Diethylstilbestrol (DES)

Diethylstilbestrol (DES) is a synthetic form of the female hormone oestrogen.1 DES was prescribed to pregnant women from the 1940s to the early 1970s to prevent miscarriage and other pregnancy-related complications.1

Due to research identifying that DES exposure increased risk for certain cancers and other health conditions,2,3 DES is no longer prescribed during pregnancy.1

While the number of women in Australia that took DES is not known, it is estimated that approximately 10,000 women were exposed to DES in utero.4

DES mothers

Women given DES while pregnant are known as DES mothers.

  • DES mothers may have a modestly increased risk of breast cancer compared with women who have not been exposed to DES.5,6,7,8 Evidence suggests that the risk of breast cancer does not increase as a DES mother gets older.6
  • There is no increased risk of developing other types of hormone-dependent cancers for DES mothers compared with women who did not take DES.

It is recommended that DES mothers:

  • Inform their GP that they took DES while pregnant.1
  • Participate in the national BreastScreen mammographic screening program. BreastScreen Australia actively invites women aged 50-74 years of age to undergo free mammographic screening every two years. Women 40-49 years of age and 75 years of age and over are also eligible for free screening mammograms.10
  • Know the normal look and feel of their breasts and promptly report persistent or unusual changes to their GP.

DES daughters

Women whose mothers took DES during their pregnancy are known as DES daughters.

  • DES daughters are at a higher risk of developing a rare type of cancer of the vagina and cervix called clear cell adenocarcinoma (CCA).2,3,9 Approximately one in 1000 DES daughters develop CCA.11
  • Women who were exposed to DES in utero may have a slightly increased risk of breast cancer.3,7,8,12,13
  • Abnormal changes to cells of the vagina and cervix are more common in DES daughters compared with women not exposed to the drug. While these cells resemble cancer cells, they may not necessarily lead to cancer.1,3,4
  • DES daughters may also have a higher risk of developing other conditions associated with reproduction. Studies have found an increased risk of premature birth, miscarriage, ectopic pregnancy and early menopause in DES daughters.3

It is recommended that DES daughters:

  • Inform their GP that their mother took DES during their pregnancy.1
  • Be offered annual Cervical Screening Tests and have a colposcopic examination of both the cervix and the vagina, as recommended by the National Cervical Screening Program.14 Screening should begin at any time at the woman’s request and continue indefinitely.14
  • Participate in the national BreastScreen mammographic screening program as the level of risk is similar to a range of other risk factors which do not require more intensive screening.15  BreastScreen Australia actively invites women aged 50-74 years of age to undergo  free mammographic screening every two years. Women 40-49 years of age and 75 years of age and over are also eligible for free screening mammograms.10
  • Know the normal look and feel of their breasts and promptly report persistent or unusual changes to their GP.

DES sons

Men whose mothers took DES during their pregnancy are known as DES sons.

  • There is no established link between DES exposure and cancer  in DES sons.8,16

DES grandchildren

The children of DES daughters or sons are known as DES grandchildren. They have had no direct exposure to DES.

  • To date, no association has been shown between DES exposure and cancer in DES grandchildren.8,9,17,18

References

  1. National Cancer Institute.  Diethylstilbestrol (DES) and Cancer. http://www.cancer.gov/cancertopics/factsheet/Risk/DES Accessed: May 2014
  2. Herbst AL, Ulfelder H, Poskanzer DC. Adenocarcinoma of the vagina: association of maternal stilbestrol therapy with tumor appearance in young women. N Engl J Med 1971;284:878-81.
  3. Hoover RN, Hyer M, Pfeiffer RM, et al. Adverse health outcomes in women exposed in utero to diethylstilbestrol. N Engl J Med. 2011 Oct 6;365(14):1304-14.
  4. Royal Australian and New Zealand College of Obstetricians and Gynaecologists.  Diethylstilboestrol (DES) in utero (C-Obs 56). http://www.ranzcog.edu.au/doc/diethylstilboestrol-des-exposure-in-utero.html
  5. Titus-Ernstoff L, Hatch EE, Hoover RN, et al. Long-term cancer risk in women given diethylstilbestrol (DES) during pregnancy. British Journal of Cancer 2001; 84(1):126–133.
  6. Colton T, Greenberg ER, Noller K, et al. Breast cancer in mothers prescribed diethylstilbestrol in pregnancy. Further follow-up. JAMA 1993; 269(16):2096–2100.
  7. National Breast and Ovarian Cancer Centre. Breast cancer risk factors: a review of the evidence. National Breast and Ovarian Cancer Centre, Surry Hills, NSW, 2009.
  8. International Agency for Research on Cancer. Diethylstilbestrol. In: Monographs on the Evaluation of Carcinogenic Risks to Humans: Pharmaceuticals Volume 100A: A Review of Human Carcinogens. Lyon, France. World Health Organisation. 2012.
  9. Giusti RM, Iwamoto K, Hatch EE. Diethylstilbestrol revisited: a review of the long-term health effects. Annals of Internal Medicine 1995; 122(10):778–788.
  10. BreastScreen Australia. About the Program. http://www.cancerscreening.gov.au/internet/screening/publishing.nsf/Content/breast-screening-1. Accessed July 30, 2014.
  11. Melnick S, Cole P, Anderson D, et al. Rates and risks of diethylstilbestrol-related clear-cell adenocarcinoma of the vagina and cervix. An update. N Engl J Med. 1987 Feb 26;316(9):514-6.
  12. Palmer JR, Wise LA, Hatch EE, et al. Prenatal diethylstilbestrol exposure and risk of breast cancer. Cancer Epidemiology, Biomarkers & Prevention 2006; 15(8):1509–1514.
  13. Verloop J, van Leeuwen FE, Helmerhorst TJ et al. Cancer risk in DES daughters.Cancer Causes Control. 2010 Jul;21(7):999-1007.
  14. Department of Health. National Cervical Screening Program. Frequently Asked Questions. http://www.cancerscreening.gov.au/internet/screening/publishing.nsf/Content/frequently-asked-questions-1. Accessed: August 2014.
  15. Evaluation of the Breastscreen Australia Program – Evaluation Final Report June 2009. Screening monograph No.1/2009. Department of Health and Aging, Commonwealth of Australia, 2009.
  16. Strohsnitter WC, Noller KL, Hoover RN, et al. Cancer risk in men exposed in utero to diethylstilbestrol. J Natl Cancer Inst. 2001 Apr 4;93(7):545-51.
  17. Titus-Ernstoff L, Troisi R, Hatch EE, et al. Offspring of women exposed to diethylstilbestrol (DES): a preliminary report of benign and malignant pathology in the third generation. Epidemiology 2008; 19(2):251–257.
  18. Reed CE, Fenton SE. Exposure to diethylstilbestrol during sensitive life stages: a legacy of heritable health effects. Birth Defects Res C Embryo Today. 2013 Jun;99(2):134-46.