To study the levels of tumor abnormal protein (TAP) in the patients with lung cancer in order to explore their efficacies in diagnosing lung cancer.

A total of 176 patients with lung cancer and 113 patients with non-lung cancer who were hospitalized in the Department of Respiratory and Critical Care Medicine, Tangdu Hospital, Airforce Military Medical University, Xi′an, China, were studied. Their levels of TAP were measured with the agglutinin affinity method. Then the TAP data were analyzed by statistical analysis.

The levels of TAP were higher in the patients with lung cancer than in the patients with non-lung cancer (P=0.002). The area under curve (AUC) of the serum TAP for lung cancer screening was 0.622 (95%CI: 0.554-0.689, P<0.001). When the cutoff value of TAP was 170 μm^2, the efficacies of sensitivity and specificity were best (P<0.05). Then the cutoff value 170 μm² and the cutoff values ≤121 μm^2, 121-225 μm^2, and ≥225 μm² were applied to the lung cancer group, non-lung cancer group and lung cancer group+ non-lung cancer group, respectively. It was found that the two groups of cutoff values were different in the screening efficacy of lung cancer. The former showed a significant difference between the three groups (P=0.006), while the latter showed no significant difference between the three groups (P=0.577).

Different cutoff values of TAP show different efficacies in lung cancer screening. If it is applied to the field of lung cancer alone, its efficacy is relatively low.