The French E3N Prospective Cohort Study (E3N)

June 22, 2026 updated by: Institut National de la Santé Et de la Recherche Médicale, France

The French E3N Prospective Cohort Study (Etude Epidémiologique auprès de Femmes de la Mutuelle Générale de l'Education Nationale)

The French E3N cohort was initiated in 1990 to investigate the risk factors associated with cancer and other major non-communicable diseases in women.

The participants were insured through a national health system that primarily covered teachers, and were enrolled from 1990 after returning baseline self-administered questionnaires and providing informed consent. The cohort comprised nearly 100 000 women with baseline ages ranging from 40 to 65 years.

Follow-up questionnaires were sent approximately every 2-3 years after the baseline and addressed general and lifestyle characteristics together with medical events (cancer, cardiovascular diseases, diabetes, depression, fractures and asthma, among others). The follow-up questionnaire response rate remained stable at approximately 80%.

A biological material bank was generated and included blood samples collected from 25 000 women and saliva samples from an additional 47 000 women.

Ageing among the E3N cohort provided the opportunity to investigate factors related to agerelated diseases and conditions as well as disease survival.

Study Overview

Status

Active, not recruiting

Conditions

Detailed Description

Who is in the cohort? In June 1990, a questionnaire was sent to 500 000 women who had been born between 1925 and 1950 and were insured by the Mutuelle Générale de l'Education Nationale (MGEN), a national health insurance plan that primarily covers teachers. The questionnaire was sent along with a leaflet explaining that an Inserm research team was launching a study of cancer risk factors and that participation would require filling in questionnaires every 2-3 years as well as the submission of a signed consent form providing permission to obtain information about each participant's vital status, address changes and medical expense reimbursements from the insurance plan. Nearly 100 000 women volunteered.

How often have they been followed-up? Until now, nine follow-up questionnaires have been sent every 2-3 years from the baseline. Approximately half of the answers were obtained after the first mailing. Two reminders were sent thereafter. The questionnaires were accompanied with newsletters that informed participants about the major results obtained to date. The participation rate remained high (77-92% according to the questionnaires) and the lost to follow-up rate was minimal because of the ability to trace non-respondents through their insurance plan files. The questionnaires were accurately filled in, with few missing or unacceptable answers.

What has been measured? To date, 11 self-administered questionnaires have been sent. The collected data are sociodemographic factors, anthropometric measurements, reproductive factors, hormonal treatments, health behaviour and lifestyle. Each follow-up questionnaire also recorded the participant's health status. The questionnaires are available at www.e3n.fr .

The questionnaires are anonymous and identified with an identification number and pin code that can be rapidly scanned to identify the respondents. The questionnaires are optically scanned and all answers are checked on screen. The scanned images are saved to allow data entry at a later time, including information regarding the addresses of medical doctors (18 000 to date) or drug names (pre-listed to avoid errors). The longitudinal data (repeats of identical questions for the purpose of updating information about topics such as menopause or smoking) are routinely homogenized. Several validation studies (e.g. dietary and anthropometrical data studies) have been performed and have revealed very satisfactory results.

Self-reported cases of cancer are validated and coded after reviewing the pathology reports obtained from medical practitioners, and nearly 90% of all cancer cases are histologically confirmed. Other diseases are also validated (e.g. diabetes, myocardial infarction, stroke, Parkinson disease) by requesting additional information about the participants (e.g. glycosylated haemoglobin levels, fracture-related circumstances, drug names) and sending questionnaires to medical doctors.

Additionally, a biological material bank was generated. Blood samples were initially collected from 1994-99. The participation rate among the invited participants was approximately 40%; this yielded approximately 25 000 blood samples that were each separated into 28 aliquots (e.g. plasma, serum, leukocytes, erythrocytes). Plastic straws were used to store each participant's samples in liquid nitrogen containers. The bio-repositories are located at the IARC (Lyon) and the EFS (Etablissement Français du Sang, Annemasse). Since 2004, approximately 10 case-control studies have been conducted (approximately 1 800 cases and 3 500 controls) with regard to the measurements of various biomarkers (e.g. fatty acids, calcium, vitamin D, vitamin B, cholesterol and C-reactive protein). A metabolomics study is currently ongoing.

