Cytokeratin 19 fragment antigen 21-1 as an independent predictor for definitive chemoradiotherapy sensitivity in esophageal squamous cell carcinoma.

Background: Patients with esophageal squamous cell carcinoma (ESCC) undergoing definitive chemoradiotherapy (CRT) seem to have a disparity in therapeutic response. The identification of CRT sensitivity-related clinicopathological factors would be helpful for selecting patients most likely to benefit from CRT. Cytokeratin 19 fragment antigen 21-1 (CYFRA21-1) and carcinoembryonic antigen (CEA) have been reported as useful tumor markers for esophageal cancer. The aim of this study was to examine the predictive value of CYFRA21-1 in comparison with CEA and other clinicopathological factors in patients with ESCC treated with definitive CRT.

Methods: Pretreatment serum CYFRA21-1 and CEA levels were measured by immunoradiometric assays. The relationships between pretreatment clinicopathological factors and the efficacy of CRT were analyzed. Overall survival (OS) was estimated by univariate and multivariate analysis.

Results: The results from a univariate analysis indicated that the efficacy of CRT was significantly associated with the serum levels of CYFRA21-1 and CEA before treatment (P = 0.001 and P = 0.023, respectively). It also indicated that the efficacy of CRT was significantly associated with the pretreatment tumor location (P = 0.041). By Logistic regression analysis, the independent predictive factor associated with efficacy of CRT was CYFRA21-1 (P = 0.002). The OS of the patients with high CYFRA 21-1 levels was worse than that of those with low CYFRA21-1 levels (P = 0.001). In multivariate analysis, a low level of CYFRA21-1 was the most significant independent predictor of good OS (P = 0.007).

Conclusions: CEA and tumor location may be useful in predicting the sensitivity of ESCC to CRT. CYFRA21-1 may be an independent predictor for definitive CRT sensitivity in ESCC.