ask about your risk of VERY serious side effects before starting 5-FU Chemotherapy


Last updated: 16 July 2021


Many Small Streams Make One Big River 

-- French Proverb



It will take the efforts of many individuals to create a change in the standard practice of administering 5-FU, a practice that fails to assess the risk of patient toxicity.


Research continues to identify genetic factors that contribute to DPD deficiency.  More importantly, some researchers are showing that compromised DPD levels are also factors of non-genetic conditions (see Research, Risk Awareness). 


While the reported rate of toxicity appears compelling, many practitioners hold to the belief that DPD deficiency is a very rare condition not worth the effort to detect.  Even if there was wide agreement on the need to screen patients, care providers have not identified a standard test.


Hope is not lost. Pre-treatment testing is now recommended in France, the UK, Germany, Austria, Switzerland, and the Netherlands. The European Medicines Agency recommended (2020) the use of either genotyping or phenotyping and adjusting doses before the start of treatment.


The US has not followed suit. At least not yet.  A new citizen's petition to the FDA (2020) and to the NCCN (2021) have recommended the US adopt the same improved standard of care now practiced in Europe.


In the meantime, before you start treatment, be sure to discuss with your oncologist, or genetic counselor,  how best to manage the risk of a toxic reaction before starting treatment. 


The more patients become aware of this risk of DPD deficiency and discuss it with their oncologists and genetic counselors, the greater the chance personalized treatment (pre-treatment screening and dose management) will become commonly accepted.


So get the care you deserve and have this important conversation with your care provider; not only will you be serving yourself and your family, you will  do your part to form the Big River that can lead to changing today's medical practices.





Colorado River, UT
Colorado River, UT