The pooled results revealed that elevated plasma fibrinogen was significantly correlated with advanced tumor stage (OR = 2.14, 95% CI: 1.83–2.50, P < .001) (Fig. 3A), lymph node metastasis (OR = 1.81, 95% CI: 1.56–2.11, P < .001) (Fig. 3B), distant metastasis (OR = 1.48, 95% CI: 1.12–1.94, P = .005) (Fig. 3C), deeper tumor invasion (OR = 2.25, 95% CI: 1.47–3.45, P < .001) (Fig. 3D), and high carcinoembryonic antigen (CEA) (OR = 1.41, 95% CI: 1.18–1.68, P < .001) (Fig. 3E). The gene discussed is CEACAM5; the disease is metastatic malignant neoplasm in the lymph nodes.