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Completed No phase listed Observational

Continuation of Follow-up of DES-Exposed Cohorts

ClinicalTrials.gov ID: NCT00340600

Public ClinicalTrials.gov record NCT00340600. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 12, 2026, 8:11 PM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

Diethylstilbestrol (DES), a drug first synthesized in 1938, was administered to several million pregnant women in the U.S. and Europe for the prevention of spontaneous abortion and premature delivery. In 1971, Herbst reported a strong association between DES use in pregnancy and the occurrence of vaginal clear cell adenocarcinoma (CCA) in exposed female offspring. Animal models have demonstrated a range of DES effects on offspring exposed in utero, including reproductive dysfunction, immune system changes, behavioral and sexual abnormalities, and increases in various reproductive cancers in males and females. In the mid-1970's, several separate cohorts of DES-exposed daughters and unexposed comparison groups were followed for the occurrence of cancer, precursor lesions, and reproductive effects, but systematic follow-up of these cohorts had ceased by 1990. In 1992, Congress passed a bill (H;.R. 4178) mandating the continued follow-up of DES-exposed cohorts. The National Cancer Institute, in collaboration with five field centers, reassembled previously studied cohorts of DES-exposed and unexposed mothers, daughters and sons, and identified subjects with documented exposure status who had not been studied previously, through familial links within the cohorts. Standardized baseline questionnaires were mailed to cohort members to ascertain the risk of cancer and other disorders. Pathology reports were collected for reported cancers and preneoplastic conditions. Two separate rounds of follow up have been conducted and a third is almost complete. Patients from the Registry for Research on Hormonal Transplacental Carcinogenesis (the Registry) will be added to the follow-up effort in the third phase. The purpose of this study is to continue the follow-up, by means of mail questionnaires and medical record collection, which was begun during the first phase of the study. Concern has arisen that DES-exposed daughters may be at higher risk of breast cancer. Exposure to high levels of endogenous estrogen in utero has been hypothesized to increase the risk of breast cancer and DES is a potent estrogen. Cancer risk in the sons will also continue to be assessed, especially for increased risks of prostate cancer. Since the offspring who were exposed to DES in utero are currently reaching their late forties, when cancer rates begin to rise, it is important to continue the follow-up of these cohorts to determine if there are long-term increases in cancer risk.

Study identification

NCT ID
NCT00340600
Recruitment status
Completed
Study type
Observational
Phase
Not listed
Enrollment
10,805 participants

Conditions and interventions

Eligibility (public fields only)

Age range
18 Years to 100 Years
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Mar 17, 1998
Primary completion
Sep 29, 2015
Completion
Nov 12, 2020
Last update posted
Nov 15, 2020

1998 – 2020

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
Boston University School of Public Health Boston Massachusetts 02118-2354

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

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About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT00340600, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Nov 15, 2020 · Synced Sep 12, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT00340600 live on ClinicalTrials.gov.

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