The relation between hormonal and lifestyle factors and breast cancer risk in nulliparae was investigated using data from two case-control studies conducted in Italy between 1983 and 1994.
The study included 1041 nulliparae with histologically confirmed incident breast cancer and 1002 nulliparous controls admitted to hospital for a wide range of acute, non-neoplastic, nonhormone-related diseases.
In premenopausal nulliparae, there was an inverse relation with age at menarche [odds ratios (OR) 0.45 ; 95% confidence intervals (Cl) 0.24-0.86 for >= 15 years vs<12], while no association emerged in postmenopausal.
Breast cancer risk increased with age at menopause, the OR being 1.91 (95% Cl 1.26-2.90) for nulliparae reporting age at menopause >= 53 years compared with<45.
Abortion was not related to breast cancer risk, the OR being 0.92 for any spontaneous, 0.97 for any induced and 0.77 for >= 2 total abortions compared to none.
The OR was 1.75 (95% Cl 1.03-2.97) for women reporting their first abortion at age >= 30 years compared with<30.
Oral contraceptives and hormone replacement therapy in menopause were moderately related to risk.
The OR was 2.71 (95% CI 1.85-3.95) in nulliparae with a family history of breast cancer and 1.60 (95% Cl 1.20-2.14) in those with a history of benign breast disease.
Compared with nulliparae reporting a low physical activity, the OR was 0.79 (95% Cl 0.54-1.16) for those reporting intermediate/high activity. (...)
Mots-clés Pascal : Tumeur maligne, Glande mammaire, Facteur risque, Epidémiologie, Reproduction, Nulliparité, Ménopause, Contraception, Voie orale, Traitement substitutif, Hormone stéroïde, Régime alimentaire, Bétacarotène, Mode de vie, Italie, Europe, Etude cas témoin, Homme, Glande mammaire pathologie
Mots-clés Pascal anglais : Malignant tumor, Mammary gland, Risk factor, Epidemiology, Reproduction, Nulliparity, Menopause, Contraception, Oral administration, Replacement therapy, Steroid hormone, Diet, Betacarotene, Life style, Italy, Europe, Case control study, Human, Mammary gland diseases
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0226300
Code Inist : 002B20E02. Création : 16/11/1999.