Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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ACTIVE_NOT_RECRUITING
100000 participants
OBSERVATIONAL
1990-06-15
2025-12-15
Brief Summary
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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.
Detailed Description
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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.
Conditions
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Study Design
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COHORT
PROSPECTIVE
Eligibility Criteria
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Inclusion Criteria
* born between 1925 and 1950
* insured by the Mutuelle Générale de l'Education Nationale (MGEN)
Exclusion Criteria
40 Years
FEMALE
Yes
Sponsors
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Université Paris-Sud
OTHER
Gustave Roussy, Cancer Campus, Grand Paris
OTHER
Ligue contre le cancer, France
OTHER
Institut National de la Santé Et de la Recherche Médicale, France
OTHER_GOV
Responsible Party
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Principal Investigators
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Gianluca Severi, PhD
Role: STUDY_DIRECTOR
INSERM (Institut National de la Sante et de la Recherche Medicale)
Marie-Christine Boutron-Ruault, PhD
Role: PRINCIPAL_INVESTIGATOR
INSERM (Institut National de la Sante et de la Recherche Medicale)
References
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Clavel-Chapelon F; E3N Study Group. Cohort Profile: The French E3N Cohort Study. Int J Epidemiol. 2015 Jun;44(3):801-9. doi: 10.1093/ije/dyu184. Epub 2014 Sep 10.
Auguste A, Jansana A, Freisling H, Ferrari P, Laouali N, Severi G, Kvaskoff M. Impact of Hypertension on Cancer Stage at Diagnosis Among French Women: The E3N Prospective Cohort. Cancer Med. 2025 Aug;14(15):e71021. doi: 10.1002/cam4.71021.
Klu YE, Amazouz H, Canonico M, Guenel P, Kvaskoff M, Severi G, Radoi L, Auguste A. Association Between Hormonal Factors and Risk of Lung and Upper Aerodigestive Tract Cancer in French Women: The E3N Prospective Cohort Study. Cancer Rep (Hoboken). 2025 Jun;8(6):e70223. doi: 10.1002/cnr2.70223.
Koemel NA, Shah S, Senior AM, Severi G, Mancini FR, Gill TP, Simpson SJ, Raubenheimer D, Boutron-Ruault MC, Laouali N, Skilton MR. Macronutrient composition of plant-based diets and breast cancer risk: the E3N prospective cohort study. Eur J Nutr. 2024 Aug;63(5):1771-1781. doi: 10.1007/s00394-024-03379-x. Epub 2024 Apr 18.
Shah S, Mahamat-Saleh Y, Ait-Hadad W, Koemel NA, Varraso R, Boutron-Ruault MC, Laouali N. Long-term adherence to healthful and unhealthful plant-based diets and breast cancer risk overall and by hormone receptor and histologic subtypes among postmenopausal females. Am J Clin Nutr. 2023 Mar;117(3):467-476. doi: 10.1016/j.ajcnut.2022.11.019.
Shah S, Mahamat-Saleh Y, Hajji-Louati M, Correia E, Oulhote Y, Boutron-Ruault MC, Laouali N. Palaeolithic diet score and risk of breast cancer among postmenopausal women overall and by hormone receptor and histologic subtypes. Eur J Clin Nutr. 2023 May;77(5):596-602. doi: 10.1038/s41430-023-01267-x. Epub 2023 Feb 1.
Frenoy P, Perduca V, Cano-Sancho G, Antignac JP, Severi G, Mancini FR. Application of two statistical approaches (Bayesian Kernel Machine Regression and Principal Component Regression) to assess breast cancer risk in association to exposure to mixtures of brominated flame retardants and per- and polyfluorinated alkylated substances in the E3N cohort. Environ Health. 2022 Feb 26;21(1):27. doi: 10.1186/s12940-022-00840-4.
Madika AL, MacDonald CJ, Gelot A, Hitier S, Mounier-Vehier C, Beraud G, Kvaskoff M, Boutron-Ruault MC, Bonnet F. Hysterectomy, non-malignant gynecological diseases, and the risk of incident hypertension: The E3N prospective cohort. Maturitas. 2021 Aug;150:22-29. doi: 10.1016/j.maturitas.2021.06.001. Epub 2021 Jun 12.
Laouali N, Shah S, MacDonald CJ, Mahamat-Saleh Y, El Fatouhi D, Mancini F, Fagherazzi G, Boutron-Ruault MC. BMI in the Associations of Plant-Based Diets with Type 2 Diabetes and Hypertension Risks in Women: The E3N Prospective Cohort Study. J Nutr. 2021 Sep 4;151(9):2731-2740. doi: 10.1093/jn/nxab158.
Cairat M, Al Rahmoun M, Gunter MJ, Severi G, Dossus L, Fournier A. Antiplatelet Drug Use and Breast Cancer Risk in a Prospective Cohort of Postmenopausal Women. Cancer Epidemiol Biomarkers Prev. 2021 Apr;30(4):643-652. doi: 10.1158/1055-9965.EPI-20-1292. Epub 2021 Feb 2.
Azevedo Da Silva M, Fournier A, Boutron-Ruault MC, Balkau B, Bonnet F, Nabi H, Fagherazzi G. Increased risk of type 2 diabetes in antidepressant users: evidence from a 6-year longitudinal study in the E3N cohort. Diabet Med. 2020 Nov;37(11):1866-1873. doi: 10.1111/dme.14345. Epub 2020 Jul 2.
Mahamat-Saleh Y, Cervenka I, Al Rahmoun M, Savoye I, Mancini FR, Trichopoulou A, Boutron-Ruault MC, Kvaskoff M. Mediterranean dietary pattern and skin cancer risk: A prospective cohort study in French women. Am J Clin Nutr. 2019 Oct 1;110(4):993-1002. doi: 10.1093/ajcn/nqz173.
Related Links
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website of the study
Other Identifiers
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C 95-01
Identifier Type: -
Identifier Source: org_study_id