Predictive role of CYFRA 21-1 for S-1 monotherapy in non-small cell lung cancer patients

S-1, an oral fluoropyrimidine derivative, is widely used for the treatment of several solid tumors. However, there are no predictive markers for its effectiveness.We retrospectively screened 108 patients with advanced non-small cell lung cancer (NSCLC) treated via S-1 monotherapy and investigated its relationship with cytokeratin 19 fragment (CYFRA 21-1) and CEA pretreatment levels.Sixty-one patients with high CYFRA 21-1 levels had a statistically significant shorter progression-free survival (PFS) and overall survival (OS) than 46 patients with normal levels (median PFS = 42 days vs. 70 days, respectively; p = 0.0014; median OS = 197 days vs. 316 days, respectively, p = 0.0239).Serum CYFRA 21-1 levels have predictive and prognostic roles in the management of patients with advanced NSCLC on S-1 monotherapy.