Preliminary Evaluation of a Novel Blood Test to Predict Delayed Nausea for Breast Cancer Patients.

e18210 Background: We have previously reported on glutathione recycling capacity (GRC) in red blood cells as a predictor of delayed nausea in cancer patients treated with platinum-based chemotherapies [1]. The test identifies individual variations in the efficiency to scavenge reactive oxygen species, produced by chemotherapy-induced cell-damage, which triggers release of serotonin – a know inducer of chemotherapy-induced nausea and vomiting. In this current study, we have examined if the GRC assay and/or changes in substance P (SP), another inducer of nausea, can predict delayed nausea among breast cancer patients receiving doxorubicin- or taxane-based therapies and thereby provide better guidance to individualized antiemetic therapies. Methods: Chemotherapy naïve breast cancer patients were asked to participate in this IRB-approved study. Consented patients donated a tube of blood prior to each treatment cycle. Commercial kits were used to measure GRC (OxPhos, Rockland Inc.) and Substance P (Parameter, R&D Systems). On-set, duration and severity of nausea, and anti-emetics prescribed were documented by the medical staff. Results: Obtained GRC and SP values were compared to documented incidences of nausea. We found that 26.8% of taxane treated patients [N = 42] had moderate/severe nausea and demonstrated a similar GRC pattern to platinum-based induced nausea, i.e. low GRC results in more severe nausea. Among doxorubicin treated [N = 31] patients, 41.9% had moderate/severe nausea but showed no correlation with GRC. However, preliminary evaluation of these patients showed a continuous increase in SP levels (average 1.74 fold increase after one cycle). Conclusions: In this initial evaluation of our on-going study, we found that fewer patients had nausea in the taxane treated group with a similar GRC predictive pattern as previously reported. However, patients in the doxorubicin treated group were more likely to experience nausea with no correlation to GRC but with a steadily rising level of SP during the early part of their regimen. Using SP testing could help identify patients that might have a medical benefit from additional NK1 antagonist therapy. 1. Kutner, T., et al. Supprot Care Cancer (2017) 25:581-587.