Declines in serum CYFRA21-1 and carcinoembryonic antigen as predictors of chemotherapy response and survival in patients with advanced non-small cell lung cancer.

The aim of this study was to investigate the clinical value of serum cytokeratin 19 fragment (CYFRA21-1) and carcinoembryonic antigen (CEA) in the prediction of chemotherapy response and prognosis in patients with advanced non-small cell lung cancer (NSCLC). Serum CYFRA21-1 and CEA levels of 98 patients with advanced NSCLC were measured using immunoradiometric kits prior to and after 2 cycles of chemotherapy. After 2 cycles of chemotherapy, 45 patients achieved a radiological objective response (OR), 30 patients achieved stable disease (SD) and 23 patients had progressive disease (PD). Serum CYFRA21-1 and CEA were significantly decreased compared to baseline levels (P<0.001). By ROC curve analysis, a ≥60% reduction in CYFRA21-1 and a ≥25% reduction in CEA were the optimal cut-off levels with best sensitivity and specificity for the diagnosis of radiologic OR. The median survival of all patients was 10.2 months (range 2.6-26.3). Univariate survival analysis showed that the Eastern Cooperative Oncology Group (ECOG) performance status (PS) score, radiologic OR, a ≥60% reduction in CYFRA21-1 and a ≥25% reduction in CEA were significant prognostic factors for better overall survival. The median overall survival time in patients with a ≥60% reduction in CYFRA21-1 was significantly longer than in those with a <60% reduction (P<0.001). Similarly, the median overall survival time in patients with a ≥25% reduction in CEA was also significantly longer than in those with a <25% reduction (P<0.001). Multivariate analysis showed that ECOG PS score, a ≥60% reduction in CYFRA21-1 and a ≥25% reduction in CEA were independent prognostic factors of survival, while radiologic OR was not. In conclusion, a ≥60% reduction in CYFRA21-1 and a ≥25% reduction in CEA may be reliable surrogate markers for the prediction of chemothrapy response and prognosis, especially for the diagnosis of radiologic OR.