Tumor-infiltrating macrophages can predict favorable prognosis in hepatocellular carcinoma after resection

To evaluate the prognostic value of tumor-associated macrophages (TAM), individually or synergistically with CD45RO + memory T cells (T-M), in hepatocellular carcinoma (HCC) patients following resection. The infiltration of TAM and T-M was assessed by immunohistochemistry in tissue microarray containing 302 HCC specimens. Correlations between TAM/T-M infiltration and clinicopathologic features, disease-free survival (DFS) and overall survival (OS) were statistically analyzed. High TAM infiltration was associated with both improved DFS (P = 0.0021) and OS (P = 0.0481). Multivariate analysis identified TAM infiltration as independent prognostic factor for DFS (P = 0.004) and OS (P = 0.049). A second analysis clarified the synergistic effect of TAM&T-M infiltration for DFS (P = 0.004) and OS (P = 0.040). Both TAM infiltration alone and concomitant infiltration of TAM&T-M are associated with improved DFS/OS, suggesting that TAM could protect HCC patients from recurrence/metastasis and prolong survival by distinct mechanisms.