Breast Cancer 'Not Linked' to IVF

Fears that IVF might raise women’s risk of developing breast cancer have been dispelled by a nationwide study in the Netherlands, which has found that the fertility treatment has no effect on the disease.

While no link between IVF and breast cancer has been firmly established, some scientists have worried about the potential effects of fertility drugs used to stimulate the ovaries so that eggs can be collected and fertilised. These expose the body to high levels of oestrogen, a female hormone to which some breast tumours are sensitive.

Some women who have had IVF and then gone on to develop breast tumours have blamed their condition on it. Sarah Parkinson, the late wife of the comedian Paul Merton, wrote before her death in 2003 of her belief that IVF had caused her cancer.

The new research, led by Alexandra van den Belt-Dusebout, of the Netherlands Cancer Institute, should reassure women considering fertility treatment that it does not pose a breast cancer risk.

Fertility treatment does not increase a woman's risk of developing breast cancer, according to a study of more than 25,000 women in the Netherlands.

The large study will help to reassure patients concerned that the powerful hormone doses that are part of fertility treatment might put them at risk of developing the disease in the future.

At the beginning of an IVF treatment cycle, women are given hormone drugs to stimulate their ovaries to produce more eggs so that clinicians can produce fertilised embryos in vitro. These lead to large spikes in oestrogen levels that could promote the development of breast cancer, which is sensitive to the hormone.

The study, carried out by Dr Alexandra van den Belt-Dusebout at the Netherlands Cancer Institute in Amsterdam, compared 18,970 women who had had at least one cycle of IVF treatment with 7,536 women who had not received fertility treatment between 1980 and 1995. They matched these patients to records in the National Cancer Registry.

Of the 378 women who developed breast cancer, 266 were in the IVF group and 112 were in the non-IVF group. After adjusting for known risk factors such as age, the number of children the women had and family history of breast cancer, the team found no statistical difference between the two groups, showing that IVF treatment does not increase a woman's chances of developing breast cancer.