Here, we demonstrated that patients with metastatic colorectal cancer before receiving cetuximab-containing therapy showed a significant decrease in the percentages of CD16+, CD56+, and CD16+CD56+ lymphocytes in the total white blood cell pool, which was accompanied by a significant decrease in lymphocyte percentages and a significant increase in the granulocyte to lymphocyte ratio, indicating tumor-specific immune alterations. This evidence concerns the gene NCAM1 and metastatic colorectal cancer.