CEACAM5 and cancer: The latest edition of the Cancer Staging Manual reviewed by the American Joint Committee on Cancer (AJCC), highlights the importance of additional parameters in the TNM system, such as preoperative serum carcinoembryonic antigen (CEA) levels, tumor regression score, lymphovascular and perineural invasion, microsatellite instability, and mutation status of KRAS, NRAS, and BRAF [4–6].