.

Referrals by clinical genetics services or oncology centres

Women who meet the very high risk criteria should be referred to their local breast screening service. This includes women who are considering risk-reducing surgery.

Completed referral forms should be sent to a nominated generic email address for the appropriate breast screening service. The breast screening service must make sure that this inbox is accessible to more than 1 person and is monitored daily. Referrals should contain all the necessary information to demonstrate the individual meets the very high risk criteria and referrals must only be accepted using a breast screening referral form for women at very high risk with sufficient supporting evidence as required.

On receipt, each referral must be transferred to the named high risk coordinators or director of breast screening without delay and be reviewed to make sure the inclusion criteria have been evidenced. This review must be completed by a consultant radiologist, consultant practitioner or breast clinician experienced in the full range of triple assessment. In the rare occurrence where women fulfill more than one risk criteria for very high risk screening (for example, BRCA1 gene mutation and previous radiotherapy to breast tissue when aged 15), the lead clinician should make an assessment regarding the most appropriate surveillance protocol.

There should be a local protocol developed for ensuring that all referrals are acknowledged by the receiving service so that the outcome of the referral (rejected or accepted) is sent back immediately to the referrer. There should be annual audit (as a minimum) of reconciliation of cases referred between the screening service and referrers as outlined in guidance for organising a very high risk screening programme. The outcomes of the annual audit should be documented and discussed at local programme board meetings when available.

Once a referral has been accepted, the woman needs to be appropriately identified as very high risk on Breast Screening Select (BSS) and NBSS. Documentation should be scanned and uploaded to the woman’s BSS record. See more detailed information regarding these processes.

Referrals by BARD

BARD identifies all women in England below the age of 36 who have been treated with radiotherapy for lymphoma to sites involving breast tissue. This occasionally may include some non-lymphoma referrals where BARD have confirmed appropriate eligibility.

Women in this group who were treated with radiotherapy between the ages of 10 and 35 years are referred into the NHS BSP very high risk programme.

Women are identified from cancer registries and then cross matched against information held at radiotherapy treatment centres and with data from the radiotherapy dataset (RTDS) to determine eligibility for inclusion in the NHS BSP for very high risk screening by BARD.

The BARD team check the NHS numbers of women who fulfil very high risk criteria on the BSS call or recall system.

BARD writes to the woman’s GP to confirm screening remains appropriate and, if so, sends services a completed referral form. The service then issues an invitation for screening. This invitation must include the BARD patient information leaflet. This is sent to the service from BARD directly with the referral or is available online.

The service must subsequently confirm with BARD:

• that the referred woman has been registered onto BSS (on the pending list if referred before her protocol screening age) or both BSS and NBSS if she is due screening now
• if and when the referred woman attended screening, using the referral form on the Breast screening: very high risk women surveillance protocols page

There should be an annual audit (as a minimum) of reconciliation of cases referred between the screening service and referrers as outlined in guidance for organising a very high risk screening programme.

Threshold for screening women in the very high risk programme

The NHS BSP screens women at very high risk of breast cancer due to:

• a proven germline pathogenic variant in BRCA1, BRCA2, TP53, A-T homozygotes, PALB2, PTEN, STK11 or CDH1 or any other high risk gene based on testing in a clinically accredited laboratory
• having received radiotherapy to breast tissue during treatment for Hodgkin and non-Hodgkin lymphoma^{[footnote 1]}

The NICE familial breast cancer guidelines categorise women at increased risk of breast cancer into moderate or high risk categories.

Only a subset of those defined by NICE as being at high risk reach the very high risk group threshold used in the NHS BSP. This has previously been set at 8 times the relative risk of women in the general population.

To differentiate between the NICE and NHS BSP guidance, very high risk is defined by the NHS BSP as:

• women with a lifetime risk of 40% or greater due to a specific genetic abnormality in the woman or her family
• those receiving radiotherapy to breast tissue during treatment for Hodgkin and non-Hodgkin lymphoma between the ages of 10 and 35 years
• a small number of women who received radiotherapy to breast tissue during treatment for cancers other than lymphoma

How to calculate women at very high risk

A woman is considered to be at very high risk if she has a test result that identifies a germline pathogenic variant in a gene that would confer a 40% to 95% lifetime risk of breast cancer.

