CEACAM5 and gastric cancer: The positive rate of CEA and CA19-9 in early GC has been shown to be low in previous studies [19].The detection rates of GST and GC by combined CDUS and serum CEA and CA19-9 were significantly higher than those by each index alone, but the difference was not statistically significant when comparing the detection rates of GST and GC by combining CDUS and serum CEA and CA19-9.