Comparison between the first-line and second-line immunotherapy drugs in the progression-free survival and overall survival in advanced non-small cell lung cancer: a systematic review and meta-analysis of randomized controlled trials

Background: Non-small cell lung cancer (NSCLC) accounts for the majority of lung cancer but with a low early diagnosis rate. With immunotherapy becomes popular in lung cancer, single immunotherapy drug treatment as the first-line or second-line plays an important role. The meta-analysis compares different clinical effects of them by overall survival (OS) and progression-free survival (PFS) because it is important to detect the best time of immunotherapy for NSCLC patients.

Methods: Randomized controlled trials (RCTs) were selected by using the Cochrane Library, Embase, PubMed and Web of science. Pool the hazard ratio (HR) and use the PFS, OS as outcomes.

Results: Ten RCTs were included. The pooled results indicated that first-line and second-line single immunotherapy drug treatment seems to have a tiny difference in PFS, with HR 0.79, 95% confidence interval (CI): 0.51-1.21, I2 =89% in first-line single immunotherapy drug treatment and HR 0.74, 95% CI: 0.62-0.89, I2 =84% in second-line single immunotherapy drug treatment. When it comes to OS, first-line immunotherapy drug treatment still has better effects than the second-line. In first-line single immunotherapy drug treatment, HR 0.78, 95% CI: 0.55-1.11, I2 =83%, but in second-line, HR 0.70, 95% CI: 0.64-0.76, I2 =53%.

Conclusions: First-line single drug immunotherapy had the tendency better than single immunotherapy drugs used in second-line treatment.