To investigate the significance of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), neuron specific enolase (NSE), cytokeratin 19 fragment (CYFRA21-1) and squamous cell carcinoma antigen (SCC) for evaluation of first-line chemotherapeutic response and the prognostic value of these markers for prediction of overall survival (OS) in patients with advanced lung cancer.

Patients diagnosed with Ⅲb/Ⅳ stage untreated, primary lung cancer and received first-line chemotherapy in Peking University Cancer Hospital & Institute from June 2013 to December 2014 were enrolled retrospectively into this study. The results of tumor markers before and after two cycles of chemotherapy and the clinical data of 181 eligible patients, including 133 males and 48 females with the average age of 58 years, were collected. The serum levels of six tumor markers were measured by electrochemiluminescence assay. Using RECISTv1.1 as standard, the sensitivity and specificity of tumor markers in classifying PR, SD, PD, were observed. The Kappa agreement test was used to evaluate the correlation between serum tumor markers and CT in evaluating chemotherapy response. The follow-up of OS was derived by telephone.

The top three positive rates of biomarkers were CEA, CA125 and NSE in adenocarcinoma patients, CYFRA21-1, NSE and SCC in squamous carcinoma patients, NSE, CA125 and CYFRA21-1 in small cell lung cancer patients, respectively. In Kappa agreement test, the changes of serum levels of CEA and CA125, CYFRA21-1 and SCC, NSE were significantly correlated with CT for chemotherapy response evaluation in the mention above three kinds of carcinomas respectively (P<0.05). The sensitivity of tumor markers predicting PR was more than 90%, but the specificity was only 20%-58.3%, meanwhile, the specificity for SD and PD was high, but the sensitivity was low 0-66.7%). In the prognostic evaluation based on RECISTv1.1, there was no statistical significance for classifying PR, SD and PD in adenocarcinoma patients (median overall survival 17 months vs 22 months vs 14 months, P>0.05), but the OS of PR was longer than SD and PD in squamous and small cell lung carcinoma (median overall survival 28 months vs 22 months vs 4 months, 12 months vs 8 months vs 8 months, P<0.05). Of these six tumor markers, only SCC was of statistical significance for classifying PR, SD and PD in squamous carcinoma (median overall survival 30 months vs 11 months vs 4 months, P<0.05).

Tumor marker has high sensitivity for predicting PR, but the value of tumor marker predicting SD and PD of advanced lung cancer was limited. The evaluation of patients would be comprehensive by combined use of tumor markers and CT. The changes of SCC after 2 cycles of chemotherapy are predictive of survival in squamous cell carcinoma patients.(Chin J Lab Med, 2017, 40: 693-699)

Lung neoplasms; Tumor markers, biological; Treatment outcome; Survivors