Serum metabolomic profiles for distinguishing lung cancer from pulmonary tuberculosis: identification of rapid and noninvasive biomarker.

Abstract

Pulmonary tuberculosis (TB) and lung cancer (LC) have similar clinical symptoms and atypical imaging findings which are easily misdiagnosed. There is an urgent need for a noninvasive and accurate biomarker to distinguish LC from TB. A total of 694 subjects were enrolled and divided into discovery set (n = 122), identification set (n = 214), and validation set (n = 358). Metabolites were identified by multivariate and univariate analyses. Receiver operating characteristic curve were used to evaluate the diagnostic efficacy of biomarkers. Seven metabolites were identified and validated. Phenylalanylphenylalanine for distinguish LC from TB yielded an area under the curve of 0.89, sensitivity of 71%, and specificity of 92%. It also showed good diagnostic abilities in discovery set and identification set. Compared with that in healthy volunteers (1.57 (1.01, 2.34) μg·mL-1), it was elevated in LC (4.76 (2.74-7.08) μg·mL-1; ratio of median, ROM = 3.03, p < 0.01) and reduced in TB (1.06 (0.51, 2.09) μg·mL-1, ROM = 0.68, p < 0.05). The metabolomic profile of LC and TB was described and key biomarker was identified. We produced a rapid and noninvasive method to supplement existing clinical diagnostic examinations for distinguishing LC from TB.