Low-dose oral etoposide in epithelial cancer of the ovary

Aims: To evaluate antitumour activity, toxicity, pharmacokinetics, and the pharmacodynamic relationship with neutropenia of low-dose oral etoposide (E) in patients (pts) with epithelial cancer of the ovary previously treated with cisplatin. Patients and methods: Eighteen pts receiving 50 mg daily of oral E for 21 days every 4 weeks. CBC with differential repeated every week. E plasma levels determined by HPLC method (sensitivity limit: 0.1 μg/ml) with evaluation during the first cycle of bioavailability and weekly 24-hour drug concentrations. Results: Among 17 evaluable pts, 1 partial remission of 9 months. Dose-limiting neutropenia of high inter-patient variability. Mean bioavailability value of 75%, ranging from 44% to 100%. No correlation between mean 24-hour E plasma levels and ANC nadir or relative decrease of ANC during the first cycle. Conclusions: Low-dose oral E is ineffective as salvage treatment in epithelial cancer of the ovary. The large variability of neutropenia requires a careful hematological monitoring to avoid severe myelosuppression.