Background: Serum carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA 21-1) levels are prognostic predictors in non-small cell lung cancer (NSCLC). However, even in patients with the same stage of cancer, the serum levels of those markers often vary.
Objective: We investigated the association between the initial biomarker levels and prognosis.
Methods: We retrospectively reviewed 445 patients with advanced NSCLC and their baseline serum CEA and CYFRA 21-1 levels. Patients were divided into four groups according to the initial levels of those markers: the NN, HN, NH, and HH group. Kaplan-Meier survival analysis with Log-rank test and Cox proportional hazards regression analysis were performed.
Results: The 5-year overall survival (OS) rate in the HN group was the highest (32.2%). Multivariate analyses indicated that the HN group (HR 0.520, 95% CI 0.309-0.878, P= 0.014), female sex (HR 0.685, 95% CI 0.498-0.944, P= 0.021), serum CRP level (HR 1.057, 95% CI 1.034-1.080, P< 0.001), chemotherapy (HR 0.324, 95% CI 0.228-0.460, P< 0.001), and chemotherapy/radiotherapy (HR 0.266, 95% CI 0.171-0.414, P< 0.001) were independent prognostic factors for overall survival.
Conclusions: In advanced NSCLC, patients with baseline high serum CEA but low CYFRA 21-1 level have a significant longer overall survival regardless of clinical stage.
Keywords: CEA; CYFRA 21-1; NSCLC; prognostic factor; tumor marker.