CEACAM5 and cancer: Higher CEA was correlated with poorer overall survival in various cancers, notably gastrointestinal cancer (GTC) (HR = 1.91, 95% CI: 1.55–2.35, p < 0.001) and non-small cell lung cancer (NSCLC) (HR = 1.80, 95% CI: 1.53–2.12, p < 0.001).