Her-2/neu and INT2 proto-oncogene amplification in malignant breast tumors in relation to reproductive factors and exposure to exogenous hormones.
J Natl Cancer Inst
; 83(20): 1483-7, 1991 Oct 16.
Article
em En
| MEDLINE
| ID: mdl-1920494
ABSTRACT
In previous studies in southern Sweden, early use of oral contraceptives has been found to be accompanied by an increased risk of developing premenopausal breast cancer, and the tumors developing in these patients have shown a more aggressive behavior. In the present study, amplification of the proto-oncogenes Her-2/neu (also known as ERBB2) and INT2 was studied in primary tumor specimens from 72 premenopausal women and was related to starting age of oral contraceptive use and other reproductive risk factors. Amplification of Her-2/neu was more common among early oral contraceptive users (i.e., those starting at less than or equal to 20 years of age) than among nonusers or late users (odds ratio [OR], 5.3; 95% confidence interval [CI], 1.6-16.7), whereas INT2 amplification did not differ significantly among those groups (OR, 0.9; 95% CI, 0.1-5.0). The likelihood of INT2 amplification was greater among users of progestins and those with a history of abortions before the first full-term pregnancy (OR, 9.0; 95% CI, 1.3-51.7; and OR, 18.6; 95% CI, 2.2-165.8, respectively). No significant relationships were found between proto-oncogene amplification and the variables of parity, age at first full-term pregnancy, or late abortion. The increased ORs persisted after adjustment for age at diagnosis and other risk factors. The findings suggest that the higher rate of Her-2/neu amplification among early oral contraceptive users is an effect of the oral contraceptive use per se rather than of the relative youth of the users. Moreover, the relationship between progestin use and early abortion and amplification of the INT2 gene is biologically plausible.
Palavras-chave
Abortion, Induced; Age Factors; Bias; Biology; Breast Cancer; Cancer; Contraception; Contraceptive Methods--side effects; Data Analysis; Demographic Factors; Developed Countries; Diseases; Endocrine System; Error Sources; Europe; Examinations And Diagnoses; Family Planning; Fertility Control, Postconception; Genetics; Hormones--analysis; Laboratory Examinations And Diagnoses; Measurement; Neoplasms; Northern Europe; Oral Contraceptives--side effects; Physiology; Population; Population Characteristics; Pregnancy; Pregnancy, First Trimester; Reproduction; Research Methodology; Risk Factors; Scandinavia; Sweden
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Reprodução
/
Proto-Oncogenes
/
Neoplasias da Mama
/
Anticoncepcionais Orais Hormonais
Tipo de estudo:
Etiology_studies
/
Risk_factors_studies
Limite:
Female
/
Humans
/
Pregnancy
Idioma:
En
Revista:
J Natl Cancer Inst
Ano de publicação:
1991
Tipo de documento:
Article
País de afiliação:
Suécia