The 13 genes, eight of which are involved in the processing of fat in the body, could also be targeted by drugs leading to new treatments for non oestrogen-sensitive breast cancer, they reported in the Cancer Prevention Research journal.

Prof Seema Khan of Northwestern University in Chicago, who led the study, explained: "We now have the possibility of predicting if a preventive drug will work for a woman at high risk of breast cancer, so that we don't expose women to the risks and side effects of this drug if it won't help them.

"Identifying these genes also gives us a target for new therapies. Once we understand what regulates these genes, we can try to develop a therapy to switch them off."

About seven in ten breast cancers are "hormone receptor positive", meaning they are sensitive to oestrogen, but a significant proportion, particularly in younger women and women of African origin, are "HR negative".

Researchers studied a group of women who had developed cancer in one breast, meaning any tumour to grow in their other breast in future would likely be of the same type.

In samples of tissue from the healthy breast, the team identified 13 genes which were more or less active depending on whether the women's tumours were HR positive or negative.

Eight of the genes were involved in the metabolism of fat and several had previously been identified at high levels in breast tumour cells, backing up the findings.

Dr Emma Smith of Cancer Research UK said further study was needed but the results could lead to doctors "lowering the threshold" for deciding which patients are given tamoxifen, because they will be more sure who will benefit from it.

"If you stop breast cancer developing, you reduce the number of women who will need chemotherapy, surgery, mastectomies, and so on," she said.

See original here:
Breast cancer gene test could allow preventive treatment

Comments are closed.