Genetic link to breast cancer

[DoctorX]

Genetic link to breast cancer



Researchers say they have identified a series of gene variations which together may play a role in the development of a common breast cancer.

A study of women in Finland and Sweden found 121 variations in their DNA.

The Singapore team think these are linked to oestrogen production - known to play a role in a breast cancer type which afflicts post-menopausal women.

The researchers say the findings might be used to identify women who might benefit from oestrogen-lowering drugs.
Poker hand

The researchers examined the genetic makeup of thousands of women with and without breast cancer in Sweden and Finland.

They found 121 tiny variations in 15 different genes which they say appear to be linked to a woman's risk of developing what is known as oestrogen receptor positive breast cancer.
Continue reading the main story

The variations are in a section of DNA close to a gene responsible for producing oestrogen and the suggestion is that the variations may play a collective role in the production of the female sex hormone.

The individual impact of each variation is minimal but if a woman is dealt a combination of these variations, say the scientists, the higher her exposure to the hormone will be, and the higher the risk of cancer.

"Breast cancer genes have been identified, for example BRCA1, BRCA2, P53, ATM. These genes have been identified with breast cancer susceptibility but mainly in breast cancers of younger women," says Dr Edison Liu of the Genome Institute of Singapore, who led the study.

"What we are finding here is potentially the genetic amplifiers for breast cancer in postmenopausal women which historically was considered not genetic in origin."

It is already established that women who start menstruating early in life or who have a late menopause have an increased risk of breast cancer, because of their longer exposure to oestrogen. This research, says Dr Liu, may reveal the genetic element to the oestrogen equation.

"It's like being dealt a bad hand in a poker game," he says. "And this risk is greatly affected by other non-genetic factors like a woman's reproductive history," he says.

Read More: http://www.bbc.co.uk/news/health-11206009