ABSTRACT
<p><b>OBJECTIVE</b>To evaluate five serum tumor markers used alone or in combination for the diagnosis of lung cancer.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>The 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).</p><p><b>CONCLUSION</b>These 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.</p>