Cancer ‘more likely’ for daughters of DES

Women whose mothers used an anti-miscarriage drug in pregnancy have double the risk of developing breast cancer than others their age, and are 50% more likely to start the menopause early, a US study suggests.

  • E-Mail
By  Joanne Bladd Published  September 27, 2006

Women whose mothers used an anti-miscarriage drug in pregnancy have double the risk of developing breast cancer than others their age, and are 50% more likely to start the menopause early, a US study suggests. Diethylstilbestrol (DES) was routinely prescribed to pregnant women worldwide from the 1940s to 1970s. It has already been linked to a higher risk of reproductive system cancers. Researchers from the Boston University School of Public Medicine monitored 4,817 women over 40 known to have been exposed to DES while in their mothers’ wombs and compared them with 2,073 unexposed women of the same age. There had been 102 cases of breast cancer across both groups. However, when other risk factors were taken into accounts, such as age at which the women gave birth and how many children they had, it was found that women exposed to DES had 1.9 times the risk of developing breast cancer, compared with unexposed women. It is thought the oestrogen in DES increases the number of breast tissue stem cells available at birth - cells which could then become cancerous. Researchers also compared the age of menopause between the two groups. Data showed the women exposed to DES were 50% more likely to have reached menopause early. The increased risk is thought to be because DES reduces the number of immature eggs produced in the womb. The results were published in the journal Cancer Epidemiology, Biomarkers and Prevention. Professor Julie Palmer, who led the research, said: “This is really unwelcome news because so many women worldwide were pre-natally exposed to DES, and these women are just now approaching the age at which breast cancer becomes more common. “Every woman who knows she is DES exposed should be having careful screening for vaginal cancer and should also approach her GP about extra screening for breast cancer.” DES, a synthetic oestrogen, was developed in 1938 as a treatment for women with low levels of natural oestrogen during pregnancy, who doctors believed were at an increased risk of abortions and premature births. However, in 1953, a clinical study found DES did nothing to reduce the risk of miscarriage. The drug continued in use until 1971, when it was found the daughters of women who took the drug were at an increased risk of cancers of the vagina and of the cervix.

Add a Comment

Your display name This field is mandatory

Your e-mail address This field is mandatory (Your e-mail address won't be published)

Security code