Guidance

Digital histopathology in the NHS cancer screening programmes

Published 5 February 2025

Applies to England

The majority of the processes and governance issues relating to the use of digital histopathology in screening programmes are also relevant to digital pathology use in all areas of histopathology and cytopathology practice, and governance issues are essentially similar to those for glass slide assessment.

1. Implementation

The Provider and histopathologists within should apply Royal College of Pathologists Best Practice Recommendations for Implementing Digital Pathology for implementation, validation and subsequent use, including ongoing monitoring and overall quality assurance in pathology departments. The provider must ensure that appropriate training and validation are undertaken by all pathologists using digital histopathology, as it is for glass slide interpretation.

It is the responsibility of the provider to supply the necessary equipment and resources for digital histopathology (such as scanners and monitors) and ensure their regular maintenance and appropriate optimisation.

Pathologists should inform their commissioners, their internal screening programme governance groups and the Quality Assurance service, when they start to utilise digital histopathology for diagnosis, both in the validation and post-validation phases. Digital reporting also has to be declared in the scope of practice for UKAS accreditation, once validation has been completed.

Local commissioners of screening should follow implementation through their programme board meetings (or equivalent). Providers must not implement if adequate means of monitoring histology performance are not in place (e.g. failure to return mandatory data returns). Further to this the UK National Screening Committee recommends that there should be regular audits to gauge the performance of digital pathology in the screening programmes, as part of implementation. Providers should put in place IT arrangements to support easy identification, data analysis and audit of material reported digitally separately from those reported on glass slides.

With regards to suitability and validation of digital pathology systems for use in screening histopathology, providers should purchase through the NHS Supply Chain framework.

2. Validation process specific to screening programmes

When undertaking the validation process for pathology reporting, those pathologists who will subsequently report screening cases must ensure that the initial validation process includes an appropriate range of lesions encountered in routine practice. This should specifically incorporate screening specimens, so that they are aware of potential difficulties and difficult lesions encountered and are professionally assured of the robustness of their individual initial validation exercise.

Pathologists are encouraged to have a low threshold to flag any issues, where the root cause could be the utilisation of digital pathology, to commissioners and the Quality Assurance service as well as through usual internal routes. This will ensure that any potential issues that could adversely affect the programme, are swiftly identified and risk assessed. This must include cases where there are significant disagreements (not minor discrepancies which may arise as difference of opinion). There should also be a low threshold for dissemination of learning from such cases, for example at screening QA learning and quality improvement pathology meetings.

Screening incidents involving digital pathology (as for incidents with glass slides) should be reported without delay. National monitoring of these should be in place across screening programmes. Incidents relating to symptomatic services should be reported as per normal practice.

3. Quality assurance

Professional clinical advisors (PCAs) supporting the programme and advising services using digital pathology for screening-derived case reporting should ideally themselves have experience in the use of digital pathology in a diagnostic setting, although it is recognised that this will not always be possible. In this situation, advice should be gained from PCAs within the programme professional network who are more experienced with the use of digital pathology.

4. Impact and next steps for NHS Bowel Cancer Screening

• It is recognised that the reporting of endoscopically removed/biopsied polyps and other lesions from the colon will already form a major component of the routine diagnostic workload in non-screening settings, within departments using digital pathology and/or glass slide-based reporting.
• The BCSP Pathology Diagnostic EQA Scheme has always been based on the use of digital images and the upcoming new version of this scheme will again use this technology.
• Remote viewing by PCAs of digital pathology images created by screening programmes may or may not be possible, depending on the digital pathology systems in use. Therefore, review of cases for QA visits or interventions are likely, at present, to be based on the examination of glass slides.
• QA visits to laboratories using digital pathology for BCSP-derived case reporting should include a review of the use of digital pathology for this purpose, e.g., documentation of digital pathology validation, evidence of the use of digital pathology in this setting and review of a selection of BCSP cases reported using digital pathology.
• Any problems arising with digital pathology in the context of the BCSP should be discussed with regional commissioners and the Quality Assurance service.

5. Impact and next steps for NHS Breast Screening

• Remote viewing by PCAs of digital pathology images created by screening programmes may or may not be possible, depending on the digital pathology systems in use. Therefore, review of cases for QA visits or interventions are likely, at present, to be based on the examination of glass slides.
• When a formal QA visit is undertaken, review should include any false positive cases, an appropriate range of cases e.g. based on national pathology audit data and Quality Assurance service knowledge, as well as cases recognised to be potentially more difficult on digital sections. The number need not be any greater than at present.
• QA visits to laboratories using digital pathology for breast screening-derived case reporting should include a review of the use of digital pathology for this purpose, e.g., documentation of digital pathology validation, evidence of the use of digital pathology in this setting and review of a selection of screening cases reported using digital pathology. Any problems arising with digital pathology in the context should be discussed, including review of a selection of cases in which deferral to glass slide reporting was considered to be necessary.
• It is noted that one-third of laboratories are low caseload breast screening biopsy sites, which will represent a challenge to a safe transition to digital pathology reporting, as it is for analysis of their results from glass slides.

6. Impact and next steps for NHS Cervical Screening

• The validation phase should encompass 3 months of routine clinical practice to ensure safety. For the purpose of the validation, cervical histopathology is not considered a low volume specialty.
• It is the responsibility of the individual pathologist to document evidence of the validation. This will not be required by the Quality Assurance service but may be required in the context of incident investigation or the national invasive cervical cancer audit, for example.
• The Quality Assurance service will continue to monitor routine data collations, without specific data on the use of digital pathology. However, staff are encouraged to audit use of digital reporting. For example:

1. Proportion of cervical histopathology slides reported using digital method.
2. Proportion of cases where pathologist has reverted to a glass slide for reporting.

• The quality management of digital pathology use within an organisation performing Cervical Histopathology comes under the umbrella of UKAS and laboratories must meet these requirements.
• Workload standards will remain in place, and there will be no minimum number for digital pathology introduced.