BREAST cancer cells can destroy a powerful immune response in the body, and allow the disease to spread to a patient's bones, researchers have reported.
They experimented with two ways to reinstate this immune response to help patients fight breast cancer, but said it will take more tests and several more years for these therapies to become routine.
"We have identified a way that breast cancer cells can turn off the immune system, allowing them to spread to distant parts such as the bone," said Belinda Parker, a research fellow at the Peter MacCallum Cancer Centre in Melbourne, who led the study.
"By understanding how this occurs, we hope to use existing and new therapies to restore this immune function and prevent the spread of cancer."
In 2010, 1.5m people were diagnosed with breast cancer, the top cancer in women around the world.
Although it kills many women in the developing world, 89pc diagnosed with breast cancer in western countries are still alive after five years.
Using tissue samples from breast cancer patients and experiments with mice, Parker and colleagues found that a gene called IRF7 is switched off in patients whose cancer spreads.
This controls the production of interferon, an important type of immune protein that fights viruses and bacteria apart from tumour cells.