Background: The combination of cyclophosphamide, methotrexate and 5-fluorouracil (CMF) is a widely used chemotherapy regimen in breast cancer patients. However, the control of nausea and vomiting induced by oral CMF is a rarely examined problem. Therefore we felt a randomized, placebo controlled study justified in order to improve currently available antiemetic therapy.
Subjects and methods: In a randomised double-blind trial ondansetron given orally, 8 mg three times a day for 15 days, was compared with placebo in 82 breast cancer patients receiving chemotherapy with CMF (cyclophosphamide 100 mg/m2 orally days 1-14, methotrexate 40 mg/m2 i.v. days 1 and 8 and 5-fluorouracil 600 mg/m2 i.v. days 1 and 8). The patients recorded nausea and the number of vomits and retches daily on diary cards. Forty-two patients received ondansetron and 40 received placebo.
Results: Significantly more patients who received ondansetron experienced neither vomiting nor retching (emesis) compared to those receiving placebo over a 15 day treatment period (60% vs. 35%, p = 0.027). The difference, with 95% confidence limits, was estimated at 25 (4.45%). Furthermore, there was a trend in favour of ondansetron in the control of nausea. Ondansetron was well tolerated, with 25 patients (59%) reporting at least 1 adverse event compared to 18 patients (45%) receiving placebo (p = 0.191).
Conclusion: The results indicate that ondansetron given orally for 15 days is safe and effective in the control of emesis induced by CMF. It is however too early to recommend ondansetron as standard antiemetic therapy for oral CMF, as the treatment of nausea and vomiting in this setting has not been studied thoroughly enough.