What is diethylstilbestrol (DES)?

Exposure routes: Patients are exposed to DES when it is used in medical therapies and in clinical trials for the treatment of prostate and breast cancer. It is typically administered orally or intravenously. Potential exposure by inhalation can occur to workers who are involved in the formulation and manufacturing of diethylstilbestrol.

Where found: DES is found at sites where it is manufactured, packaged, and supplied. It can be found at medical facilities where it is prepared and administered during cancer clinical trials and treatments. During the 1970s, it was found in cattle and sheep that were injected with diethylstilbestrol to promote their growth.

At risk: Patients who are treated with DES for prostate cancer and breast cancer are at high risk. Workers at locations where diethylstilbestrol is manufactured, packaged, and supplied for cancer clinical trials are at risk for contamination. Health care professionals who prepare and administer DES for cancer therapy risk contamination, as do workers in labs where diethylstilbestrol is used in biochemical research.

Etiology and symptoms of associated cancers: DES behaves as a hormonal therapy. By acting as a chemical messenger in the body, it helps control the activity of cells and organs. When administered to pregnant women to help prevent miscarriages or premature deliveries, DES can cause clear-cell adenocarcinoma (CCA) of the vagina and cervix in the mother and in daughters exposed before birth. In sons exposed before birth, DES can increase the risk of testicular cancer. Since DES reduces the level of testosterone in the body, it helps slow down the growth of prostate cancer cells. Side effects of diethylstilbestrol chemotherapy include breast tenderness, lowering of sex drive, tiredness, nausea, and weight gain.

History: DES was first synthesized in 1938 at the University of Oxford. It was the first synthetic estrogen. In 1941 diethylstilbestrol was found to be effective in the treatment of gonorrheal vaginitis, menopausal symptoms, and metastatic prostate cancer. Between the 1940s and the 1980s, it was used as estrogen-replacement therapy in estrogen-deficient women. After epidemiological studies of women linked DES to vaginal and cervical cancers, the US Food and Drug Administration (FDA) advised in 1971 that it no longer be given to pregnant women. To a large extent, tamoxifen has replaced the use of DES in breast cancer treatments, as has leuprolide in the treatment of prostate cancer.

Bibliography

Amer. Cancer Soc. "Known and Probable Human Carcinogens." Cancer.org. ACS, 17 Oct. 2013. Web. 29 Sept. 2014.

Langston, Nancy. Toxic Bodies: Hormone Disruptors and the Legacy of DES. New Haven: Yale UP, 2010. Digital file.

Natl. Cancer Inst., Natl. Inst. of Health. "Diethylstilbestrol (DES) and Cancer." Cancer.gov. NCI/NIH, 5 Oct. 2011. Web. 29 Sept. 2014.

Natl. Cancer Inst., Natl. Inst. of Health. "Women Exposed to DES in Womb Face Increased Cancer Risk." Cancer.gov. NCI/NIH, 5 Oct. 2011. Web. 29 Sept. 2014.

Natl. Inst. of Environmental Health Sciences. Endocrine Disruptors. Research Triangle Park: NIEHS/NIH, 2010. Digital file.

Natl. Inst. for Occupational Safety and Health, CDC, Dept. of Health and Human Services. NIOSH ALERT: Preventing Occupational Exposures to Antineoplastic and Other Hazardous Drugs in Health Care Settings. Cincinnati: NIOSH/CDC, 2004. Digital file.

Natl. Toxicology Program, Dept. of Health and Human Services. "Diethylstilbestrol." Report on Carcinogens, Twelfth Edition. N.p.: NTP/NIEHS/NIH, 2011. Digital file.