jueves, 6 de octubre de 2011

Women exposed to DES in the womb face increased cancer risk - National Cancer Institute

 
 
 
Women exposed to DES in the
womb face increased
cancer risk: NCI Press Release
NIH study followed daughters of women given
diethylstilbestrol during pregnancy
and found increased fertility problems and cancer risks

A large study of the daughters of women who had been given
DES, the first synthetic form of estrogen, during pregnancy has
found that exposure to the drug while in the womb (in utero) is
associated with many reproductive problems and an increased
risk of certain cancers and pre-cancerous conditions. The results
of this analysis, conducted by researchers at the National Cancer
Institute (NCI), part of the National Institutes of Health, and
collaborators across the country, were published
Oct. 6, 2011, in the New England Journal of Medicine.

Beginning in 1940, diethylstilbestrol, known as DES, was used
clinically to prevent certain complications of pregnancy. In the
1950s, clinical studies showed DES was ineffective for this purpose.
In the late 1960s, an unusual occurrence of a rare cancer of the
vagina among young women, called clear cell adenocarcinoma
(CCA), was observed and subsequently linked to their exposure
to DES while in the womb.

In 1971, the U.S. Food and Drug Administration notified physicians
that DES should not be prescribed to pregnant women. However,
between 5 million and 10 million pregnant women and babies had
been exposed to the drug. It was manufactured under many different
product names, and came in various forms, including pills, creams and
vaginal suppositories.

"Our study carefully documents elevated risk for DES-exposed
daughters for a host of medical problems—many of them also
quite common in the general population," said study author
Robert N. Hoover, M.D., director of the Epidemiology and
Biostatistics Program in NCI's Division of Cancer Epidemiology
and Genetics. "Without the sentinel finding of a very rare cancer
in young women, and without the sustained follow-up of those
who were exposed, we would not know the full extent of harm
caused by DES exposure in the womb."

In this study, which included over 6,500 women (4,600 exposed
and 1,900 unexposed), the researchers found that the daughters
with exposure to DES while in the womb had an increased risk
of 12 medical conditions, including a twofold higher risk of
infertility and a fivefold increased risk of having a preterm
delivery. (See table below for complete list of increased risks.

This study is also the first to estimate the cumulative proportion of
all DES-exposed women who developed these conditions because
of their exposure.  Of all DES-exposed women, 1 in 5 will
experience some level of infertility because of their exposure.
And of all those exposed women who are successful in having at
least one birth, 1 in 3 will have a preterm delivery due to DES.
Risks for DES-Exposed Daughters Compared to Non-Exposed
Outcome
Increased Risk
Clear-cell adenocarcinoma
40 times higher
Neonatal death
8 times higher
Pre-term delivery
4.7 times higher
Loss of 2nd-trimester pregnancy
3.8 times higher
Ectopic pregnancy
3.7 times higher
Stillbirth
2.4 times higher
Infertility
2.4 times higher
Early menopause
2.4 times higher
Cervical intraepithelial neoplasia
2.3 times higher
Breast cancer
1.8 times higher
First trimester miscarriage
1.6 times higher
Preeclampsia
1.4 times higher

Although DES-exposed daughters have about 40 times
the risk of developing CCA than unexposed women,
CCA is still a rare disease, occurring in 1 in 1,000
DES-exposed daughters. While the first women diagnosed
with this condition in the late 1960s were adolescents and
young adults at the time of their diagnosis, the research now
shows that the risk for DES-exposed daughters continues
through at least age 40. In addition, these women are more
than twice as likely to develop pre-cancerous cells in the cervix
or vagina (called cervical intraepithelial neoplasia) and have an
80 percent higher chance of developing breast cancer after age 40.
According to the results of this study, by age 55, 1 in 25
DES-exposed daughters will develop abnormal cellular changes
in the cervix or vagina, and 1 in 50 will develop breast
cancer due to their DES exposure.

This study was the first to assess risk based on the presence
of vaginal epithelial changes as a biomarker of timing and dose
of DES exposure. Exposed daughters with higher total dose of DES
and younger age of the embryo at first exposure had evidence of
these changes in the lining of the vagina. Women with these changes
were at even greater risk for 9 of the 12 conditions compared to
exposed women who did not have the biomarker.

This study did not evaluate sons with DES exposure in the womb,
but previous reports have indicated an increased risk for certain
testicular abnormalities, including undescended testicles or the
development of cysts in the epididymis, tightly coiled tubes
connected to the testicles. As DES-exposed sons grow older,
more data will be available to assess their cancer risk. So far,
research has shown no decreased fertility for these men, even
with testicular abnormalities.

The women in this study were followed as part of the NCI's
DES Follow-up Study, which began in 1992. NCI researchers
will continue to study DES-exposed daughters as they move
into menopausal years. The cancer risks for exposed daughters,
as well as sons, are continually being studied to determine if they
differ from an unexposed population. In addition, researchers are
studying possible health effects on the grandchildren of mothers
who took DES during pregnancy, because some of the genetic
changes caused by DES exposure in the womb may be inherited.

The other research centers involved in this work are Boston
University Slone Epidemiology Center, Boston; Cedars-Sinai
Medical Center DES Project, Los Angeles; University of Chicago
Department of Obstetrics and Gynecology; Dartmouth-Hitchcock
Medical Center, Lebanon, N.H.; The Mayo Clinic DES Project,
Rochester, Minn.; The Methodist Hospital-Research Institute Department
of Obstetrics and Gynecology, Houston; and Tufts Medical Center, Boston.
###
For more information about DES exposure and cancer risk,
please go to

For more information about NCI's Division of Cancer Epidemiology
and Genetics, please visit http://dceg.cancer.gov/.

Reference: Hoover RN, Hyer M, Pfeiffer RM, Adam E, Bond B,
Cheville AL, Colton T, Hartge P, Hatch EE, Herbst AL, Karlan BY,
Kaufman R, Noller KL, Palmer JR, Robboy SJ, Saal RC, Strohsnitter
W, Titus-Ernstoff L, Troisi R. Adverse Health Outcomes in Women
Exposed In Utero to Diethylstibestrol. NEJM. Oct. 6, 2011.

Women exposed to DES in the womb face increased cancer risk - National Cancer Institute

No hay comentarios:

Publicar un comentario