Some women may choose not to have genetic testing. In order to avoid a situation where a woman with a known pathogenic variant in her family is obliged to proceed with predictive genetic testing to access very high risk screening, the following risk assessment process will apply:

If a woman has not been tested but has a first degree relative with a germline BRCA1, BRCA2 or TP53 pathogenic variant, she has a 50% chance of carrying this variant. As a result, she will be eligible for very high risk screening from age 30 up to and including the age of 50. For such a woman to be eligible for very risk screening when aged between 25 and 29 years, she should have an 8%, 10-year risk confirmed by an NHS clinical genetics service (as detailed below by age cohort).

To access this, confirmation is required from the genetics service that a first degree relative carries a germline pathogenic variant. After the age of 50 a previously untested woman will be returned to the routine screening programme.

After the age of 50, a personal test result identifying a pathogenic variant is required to continue to access the very high risk programme, as the residual lifetime risk associated with a pathogenic variant will have reduced by this time. A woman with only a 50% chance of carrying this pathogenic variant would no longer reach the 40% lifetime risk threshold to access very high risk screening. More detailed information regarding these processes is available.

How to decide lifetime risk in absence of genetic test

Risk assessment completed by the NHS clinical genetics service, must provide clear confirmation of the level of risk using an NHS endorsed computer risk modelling software programme, BOADICEA (CanRisk) or Tyrer Cuzick. The 10-year risk estimate must be submitted with the referral proforma as evidence that the woman satisfies the appropriate risk at time of screening entry.

Age 25 to 29

A small proportion of women at very high genetic risk will meet the 8% threshold for screening earlier than 30 years of age. Assess 10-year risk for each year between 25 and 29 years to determine at what age the risk meets the 8% threshold and hence age at entry to screening. A woman should have an 8%, 10-year risk confirmed by an NHS clinical genetics service (required by the NHS BSP). This is required for all equivalent risk categories.

Age 30 to 39

The 10-year risk at age 30 should be determined by an NHS clinical genetics service (required by the NHS BSP) and screening requested if an 8%, 10-year risk is confirmed. This additional evidence is required for all equivalent risk categories except where a first degree relative with a BRCA1, BRCA2 or TP53 pathogenic variant has been confirmed.

Age 40 to 49

The 10-year screening risk at age 40 should be determined an NHS clinical genetics service (required by the NHS BSP) and screening requested if a 12%, 10-year risk is confirmed. This additional evidence is required for all equivalent risk categories except where a first degree relative with a BRCA1, BRCA2 or TP53 pathogenic variant has been confirmed.

Women with proven pathogenic variants in high-risk genes

Referrals for women aged 30 and above with a proven germline BRCA1/2 or PALB2 pathogenic variant can be automatically accepted into the very high risk programme, with supporting evidence.

Referrals for BRCA1, BRCA2 gene and PALB2 carriers aged between 25 and 29 years must include evidence of risk, using an NHS endorsed computer risk modelling software programme as detailed above, to be accepted into the very high risk programme.

Surveillance starts at 20 years for TP53, at 25 years for A-T homozygotes and at 30 years for PTEN, STK11 and CDH1. Evidence is required from the NHS clinical genetics service confirming the presence of a pathogenic variant and stating the name of the gene.

Women previously treated with total body irradiation

Women who have previously received total body irradiation are at an elevated risk of breast cancer in the years following treatment. However, there is insufficient evidence to show that the risk reaches the threshold to qualify this cohort of women for screening in the very high risk programme.

See Tests and frequency of tests for women at very high risk.

Queries over entitlement following previous radiotherapy

Most women who have had radiotherapy fields involving breast tissue at a young age are those receiving treatment for Hodgkin or non-Hodgkin lymphoma. However, other diagnoses may also result in similar radiotherapy treatment fields.

If a woman had radiotherapy involving breast tissue below the age of 36 years but it is unclear if she is eligible for very high risk screening within the NHS BSP, contact BARD for advice on chn-tr.bard@nhs.net.

