CEACAM5 and lymphopenia: As shown in Table 4 and Table 5, pretreatment CEA ≥10 ng ml-1 was the independent risk factor for chemotherapy-associated lymphopenia <0.66 × 109/L(OR, 3.338; 95% CI = 1.523-7.315), and age >60 years was the independent risk factor for chemotherapy-associated lymphopenia <0.91 × 109/L(OR, 2.872; 95% CI = 1.344-6.136).