Optimal Cutoff Points of CYFRA21-1 for Survival Prediction in Non-small Cell Lung Cancer Patients Based on Running Statistical Analysis

Purpose: To determine pretreatment serum CYFRA21-1 levels as indicators of poor prognosis in patients with non-small cell lung cancer (NSCLC). Methods: 1,202 consecutive patients, diagnosed pathologically with NSCLC from January 1999 to December 2009, were entered in this study. To obtain optimal cutoff points of CYFRA21-1 for these endpoints, a running log-rank statistical method was applied. Results: The cutoff level for the maximum log-rank statistical value of one-year survival in patients with NSCLC was 18.0 ng/ml. These results could be applied to patients with squamous cell carcinoma. In multivariate analysis, elevated (>18.0 ng/ml) levels of CYFRA21-1 was confirmed as being an unfavourable prognostic factor. Conclusion: CYFRA21-1 assay has a clinical significance for identifying patients with poor prognosis among those with early and advanced NSCLC. Elevated serum CYFRA21-1 levels at the time of diagnosis may be a useful noninvasive marker for identifying the risk of early death from NSCLC. Non-small cell lung cancer (NSCLC) accounts for 80% of all lung cancer cases, presenting as locally advanced in approximately 25-30% of cases and as metastatic disease in approximately 40-50% of cases. After radical treatment for seemingly localised disease, 20% of these patients develop an early distant relapse, probably due to systemic micro-