However, only poor performance status (ECOG ≥ 1), higher preoperative CEA levels (≥ 5 ng/mL), poorly differentiated tumors, more advanced stage (stage II–IV), and type of primary malignancy other than breast or thyroid cancer were independent factors significantly associated with poor OS in the multivariate analysis (Table 4). Here, CEACAM5 is linked to thyroid gland carcinoma.