MKI67 and neoplasm: The results showed that both CTCs counts and CTCs’ positive rate detected were significantly different in patients with different status of tumor differentiation (P = 0.026; P = 0.030, respectively) (Fig. 4c), lymphovascular invasion (P < 0.001; P = 0.025, respectively) (Fig. 4d), perineural invasion (P < 0.001; P = 0.028, respectively) (Fig. 4e), TNM stage (P < 0.001; P = 0.033, respectively) (Fig. 4f) and Ki-67 level (P < 0.001; P = 0.024, respectively) (Table 2).