Screening test

The screening test should be as indicated, depending upon a woman’s current age and referral reason. Where MRI is stated, but cannot be tolerated, or is contra-indicated, she and the lead radiologist should discuss and agree potential alternatives such as wide scanners.

Breast ultrasound is not routinely provided by the NHS BSP as a screening tool. If a woman cannot be screened with MRI, a unit may elect to perform ultrasound screening for an individual. This should only be carried out following a full discussion and documentation regarding the potential benefits and limitations of the test.

This is supported by NICE guidance, which states:

• do not routinely offer ultrasound surveillance to women at moderate or high risk of breast cancer but consider it:

  • when MRI surveillance would normally be offered but is not suitable (for example, because of claustrophobia)
  • when results of mammography or MRI are difficult to interpret

Process before MRI screening

Local protocols should be followed regarding MRI with gadolinium enhancement. There is also Royal College of Radiologists guidance. If a woman cannot tolerate gadolinium or refuses to have MRI with a contrast agent, MRI should not be performed. Depending on the woman’s age and breast density, other modalities such as mammography may be offered. This decision must be made and documented by clinicians locally.

Review of background density

Some of the screening protocols state that women aged 50 or over require mammography with or without an MRI. The decision for MRI is based on an annual review of breast density.

Women covered by this guidance should have both procedures up to and including the age of 50. At the screen when the woman is aged between 50 and before her 51st birthday, breast density should be reviewed by the reporting image reader at the time of her breast screening. If the mammogram shows an entirely fatty breast (BI-RADS A, see the BI-RADS Atlas - Reporting System), MRI is unlikely to add value and her screening protocol should change to mammography only for the remainder of her screening invitations. The review is undertaken by one image reader and the outcome recorded on NBSS. The breast density measurement can also be reported using an automated tool which can measure density giving a BI-RADS score. If there is uncertainty over the category of breast density, a further image reader should be consulted.

If a decision is made that a woman no longer needs MRI due to a breast density classification of BI-RADS A, her protocol should be updated within the client record on NBSS to show mammography only is required for her subsequent screening appointments and a letter should be sent to the woman and her GP informing them of this change to her screening protocol. More detailed information regarding this process is available. If on review her breast density BI-RADS classification is B to D, no change to her protocol is required.

The woman’s breast density is likely to reduce over time. If the initial breast density review indicated that the woman should continue to have MRI and mammography, images should be reviewed annually when a woman is screened (at the time of screening) up to her 71st birthday (or beyond on an annual basis if she opts to self-refer for screening). She should remain on an MRI plus mammography protocol until a clinical decision is made that MRI is no longer required. Annual reviews of breast density are no longer required once a woman has been changed to a mammography only protocol.

Where women move between services, the receiving service should contact the previous service to determine the outcome of the density review and set her protocol on NBSS accordingly.

Any women who are newly referred into the VHR programme after the age of 50 should have both MRI and mammography performed at the initial screen and a breast density review undertaken at this point to assess whether MRI is required at subsequent screens. If breast density is not initially classified as BI-RADS A, annual review should take place thereafter.

Baseline MRIs for women considering risk-reducing surgery

A woman newly referred into the programme and meeting the very high risk criteria is entitled to MRI screening in accordance with her protocol, even if she is considering risk-reducing surgery. This may help identify malignancy before surgery.

After risk-reducing surgery, a woman can either opt out of the programme by signing a form or the service can cease the woman if there is clinical evidence that bilateral mastectomy has been carried out. Details are available in the opting out of breast screening guidance, which include copies of the required form.

Policy for short-term recalls following screening assessment

Short-term recalls (STR) are defined as a further appointment to attend a screening assessment indicated before the normal screening interval (one year).

All women on short-term recall should have previously attended assessment. Short-term recall should not be used as a routine outcome following assessment. Every effort should be made to obtain a definitive diagnosis at initial assessment. Short-term recall should only be made in exceptional circumstances and with fully informed consent as it is associated with significant anxiety.

If recall is within 6 weeks of the original assessment then it should be part of the same episode. If recall is after 6 weeks, it should be logged on NBSS as a short-term recall (STR) episode. The default period for VHR short-term recalls is 3 months following assessment. No more than 6 months should elapse between previous screening assessment appointments and the STR episode.

