Instead of a cell just breaking off from a tumour and travelling through the bloodstream to another organ where it forms a secondary tumour, or metastasis, researchers in the United States have shown that the cancer sends out envoys to prepare the new site.

"We are basically looking at all the earlier steps that are involved in metastasis that we weren't previously aware of. It is complex, but we are opening the door to all these things that occur before the tumour cell implants itself," said Professor David Lyden of Cornell University in New York.

Colonisation of organs

Cancer's ability to colonise other organs is what makes the disease so deadly.

"The authors show that tumour cells can mobilise normal bone marrow cells, causing them to migrate to particular regions and change the local environment so as to attract and support a developing metastasis," Patricia Steeg, of the National Cancer Institute in Bethesda, Maryland, said in a commentary. 


Professor David Lyden, Cornell University in New York


"These nests provide attachment factors for the tumour cells to implant and nurture them. It causes them not only to bind but to proliferate. Once that all takes place we have a fully formed metastatic site or secondary tumour," said Lyden.


Without the landing pad, the cancerous cell could not colonise the organ.


The envoys from the tumour determine the site of the secondary site.
"This opens up the door to new concepts of how metastasis is taking place. If we can understand all these multiple processes we can develop new drugs that block each step. That way we have a much better future than just trying to treat the tumour cell, which is almost like a last step in this process," he added.