Cancer patients who receive their chemotherapy in the afternoon appear to develop permanent heart damage more often than patients who are treated in the morning. This is according to observational research conducted by UMC Utrecht into the effect of the time of day at which anthracyclines are administered: powerful but heart-damaging chemotherapies used to treat breast cancer and lymph node cancer, for example.
An analysis of 270 patients in the cardio-oncology clinics of UMC Utrecht and St. Antonius Hospital Nieuwegein shows a link between the timing of administration and the risk of heart failure and other forms of heart damage. Of the patients, 66 (almost 1 in 4) developed signs of permanent heart damage. In 17 of them, this led to heart failure, a serious condition associated with a greatly reduced quality of life and an increased risk of death. In patients who received their treatment mainly in the afternoon, the risk of serious heart damage was almost three times higher than in patients who received their medication in the morning.
“The timing of chemotherapy administration does not seem to be a logistical detail, but possibly a factor that influences serious side effects such as heart damage,” says Prof. Linda van Laake, principal investigator. “Our findings provide an important clue, but further research is essential.”
Van Laake was able to conduct this research thanks to a Dekker grant from the Dutch Heart Foundation, which she received in 2020. Together with her colleagues, she now wants to set up a clinical trial. This is a follow-up study in which patients are randomly assigned to a morning or afternoon group in order to determine the effect of the time of treatment more accurately.
The findings are consistent with previous laboratory research by Van Laake and her colleagues: heart cells appear to be less resistant to damage at certain times of the day. This has to do with our biological clock: processes such as DNA repair, energy production, and waste removal in heart cells follow a 24-hour rhythm. Chemotherapy administered at a time other than in the morning can therefore be particularly harmful.
In the Netherlands, thousands of cancer patients receive chemotherapy with anthracyclines every year. Many of them survive their illness, but are left with permanent heart problems. The discovery that a simple adjustment in the timing of chemotherapy could potentially save or improve hundreds of lives is therefore very promising and was published in European Heart Journal Open.
Despite these initial indications, it is important that patients continue to follow their treatment as agreed. Only after additional research can it be determined whether and how the timing of chemotherapy should actually be adjusted.
