Cannabis extract 'stops aggressive cancers from spreading'

Researchers found that the compound, called cannabidiol, had the ability to 'switch off' the gene responsible for metastasis in an aggressive form of breast cancer.

This substance, importantly, does not produce the psychoactive properties of the cannabis plant, the 'Daily Mail' reported.

The research team from the California Pacific Medical Center in San Francisco, first spotted its potential five years ago, after it stopped the proliferation of human breast cancer cells in the lab.

"The preclinical trial data is very strong, and there's no toxicity. There's really a lot or research to move ahead with and to get people excited," study co-leader Dr Sean McAllister told the San Francisco Chronicle.

McAllister along with colleague Dr Pierre Desprez acknowledge that they are some way off from turning their finding into a pill, they are already developing human trial models.

They hope to eventually test the drug in combination with current chemotherapies.

Desprez had previously found that a protein called ID-1 seemed to play a role in causing breast cancer to spread. Dr McAllister had discovered the cannabidiol had anti-cancer potential.

Scientists discovered that the compound had turned off the over-expression of ID-1, stopping them from travelling to distant tissues.

Other potentially treatable cancers are forms of leukaemia, lung, ovarian and brain cancers, which also have high levels of ID-1.

Cannabis is a Class B drug that is illegal to have, give away or sell. It is associated with an increase in developing psychotic illnesses later in life including schizophrenia.

Heavy-use can also affect learning ability and concentration levels.