Discovery of gene linked to 60% of breast cancers could lead to new treatments

Scientists have discovered a gene that could be linked with 60 per cent of breast cancers.

The gene, known as DBC2, is one of the first tumour suppressor genes to be implicated in sporadic breast cancer, which accounts for 90 per cent of cases of the disease.

The discovery could lead to new breast cancer treatments.

Sporadic breast cancer, which affects women with no family history of the disease, is distinct from inherited breast cancer, which is handed down through generations but which accounts for only a small proportion of cases.

In sporadic breast cancer, mutations in a gene during the life of the patient may encourage development of the disease. Understanding how the gene works and why cancer develops when it mutates could open the way to new treatments.

Researchers from the Cold Spring Harbour Laboratory in New York and the University of Washington found the gene DBC2 was missing or inactive in 11 out of 19 cases (58 per cent) of sporadic breast cancer and in seven out of 14 cases of lung cancer (50 per cent).

When they examined cancers of the uterus, stomach, colon, brain and blood, they found the gene was still present suggesting its action is specific to the tissues of the lung and the breast. Studies showed when the active gene was introduced to breast cancer cells it had the power to kill them or stop them growing.

Dr Masaaki Hamaguchi, lead researcher, said: "More than half of sporadic breast cancer has some kind of genetic activity that can switch off DBC2, suggesting this gene has an anti-breast cancer effect.

"This is a totally new type of gene and its role in the normal cell is not known. People thought this type of gene was not important but our research is a sign that it may have a role in cancer."

The same research group at Cold Spring Harbour Laboratory, led by Dr Michael Wigler, identified one of the only other tumour suppressor genes – called PTEN – to be clearly associated with sporadic cancer in 1997.

The research group at the University of Washington, led by Dr Mary-Claire King, discovered the first gene linked to hereditary breast cancer, BRCA1, in 1990. The Cold Spring group's findings will be published next week.