In LL3 and LL6, EGFR mutation-positive patients who were cfDNA+ tended to have more advanced disease characteristics compared with cfDNA− patients, including higher ECOG performance scores, greater tumour burden, a higher number of metastatic sites, metastases to the bone and liver, and higher laboratory values (e.g., ALP and LDH), which are associated with metastatic spread to the bone/liver. Here, EGFR is linked to neoplasm.