'Not only is this an exciting advance towards understanding how breast cancer develops, but it also heralds a revolutionary new era in the discovery of genes linked to disease.'

Now, new state-of-the-art technology has helped discover four more likely candidate genes, according to the study published in the journal Oncogene.

The vast majority of breast cancers are caused by damage to genes, which is acquired during a woman's lifetime. But so far, researchers have only pinpointed a few of the possible genes involved, such as the high-risk breast cancer genes BRCA1 and BRCA2.

Research Speeds Up

A team of Cancer Research UK scientists at Cambridge University used a technique called DNA microarrays to identify the new genes. DNA microarrays are microchips that are capable of scrutinizing the activity of hundreds of genes at once -- dramatically speeding up the pace of research.

Cancer Research UK said that before the map of the human genome was completed and better technology developed, this type of analysis would have taken years, because scientists were only able to study one gene at a time.

The researchers examined tissue from 53 tumors and also breast cancer cells that were grown in the lab.

Specific Genes Implicated

The search was concentrated on a specific group of genes on chromosome eight. These genes are implicated in the development of cancer because multiple copies of them are often found in tumors, but not in healthy tissue.

The researchers used the DNA microarrays to narrow down which of the hundreds of genes in the set were likely to be actively involved in the development of tumors.

Lead researcher Professor Carlos Caldas said, "Not only is this an exciting advance towards understanding how breast cancer develops, but it also heralds a revolutionary new era in the discovery of genes linked to disease."