Tumor-associated macrophages infiltration is associated with peritumoral lymphangiogenesis and poor prognosis in lung adenocarcinoma

Tumor-associated macrophages (TAMs) have been implicated in promoting tumor progression. Nowadays, adenocarcinoma has surpassed squamous cell carcinoma as the most frequent type of lung cancer, but in lung adenocarcinoma, the correlation of TAMs with lymphangiogenesis patients remains unclear. The aim of this study was to examine the relationship between TAMs and lymphangiogenesis and the lung adenocarcinoma patients’ prognosis. Tumor specimens from 65 patients with lung adenocarcinoma were determined for TAMs count and lymphatic microvessel density (LMVD) by immunohistochemistry. A positive correlation existed between TAMs count and D2-40-positive peritumoral LMVD (r = 0.069, P < 0.001). TAMs infiltration was significantly associated with P-TNM staging (P = 0.042) and lymph node metastasis (P = 0.037), and peritumoral LMVD was correlated with lymph node metastasis (P = 0.003). A significant difference in overall survival was detected not only between tumors with a high TAMs count and a low TAMs count (P = 0.009) but also between tumors with a high peritumoral LMVD and a low peritumoral LMVD (P = 0.005). Both TAMs count and peritumoral LMVD were independent prognostic factors for overall survival. Our results indicate that TAMs infiltration correlates with tumor lymphangiogenesis and poor survival in lung adenocarcinoma.