High serum YKL-40 level is associated with poor prognosis in patients with lung cancer

Introduction: YKL-40 is a glycoprotein that plays role in inflammation and malignant processes. High serum YKL-40 levels are associated with short survive in cancer and chronic obstructive pulmonary disease (COPD) is another reason to increase it's level. However, limited knowledges are known in YKL-40 along with lung cancer and COPD. Materials and Methods: One hundred patients were involved to study with lung cancer (84 men, 16 women, and median age 62). Results were compared with 30 healthy volunteers. Thirteen patients were small cell lung cancer (SCLC), 87 patients were non-small cell lung cancer (NSCLC). 62% of patients were inoperable. Results: Median YKL-40 level was 222.7 +/- 114.1 ng/mL in patients and was 144.5 +/- 105.7 ng/mL in controls (p< 0.001). Stage, tumour size, lymph node involvement and distant metastasis weren't associated with serum YKL-40 level. Above all cut-off values (133.159 and 162 ng/mL) survival was shorter (p> 0.05). Patients with COPD had worse survive above all cut-off values (p< 0.05), especially according to 133 ng/mL (p= 0.01). Conclusion: YKL-40 level is useful in lung cancer however it's not related to cell type and prognosis. It is associated with poor prognosis in lung cancer patients with COPD.