Currently, the diagnosis and management of lung cancer are still in intractable challenges worldwide. In order to achieve the early detection of screening lung cancer, it is necessary to take actions in the pre-cancerous and diagnoses in early stages.(11) For high risk population whose smoking pack-years over thirty in the past or at present, blood testing was recommended as the assistance for chest imaging examination with minor trauma instead of continual CT scan(11),(12),(13). CT scan showed a low specificity for lung cancer screening.(6),(14) We therefore performed this study to estimate the clinical value of six tumor markers in discriminating lung cancer from benign diseases.
The results showed higher concentration of GTM, CETM, PTM, CTM, ETM and HTM in patients with lung cancer than those with benign diseases, which may be useful for recognizing pulmonary malignant. Moreover, when lung cancer was classified into the pathological subtype groups, statistically significant differences in the serum levels of six biomarkers were observed in the comparison with benign diseases. Each marker showed considerable sensitivity and specificity for recognizing patients with SCC and SCLC. For adenocarcinoma, GTM, PTM, CTM, ETM and HTM were significant increased in cancer patients, which was not found in CETM.
GTM showed the highest sensitivity of 63.35% and specificity of 72.34%, with the under area of 0.6840 by ROC curves, to differentiating lung cancer from benign diseases. Similar results were also observed for CETM, PTM, CTM, ETM and HTM in differential diagnosis of lung cancer. It has been reliably proved that GTM was closely related to tumor initiation and invasion(15),(16),(17). In this study, its utility for screening malignant cancer was close to the results of Li et al, which enrolled 155 colorectal cancer and found notable differences with the comparison in the serum concentrations of 66 non-cancer diseases, representing the diagnostic value of 0.881 for discrimination.(18) Several researches also had reported the usefulness of materials therein CETM(19),(20), PTM(21), CTM, ETM(22) and HTM(23),(24) in lung cancer differential diagnosis, therapy monitoring and prognostics(25),(26). Age, gender, and smoking history had been found seldom effect for research population.(18)
In subgroup analysis by tumor histology, the concentrations of six tumor markers were significant higher in patients with SCC and SCLC than benign ones. With the optimum threshold of 89.65 U/ml, GTM showed the highest sensitivity of 89.29% and specificity of 82.98% with 0.9054 of AUC, to identify a patient with SCC, CETM, PTM, CTM, ETM and HTM were in equivalent and intensive ability to predict the malignant nature. For patients of SCLC, six tumor markers’ sensitivity were collectively up to 75.00%, and GTM, CTM, ETM presented 89.36% of specificity to recognize malignant patients and benign ones. Several studies set out by local hospitals in different distribution region revealed remarkable alternative function for early malignant tumors instead of using conventional markers like carcinoembryonic antigen, carbohydrate antigen 125, carbohydrate antigen 19 − 9.(27),(28),(29) Carcinoembryonic antigen, squamous cell associated antigen, neuron specific enolase as traditional tumor markers, have been reported passable specificity about 70%-80% in single detection for lung cancer,(20),(22) however, in this study, there were no statistical differences between patients groups and control ones (figures were not shown). Bad diagnostic relevance was found in these six tumor markers for ADC, and there was no significantly increased in serum concentration of CETM among patients with ADC.