Comparison of the efficacy and safety of single-agent and doublet chemotherapy in advanced non-small cell lung cancer in the elderly: a meta-analysis

Abstract

Background: In patients with advanced non-small cell lung cancer (NSCLC) aged more than 70 years, the benefit-to-risk ratio of doublet chemotherapy vs single-agent is not established.

Methods: We performed a meta-analysis (MA), with a PubMed query using keywords simultaneously (Randomized controlled trial, Aged, Anti-neoplastic combined chemotherapy protocols/therapeutic use, Carcinoma, Non-small cell lung/drug therapy). Abstracts from ASCO, WCLC, and ESMO proceedings were reviewed. Articles were also obtained by cross-checking references. Third-generation agents (gemcitabine, vinorelbine, paclitaxel, docetaxel) in combination with or without platinum were included. The efficacy outcomes were Overall Response Rate (ORR) and 1-Year Overall Survival (OS). We used EasyMA software and a random-effect model in case of heterogeneity.

Results: This MA comprised 10 studies including 2605 patients (mean age 74; 1866 men and 620 women; 654 stage IIIB and 1677 stage IV; 839 squamous cell cancers, 968 adenocarcinomas, 521 other pathological types). One-year OS (including the last trial by Abe) did not significantly improve for doublets compared with single-agents (HR 0.92; 95% Confidence Interval or CI: 0.82-1.03) whereas it improved significantly before inclusion of this last study, when the study by Quoix et al., the most favorable to doublets, was included. However, doublet chemotherapy significantly improved ORR after inclusion of Abe study (HR 1.51; 1.22-1.86; p<0.001). OS was not significantly improved, neither by doublets including platinum (HR 0.90, 0.70-1.16), nor by those without platinum (HR 0.94, 0.84-1.07). ORR, but not OS, was improved by doublets including a taxane (docetaxel and paclitaxel) (HR 1.72; 1.28-2.33) except for paclitaxel with a significant OS and ORR benefit. All-grade neutropenia thrombocytopenia and anemia were significantly more frequent with doublets than with single-agents (HR 1.26, 1.15-1.39; 1.75, 1.11-2.77 and 1.33, 1.17-1.52 respectively). Grade 3/4 thrombocytopenia and anemia but not neutropenia were significantly more frequent with doublets (HRs 2.13, 1.01-4.49 and 1.84, 1.29-2.63 respectively).

Conclusion: Compared with single-agents, doublets significantly improved ORR but not OS. They induced significantly more frequent thrombocytopenia and anemia. The benefit-to-risk ratio of doublets in advanced NSCLC might be more favorable than that of single agents, based on ORR but not OS.