Glutathione Plays a Role in Treatment-Related CINV
Chemotherapy-induced nausea and vomiting (CINV) can negatively affect nutritional intake, ability to work, and treatment adherence. Research suggests that younger age and female gender are the strongest predictors of CINV, but those may not be the only factors, particularly for delayed nausea, according to research findings presented at the San Antonio Breast Cancer Symposium on December 5, 2018 (https://www.abstracts2view.com/sabcs18/view.php?nu=SABCS18L_195).
Most chemotherapeutic agents cause bursts of reactive oxygen species (ROS) that result in cellular damage and release substances that can activate receptors in the chemoreceptor trigger zone. Glutathione (GSH) is a key antioxidant responsible for maintaining redox homeostasis by neutralizing ROS caused by chemotherapy.
The researchers enrolled more than 300 patients receiving highly or moderately emetogenic chemotherapies for lung, colon, or breast cancer; the findings represent data for 133 patients. Researchers collected blood samples from chemotherapy-naïve patients to determine their glutathione recycling capacity. The assay detects the conversion of hydroxyethyl disulfide into mercaptoethanol, which indicates GSH recycling capacity (ChemoTox) once normalized to red blood cell count. Patients reported nausea severity for each treatment cycle using the Rotterdam Symptom Check-List.
In a previous study, the research team observed a correlation between low ChemoTox and risk of delayed nausea for patients receiving platinum-based therapy for lung and colon cancer (n = 64; correctly classified = 88.5%; area under the curve [AUC] = 0.77).
In the current evaluation, researchers presented results for patients with breast cancer treated with anthracycline- or taxane-based chemotherapies. An early evaluation found that anthracycline-based therapies (n = 37) had a weak association between ChemoTox and nausea (correctly classified = 69.2%; AUC = 0.64). However, patients treated with taxane-based therapies (n = 32) had a correlation between ChemoTox and severity of nausea similar to previous reports in the platinum-based cohort. ChemoTax may also accurately identify patients at risk of moderate-severe nausea (correctly classified = 77.3%; AUC = 0.79).
“Our prospective study suggests that a reduced ability to recycle GSH in the blood may offer an objective prediction of delayed nausea, possibly allowing for optimal antiemetic regimen to improve the quality of life for [patients with] breast cancer,” the researchers concluded.