Impact of Advantage in Tumor Response on the Correlation Between Progression-Free Survival and Overall Survival: Meta-Analysis of Clinical Trials in Patients with Advanced Non-Small Cell Lung Cancer.

BACKGROUND: Progression-free survival (PFS) has not been validated as a surrogate endpoint for overall survival (OS) in patients with advanced non-small cell lung cancer.

OBJECTIVE: This study aimed to investigate an impact of advantage in tumor response on the correlation between PFS and OS in advanced non-small cell lung cancer.

METHODS: Based on a literature search, we identified randomized controlled trials of first-line therapy for advanced non-small cell lung cancer. The impact of absolute difference in objective response rate between treatment arms on the correlation between hazard ratios (HRs) for PFS and OS was evaluated based on Spearman rank correlation coefficients.

RESULTS: Sixty trials with a total of 29,134 patients were identified. The HR for PFS showed a relatively higher correlation with HR for OS (rs = 0.75) when the trials were limited to those that demonstrated a larger advantage in objective response rate, compared with the case for trials that demonstrated a smaller advantage (rs = 0.66). This tendency was also observed in the subgroup analysis stratified by the types of treatment agents (non-targeted, anti-angiogenic, and immunotherapy) except for the group of epidermal growth factor receptor-targeted agents.

CONCLUSIONS: The magnitude of advantage in tumor response was suggested to contribute to a better prediction of OS-HR based on PFS-HR in clinical trials in patients with advanced non-small cell lung cancer.