New research finds more patients suffering from breast cancer could be treated with a drug previously thought to only help those with a genetic gene deficiency, it was revealed on Tuesday. When there's a mutation or deficiency in specific genes, a person can become more susceptible to develop breast cancer.

"The BRCA1 and BRCA2 genes are guardians that look after DNA in our body," study researcher Dr. Peter Simpson told Xinhua.

"These are really critical genes in every cell of our body and they go through and repair DNA when it gets damaged."

By using a computer program to map the Genome sequencing of mutations in 560 breast cancers, the University of Queensland in Australia, along with the Sanger Institute in Britain, were able to look at different patterns of mutation and understand how a tumour had arisen.

"Results showed that almost 22 percent of breast tumours had a genetic signature reflecting a BRCA deficiency, even though the patient had not always inherited a mutation in one of the two genes," Simpson said.

In clinical trials at the moment, PARP inhibitor drugs can act to restore these BRCA1 or BRCA2 genes.

"It's very significant, it's building a really big body of evidence to suggest that in the future we can sequence a patient's tumour, we can understand the mutation and say whether the patient will respond better to chemotherapy of the PARP drug," he said.

"In the future we can see this kind of test becoming a kind of diagnostic that will determine what type of therapy a patient will have, this pattern of mutation will be a useful bio-marker."