This article is part of a series of commentaries by Nora Cody, First Do No Harm: A Consumer Health Advocate's Cautionary Tales, which examines issues in health and medical research, with a special focus on women's health topics.

A recently published scientific study suggests that the grandchildren, or "third generation" offspring of DES-exposed women (Note: It has been known since 1971 that DES - diethylstilbestrol - , a synthetic hormone drug, causes cancer in women exposed in-utero.), may be at risk for reproductive cancers and abnormalities like those suffered by DES daughters.

The study, which was published in the September, 1998, issue of the journal Carcinogenesis and entitled "Increased Tumors but Uncompromised Fertility in Female Descendants of Mice Exposed Developmentally to DES," reports a significant increase in reproductive cancer in the elderly female "grandchildren" of mice who were injected with DES.

Scientists have previously established that the 2.4 million U.S. women who were exposed to DES in utero from 1938-1971 have a risk for a rare cancer of the vagina and cervix, as well as many reproductive abnormalities. There has been very little research, however, about the possible effects of the drug on the offspring of DES daughters, the so-called "third generation."

This study raises some very alarming questions for DES daughters and their children. DES Action, the nonprofit organization representing those exposed to DES, called on Congress to increase funding to the National Institutes of Health so that they can further explore the health effects this powerful drug could have on the third generation of DES-exposed humans.

DES daughter (and mother of a 13-year old daughter) Stephanie Kanarek echoed these concerns. "I worry about what the future holds for our children - not only for my daughter Amy who is handicapped as a result of my exposure to DES - but for the many apparently healthy third generation children."

In the study reported in Carcinogenesis, scientists at the National Institute of Environmental Health Sciences (NIEHS), working with researchers from other institutions, injected several groups of mice at varying stages of fetal development with doses of DES similar to those received by humans. A matched group of control mice received a placebo. The female offspring of the DES-exposed mice were mated with control mice. Scientists then studied their offspring, the unexposed "third generation" or "DES lineage mice."

The study's authors report "an increased incidence of malignant reproductive tract tumors, including uterine adenocarcinoma in DES-lineage mice but not in corresponding controls." The study goes on to note that the findings suggest that mice exposed to DES in utero do not appear to pass their reduced fertility (a common problem among DES daughters) to their descendants. However, they do appear to transmit their increased susceptibility for tumor formation. The tumors afflicted from two to eleven percent of the total DES lineage mice, in their old age, depending on the timing of exposure and the dose. Studies of the male offspring of DES daughter mice are being completed.

"In utero exposure to DES of both mice and humans triggers a cascade of events that results in reproductive tract dysfunction and disease including tumors in the exposed population," commented lead author Retha R. Newbold of the NIEHS. "Our recent studies indicate that this in utero exposure may also cause changes in the oocyte that lead to the transmission of an increased susceptibility for tumors in subsequent generations."

Reinforcing these findings is another article, published in Carcinogenesis in 1997, which reports both a third and a fourth generation effect in DES-treated mice. The article, entitled "Intensity of multigenerational carcinogenesis from diethylstilbestrol in mice," reports on the work of Dr. Bruce E. Walker and Madge I. Haven. These scientists also found significant increases in reproductive tumors in the descendants of mice injected with DES. In addition this research showed an effect into the fourth generation, or the great-granddaughters of DES-exposed mice.

The significance of this study extends beyond DES daughters and sons to the "endocrine disruption" observed in wildlife. Says Theo Colborn, co-author of Our Stolen Future and a senior scientist with the World Wildlife Fund: "This landmark study confirms the need for better screening and testing of the 86,000 synthetic chemicals in use today. Chemicals that induce multigenerational harm should never be released in the environment."

Members of the public who would like more information about DES can go to DES Action's web site at http://www.desaction.org.

The abstract of the article cited can be found on the Web at http://www.oup.co.uk/carcin.

Related articles:

• DES given to young "too tall" girls in appalling medical experiment
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  Oakland, California
  
  
• Environmental Estrogen - Global Problem
  A model for study of exposure to pollutants around the world
  by Pat Cody
  Berkeley, California
  
  
• Ohio Decision Against DES Daughters
  An update on the ongoing efforts for compensation
  from drug companies who produced DES
  by Pat Cody
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