Australian researchers believe they have identified what causes the onset and development of bowel cancer, opening up new possibilities for treatment of the disease.

Bowel cancer is the second most common cause of cancer related death in Australia, claiming around 4,000 lives each year.

Researchers at Melbourne’s MacCallum Cancer Centre have found a failure in a two-part protective ‘braking system’ in bowel cancer cells, which cause the onset and acceleration of the disease and the development of resistance to cancer treatments.

They said the discovery showed the usual orderly process of cell division failed in two ways, causing chromosomal instability.

Researchers said they have known of this instability for some time, but until now did not know what caused it.

“Previously, in most bowel cancers, we thought this instability built up randomly over time as cancer cells evolved, while a signalling network, called the Wnt pathway, held cells back from chromosome chaos,” researchers said.

“Now we have proven this instability begins immediately with the breakdown of the Wnt pathway, which occurs in two steps and sets off an unstoppable acceleration of disease.”

The finding is the result of five years’ work and has already prompted discussions about using current chemotherapy drugs differently to improve their efficacy.