Melbourne, Jun 7 (IANS): Australian scientists began a clinical trial of injecting radiotherapy to combat aggressive breast cancer, media reported on Wednesday.

Women suffering from the most aggressive types of breast cancer will undergo treatment combining radiation with immunotherapy in an attempt to "reawaken" the immune system to fight the disease, Xinhua news agency said.

"The trial was approved after promising studies on animals where radiation was used to prepare the immune system to fight cancer," Sherene Loi, head of translational breast cancer research at the Peter MacCallum Cancer Centre in Melbourne, said.

She said using radiation and immunotherapy in conjunction was an "emerging idea."

Primary cancer in the breast is usually curable, but if it comes back it is "incurable", Loi was quoted as saying.

"We think that's because it outwits the immune system. Once you develop cancer, your immune system has failed. It can't see the cancer any more, and it also actively suppresses the immune system."

Loi's study was the first in the world to trial both immunotherapy and gene therapy together.

Breast cancer is the biggest killer of young and middle-aged Australian women.

Cancer Australia estimated that 17,586 women would be diagnosed with breast cancer in Australia in 2017, accounting for 13 percent of all new cancers in the country.