Scientists discover genes linked to spread of breast cancer

Jul 28 2005

In new research scientists have identified genes which enable breast cancer cells to spread to the lungs, and the discovery could very well improve diagnosis and treatment of the disease.

According to the researchers, the set of genes reveals not only where the cancer will spread, but also how virulent it is likely to be.

The researchers believe the genes could be potential targets for existing or new breast cancer.

Dr Joan Massague, of the Howard Hughes Medical Institute at the Memorial Sloan-Kettering Cancer Center in New York, says they were looking for, and found, a specific set of genes that some breast cancers utilise, to form metastasis, specifically to the lungs.

The genes which can be found in some primary breast tumours, seem to predict a high risk of spread to the lungs even years later.

The main organs to which breast cancer spreads are, the lungs, bones, liver and brain, and for each organ the cancer invades, it needs a specific set of genes.

Breast cancer is one of the most common cancers in women worldwide, so the findings are important, because if breast cancer is diagnosed and treated early, women have a better chance of beating the disease.

Once it has spread beyond the breast it is more deadly because treatments are less effective.

The International Agency for Research on Cancer in Lyon, France, says more than a million new cases occur each year.

This exciting discovery could help doctors to identify women whose cancer is most likely to spread to the lungs so they can closely monitor them and try to block it, or treat it as early as possible.

The pattern of gene activity was discovered by Massague and his team by studying tumours from 82 patients whose breast cancer had spread to the lungs.

When they analysed data from a similar group of patients from the Netherlands they found the same genetic signature.

According to Massague, the genes are not only markers for cancer spreading, but are also mediators that cause it to spread.

The proteins they produce could become prime targets for existing or new drugs to prevent the spread of cancer.

Massague also says that compounds already exist to block some of the genes they have identified, or the cell function they regulate, and the next step is to test those compounds in animal models to see if they can block metastasis.

The scientists believe the technique could be expanded to pinpoint genes involved in the spread of breast cancer to other organs or other types of cancer.

Massague confirms that they have already identified a set of genes that mediate metastasis to the bone.

The findings are reported in the science journal Nature.