Breakthrough chemotherapy-induced nausea and vomiting: report of a nationwide survey by the CINV Study Group of Japan

Background: We conducted a nationwide survey on chemotherapy-induced nausea and vomiting (CINV) in Japan and demonstrated good compliance with Japanese CINV guidelines, resulting in good control of vomiting. However, almost half the patients experienced breakthrough CINV. We analyzed the survey results in relationship to the management of patients with breakthrough CINV. Methods: This multicenter, prospective, observational study analyzed data for 1910 patients in Japan scheduled for moderately or highly emetogenic chemotherapy (MEC and HEC, respectively). Patients who developed CINV despite prophylactic use of antiemetics were administered rescue drugs. Patients who received cisplatin-based HEC (C-HEC), non-cisplatin-based HEC (N-HEC), or MEC were evaluated separately. Results: A total of 989 patients experienced CINV, of whom 412 (44%) received rescue antiemetics during the study period. The rate at which patients with breakthrough CINV were started on rescue drugs ranged from 13% to 24%. Rescue drugs were given more frequently on days 2–4 for C-HEC and MEC and on days 1–2 for N-HEC. Eighty-six percent of patients received metoclopramide or domperidone. 5-HT₃ receptor antagonists, antipsychotics, and anti-anxiety drugs were used for 11–5% of patients. The mean duration of antiemetic use was 2.6 days. Conclusions: Fewer than half of the patients with breakthrough CINV were treated with rescue antiemetics, suggesting that CINV was mild in the remaining patients. However, CINV was sufficiently severe to prevent eating in other patients, indicating the need for new drugs with different mechanisms to control CINV.