PREVALENCE OF ANTICIPATORY NAUSEA AND VOMITING IN CANCER PATIENTS EXPOSED TO HIGHLY EMETOGENIC CHEMOTHERAPY

Introduction: Anticipatory nausea (AN) and vomiting are unpleasant symptoms observed in anticipation of chemotherapy regimens. It is best described as a learned response throw classical conditioning when one or more distinctive features of the chemotherapy clinic (conditioned stimuli) associated with the administration of emetogenic chemotherapy (unconditioned stimuli) trigger the emetogenic reflex. Little is known about the occurrence of AN after the advent of the new neurokinin-1 antagonist. Objective: Investigate the prevalence of AN in ambulatory breast cancer patients receiving high effective antiemetic prophylaxis. Evaluate potential predictors of AN. Methods: This was a prospective observational study performed in a single Brazilian institution. Key inclusion criteria were patients with breast cancer scheduled to receive anthracycline chemotherapy with an appropriate antiemetic regimen, including a neurokinin-1 receptor antagonist, a serotonin-3 receptor antagonist, and a corticosteroid. Eligible patients were assessed by a diary regarding nausea, vomiting, and use of rescue medication from the chemotherapy administration (Dayn1) to Day 6 during cycles one and two. AN was assessed on day 1 of cycle two. Results: A total of 34 patients were enrolled, who had a mean (range) age of 52 (31 – 69), the majority with non-metastatic disease (91.18%). The prevalence of AN was 20.59%. Nausea and vomiting occurred in 58.82% after cycle 1. Failure to achieve complete control of nausea and vomiting was the only observed predictor of AN (p=0.026). Patients who achieved full control of nausea and vomiting on cycle one did not have AN. Conclusion: The prevalence of AN is still high in the era of neurokinin-1 antagonists. All efforts should be made to achieve complete control of chemotherapy-induced nausea or nausea and vomiting on cycle one to avoid AN.