Table 1.

Classification performance of SLMS and other traditional gastrointestinal tumor-related biomarkers in GC patients of different cohorts.

Cohort	Panel	Accuracy (95%CI)	Sensitivity (95%CI)	Specificity (95%CI)
Training cohort	SLMS	0.967 (0.946–0.981)	0.960 (0.926–0.982)	0.974 (0.943–0.990)
	CEA	0.520 (0.473–0.567)	0.075 (0.044–0.117)	0.965 (0.932–0.985)
	CA19-9	0.540 (0.493–0.586)	0.093 (0.058–0.138)	0.987 (0.962–0.997)
	CA72-4	0.518 (0.471–0.564)	0.154 (0.110–0.208)	0.881 (0.832–0.920)
	CDP	0.549 (0.501–0.595)	0.260 (0.204–0.322)	0.837 (0.782–0.883)
Testing cohort	SLMS	0.974 (0.910–0.997)	0.949 (0.829–0.994)	1.000 (0.910–1.000)
	CEA	0.551 (0.434–0.664)	0.128 (0.043–0.274)	0.974 (0.865–0.999)
	CA19-9	0.538 (0.422–0.652)	0.103 (0.029–0.242)	0.974 (0.965–0.999)
	CA72-4	0.500 (0.985–0.615)	0.154 (0.059–0.305)	0.846 (0.695–0.941)
	CDP	0.564 (0.447–0.676)	0.308 (0.170–0.476)	0.821 (0.665–0.925)
External validation cohort	SLMS	0.913 (0.865–0.949)	0.929 (0.859–0.971)	0.898 (0.820–0.950)
	CEA	0.561 (0.489–0.632)	0.143 (0.080–0.228)	0.980 (0.928–0.998)
	CA19-9	0.566 (0.494–0.637)	0.143 (0.080–0.228)	0.990 (0.945–1.000)
	CA72-4	0.515 (0.443–0.587)	0.153 (0.088–0.240)	0.878 (0.796–0.935)
	CDP	0.622 (0.551–0.691)	0.398 (0.300–0.502)	0.847 (0.760–0.912)

The combined diagnostic panel (CDP) was proposed based on CEA, CA19-9 and CA72-4. Specifically, participants who were positive for any of these three biomarkers would be identified as patients with gastric cancer.

CA19-9 carbohydrate antigen 199, CA72-4 carbohydrate antigen 724, CEA carcinoembryonic antigen, CI confidence interval, GC gastric cancer, SLMS serum lipid metabolic signature.