Clinicopathological significance of overexpression of interleukin-6 in colorectal cancer

Figure 1 Interleukin-6 expression is elevated in human colorectal cancer tissue samples. A: Individual FFPE sections demonstrated that colorectal cancer cells had invaded underneath the colorectal mucosa. The IL-6 expression level was elevated in colorectal tumour tissues compared to adjacent non-tumour tissues. “T” refers to tumour tissue, and “N” indicates adjacent non-tumour tissue from the same patient; B: IL-6 expression scores are shown as box plots, with the horizontal lines representing the median, the bottom and top of the boxes representing the 25^th and 75^th percentiles, respectively, and the vertical bars representing the range of data.

Figure 2 Interleukin-6 expression is associated with invasion depth and lymph node metastasis in colorectal cancer. A: Increased expression of IL-6 at the invasive front of human CRC samples compared with tumour centre; B: The tumor cells in lymph node metastases were also IL-6-immunopositive. IL: Interleukin.

Figure 3 Interleukin-6 expression is significantly correlated with histological differentiation and TNM stage. A: Poorly differentiated colorectal tumours showed higher expression of IL-6 than moderately and well differentiated colorectal tumours; B: Comparison of immunohistochemical scores of IL-6 according to histological differentiation (P < 0.05); C: Strong immunoreactivity was more likely to present with advanced-stage (stage III/IV) CRC compared to early-stage (stage I/II); D: Comparison of immunohistochemical scores of IL-6 according to TNM stage (P < 0.001).