Tumor markers of lung cancer: carcinoembryonic antigen and TuMark.

Abstract

To assess the value of tumor marker determinations in diagnosing lung cancer and monitoring the response to therapy in lung cancer patients, we tested the serum concentration of TuMark-reactive protein and carcinoembryonic antigen (CEA) in 78 patients with lung cancer and 81 patients with non-malignant diseases. The sensitivity of TuMark in detecting the presence of lung cancer was 63.8%, compared to 37.2% for CEA (p less than 0.05). The specificity was 91.3% for TuMark and 97.5% for CEA. The combination of TuMark and CEA increased the sensitivity to 74.3%. The sensitivity of TuMark for non-small cell carcinoma was significantly higher than that for small cell carcinoma (67.6% vs 30.0%) (p less than 0.05). The incidence of positive TuMark reactivity did not correlate with the stages of lung cancer. Since the incidence of positive CEA reactivity was lower in the limited stage than in the extensive stage of lung cancer (20.0% vs 43.1%), the sensitivity of TuMark with regard to the detection of early stage lung cancer appeared far superior to CEA (65.0% vs 20.0%, p less than 0.05). Serial monitoring of TuMark levels in 32 patients with all types of lung cancer showed that 84% correlated with their clinical courses. Six patients with stage I or II disease received complete surgical resection of tumors. All showed a decline of the TuMark level to normal levels in 17 to 48 days (average of 32 days). These results suggested that the TuMark test may be a useful new marker for diagnosing lung cancer and monitoring response to therapy, especially for non-small cell lung cancer.