BACKGROUNDTo determine the clinical value of serum TPA, Cyfra 21.1 and NSE in the diagnosis of lung cancer.

METHODSThe serum samples of 136 patients were measured: including 15 adenocarcinomas, 39 squamous cell carcinomas, 8 small-cell lung cancers (SCLC), 34 unclassified lung cancers, and 40 benign pulmonary diseases. Serum TPA and Cyfra 21.1 were detected by ELISA and the normal value was ≤0.9μg/l and ≤3.6μg/l respectively. Serum NSE was detected by radioimmunological method and the normal value was ≤20μg/l. All data were dealed with t and Chi-square test.

RESULTSThe level of TPA in each lung cancer group was significantly higher than the normal value except for that in SCLC group. The level of Cyfra 21.1 in adenocarcinoma, squamous cell carcinoma, and unclassified lung cancer groups was significantly higher than the normal value; The level of NSE in SCLC group was significantly higher than the normal value. In the benign pulmonary disease group the level of TPA was significantly higher than the normal value. TPA was sensitive for the diagnosis of lung cancer and the sensitivity was from 69.2% to 87.5%, but the specificity was low (29.3%); the specificity of Cyfra 21.1 was 97.6%, but the sensitivity was low (12.5%-35.9%); the sensitivity (75.0%) and specificity (82.9%) of NSE were high for SCLC.

CONCLUSIONSTPA shouldn't be a qualified tumor marker for lung cancer because of low specificity; the specificity of Cyfra 21.1 is higher, but the sensitivity is lower; NSE may be a satisfactory tumor marker for SCLC.