From 2009-11, saliva samples (Oragene, DNA Genotek, Kanata, ON, Canada) were requested from 68 242 living women and were obtained from 47 000 women (participation rate, 69%). Salivary DNA has been extracted and has been used for genotyping in two case-control studies (approximately 2 500 cases and 850 controls) since December 2010.

The research team is currently planning to set up a tumour tissue bank and will begin with the collection of breast cancer tissues.

What has it found? The E3N cohort has produced a spectrum of results regarding the complex roles played by nutrition, hormonal factors, physical activity, anthropometric characteristics and other major lifestyle-related factors with respect to various diseases.

Study Type

Observational

Enrollment (Actual)

100000

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • France
      • Villejuif, France, 94800

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

36 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

The cohort comprised nearly 100 000 women with baseline ages ranging from 40 to 65 years, all insured through a French national health system (MGEN).

Description

Inclusion Criteria:

  • only women
  • born between 1925 and 1950
  • insured by the Mutuelle Générale de l'Education Nationale (MGEN)

Exclusion Criteria:

- men

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Anthropometric measurements
Time Frame: From 1990 until now
Height, weight, hip circumference and waist circumference
From 1990 until now
Educational level
Time Frame: 1990
1990
Professional activity
Time Frame: 1992 and 2005
Insee categories
1992 and 2005
Age at cessation of activity
Time Frame: From 2005 until now
From 2005 until now
Menstrual factors
Time Frame: From 1990 to 2002
Age at menarche, length of menstrual cycle
From 1990 to 2002
Reproductive history
Time Frame: From 1990 to 1992
Number of pregnancies, age at each pregnancy, durations and outcomes of pregnancies, breastfeeding, infertility
From 1990 to 1992
Menopause
Time Frame: 1990, 1995, 1997, 2000, 2002, 2005
Age, type
1990, 1995, 1997, 2000, 2002, 2005
Hormonal Treatments
Time Frame: From 1992 to 2008
Menopausal Hormonal Treatments (MHT), oral contraceptives
From 1992 to 2008
Tobacco consumption
Time Frame: From 1990 until now
Type, quantity, time of smoking
From 1990 until now
Alcohol consumption
Time Frame: 1993, 1997, 2005
Type of alcohol, quantity
1993, 1997, 2005
Physical activity
Time Frame: 1990,1997,2002, 2005, 2014
Moderate and intense activity, sedentarity
1990,1997,2002, 2005, 2014
Diet questionnaire
Time Frame: 1993 and 2002
Precise annual diet questionnaire
1993 and 2002
Family history of diseases
Time Frame: 1990 to 2005
Cancer, diabetes and cardiovascular diseases
1990 to 2005
Medication use
Time Frame: From 1990 until now
linked with the drug reimbursement files from the health insurance
From 1990 until now
Medical and surgical history
Time Frame: From 1990 until now
From 1990 until now
Mental Health
Time Frame: From 1990 until now
Centre for Epidemiologic Studies Depression Scale (CESD) and Depression
From 1990 until now
Health outcomes
Time Frame: From 1990 until now
From 1990 until now

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Institut National de la Santé Et de la Recherche Médicale, France

Collaborators

Gustave Roussy, Cancer Campus, Grand Paris
Ligue contre le cancer, France
Université Paris-Sud

Investigators

  • Study Director: Gianluca Severi, PhD, INSERM (Institut National de la Sante et de la Recherche Medicale)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 15, 1990

Primary Completion (Actual)

November 15, 1991

Study Completion (Estimated)

December 31, 2046

Study Registration Dates

First Submitted

July 27, 2017

First Submitted That Met QC Criteria

September 12, 2017

First Posted (Actual)

September 15, 2017

Study Record Updates

Last Update Posted (Actual)

June 25, 2026

Last Update Submitted That Met QC Criteria

June 22, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • C 95-01

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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