Subgroup analysis revealed that next-generation sequencing outperformed PCR-based techniques in detecting <i>KRAS</i> mutation using plasma sample of patients with NSCLC, with sensitivity, specificity, and diagnostic odds ratio of 73%, 94%, and 82.60, respectively.<h4>Conclusion</h4>Compared to paired tumor tissue sample, plasma sample showed overall good performance in detecting KRAS mutation in patients with NSCLC, which could serve as good surrogate when tissue samples are not available. The gene discussed is KRAS; the disease is neoplasm.