Nature news piece in my to-process pile, with a nice quote from Shibata and an amusing one from Swanton. One day I'll get my very specialised topic tumour evolution blog launched… only been in the pipeline since 2008 :o
The main tumour was surprisingly varied. Just one-third of the mutations were common to all 14 samples, and one-quarter were found in just one sample and no others. Only one known kidney cancer gene ??? VHL ??? was consistently mutated. Swanton and his team even found signs of convergent evolution: the tumours had disabled the same gene ??? SETD2 ??? in three different ways. ???There is a bewildering amount of diversity present in each tumour,??? he says.
These results show that any one biopsy presents only a keyhole view of a much bigger landscape. ???I think many cancer researchers intuitively feel that this heterogeneity is present, but this [study] provides solid evidence,??? says Darryl Shibata, a cancer geneticist from the University of Southern California, Los Angeles.
This could explain why some patients with kidney cancer fare better if surgeons remove their main tumour even if the cancer has spread. ???It may be that by removing the evolutionary reservoir of diversity, you improve a patient???s outcomes,??? says Swanton. ???There is less material for the tumour to adapt to environmental pressures.???
The study has immediate implications for cancer genome projects ??? such as the US National Institutes of Health???s The Cancer Genome Atlas ??? that are trying to identify the full suite of mutations underlying individual tumours. These have all relied on single biopsies, and for many cancers it will be difficult to obtain samples with enough of a spatial spread.
pretty much what I pointed out when the first cancer genomes were trickling out…