Peripheral blood tumor marker levels can indicate the location of lung cancer metastasis

Early detection of lung cancer metastasis is of great importance for improving patient survival and reducing the economic and social burden of the disease. Omics analysis is widely used in the screening of tumor markers. However, effective markers that can indicate tumor metastasis in tissues and organs have not been screened out. The present study aimed to use the existing commonly used clinical tumor marker detection indicators to simply indicate possible metastatic organs through abnormal changes in their content. For this, three types of lung cancer, namely, lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC) and small cell lung cancer (SCLC), were selected for analysis. Patients of each type were grouped according to whether the tumor metastasized and whether it metastasized to a single tissue or organ, such as the lymph nodes, pleura, bones, liver and brain. The pre‑treatment peripheral serum carcinoembryonic antigen (CEA), carbohydrate antigen (CA)15‑3, CA125, CA19‑9, squamous cell carcinoma (SCC) antigen and cytokeratin 19 fragment antigen 21‑1 (CYFRA21‑1) levels were recorded. The tumor markers that differed from the non‑metastasis group were preliminarily determined by one‑way analysis of variance, and the ROC curve method was used to determine the marker's ability to evaluate metastasis to a certain organ. In LUAD, compared with levels in patients without metastasis, CA15‑3 and CA19‑9 levels were significantly increased in the group with lymph node metastasis, only the CA15‑3 level was significantly increased in the group with pleural metastasis, CEA, CA15‑3 and CA125 levels were significantly increased in the group with bone metastasis, only the CA125 level was significantly increased in the group with liver metastasis and only the CYFRA21‑1 level was significantly increased in the group with brain metastasis. Compared with that in LUAD without metastasis, CEA and CA15‑3 had a good diagnostic effect on bone metastasis screening, and CYFRA21‑1 also had a good diagnostic effect on brain metastasis. There was no significant difference in the levels of tumor markers in the peripheral blood of LUSC patients with tissue and organ metastasis. In SCLC, compared with levels in the control group, CEA and CA125 levels were significantly increased in patients with bone metastasis, and CA125 and CA19‑9 levels were significantly increased in patients with liver metastasis. In SCLC tumors, CEA and CA125 exhibited good diagnostic value for determining bone metastasis. CA125 and CA19‑9 also exhibited some diagnostic value for liver metastasis. In conclusion, the levels of peripheral blood tumor markers CEA, CA15‑3, CA125, CA19‑9, SCC and CYFRA21‑1 in patients lung cancer have clinical diagnostic value in specifically indicating the organs where lung cancer metastasizes.