Indeed, in some patients who have total or partial deficit of a particular enzyme, the toxic effects of 5-FU are increased tenfold.
Tests exist to screen patients at risk, but until recently, some hospitals and oncologists did not use them. Surprisingly, at the moment, the systematic detection of DPD deficiency is not recommended in any country.
In a note recently sent to health professionals, the National Agency for Drug Safety (ANSM) merely recollected the existence of tests without making them mandatory citing a lack of “consensus […] on screening methods”. The National Cancer Institute (Inca) has indicated that an independent scientific assessment of the different tests has been launched to identify which ones are most relevant. The conclusions should be issued in the coming weeks.
Used for more than sixty years, 5-Fluoro-Uracil (5-FU) is one of the most prescribed drugs in the treatment of cancerous tumors.
According to a report by the regional pharmacovigilance center in Marseille, serious adverse reactions related to 5-FU were observed in 1,505 people between 2005 and 2015 in France. Of these, 133 died after receiving the treatment, and 155 people had a poor prognosis.
By multiplying that number by 5 (equivalent to 50 years of chemotherapy), more than 7,500 people have become much sicker than before, at least 1,000 people have died, and about 800 people have a poor prognosis.
5-FU is a very powerful medicine. By preventing DNA synthesis in rapidly dividing cells, whether cancerous or not, it condemns them to certain death. Among the undesirable effects identified are hematological disorders (reduction of the number of platelets and immune cells in the blood), digestive disorders (diarrhea, vomiting) and cardiac disorders. These serious effects are seen in 15% to 40% of patients receiving 5-FU.
It turns out that most of these 5-FU poisonings could have been avoided. Indeed, the main cause of these severe toxicities has been known since the 1990s. This is the lack or absence of an enzyme, dihydropyrimidine dehydrogenase (DPD), responsible for inactivating 5-FU in the liver.
But for people who have a deficit, the standard dose of 5-FU administered to them is too large compared to what they should receive, which induces toxicity that can be fatal. Clearly, administering 5-FU to a patient without knowing whether he has the enzyme or not, is like playing Russian roulette.
The test requires a simple blood test 10 days before treatment. It is performed in many laboratories throughout France, but it is not mandatory despite regular deaths caused by 5-FU in people with DPD deficiency.
Until a decision is made, it is vital to warn everyone about the danger of blindly prescribing 5-FU-based chemotherapy.
Each patient has the right to demand a screening test and a chemotherapy appropriate to the test results.
The negligence of many chemotherapy prescribers leads to a rapid death of hundreds of patients every year. It is therefore urgent to impose this test on practitioners.
The Anti-Zionist Party is surprised that a problem that can be easily solved by practicing the proper tests has taken so long to be revealed.
Why wait for nearly thirty years to try to remedy this, and still, no decision has been taken for the moment.
The answer, once again, certainly lies in the influence of the pharmaceutical lobby on our health system; an influence that still places financial interests above the health of patients.
Fortunately, there are many honest doctors who are aware of this and try, at the risk of putting their career at risk, to alert others. An alert which finds support and interest only in a few rare therapists who maintain their independence vis-à-vis the overpowering lobbies of the drug.