OBJECTIVETo evaluate five serum tumor markers used alone or in combination for the diagnosis of lung cancer.

METHODSThe level of five serum tumor markers: NSE, pro-GRP, CYFRA21-1, p53 antibody and CEA was detected by ELISA in 50 healthy adults, 170 lung cancer patients and 60 patients with respiratory infection.

RESULTSThe level of the five serum tumor markers in lung cancer patients was significantly higher than that of healthy adults and patients with respiratory infection (P < 0.01). The level of NSE and pro-GRP in patients with small-cell lung cancer was significantly higher than those of the other subtypes of lung cancer (P < 0.01); The level of CYFRA21-1 in patients with squamous-cell carcinoma was significantly higher than that of other subtypes (P < 0.01). The specificity of p53 antibody was 100% in diagnosing lung cancer and the sensitivity of NSE, pro-GRP was much higher for small-cell lung cancer than for other subtypes (P < 0.01); The same was observed in CYFRA21-1 for the diagnosis of squamous-cell carcinoma (P < 0.01). The sensitivity of the tumor markers in diagnosing lung cancer was significantly enhanced if used in combination (P < 0.01).

CONCLUSIONThese five tumor markers are valuable auxiliary parameters in diagnosing lung cancer. The combination of NSE and pro-GRP is more appropriate than other combinations in diagnosing small-cell lung cancer; the combination of CYFRA21-1, CEA and p53 antibody is the most valuable combination for diagnosing non-small-cell lung cancer. p53 antibody has the highest specificity for diagnosing lung cancer; CYFRA21-1 is the most valuable parameter for diagnosing squamous carcinoma.