Prevention and treatment of cancer targeting chronic inflammation: research progress, potential agents, clinical studies and mechanisms

Numerous experimental and clinical studies indicate that chronic inflammation is closely related to the initiation, progression, and spread of cancer, in which proinflammatory cytokines, such as interleukin (IL)-6, IL-1 beta, and tumor necrosis factor-alpha (TNF-alpha), and transcription factors, such as nuclear factor-kappa B (NF-kappa B), and signal transducer and activator of transcription 3 (STAT3), play pivotal roles. Stimulated by proinflammatory cytokines, NF-kappa B and STAT3 can modulate the expression of target genes, most of which are oncogenic ones, and promote the survival, proliferation, invasion, and metastasis of cancer cells. Now it is generally accepted that inflammation-related molecules and pathways are useful targets for the prevention and treatment of cancer. In this review, we summarize the relationship between chronic inflammation and cancer and describe some potentially useful agents including aspirin, meformin, statins, and some natural products (green tea catechins, andrographolide, curcumin) for their cancer prevention and treatment activities targeting chronic inflammation. The results of typical clinical studies are included, and the influences of these agents on the proinflammatory cytokines and inflammation-related pathways are discussed. Data from the present review support that agents targeting chronic inflammation may have a broad application prospect for the prevention and treatment of cancer in the future.