Chemotherapy-induced nausea and vomiting in patients with breast cancer: a prospective cohort study

PURPOSE: To explore the actual status of chemotherapy-induced nausea and vomiting (CINV) through a multicenter prospective cohort study. METHODS: Patients with breast cancer treated with moderately emetogenic (MEC) or highly emetogenic (HEC) chemotherapy were eligible. A 7-day diary was provided for all patients. Acute and delayed CINV were defined as nausea and vomiting that developed ≤ 24 or > 24 h after the start of chemotherapy, respectively. The severity of nausea was evaluated with a visual analog scale (VAS). We also assessed the accuracy of estimations of CINV by medical staff. RESULTS: In total, 426 patients were included; 352 patients (82.6%) received HEC, and 74 (17.3%) received MEC. In the acute phase, 44.9% of patients receiving HEC and 5.4% receiving MEC experienced nausea, and 12.8% receiving HEC and none receiving MEC experienced vomiting. More patients experienced nausea in both groups and vomiting in MEC during the delayed phase (nausea: 59.4% in HEC and 44.6% in MEC group; vomiting: 11.1% in HEC; and 13.5% in MEC group) than during the acute phase. Estimations of CINV by medical staff were not accurate, with a kappa coefficient of 0.10 and 0.08 for acute nausea and vomiting and 0.02 and 0.01 for delayed. The VAS scores showed that in the HEC group, the degree of nausea was worst on the first day. CONCLUSIONS: The degree of nausea was worst in the acute phase, although delayed nausea was more in proportion in HEC. Estimation by medical staff is not accurate.