Compared with patients in the non-anemia group, anemic patients were older (60.2 ± 13.5 years vs. 58.3 ± 11.6 years, p < 0.001), received preoperative chemotherapy more frequently (10.2 vs. 7.5%, p < 0.001), had higher preoperative serum CEA levels (3.7 ng/mL vs. 2.8 ng/mL, p < 0.001), had worse tumor differentiation (23.0 vs. 18.8%, p < 0.001), and had a more advanced TNM stage (stages III–IV 51.9 vs. 47.2%, p < 0.001). The gene discussed is CEACAM5; the disease is anemia (phenotype).