Hypoxia, tumour-associated macrophages, microvessel density, VEGF and matrix metalloproteinases in human gastric cancer: interaction and impact on survival.

Hypoxia is a key feature of the microenvironment of cancer cells actively participating in tumour progression. Our study was aimed to evaluate the impact of hypoxia and hypoxia-associated factors on tumour progression and survival of patients with gastric cancer. One hundred and five resected specimens were used. The level of tumour hypoxia was evaluated using (31)P NMR spectroscopy, CD68 (tumour-associated macrophages), CD34 (microvessel density, MVD) and VEGF expression, immunohistochemistry, MMP-2 and MMP-9 activity, zymography. Statistical analysis was conducted using Pearson's test, Kaplan-Meier survival analysis, log-rank test and Cox proportional hazards model. Intratumoral hypoxia level has been significantly correlated with VEGF expression, TAM number and total protease activity. The overall survival rate of patients with strong tumour hypoxia, high level of MVD, VEGF expression, TAM and MMP activity was significantly lower than that of the patients without the mentioned tumour characteristics. The hypoxia-associated signalling that is activated in tumours promotes tumour progression through the recruitment of macrophages, remodelling of extracellular matrix and neoangiogenesis.