Heiskala M, et al. - As tumor-associated macrophages (TAM) promote tumor cell survival, proliferation, and dissemination, and CCL2 (synthesized by tumor and stromal cells) initiates a chemokine cascade inducing these processes, researchers studied the frequency of TAMs and CCL2 expressing cells by immunohistochemistry (IHC) in three groups of primary tumor (PT)-recurrence (R) pairs, where relapse was recorded within 2 years (group 1), between 5 and 10 years (group 2), and after 10 years (group 3). In PTs and in R lesions, the peritumoral stroma showed more abundant infiltration vs the intratumoral stroma. The Rs showed higher mean frequency of M2 marker and CD14 positive cells in the intratumoral stroma and CCL2 expressing tumor cells vs the corresponding PTs. A high frequency of CD14 positive cells and a high expression of CCL2 by tumor cells in PTs was linked with early recurrence. For rapid tumor recurrence, these results suggest that a high frequency of CCL2 positive tumor cells and CD14 positive TAMs are significant risk factors.