Among patients diagnosed with adenocarcinoma, patients with elevated preoperative serum tumor markers showed significantly worse RFS compared with those with normal serum tumor markers (CEA: P<0.0001, CYFRA21-1: P<0.0001, NSE: P=0.0026, CA153: P<0.0001, CA125: P<0.0001, CA199: P<0.0001) (Figure 2). Here, CEACAM5 is linked to adenocarcinoma.