When sub-grouped by the chemotherapeutic regimens, the pooled HRs were 1.83 (95%CI = 1.31–2.58; P = 0.011) for studies using EGFR-TKIs, and 1.53 (95%CI = 1.53–1.99; P = 0.001) for studies applying platinum-based chemotherapy (Figure 5), again, indicating a relationship between high serum CYFRA 21-1 level and poor outcome for NSCLC. This evidence concerns the gene EGFR and non-small cell lung carcinoma.