Phase II randomized study of cisplatin plus etoposide phosphate or etoposide in the treatment of small-cell lung cancer.

Purpose: This randomized phase II study evaluated the efficacy and toxicity of etoposide phosphate when used in combination with cisplatin in the treatment of small-cell lung cancer.

Patients And Methods: Patients with previously untreated small-cell lung cancer were randomized to receive cisplatin in combination with either etoposide or etoposide phosphate. Molar-equivalent doses of etoposide and etoposide phosphate were used. Response rate, time to progression, survival, and toxicity were compared.

Results: Major response rates with etoposide phosphate and etoposide were 61% (95% confidence interval, 55% to 67%) and 58% (95% confidence interval, 52% to 64%), respectively (P = .85). No significant differences in median time to progression or survival were observed in patients who received etoposide phosphate versus etoposide. Grade 3 and 4 leukopenia occurred in 63% of patients who received etoposide phosphate compared with 77% who received etoposide (P = .16).

Conclusion: The combination of etoposide phosphate and cisplatin is effective in the treatment of small-cell lung cancer, and can be administered with acceptable toxicity. Although this study was not designed to be a formal comparative trial, the efficacy and toxicity observed with this regimen were found to be similar to a standard etoposide/cisplatin regimen, using molar-equivalent etoposide doses. Because of its greater ease of administration, etoposide phosphate is preferable to etoposide for routine clinical use.