Organ tropism in solid tumor metastasis: an updated review

Lay abstract Tumors of solid organs choose specific organs as their secondary foci; tumor cells dissociated from the primary tumor are not able to grow in all body tissues, so there are a number of organs designated to provide an appropriate growth environment for colonization of these detached cells. Brain, lymph nodes, bone, liver and lung are the five most common sites of metastasis for solid tumors. These organs attract disseminated tumor cells by displaying characteristics that can be either specific or shared among them. Detection of the promoters of organ tropism in cancer metastasis and their targeting can be a promising strategy for reducing the possibility of tumor dispersion. Tumors are equipped with a highly complex machinery of interrelated events so as to adapt to hazardous conditions, preserve a growing cell mass and thrive at the site of metastasis. Tumor cells display metastatic propensity toward specific organs where the stromal milieu is appropriate for their further colonization. Effective colonization relies on the plasticity of tumor cells in adapting to the conditions of the new area by reshaping their epigenetic landscape. Breast cancer cells, for instance, are able to adopt brain-like or epithelial/osteoid features in order to pursue effective metastasis into brain and bone, respectively. The aim of this review is to discuss recent insights into organ tropism in tumor metastasis, outlining potential strategies to address this driver of tumor aggressiveness.

Automated summary

Tumors of solid organs have a tendency to metastasize to specific organs, relying on the plasticity of tumor cells to reshape their epigenetic landscape and successfully colonize new areas.