Biomarkers and cancer precision medicine

A set of consensus statements on the use of biomarkers in cancer research and treatment were released this month. They aim to accelerate the discovery, development, and adoption of biomarkers into the healthcare system and enable wider use of precision medicine for cancer.
The statements, developed by the Institute of Cancer Research alongside expert stakeholders, detail current bottlenecks and areas that hinder the development and implementation of biomarkers in cancer.

What are biomarkers?

Biomarkers are, as their name suggests, biological markers that are measurable and that help to identify disease or other processes occurring within an individual. Biomarkers can be:

• Diagnostic, distinguishing between those with a particular disease and those without
• Prognostic, helping to predict a patient’s outcome
• Therapeutic, which predict how a patient will respond to a given treatment.

Biomarkers are a diverse group and can include proteins, genes, markers of gene expression, metabolites, or areas identified using imaging, such as lung nodules on a CT scan.

Biomarkers allow for a more personalised and precise approach to medicine by giving insight into the biological processes happening within the patient. They support accurate and timely diagnoses and prognoses, and more informed treatment choices. Precision medicine based on biomarker tests should reduce uncertainty for patients, increase treatment success rates, and reduce the frequency of side effects in response to treatment.

The consensus statements focus on prognostic and therapeutic biomarkers in cancer precision medicine. But many of the considerations can be applied more broadly to biomarkers in other disease areas and even to other innovative healthcare approaches.

Increasing awareness of biomarker benefit

Biomarkers need to be measurable, accurate, with a proven association with a particular outcome. This requires research, validation, regulation, and approval of tests that can measure the biomarker of interest, similar to the approach used for drug development. However, as highlighted in the consensus statements, the pathway from research to approval is currently unclear for biomarkers, in contrast to that for drug development.

Wider knowledge of the opportunities associated with biomarkers among key stakeholders, including clinicians, patients, funders, and regulators, may create opportunities for improving the current situation. Indeed, if oncologists and patients become aware of the potential benefits associated with the use of biomarkers, the consensus statements conclude this may lead to advocacy groups to campaign for their adoption. This would put pressure on decision makers to prioritise their implementation, as already happens for new innovative cancer drugs.

Learnings from genomics

Genetic biomarkers seem to be treated differently to other biomarkers in the NHS, having a separate system in place in the form of the Genomic Medicine Service and National Genomic Test Directory. Recognising this, one statement suggests that testing for other biomarkers in the NHS could in fact benefit from a similar process to that adopted for genetic testing.

The National Genomic Test Directory lists all available genetic tests, including those for cancer. There is a process for adding new tests when there is sufficient evidence to do so. New tests are submitted to a panel of experts who review the associated evidence and decide whether it should be made available. Although this process is still being refined, it represents an improvement to the use of other biomarker tests within the NHS, which lack a single centralised repository and pathway to implementation and could benefit from a more standardised approach.

Equitable access

A significant benefit of the National Genomic Test Directory is its potential to achieve a consistent service across the country. Standardisation of genomic testing should enable equitable access and thus avoid a postcode lottery, which is all too often associated with new healthcare innovations. This is an important consideration when implementing new tests to ensure current health inequalities are not exacerbated.

The COVID-19 pandemic has put in sharp focus the need for reducing health inequalities and the consensus statements recognise this need. The opportunities associated with precision medicine should be available for everyone, regardless of their area or situation. Furthermore, the statements recognise the need for monitoring the use of biomarker tests across the UK to track progress and provide awareness of where equitable access is not being achieved.

Workforce challenges

It is important to remember that these statements sit within a wider landscape and, as they acknowledge, there are significant workforce challenges facing the NHS at the moment. The addition of new biomarker tests may increase burden on the existing workforce, both in volume of work and requirement to develop new expertise across a variety of disciplines, including but not limited to oncologists, pathologists, radiologists, and clinical scientists.

Careful consideration of how to adopt more widespread biomarker use without overloading an already thinly spread workforce will be required, alongside engagement and support for use of biomarkers to benefit patient care.

On the other hand, the more extensive use of biomarkers may provide opportunities to reduce workload in some areas if a single test could replace several individual tests, which together constitute a significant workload. Recognising this, the statements highlight the importance of large genomic panel tests, additionally citing the increased information that can be gained on many areas at once and the potential for feedback loops back to research to identify new biomarkers.

Bringing the benefits to patients

These consensus statements highlight some key considerations and bottlenecks associated with increasing the use of biomarkers in the cancer care pathway but also highlight wider challenges for the healthcare system. For new innovations to have the best chance of positive impact for patients, all aspects of their adoption need to be considered and addressed prior to implementation.

The healthcare workforce and allied professions need to come together to face these challenges, ensuring no one is left out and that the benefit of new technologies, including new biomarker tests, are clear to everyone involved.

The potential benefits of precision medicine and obvious requirements for new and better biomarkers to make this happen mean the considerations set out in the consensus statements are important and timely. They provide a perspective that is specific to – but often applicable beyond – biomarker use in cancer healthcare.