Diethylstilbestrol (DES) and Cancer

Diethylstilbestrol (DES), a synthetic form of the female hormone oestrogen first manufactured in 1938, was prescribed in Australia in the late 1940s and 1950s, less often in the 1960s and 1970s, and was prescribed in some instances beyond 1971.
DES was primarily given to prevent miscarriage and other pregnancy complications, such as tubal pregnancy and early delivery.
Other therapeutic uses included suppression of lactation and post menopausal syndrome.
Separately it was later used as a growth promoter in chicken, sheep and cattle.

Key facts around  Diethylstilbestrol (DES) and Cancer

  • Although the majority of persons exposed to DES will not experience any negative health effects, available research findings indicate that exposure to DES increases the risk of the following health problems:
    • Women who took DES during pregnancy have a small increased risk for breast cancer.
    • Women exposed to DES in utero (DES daughters) are at increased risk for clear cell adenocarcinoma of the vagina/cervix, structural abnormalities in the reproductive tract, miscarriage, tubal (ectopic) pregnancy, infertility and premature birth. Women over 40 years of age who were exposed to DES in utero are at increased risk of breast cancer.
    • Men exposed to DES in utero (DES sons) are at increased risk of abnormally small testes, undescended testes and non-cancerous epididymal cysts.
    • Research into the health of DES grandsons and granddaughters has not found conclusive evidence of an increased cancer risk except for the possibility of a heightened ovarian cancer risk in DES granddaughters. Research studies on this group are continuing.
  • Relevant health care providers such as General Practitioners, midwives and women’s health nurses who are familiar with DES can assist individuals affected by DES to identify possible complications.
  • Women prescribed DES while pregnant and DES daughters who are over the age of 40 are advised to follow normal screening recommendations for their age groups. They should also be ’Breast Aware’ by familiarising themselves with the normal look and feel of their breasts, and report any unusual breast changes to their doctor, irrespective of both the time since their most recent mammogram and the results of that mammogram.
  • Routine Pap testing is not an adequate gynaecological cancer screening test for DES daughters. An annual DES-specific pelvic examination is required (see page 4).
  • DES daughters planning pregnancy should alert their clinician of exposure prior to conception so they can be evaluated for cervical and uterine abnormalities. During pregnancy, DES daughters should be treated as ’high risk’ patients.
  • DES sons should regularly check for lumps or swellings on the surface of the testes and promptly report any testicular masses, blood in the urine, or genital complaints to their doctor.
  • Continued monitoring of the third generation of individuals whose grandmothers were exposed during pregnancy to DES is needed to conclusively determine whether there is an increased risk of cancer in this population.