Therapeutic drug monitoring of 5-fluorouracil in patients with cancer
Research type
Research Study
Full title
Determining the value of establishing a therapeutic drug monitoring assay for the steady state measurement of 5-fluorouracil in patients with cancer.
IRAS ID
325811
Contact name
Allison Chipchase
Contact email
Sponsor organisation
Norfolk and Norwich University Hospital
Duration of Study in the UK
0 years, 10 months, 30 days
Research summary
5-fluorouracil (5-FU) is a chemotherapy drug which is commonly used to treat cancers in the gut, breast and pancreas. In the body, approximately 80% of 5-FU is broken down by the liver, and then excreted in the urine and faeces. Roughly, a further 17-19% of 5-FU will be excreted unchanged in the urine. Therefore, only 1-3% of the drug given to the patient ends up at the site of the cancer, and contributes to destroying cancer cells. When calculating how much drug each patient should be given, this is taken into account.
However, some patients (approximately 1 in 20), cannot break down 5-FU as efficiently as expected. For these patients, the risk of experiencing toxic side effects is greater. All patients who start 5-FU treatment are tested to ensure that they will be able to break it down in the expected way, which reduces the chance of patients experiencing the dangerous consequences caused by an overdose.
Nevertheless, at present, 5-FU levels are not routinely monitored in patients being treated with this drug. Therefore, just as some patients are incapable of breaking down 5-FU, other patients may break it down more quickly, meaning less of the drug will be available to attack the cancer cells. This could lead to poorer outcomes for the patient, compared to if they were given a higher dose of 5-FU, because the cancer cells would not be treated as rigorously as possible. This means the cancer cells have more opportunities to grow, spread, and cause damage.
This project will investigate the effects of monitoring patients undergoing 5-FU treatment, using an analytical technique known as mass spectrometry. The purpose of this is to determine if the patients involved in the trial are being given the correct amount of 5-FU for it to treat their cancer most effectively.Lay summary of study results:
The aim of this project was to set up a test using a laboratory technique known as mass spectrometry, which will allow us to measure the amount of 5-FU in each patient sample, and then compare this method to a different one, known as the My5FU™ test. This is to develop an understanding of which method may be more suitable for use in our laboratory, and to help ensure the trueness of our results. Five patients with colorectal cancer who were receiving 5-FU treatment donated blood samples which were then assessed using both methods. The methods were also assessed using a range of other parameters to deduce which assay may be more suited for routine use in our laboratory.
Unfortunately, the results generated by the mass spectrometry method have shown that it has not performed to the standards required and expected of a method of this type. However, we believe this to be, in part due to an analyser error during a critical period, and so the reassessment of this assay is required, as the assay has shown to exhibit many positive attributes. Meanwhile, the My5FU™ assay has shown itself to be utile, precise, and accurate when assessed using quality controls, but may lack accuracy near the lower end of its measurement range. Therefore, if the mass spectrometry assay becomes fully operational, a further assessment using diluted patient samples would be beneficial. At present, more work is still to be done before giving a final verdict regarding our preferred assay, which could be used for dose adjustment purposes, but unfortunately, due to time constraints, the study was unable to continue past February.REC name
West Midlands - Coventry & Warwickshire Research Ethics Committee
REC reference
23/WM/0198
Date of REC Opinion
5 Sep 2023
REC opinion
Further Information Favourable Opinion