14 June : For the first time, a research at the University of Oxford has shown how cancers that spread to the brain establish themselves and begin to grow.This could allow new drugs to be developed to stop cancers from spreading and growing in the brain.
Metastasis is the process where cancer breaks out from where a tumor has initially grown and spreads to other parts of the body. It is usually the reason why cancer is fatal.Brain metastases are the most common malignant tumors of the central nervous system, outnumbering by ten times those that originate in the brain.
Once such cancers have reached the brain the prognosis is not good, the median survival is 9 months with maximal treatment.Over 20 per cent of all cancer patients will eventually develop metastatic cancer in the central nervous system, a university release said.
The Oxford University team set out to answer the question: how do tumour cells grow in the brain. They looked at a comprehensive range of cancer cell types from humans and mice breast cancer cell lines, melanoma cells and a lymphoma cell line and examined how the cells establish themselves in the brain in laboratory studies, using both mice and human tissue samples.
Previously it had generally been assumed that tumor cells grew on the cells that make up the grey and white matter of the brain: the neurons and glial cells.
Instead, the researchers found that the metastatic cancer cells start to grow on the walls of blood vessels in the brain in over 95 per cent of cases, and not on the nerve cells.
The researchers suggest that by ‘co-opting’ the vascular networks in the brain, the cancer cells can get all the nutrients and oxygen they need to start growing without having to grow new blood vessels of their own first.
The team also discovered that a particular protein called an integrin on the outside surface of the cancer cells is necessary for them to stick to the blood vessels.
Removal of the integrin stopped the cancer cells from attaching and starting to grow. This discovery is promising, as it may be possible to develop drugs to target the integrin and stop brain metastasis.
According to the team’s research the protein which assist cancer to multiply its cells in brain has been identified which is known as integrin, it is located on the outside surface of cancer cell is necessary for them to stick to the blood cells.
Removal of the protein can stop the growth of cancer.
Dr Helen George, Cancer Research UK’s head of science information, told that the research shows that cancer cells which spread to the brain latch on to blood vessels, paving the way for new and much-needed treatments to tackle cancers that have spread to the brain, in the future.