Aim: The aim of this study was to examine the clinical usefulness of cytokeratin 19 fragments (CYFRA 21-1) compared with squamous cell carcinoma (SCC) antigen in patients with esophageal cancer treated with radiation therapy.
Methods: Fifty-one patients with stage I-IV esophageal cancer were evaluated. CYFRA 21-1 and SCC antigen serum levels were measured at the start and the end of radiation therapy.
Results: CYFRA 21-1 (> 3.5 ng/mL) and SCC antigen (> 1.5 ng/mL) before radiation therapy were elevated in 63% and 53% of the patients, respectively. The CYFRA 21-1 levels were significantly correlated with TNM stages, tumor depth and lymph node metastasis (P = 0.0003, P = 0.019 and P = 0.019, respectively), whereas no correlation was observed between SCC antigen and these factors. The values of CYFRA 21-1 in all patients who survived without recurrence were under the cutoff level at the end of treatment, but the values in all patients with locoregional recurrence were above the level. However, there was no significant correlation between SCC antigen level at the end of treatment and any clinical outcome.
Conclusions: The results suggest that the evaluation of CYFRA 21-1 would be useful not only for assessment before radiation therapy but also for monitoring after radiation therapy in the treatment for esophageal cancer.