[Detection and diagnostic value of serum carcinoembryonic antigen and cytokeratin 19 fragment in lung cancer patients].

OBJECTIVE: To explore the diagnostic value of carcinoembryonic antigen (CEA) and cytokeratin-19-fragment (CYFRA21-1) in lung cancer patients. METHODS: The levels of serum CEA and CYFRA21-1 were measured in 102 patients with lung cancer, 45 patients with benign lung disease and 36 health controls by electrochemiluminescence. RESULTS: The level of serum CEA and positive rate [(25.77 ± 15.34) ng/ml, 47.1%] were significantly higher in the lung cancer group than that in the benign lung disease group [(4.67 ± 2.21) ml, 7.7%; P < 0.05] and controls [(3.98 ± 3.00) ng/ml, 3.8%; P < 0.05], The level of serum CYFRA21-1 and positive rate [(14.08 ± 8.34) ng/ml, 62.7%] were also significantly higher in the lung cancer group than that in the benign lung disease group [(3.27 ± 2.87) ml, 7.7%; P < 0.05] and controls [(2.69 ± 2.02 ng/ml, 3.8%; P < 0.05]. The difference of level of CEA and CYFRA21-1 between the benign lung disease group and controls was statistically not significant (P > 0.05). Both tumor markers were increased to a different degree in the lung cancer patients at various TNM stages [(CEA: stage II (17.78 ± 8.71) ng/ml, stage III (25.84 ± 7.34) ng/ml, stage IV (34.85 ± 6.99) ng/ml; and CYFRA21-1: stage II (10.05 ± 6.76) ng/ml, stage III (15.93 ± 6.66) ng/ml, stage IV (22.78 ± 4.12) ng/ml]. Combined use of both makers showed a significant higher sensitivity (77.5% vs. 47.1%, 62.8%), but reduced specificity (86.8% vs. 94.0%, 95.6%), and not significantly changed accuracy (83.5% vs. 77.1%, 83.8%) in the diagnosis of lung cancer. CONCLUSIONS: CEA and CYFRA21-1 employed separately are helpful in the diagnosis of lung cancer. Combined detection of these two tumor markers can improve the positivity for diagnosis of lung cancer.

Serum thymidine kinase 1 levels correlate with clinical characteristics of esophageal squamous cell carcinoma.

Patients with esophageal cancer are often diagnosed at advanced stages, leading to poor prognosis. Biomarkers are needed to enable earlier detection as well as to aid in the prediction of prognosis, but to date these tools remain scarce. Thymidine kinase (TK1) has been shown to exhibit altered expression levels in esophageal tumor cells, therefore this study sought to determine whether serum TK1 levels are also altered and, if so, to assess the utility of TK1 as a biomarker in esophageal squamous cell carcinoma. Eighty patients with esophageal squamous cell carcinoma were included as the case group and 80 healthy persons were selected as the control group. Serum TK1 levels, postoperatively for cancer patients, were detected by chemiluminescence. Follow-up was performed for cancer patients to determine the progression free survival (PFS) and overall survival (OS). Serum TK1 levels were significantly higher in cases of esophageal cancer than in healthy control individuals (t=7.235, P<0.05). When cancer cases were sub-divided into lower and higher serum TK1 levels, based on the mean level of 3.38 pmol/L, statistically significant differences in TNM stage, tumor differentiation, and lymph node metastasis were observed between patients with ≥3.38 pmol/L and <3.38 pmol/L (χ(2)=28.134, 3.187, 7.234, P<0.05). The average OS of all esophageal cancer patients was 30.13 months, and the average PFS was 24.73 months. However, when the cases were divided by serum TK1 level, average OS of those with higher serum TK1 (≥3.38 pmol/L) was significantly lower (23.98 mo) than those with lower serum TK1 (32.96 mo) (χ(2)=5.439, P<0.05). Similarly, average PFS was significantly lower in patients with higher serum TK1 (17.65 mo versus 27.62) (χ(2)=4.640, P<0.05). OS was correlated with TNM stage (hazard ratio, HR=3.116), degree of tumor differentiation (HR=0.427), lymph node metastasis (HR=0.535), and serum TK1 level (HR=1.913) (Wald χ(2)=6.782, 6.228, 4.562, 5.681, P<0.05). Similarly, PFS was correlated with TMN stage (HR=2.153), degree of tumor differentiation (HR=0.627), and serum TK1 level (HR=1.632) (Wald χ(2)=7.035, 5.335, 4.887, P<0.05). Thus, patients with esophageal squamous cell carcinoma exhibit higher circulating TK1 levels, consistent with findings of increased TK1 expression in tumor cells. Further, the correlation of serum TK1 levels with clinical features of esophageal cancer and with patient survival suggest that serum TK1 may serve as a valuable biomarker for predicting patient prognosis.