Tumour‐associated macrophages correlate with microvascular bed extension in colorectal cancer patients

Tumour‐associated macrophages ( TAM s) represent pivotal components of tumour microenvironment promoting angiogenesis, tumour progression and invasion. In colorectal cancer ( CRC ), there are no conclusive data about the role of TAM s in angiogenesis‐mediated tumour progression. In this study, we aimed to evaluate a correlation between TAM s, TAM immunostained area ( TAMIA ) microvascular density ( MVD ), endothelial area ( EA ) and cancer cells positive to VEGF ‐A ( CCP ‐ VEGF ‐A) in primary tumour tissue of locally advanced CRC patients undergone to radical surgery. A series of 76 patients with CRC were selected and evaluated by immunohistochemistry and image analysis. An anti‐ CD 68 antibody was employed to assess TAM s and TAMIA expression, an anti‐ CD 34 antibody was utilized to detect MVD and EA expression, whereas an anti‐ VEGF ‐A antibody was used to detect CCP ‐ VEGF ‐A; then, tumour sections were evaluated by image analysis methods. The mean ± S.D. of TAM s, MVD and CCP ‐ VEGF ‐A was 65.58 ± 21.14, 28.53 ± 7.75 and 63% ± 37%, respectively; the mean ± S.D. of TAMIA and EA was 438.37 ± 124.14μ 2 and 186.73 ± 67.22μ 2 , respectively. A significant correlation was found between TAM s, TAMIA , MVD and EA each other ( r  ranging from 0.69 to 0.84; P ranging from 0.000 to 0.004). The high level of expression of TAM s and TAMIA in tumour tissue and the significant correlation with both MVD and EA illustrate that TAM s could represent a marker that plays an important role in promoting angiogenesis‐mediated CRC . In this context, novel agents killing TAM s might be evaluated in clinical trials as a new anti‐angiogenic approach.