*2.4. Statistical Analysis*

Student's *t*-test was used for the quantitative analysis of Ki-67, mitotic count, Foxp 3, CD 163, PD-1, CD 4, and CD 8 (+) cells and the ratio of Foxp3 (+) cells to CD8 (+) cells in the CS (+) group and the CS (−) group. For the scores of VEGF-A, VEGFR1, VEGFR2, HIF-1α, and p53 the chi-squared test was used. PD-L1 expression on tumor cells was scored according to the percentage of PD-L1 positive cells (score 0–4). Therefore, nonparametric analysis of Mann-Whitney U-test was used to test the immunostaining raw scores of PD-L1 expression between the two groups, considering that the analytical immunohistochemistry scores were not normally distributed. All statistical analyses were performed using IBM SPSS statistics (IBM Corp., Armonk, NY, USA). A *p*-value of <0.05 was considered statistically significant.
