Clinical value of serum cytokeratin 19 fragment and sialyl-Lewis x in non-small cell lung cancer

Background. This study aimed to establish the clinical significance of preoperative serum cytokeratin 19 fragment (CYFRA21-1) and sialyl-Lewis x (SLex) as prognostic markers. Methods. The study involved 272 patients (181 male, 91 female; median age 69 years; range, 32 to 92) with non-small cell lung cancer (NSCLC) who underwent pulmonary resection with mediastinal lymph node dissection. Tumor markers carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), CYFRA21-1, and SLex were examined. Results. A log-rank test revealed that age, gender, performance status, CEA, SCC, CYFRA21-1, and SLex were associated with the survival rate. By multivariate analysis, age, gender, performance status, CYFRA21-1 (risk ratio, 2.42) and SLex (risk ratio, 6.18) were independent prognostic factors. For patients positive for both markers, the relative risk was 6.10 compared with patients negative for both markers. The patients were divided into three groups: negative for both CYFRA21-1 and SLex (n = 97); positive for either marker (n = 136); and positive for both markers (n = 39). The 1-, 3-, and 5-year survival rates were the following: 98%, 82%, and 75% in the first group; 90%, 63%, and 49% in the second group; and 62%, 31%, and 25% in the third group (p < 0.001). Sixty-four percent of patients positive for both markers were histologic stage III/IV, and 68% of patients negative for both markers were stage I. Conclusions. Serum CYFRA21-1 and SLex were prognostic markers for NSCLC. Their combination should contribute to the classification of NSCLC patients. Preoperative staging should be carefully performed in patients positive for both tumor markers.