The clinical value of new tumor biomarker cytokeratin 2G2 detection in non-small cell lung cancer patients.

BACKGROUND: Many tumor markers are analyzed for usefulness in diagnosis, prognosis, and monitoring. The purpose of this study was to evaluate a new type of tumor biomarker, cytokeratin (CK)-2G2, in serum for the early diagnosis, confirmative diagnosis as well as assessment of treatments of non-small cell lung cancer (NSCLC). METHODS: Use a chemiluminescent method to examine the serum CK-2G2 levels in 100 patients with non-malignant lung diseases and 100 cases from the healthy population, as well as 124 cases of NSCLC patients prior to chemotherapy, after one course of treatment and after two courses of treatment. RESULTS: The average levels of CK-2G2 in the serum of NSCLC patients was found to be significantly higher than that of the group of non-malignant patients as well as the healthy control group (p < 0.01). It was further observed that CK-2G2 is markedly higher in squamous-cell carcinoma than in adenocarcinoma (p < 0.05) whereas CK-2G2 was found to be higher in stages III and IV than stages I and II (p < 0.05) and CK-2G2 is markedly higher in large tumor size (> 3cm) than in small tumor size (< or = 3cm) (p < 0.05). Serum CK-2G2 levels for patients with cancer progression were found to increase after two courses of chemotherapy (p < 0.01) whereas patients with stabilized tumorigenesis or tumor regression showed a significant trend of CK-2G2 decrease (p < 0.01). CONCLUSIONS: Detection of the new tumor biomarker CK-2G2 has certain clinical values for early diagnosis, verification of diagnosis as well as classification of patients. Thus it is warranted that CK-2G2 be widely deployed as a new type of cost effective parameter for evaluating efficacy of chemotherapy of NSCLC.