Cancer bronchique et inflammation

Tumor microenvironment consists in immune and inflammatory response cells, fibroblasts and endothelial cells. Innate immunity induces inflammation and is the first non-specific line of defense against pathogens or “transformed” cells. It consists mainly of mast cells, macrophages, neutrophils and natural killer cells (NK). Chronic inflammation is associated with cancer. Many chronic inflammatory diseases are associated with an increased risk of cancer. Regarding lung cancer, chronic inflammation seen in COPD, emphysema or idiopathic pulmonary fibrosis is associated with the development of lung cancer. In this article, we will review the pro and anti-tumor effects of inflammation related to the innate immune system in lung cancer. The specific immune system is described in another chapter. During tumor progression, cancer cells will be able to use and/or bypass the signals from the inflammatory cells to promote tumor proliferation, tissue invasion and metastasis. No therapeutic agents that specifically target inflammation are available. Several strategies are being studied to target innate immunity: 1) stimulate the induction of cytotoxic M1 macrophages or natural killer cells NK, 2) limit the induction of pro-tumor M2 macrophages or neutrophils, 3) block growth factors or secreted cytokines.