Introduction: The gastrointestinal microbiome has been suggested to contribute to the development of both primary and secondary colorectal cancer. Despite advances in understanding the prognostic and predictive value of clinico-pathological parameters, the underlying mechanisms that result in progression to metastatic disease have yet to be defined. The metastatic cascade involves a number of sequential steps, including detachment of tumour cells from the primary site, intravasation and dissemination within the circulatory and lymphatic systems, with extravasation and proliferation at a secondary site.
Objective: An analysis of the literature relating to the gastrointestinal microbiome and its role in colorectal metastasis was conducted. This review aims to examine the current evidence supporting a role for the microbiome in colorectal metastasis and to describe the mechanisms by which it may contribute to metastatic progression.
Conclusion: The invasive pathways utilized by bacteria and how they may be manipulated by tumour cells for migration and metastasis are presented and the potential of the intestinal microbiome as a therapeutic target in colorectal carcinogenesis and metastasis is detailed here.
Keywords: Colorectal; cancer; metastasis; microbiome.
© 2019 The Association of Coloproctology of Great Britain and Ireland.