The plasma cfDNA concentration correlated with gender (males vs.females =11.69 ng/mL vs. 9.508 ng/mL; p=0.044), EGFR mutation status (tumor-tissue EGFR mutation-positive (EGFR M+) vs. EGFR mutation-negative (EGFR M-) = 9.61 ng/mL vs. 12.82 ng/mL; p =0.049) and specimen collection time (=2 years vs. >2 years=13.83 ng/mL vs. 6.575 ng/mL; p <0.001), and was greater in tumor-tissue EGFR M+ / plasma EGFR M+ patients than in tumor-tissue EGFR M+/plasma EGFR M- patients (11.61 vs. 7.73 ng/mL, respectively; p=0.003). Here, EGFR is linked to neoplasm.