Relationship Between Tumor-associated Macrophages Infiltration And Lymphangiogenesis As Well As Lymphatic Metastasis In Gastric Cancinoma

Objective: To quantify tumor-associated macrophages (TAMs) numbers and lymphatic microvessel density (LMVD) in benign gastric mucosa tissues and gastric carcinoma tissues. To analyze the relation between TAMs infiltration and lymphangiogenesis (LMVD) in gastric carcinoma, and their connection with clinicopathological characteristics. To investigate the role of TAMs in lymphangiogenesis and lymphatic metastasis of gastric carcinoma.Methods: Collected 15 benign bioptic gastric mucosa samples and 68 archive paraffin samples of gastric carcinoma coming from the patients who were treated by operation in the first hospital of Lanzhou University from August 2003 to June 2005. Gastric carcinoma samples were divided into 8 group: Group A: (n=30): differentiated carcinoma group, Group B: (n=38): undifferentiated carcinoma group, Group C (n=32): T1+T2 group, Group D (n=36): T3+T4 group, Group E (n=38): lymph node metastasis group, Group F (n=30): no lymph node metastasis group, Group G (n=27): I + II group, Group H (n=41): III+IV group. All patients were not accepted any treatment before operation. The samples were cut continuously into sections 5μm thick. Macrophages and lymphatic endothelial cells were labelled with CD68 and VEGFR-3 respectively by immunohistochemical S-P method. Macrophages numbers and LMVD were counted under optical microscope by Weidner's method. The data was analyzed by SPSS 10.0.Results: Mean TAMs numbers and LMVD were significantly higher in gastric carcinoma tissues than in bioptic benign gastric mucosa tissues (P=0.016 or 0.011), and significantly higher in lymph node metastasis group than in non-metastasis group (P=0.008 or 0.001), as well as significantly higher in III+IV group than in I + II group (p=0.041 or 0.011), but could not be confirmed to correlate with tumor grade and tissue invasion (P>0.05). There was a positive correlation between mean TAMs numbers and LMVD (r=0.778, P=0.000).Conclusion: TAMs numbers and LMVD were significantly higher in gastric carcinoma tissues than in bioptic benign gastric mucosa tissues, and remarkably correlated with lymph node metastasis and TNM stages, which indicated TAMs infiltration may trigger lymphangiogenesis and be involved in lymph node metastasis in gastric carcinomas, furthermore may be an important factor in lymphangiogenesis of gastric carcinoma.