Dihydropyrimidine dehydrogenase (DPYD) gene testing to increase safety of chemotherapy for cancer patients.

Fluoropyrimidines, such as 5-fluorouracil (5FU), capecitabine and tegafur, are an important and common type of chemotherapy medicine for treating cancer (e.g. breast, colon, rectal, and head and neck cancer).

They are associated with a small risk of side effects (drop in white blood cells, nausea, vomiting, diarrhoea, mouth ulcers and sore hands and feet). There is a risk of potentially life-threatening side-effects if a patient’s genetic make-up is such that they cannot break down the drug properly. This is called DPD deficiency.

Pharmacogenomic testing prior to prescribing fluoropyrimidines can help to identify those patients, who are at an increased risk of experiencing treatment-related toxicity.  Affected individuals can then receive treatment tailored to their needs (e.g. a lower dose or alternative type of medication).

This national project is led by NHS North West and NHS South East GMS Alliances.  We are supporting the national dihydropyrimidine dehydrogenase (DPYD) gene testing project in our region.  It aims to ensure that DPYD testing is equitable, standardised and optimised across England and that it is clinically effective by looking for other potential variants, which will help to ensure that testing is effective for all communities and ethnic backgrounds.

What is DPYD and why is it important?

The test works by identifying specific genetic variants in the DPYD gene, which indicate that an individual lacks the enzyme responsible for breaking down certain types of chemotherapy drugs, allowing them to be removed from the body.

Tests for common genetic variations in the DPYD gene can now be ordered by all clinicians through the Genomic Medicine Cancer Test Directory.

What have we done?

Initially, the NHS North East and Yorkshire Genetic Medicine Service Alliance (NEY GMSA) supported the national project by working with NHS Trusts to map the clinical pathway and encouraging completion of a NHS professional survey, to understand the processes in place for DPYD testing.

Following the introduction of DPYD testing across all hospitals where these chemotherapy drugs are being used, the NEY GMSA worked in collaboration with local hospitals to audit DPYD testing, ensure equitable access to DPYD testing, utilisation of DPYD in clinical decision making, and to raise awareness of pharmacogenomics.

The NEY GMSA has engaged with patient and public representatives to captured cancer patients’ experiences and perceptions of DPYD pharmacogenomic testing. This work will inform future engagement and shape the NEY GMSA strategy for pharmacogenomics.  We are also supporting Macmillan genomics working group with patient information development for DPYD

Each month, 115 hospitals across England refer patients for testing, with NHS Genomic Laboratory Hubs (GLHs) processing approx. 3,100 samples every month.

What’s next?

DPYD gene testing is now implemented in relevant NHS Trusts nationally and the project is complete.  The NEY GMSA continuing to support and review the service with NHS Trusts.

If you’re an NHS colleague you can order DYPD testing here

“I feel it is important that we become less afraid of the term ‘genetic’ as it is going to become more involved in cancer treatment.”

“Always important to empower patients with this (genetic) level of knowledge and increase partnership working.”

Quotes from members of the Northern Cancer Alliance Public Involvement Accountability Forum online survey for ‘DPYD Testing Patient and Public Feedback.’


Learn more about pharmacogenomics – the study of how genes affect the way the body processes and responds to medicines.
What is pharmacogenomics? – Genomics Education Programme (hee.nhs.uk)

Further information on DPD deficiency can be found on the Cancer Research UK website
DPD deficiency | Cancer information | Cancer Research UK

The Scouse Scientist Ep 9 – DPYD: a pharmacogenomics test that could literally save your life – YouTube

Personalised medicine approach for fluoropyrimidine-based therapies –  Guidelines for clinical staff with guidance as to which patients should receive a DPD test and then subsequently to provide advice to clinical staff on the outcome of that test.
Publications | UK Chemotherapy Board

Clinical Commissioning Urgent Policy Statement: Pharmacogenomic testing of DPYD polymorphisms with fluoropyrimidine therapies
NHS England » Clinical Commissioning Urgent Policy Statement: Pharmacogenomic testing for DPYD polymorphisms with fluoropyrimidine therapies

How can I learn more?

Contact us to learn more.

[email protected] 

Our project team are:

Emma Groves, Lead Pharmacist NEY GMSA and Pharmacy Subject Matter Expert – Genomics education programme

Joanne Wragg, Director of Pharmacy and Medicines Management and NEY GMSA Director of Pharmacy and Medicines Management

Jackie Cook, Clinical Director, NEY GMSA