Researchers from the University of Adelaide are hoping to better understand why the mutated genes for breast and ovarian cancer are not passed on more frequently from one generation of women to the next.

 

That's despite a documented link between breast cancer genes and increased fertility in women.

 

Dr Jack da Silva from the University's School of Molecular & Biomedical Science says that because women who carry breast cancer genes are more fertile, in theory they have a greater chance of passing these genes on to future generations.

 

"A recent study in the United States found that mutations in the breast cancer genes BRCA1 and BRCA2 were directly linked with a 50% increase in the fertility of women, which is a huge number," Dr da Silva says.

 

"With such an increased fertility rate, you would expect to see a high frequency of these cancer-causing genes in modern populations, but in fact that is not the case - the frequencies are relatively low."

 

In a paper being published today in the Proceedings of the Royal Society B, he argues that the so-called "grandmother effect" may in part be the reason behind this phenomenon.

 

"In an earlier study, researchers found that post-menopausal women create a 'grandmother effect' - that is, the longer they live, the more they are able to support their daughters and their grandchildren, thereby creating an environment in which more grandchildren are born,” says Dr da Silva.