Scientists discover how cancer becomes so deadly

Previously believed that cancer cells split to create two new cells The way cancers cells works, particularly how they alter their genetic code in order to thrive has been explained by a group of UK researchers. Cancer cells can differ hugely within a tumour it helps them develop ways to resist drugs and spread round the body.
A study in the journal Nature showed cells that used up their raw materials became "stressed" and made mistakes copying their genetic code.
Intriguingly, scientists at the Cancer Research UK London Research Institute and the University College London Cancer Institute are claiming that supplying the cancer with more fuel to grow may actually make it less dangerous.
Most normal cells in the human body contain 46 chromosomes, or bundles of genetic code. However, some cancerous cells can have more than 100 chromosomes.
And the pattern is inconsistent - pick a bunch of neighbouring cells and they could each have different chromosome counts.
This diversity helps tumours adapt to become untreatable and colonise new parts of the body. Devising ways of preventing a cancer from becoming diverse is a growing field of research.
It has previously been thought that when a cancer cell split to create two new cells, the chromosomes were not split evenly between the two.
However, lead researcher Prof Charles Swanton's tests on bowel cancer showed "very little evidence" that was the case.
Instead the study showed the problem came from making copies of the cancer's genetic code.
Cancers are driven to make copies of themselves, however, if cancerous cells run out of the building blocks of their DNA they develop "DNA replication stress".
The study showed the stress led to errors and tumour diversity.
"It is like constructing a building without enough bricks or cement for the foundations. However, if you can provide the building blocks of DNA you can reduce the replication stress to limit the diversity in tumours, which could be therapeutic," Prof Swanton told the BBC.
The latest discovery is considered a breakthrough, as it can be used to develop new tools to combat cancer and tumours.
"Scientists can now start looking for ways to prevent this happening in the first place or turning this instability against cancers," said Prof Nic Jones, a chief scientist with Cancer Research UK.