Purpose: The combination of carboplatin and etoposide is currently considered the most appropriate regimen for treating elderly patients with small-cell lung cancer (SCLC). Previous reports on elderly patients, 70 years or older, found that the recommended dose was close to that of younger patients. Then, we conducted a phase I study of carboplatin and etoposide in elderly patients, 75 years or older, with SCLC. This study aimed to determine the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT).
Methods: Twenty-six patients fulfilling the eligibility criteria, chemotherapy-naive, performance status (PS) of 0-2, age>or=75, and adequate organ functions were enrolled. Patients' characteristics were: male/female=21/5; PS 0/1/2=9/11/6; median age (range)=78 (75-82); and limited/extensive stage=16/10. The patients intravenously received carboplatin with a target AUC of 4 or 5 mg min/ml (Chatelut formula) on day 1 and etoposide at 80-120 mg/m2 on days 1, 2 and 3. Therapy was repeated four times in every 4 weeks.
Results: The MTD of carboplatin/etoposide was AUC=5/80, 4/110, and 4/120. The DLTs were thrombocytopenia, neutropenia, leukopenia, and febrile neutropenia. Overall, grade 4 thrombocytopenia, neutropenia (>or=4 days), leukopenia (>or=4 days), and febrile neutropenia occurred in 27, 20, 7, and 13% of cases at MTD levels, respectively, and 0% at other levels. Twenty of 26 patients showed objective responses (2CR, 18PR; RR=77%).
Conclusion: A dose of carboplatin of AUC=4 and etoposide of 100 mg/m2 was recommended in this regimen.