Carcinoembryonic antigen and CYFRA 21-1 responses as prognostic factors in advanced non-small cell lung cancer

Background: It is unclear whether changes in serum tumor marker expression post-treatment are of prognostic value. We investigated the associations between changes in serum carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA 21-1) after first-line treatment and overall survival (OS) in non-small cell lung cancer (NSCLC). Methods: Advanced NSCLC patients (April 2010 to December 2015) with elevated serum CEA or CYFRA 21-1 were included. The associations between tumor marker changes after treatment initiation and OS were analyzed. Results: Ninety-six and 55 patients were CEA- and CYFRA 21-1-positive, respectively. The serum CEA response at 4 months and CYFRA 21-1 responses at 1 and 4 months were significantly associated with OS in the univariate analyses (P=0.025, P=0.016 and P<0.001, respectively). Moreover, in the multivariate analyses, serum CYFRA 21-1 response at 4 months was significantly associated with improved OS (P=0.038). Conclusions: In NSCLC patients, serum CEA and CYFRA 21-1 responses after treatment initiation may predict longer OS.