How the study of Helicobacter infection can contribute to the understanding of carcinoma development.

The inflammatory environment dramatically impacts the formation of cancer at many levels, acting on the stem cell to foster the initiation of cancer all the way through its contribution to metastatic disease. Using Helicobacter-induced gastric cancer as an example, it can be seen that, early on, chronic inflammation exhausts tissue stem cells, forcing the remaining stem cells to work overtime and calling in replacement cells from marrow sources. Marrow-derived stromal cells orchestrate growth and remodelling through secreted factors and cell-cell communication. Once cancer is present, the inflammatory environment is responsible for the continued growth signals to the cancer stem cells and to the stromal cells which become a vital part of the cancer niche as well as the pre-metastatic niche which will effectively lure cancer cells into peripheral organs for distant growth. This understanding of the inflammatory environment and its many effects on cancer throughout its natural history provides intervention targets directed at the unique aspects of cancer behaviour.