Evaluation of calculating carboplatin dosage in carboplatin–pemetrexed therapy as the first-line therapy for Chinese patients with advanced lung adenocarcinoma

Abstract

Objective: This study aims to explore the application of actual carboplatin in carboplatin plus pemetrexed regimen as first-line treatment for advanced lung adenocarcinoma, and to determine the recommended dose of carboplatin for Chinese populations. Methods: From January 2014 to April 2016, 151 advanced lung adenocarcinoma patients who received carboplatin and pemetrexed (500 mg/m2) were included. The area under the curve (AUC) of carboplatin was back-calculated from actual dosages using the Calvert formula. According to the median of calculated AUC, patients were divided into AUC ≥4 and <4 groups. Results: The median of AUC was 4 (1.8–5.5). A total of 79 patients had an AUC ≥4 and 72 patients had an AUC <4. The mean relative dose intensities of pemetrexed were 100.4% for the AUC ≥4 group, and 101.4% for <4 group. Baseline characteristic variables were balanced between the two groups, except for Eastern Cooperative Oncology Group Performance score (P = 0.044). The overall response rate (ORR) and disease control rate (DCR) were 33.8% and 90.1%, respectively, 35.4% and 86.1% for the AUC ≥4 group, and 31.9% and 94.4% for the AUC <4 group. No significant difference was observed in ORR (P = 0.650) and DCR (P = 0.086) between the two groups. Conclusion: Compared with an AUC of 5 or 6, the actual clinical application of AUC was generally insufficient for Chinese populations; fortunately, therapeutic efficacy remained equal. We found that AUC <4 was as adequate as AUC ≥4 in pemetrexed plus carboplatin regimen as first-line treatment for them.