We observed significant association of ctDNA level with liver metastasis and sum of the tumor diameter in metastatic sites, which were commonly reported to be strongly associated with ctDNA level.20, 34, 35 While the controversial or null association of ctDNA level with the lung, lymph node and peritoneal metastasis, tumor markers, primary tumor location, and number of metastatic organs has been reported,20, 34, 36, 37 we observed significant association between ctDNA level and lymph node metastasis, number of metastatic organs, and tumor markers (CEA, CA19‐9, and LDH). The gene discussed is CEACAM5; the disease is metastatic malignant neoplasm in the lymph nodes.