The role of inflammation in lung cancer

Lung cancer remains a serious public health problem and is the first cause of cancer death worldwide, and the overall 5-year survival rate for all stages is 14-17 % for Non-small-cell lung cancer and 6 % for small-cell lung cancer. Clinical and epidemiologic studies have suggested a strong association among chronic infection, inflammation, and cancer. Immune system plays a critical role in maintaining tissue homeostasis, cell turnover, tissue remodeling, and preventing infection and cell transformation. The inflammatory component in the development of the neoplasm includes a diverse leukocyte population; these components are considered inflammatory tumor key factors promoting tumor progression due to its ability to release a variety of cytokines, chemokines, and cytotoxic mediators such as reactive oxygen species (ROS), metalloproteinases, interleukins, and interferons. Cancer-related inflammation affects many aspects of malignancy, including the proliferation and survival of malignant cells, angiogenesis, tumor metastasis, and tumor response to chemotherapeutic drugs and hormones. Moreover, epidemiologic studies and meta-analysis have shown that prolonged use of non-steroid anti-inflammatory (NSAID) drugs reduces the risk of several solid tumor including lung cancer. Strong lines of evidence suggest that the chemopreventive properties of chronic NSAID administration are based on their COX-inhibitory activity. However, the prevention is a much better and more economical way to fight against cancer than treating an already advanced and often incurable disease.