Scientists uncover ‘genetic key’ to breast cancer

Scientists have detected a protein which prevents anti-hormone drugs working as well as they can in women with a certain type of breast cancer.

Some 44,000 women have breast cancer in the UK and ten to 15 per cent of these have lobular cancer, which is treated with anti-hormone drugs but does not respond as well as hoped.

Women with this type of cancer also do not respond as well to chemotherapy given before surgery.

Researchers at the Breakthrough Toby Robins Breast Cancer Research Centre at the Institute of Cancer Research analysed the genetics of lobular breast cancer using biopsy samples.

They discovered that almost half of the breast cancers had too much FGFR1 protein.

Previous studies have shown that too much FGFR1 is associated with a poor prognosis and an increased chance of the breast cancer returning.

Scientists removed the gene from cells which mimicked the genetic features of lobular breast cancers and found that the tumours relied on FGFR1 to be able to grow.

When FGFR1 was removed the rate of cell growth was reduced.

And when it was targeted with the compound SU5402 the growth of cells was slowed down.

Writing in the journal Clinical Cancer Research, the researchers argue that targeting the FGFR1 protein with specific drug compounds could be effective in blocking the growth of this particular type of tumour.

Dr Jorge Reis-Filho, team leader of the molecular pathology laboratory at the Breakthrough Breast Cancer Research Centre, said: “Breast cancer is a complex disease made up of many subtypes.

“Currently, most breast cancers are treated similarly but we’d like to be able to tailor treatment for each type. To do this, it is important that we find new targets for drug development. The discovery of FGFR1 is the first step on the road to tailoring treatment for the 10 to 15 per cent of women diagnosed with lobular breast cancer.”

He added: “The identification of FGFR1 in this sub-group of breast cancers is a very promising finding and although we are a few years away from clinical trials we are moving closer towards our vision of a future free from the fear of breast cancer.”

Further research will be undertaken to confirm the findings and to see whether they can be applied to other types of cancer with abnormally high levels of FGFR1.

If the findings are confirmed, drugs which can stop FGFR1 from working could be accepted to clinical trials for this particular type of breast cancer within the next two years.