Information on DES

Background:
Diethylstilbestrol, or DES, a synthetic form of estrogen, was prescribed from the early 1940s until 1971 to help women with certain complications of pregnancy, primarily miscarriages. Use of DES declined in the 1960s after studies showed that it might not be effective in preventing pregnancy complications. Few reliable estimates exist of the number of U.S. women exposed to DES during pregnancy. One source estimates that between 5 and 10 million United States women were given DES either during pregnancy or in utero.

In 1970, a report was published in Cancer documenting a rare form of vaginal cancer, clear cell adenocarcinoma (CCAC). A study published in 1971 in the New England Journal of Medicine documented the association between in utero exposure to DES and the subsequent development of CCAC. In 1971, the Food and Drug Administration (FDA) issued a drug bulletin calling attention to the potential adverse effects of DES and warned against its use during pregnancy. By 1981, more than 400 cases of CCAC had been reported. A number of studies have been conducted since the mid-1970s to study DES-exposed women.

Health effects that have been associated with the use of DES:
Health effects include CCAC in young women, vaginal epithelial changes, reproductive tract abnormalities (e.g., gross anatomical changes of the cervix, T-shaped and hypoplastic uteri), ectopic pregnancies, miscarriages, and premature births. An increased risk for breast cancer also has been noted for DES mothers.

Probable effects of DES exposure include infertility in DES daughters and reproductive tract abnormalities (e.g., epididymal cysts, hypoplastic testis, cryptochordism) in DES men.

Possible effects include cervical dysplasia and carcinoma in situ as well as autoimmune disorders (DES daughters), and infertility and testicular effects (DES sons).

Suspected health effects include breast cancer (DES daughters), psychosocial effects (DES daughters and sons), prostatic hyperplasia and cancer (DES sons), and third-generation effects (DES grandchildren).

Current information:
On July 19-20, 1999, the National Cancer Institute co-sponsored a meeting entitled "DES Research Update 1999." The purpose of this meeting was to provide an update on research results, discuss current and future needs, and identify gaps in DES-related research, education and outreach that still exist. The following is a summary of the results of that meeting.

Three general topics were identified as breakout topics-basic research priorities, clinical/epidemiology research priorities, and education/outreach priorities. The following are recommendations from the breakout groups.

Basic Research Priorities

• Establish new and maintain existing tissue repositories of DES-exposed persons.
• Identify biomarkers of susceptibility.
• Investigate and define DES-induced genetic effects.
• Conduct studies that allow researchers to predict whether other compounds such as drugs, pesticides or other agents might have DES-like adverse outcomes.

Clinical/Epidemiology Research Priorities

• Continue the followup of established cohorts and expand existing, or establish new, cohorts to include more DES mothers, daughters, sons, and long-term cancer survivors.
• Improve and expand monitoring and tracking of DES sons.
• Study DES effects on other organ systems including the immune system, cardiovascular system, breast, bone, brain/nervous system, and bowel/intestines.
• Study the effects of other hormones such as hormone replacement therapy, fertility drugs, and other agents, alone or in combination, or as a cumulative effect over time, on DES daughters' health.
• Identify or develop clinical markers for cancer and infertility among DES-exposed women.
• Assess cohorts of DES-exposed persons in other countries such as the Netherlands.
• Develop guidelines for the treatment of hormonally sensitive cancers in DES-exposed men and women. Continue to revise and update guidelines for DES daughters as needed and disseminate widely.
• Conduct an assessment of the DES experience in clinical trials and in cancer databases.
• Incorporate questions about DES use into cancer information databases.

Education/Outreach Priorities

• Continue to coordinate efforts of researchers, consumers/advocates, and clinicians. Bring key players together on a regular basis.
• Promote maintenance of current and establishment of new partnerships.
• Disseminate screening and treatment guidelines widely.

NCI Activities:
The National Cancer Institute funded 5 pilot DES education programs from 1993-1997. The National Educational Campaign on DES is currently reviewing the results of those programs and hopes to build on the successes of those projects. There will be a national educational campaign to educate both consumers and providers on issues surrounding DES. This campaign will begin in 2001.

References:

Further Information:

If you have questions on DES, please call the National Cancer Institute's Cancer Information Service at 1-800-4-CANCER or access their web site at www.nci.nih.org. Booklets for DES daughters, DES sons, and women who took DES can be found at www.desaction.org or by calling 1-800-DES-9288.

For information on research funding opportunities through the Breast and Cervical Cancer Income Tax Checkoff, please contact the Pennsylvania Department of Health, Cancer Control Program, at (717) 787-5251.