5FU Holter

Brief description:

Fluorouracil (5-FU) is the key chemotherapy component in systemic treatment of colorectal cancer, however, it is associated with the risk of potentially fatal cardiotoxicity. Re-challenging 5-FU is not recommended for most patients due to the high risk of recurrence. In the absence of PHARMAC funded alternatives, this is likely to lead to worse oncological outcomes. Understanding the mechanism by which 5-FU causes cardiotoxicity is therefore vital in helping to identify patients who are at risk and develop risk mitigation strategies.

The overall aim of this study is to assess the feasibility of using ambulatory ECG monitoring (Holter monitor) for patients receiving 5-FU chemotherapy.

The main objective of this study is to assess feasibility of:

1. Recruitment, proportion who agree to participate after receiving study information sheet.
2. Acceptability to patients, completion rate of study investigations.
3. Clinician experience of recruitment

This study will recruit 10 patients from Auckland Hospital with a diagnosis of gastrointestinal malignancy planning to undergo their first cycle of treatment with FOLFOX (infusional 5-FU in combination with oxaliplatin) chemotherapy.

Patients will have blood samples collected after the start of the 5-FU infusion at the time points: 20 minutes, 1 hour and 3 hours. A cumulative urine sample will be collected from the initiation of the 5-FU infusion for a total of 3 hours. At 3 hours an ECG will be performed, and then a Holter monitor will be fitted. The patient will be discharged home.

After 46 hours patients will return for disconnection of the 5-FU infusion pump, return of the Holter monitor and an ECG.

Documentation of any symptomatic cardiac events will occur at the time of return of the Holter monitor and one month later, during a routine assessment prior to a cycle of chemotherapy.