Promoting awareness of 5FU toxicity and
the need for DPYD/DPD testing

Our Motivation

We have been motivated to form this Alliance because of our own experience of the terrible effects of 5FU or capecitabine toxicity that has devastated so many lives. We know that we are not alone and we welcome any individuals or families affected to join our cause. We want to prevent others being injured or stop others suffering in the way we or our families have suffered. We recognise that 5FU and capecitabine are highly effective treatments for cancer and we do not wish to prevent their safe use, meaning only after the person who will receive them has been tested for DPYD deficiency. However, it is important to know that the first and only dose of 5FU can be fatal if people are completely deficient in the DPYD gene.

Whilst a genetic test is now available and clinically proven to identify almost all people at risk of toxic effects before they receive chemotherapy, this is still not widely available to patients on the NHS. This means that each year, as many as 5,000 people are put at risk of severe toxic effects and up to 500 people die in the UK.

You can help change this situation:


Our Aim

To Make comprehensive,
clinically proven DPYD testing
freely available to all cancer
patients through the NHS
before treatment with
5FU or capecitabine.

How to spot the warning signs of 5FU or capecitabine severe toxicity

If you see signs of abnormal toxic effects, demand to speak to your oncologist immediately

Click here for fact sheet
Click here for video

About 5FU and
DPYD testing

One of the main ways doctors treat cancer is with chemotherapy. This comes in several forms, but one of the most commonly used drugs to treat cancers including breast cancer, head and neck cancers, anal cancer, stomach cancer and colon cancer is called 5FU or capecitabine.



The urgent need for DPYD testing


Aims and objectives of the 5FU Test Alliance

Know the risk of 5FU chemotherapy
Association Victimes 5-FU