Metastisis happens earlier than previously thought

[Astronuc]

Cancer spread 'happens earlier'
http://news.bbc.co.uk/2/hi/health/7586444.stm
Apparently "normal" cells may carry cancer to new sites long before a tumour develops, lying dormant until key genes are activated, experts say.

US researchers say their findings, published in Science, could explain why some breast cancers lead to new tumours long after the disease is treated.

Secondary, or metastatic, cancers are responsible for the majority of deaths from the disease.

UK experts said it was essential to know more about how the cancer spreads. Something to keep in mind as one ages, and the risk of cancer increases. Prevention is certainly much better than treatment.

[Andy Resnick]

Another interesting point is that the secondary tumors are very specific: for example, prostate cancer cells will preferentially seed bone.

The discussion of this effect (among the MDs) is referred to as "the seed or the soil". As in, is this phenomenon due to the cell or to the environment. Yes, it may be both- but the question in that context revolves around treatment options, as opposed to basic science.