Cancers with Higher Density of Tumor-Associated Macrophages Were Associated with Poor Survival Rates

Background: Macrophages are a component of a tumor's microenvironment and have various roles in tumor progression and metastasis. This study evaluated the relationships between tumorassociated macrophage (TAM) density and clinical outcomes in 14 different types of human cancers. Methods: We investigated TAM density in human tissue microarray sections from 14 different types of human cancers (n = 266) and normal thyroid, lung, and breast tissues (n = 22). The five-year survival rates of each cancer were obtained from the 2011 Korea Central Cancer Registry. Results: Among 13 human cancers, excluding thyroid cancer, pancreas, lung, and gallbladder cancers had the highest density of CD163-positive macrophages (7.0 +/- 3.5%, 6.9 +/- 7.4%, and 6.9 +/- 5.5%, respectively). The five-year relative survival rates of these cancers (pancreas, 8.7%; lung, 20.7%; gallbladder, 27.5%) were lower than those of other cancers. The histological subtypes in thyroid cancer exhibited significantly different CD163-positive macrophages densities (papillary, 1.8 +/- 1.6% vs anaplastic, 22.9 +/- 17.1%; p < .001), but no significant difference between histological subtypes was detected in lung and breast cancers. Moreover, there was no significant difference in CD163-positive macrophages densities among the TNM stages in lung, breast, and thyroid cancers. Conclusions: Cancers with higher TAM densities (pancreas, lung, anaplastic thyroid, and gallbladder) were associated with poor survival rate.