Following the STR appointment, the next test due date (NTDD) should be reset as follows:

• at 12 months from the date of the STR attendance, if the woman’s routine screening protocol (MRI and/or mammogram) is repeated at the STR appointment
• at 12 months from the date of the original screen, if the STR appointment did not include complete imaging of both breasts, compatible with the woman’s VHR screening protocol. Some women deviate from their recommended protocol, for example, if they cannot tolerate MRI. In this instance, she should have her personalised mode of routine screening of both breasts, within 12 months of her previous complete screen (either STR or previous VHR screen)

If the STR appointment is delayed beyond 6 months due to clinical factors or delay by the woman, and the woman did not have her complete VHR screening protocol repeated at the STR appointment, the following should apply:

• if the complete VHR protocol includes MRI only, her NTDD moves to 12 months from the date of the original screen (for MRI)

• if the complete VHR protocol includes MRI and mammography, her NTDD moves to 12 months from the date of the original screen (for MRI) and mammography should be requested 6 months after this date. Her next VHR screening invitation should be for both MRI and mammography (as per protocol), 6 months after the date of her previous screening mammography appointment.

Worked example 1 - woman on MRI and mammography protocol:

• date of initial screen - 1 January 2022 (MRI and mammography)
• screening assessment - 1 February 2022
• short term recall - offered August 2022
• short term recall - attended October 2022 (mammography only undertaken)
• NTDD for VHR screening 1 January 2023 (MRI examination)
• NTDD for mammography only 1 July 2023 (6 months after MRI examination)
• next test due date for next VHR screening with both MRI and mammography 1 January 2024

Worked example 2 – woman on mammography only protocol:

• date of initial screen - 1 January 2022 (mammography only)
• screening assessment - 1 February 2022
• short term recall - offered August 2022
• short term recall - attended October 2022 (mammography on one breast only undertaken)
• NTDD for VHR screening 1 January 2023

When very high risk screening stops

A woman at VHR should continue to be invited for screening up to her 71st birthday or up to the age of 50 where she is determined to be at an equivalent, but untested, risk level.

When a woman reaches 71 years of age routine invitations for very high risk screening will stop. At this stage she is entitled to self-refer for screening. For women in the very high risk programme, this will be annual screening in accordance with her VHR screening protocol. At this point, if her breast density score is not BI-RADS A, screening should continue to include MRI and mammography and be subject to annual review.

Eligible women over the age of 70 should be informed that they need to contact their local screening service each year to arrange annual screening.

Screening women in pregnancy and lactation

Screening with mammography can be safely performed during pregnancy but as mammographic density increases during pregnancy and lactation, its effectiveness is reduced. Women can be screened during lactation but are advised to breastfeed or express milk prior to the examination. Shielding is not considered necessary due to the low radiation dose of mammography. See guidance on using shielding on patients for diagnostic radiology applications.

MRI during pregnancy is not recommended due to the high level of background parenchymal enhancement during pregnancy and lactation. However, each woman should be reviewed and Royal College of Radiologists (RCR) symptomatic breast screening imaging guidance covering imaging surveillance in pregnancy and lactation should be followed.

If women opt to postpone screening due to pregnancy or lactation, MRI screening should resume 3 months both postpartum and following cessation of lactation.

Screening transgender people

Transgender (trans) men and non-binary people who have breast tissue and fulfil the criteria to be eligible for very high risk screening will be invited for screening if they are registered with a GP with a gender marker of female or indeterminate. If they are registered with a gender marker of male, they will not be automatically invited. They will need to speak to their GP who can arrange for a referral to a local hospital for the appropriate screening on an annual basis.

People identifying as trans women who have breast tissue and are registered as a female and who are eligible for very high risk screening will be invited for screening. For more information, see NHS population screening: information for trans and non-binary people.

Related guidance

Technical guidelines on the use of MRI for the surveillance of women at higher risk must be followed. This includes information relating to physics quality control and guidance for radiologists reporting MRI.

There are also practical guidelines on setting up and providing screening for women at higher risk.

1. Younger women treated with radiotherapy due to breast cancer (under 50) are excluded from the NHS BSP very high risk programme. ↩