Debate on the potential merits of equal patient access to tissue freezing for advanced brain cancer treatment, diagnostics and research

What is tissue freezing?

Tissue freezing, called cryopreservation, is a method for preserving biological samples. Freezing samples of body tissues allows them to be stored without the use of chemical preservatives like formalin, which allows them to be used for molecular studies, including genetic testing.

Flash-freezing, also known as snap-freezing, is a technique for freezing tissue samples by rapidly cooling them to very low temperatures. This helps to avoid the formation of ice crystals and preserves the structure of body tissues.

How is tissue freezing regulated?

The Human Tissue Authority (HTA) regulates the storage and use of tissue samples in England, Wales and Northern Ireland under the Human Tissue Act 2004. The HTA licences organisations that remove, store and use human tissues, including for medical treatment and research.

In Scotland, the Human Tissue (Scotland) Act 2006 governs the removal, storage and use of body organs and tissues from deceased people only. The use of body tissues from living donors for research is governed by the requirements of common law. The NHS Research Scotland Human Tissue Accreditation Scheme (PDF) is used to ensure that organisations who work with human tissue meet required standards for tissue collection, storage and use.

Section 45 of the Human Tissue Act 2004 regulates DNA analysis of human tissues, and applies throughout the UK. The act makes it an offence to hold ‘bodily material’ with the intent to analyse its DNA and use the results for research without proper consent (PDF).

How can frozen brain tissue be used to help patients with brain cancer?

Frozen samples of brain tissue can be used in the diagnosis and treatment of brain cancers, and in research studies.

Brain tissue samples can be taken during brain surgery, including surgery to remove all or part of a brain tumour, or a biopsy (where a smaller sample of a tumour is removed for testing).

Samples of brain tissue are analysed to diagnose brain tumours, and understand the type and grade of tumour to guide treatment decisions. Whole genome sequencing for brain tumours involves sequencing DNA taken from a brain tumour, to identify genetic mutations and provide a more precise diagnosis and prognosis for an individual patient, and for research.

Frozen brain tissue can also be stored in a tissue bank for future use. This could potentially include being used as part of new diagnostic or treatment options that are still being developed, or in research studies.

In 2023, the British Neuro-Oncology Society (BNOS) published a position statement, Guideline for tissue sampling of brain tumours. This statement explains that patients increasingly request that tissue samples from their tumour are frozen, “for later testing or evolving therapeutic options”. BNOS recommends that during brain cancer surgery, enough tissue should be collected to allow a sample to be frozen and used for genetic testing, wherever possible.

Can all brain cancer patients access tissue freezing?

The BNOS position statement acknowledges that there is significant variation in the availability of genetic testing for brain tumours across the UK. It explains that there are multiple barriers to obtaining frozen brain tissue samples and conducting genetic tests, including:

• Not obtaining enough tissue during sampling to be used for diagnosis and genetic testing
• A lack of awareness and knowledge about how to act on the results of genetic testing, and about new treatments that rely on these tests
• Variation in how samples are collected and submitted in different organisations, leading to delays, and in how test results are reported and delivered.

In September 2024, the Tessa Jowell Brain Cancer Mission published a report, Closing the Gap, which estimated that only 5% of UK adult brain tumour patients had their brain tumour sequenced via the NHS. The report describes the process for whole genome sequencing, from sample collection to analysis. Part of this process is snap freezing samples in liquid nitrogen, storing samples at -80 degrees Celsius, before being transported to other sites for processing and analysis. The report described multiple barriers to providing whole genome sequencing, including staff concerns about system capacity, slow turnaround times, a lack of non-standard treatments and limited access to clinical trials.

The charity Brain Tumour Research has also drawn attention to variations in the availability of “basic infrastructure” to support brain tissue freezing, including access to freezers to store samples and a lack of workforce capacity. The charity has also noted a lack of commissioned genome sequencing services in Scotland and Wales.

Brain Tumour Research provides the secretariat for the All Party Parliamentary Group (APPG) on brain tumours and notes that the issue of tissue storage was discussed at its meeting in September 2025 (PDF).

The charity Brainstrust has published an information sheet for patients, Know how to talk with your neurosurgeon about tissue collection (PDF).

Government policy

In November 2025, the government said that there were no plans to expand flash-freezing facilities for brain cancer tissue. It says that existing services offer comprehensive tests, including the analysis of brain tissue but that it does not hold information about how many NHS trusts have facilities for flash freezing brain cancer tissue.

The government also says that NHS England has published national guidance for the whole genome sequencing of solid tumours, including brain tumours, and that approaches to handling fresh tissue have been reviewed.

Further reading

Commons Library, Rare Cancers Bill 2024-2025, 9 July 2025

Commons Library, Debate on research and treatment of brain tumours, 6 May 2025

Commons Library, Brain tumour research funding, 7 March 2023