An observational study in Solid Cancer, Gastric (Cardia, Body) Cancer and Esophageal Cancer, sponsored by Erasmus Medical Center. Recruiting at 1 site in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-08-11.
Sponsored by Erasmus Medical Center · Observational
In this study, the drug capecitabine is investigated. Capecitabine is commonly used to treat breast, colon, and stomach cancers. Capecitabine is taken in tablet form. In the body, capecitabine is converted into the active molecule that has anti-cancer effects. This molecule is called 5-FU. The transformation of capecitabine to 5-FU occurs through specific proteins in the liver, also known as enzymes.
Unfortunately, capecitabine can also cause side effects. One of the most common side effects is hand-foot syndrome. In hand-foot syndrome, the palms of the hands and soles of the feet become red and painful. Previous research has shown that patients in whom one of the enzymes responsible for converting capecitabine in the liver does not function properly experience an increase in side effects frequency, particularly severe hand-foot syndrome. This specific enzyme is called CES1. It is believed that side effects occur more frequently because capecitabine is transformed more slowly, eventually leading to a prolonged exposure to 5-FU in the body.
In roughly one in three people, this enzyme functions less efficiently. To gain a better understanding of how this mechanism works, we aim to conduct this study. In this study, we will examine if patients with a less effective CES1 enzyme have higher amounts of 5-FU in their blood. We will also look into whether these patients develop side effects, such as hand-foot syndrome, more frequently. This information could eventually help us develop new strategies to reduce side effects for these patients in the future.
Patients with cancer who are intended to start with CAPOX treatment.
In order to be eligible to participate in this study, a subject must meet all of the following criteria:
Exclusion Criteria:
A potential subject who meets any of the following criteria will be excluded from participation in this study:
Oncological patients who are treated with CAPOX (with or without additional anti-neoplastic agents, including but not limited to nivolumab, trastuzumab or bevacizumab) according to standard of care. These patients are known carriers of the CES1 1165-33 C\>A (rs2244613) SNP.
Drug: Blood sampling for pharmacokinetics
Oncological patients who are treated with CAPOX (with or without additional anti-neoplastic agents, including but not limited to nivolumab, trastuzumab or bevacizumab) according to standard of care. These patients are known carriers of the wild-type CES1 gene.
Drug: Blood sampling for pharmacokinetics
Extra blood samples are collected for assement of the pharmacokinetics of capecitabine.
Pharmacokinetic Exposure
Difference in Area Under the Curve (AUC)
Time frame: Up to 6 hours after intake of capecitabine
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
No contact was published for this record. The registry link below has the sponsor’s details.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Erasmus Medical Center