Prevalence of anticipatory nausea and vomiting in breast cancer patients undergoing highly emetogenic chemotherapy.

Objective: Anticipatory nausea and vomiting are unpleasant symptoms observed before undergoing chemotherapy sessions. Less is known about the occurrence of symptoms since the advent of the new neurokinin-1 antagonist.

Methods: This prospective cohort study was performed at a single Brazilian Institution. This study included breast cancer patients who received doxorubicin and cyclophosphamide chemotherapy and an appropriate antiemetic regimen (dexamethasone 10 mg, palonosetron 0.56 mg, and netupitant 300 mg in the D1 followed by dexamethasone 10 mg 12/12 h in D2 and D4). Patients used a diary to record nausea, vomiting, and use of rescue medication in the first two cycles of treatment. The prevalence of anticipatory nausea and vomiting was assessed before chemotherapy on day 1 of C2.

Results: From August 4, 2020, to August 12, 2021, 60 patients were screened, and 52 patients were enrolled. The mean age was 50.8 (28-69) years, most had stage III (53.8%), and most received chemotherapy with curative intent (94%). During the first cycle, the frequency of overall nausea and vomiting was 67.31%, and that of severe nausea and vomiting (defined as grade>4 on a 10-point visual scale or use of rescue medication) was 55.77%. Ten patients had anticipatory nausea and vomiting (19.23%). The occurrence of nausea and vomiting during C1 was the only statistically significant predictor of anticipatory nausea and vomiting (OR=16, 95%CI 2.4-670.9, p=0.0003).

Conclusion: The prevalence of anticipatory nausea is still high in the era of neurokinin-1 antagonists, and failure of antiemetic control in C1 remains the main risk factor. All efforts should be made to control chemotherapy-induced nausea or nausea and vomiting on C1 to avoid anticipatory nausea.