Purpose: to evaluate the association between second-degree family history of breast cancer and the risk to develop the disease. Methods: case-control study of incident cases. Sixty-six incident breast cancer cases and 198 controls were selected among women who were submitted to mammography in a private clinic between January 1994 and July 1997. Cases and controls were paired regarding age, age at menarche, at first live birth, at menopause, parity, oral contraceptives and use of hormonal replacement therapy. Results: there was no significant difference between cases and controls regarding all risk factors evaluated, besides second-degree family history. Patients with breast cancer were more likely to have second-degree relatives with breast cancer when compared to controls (OR=2.77; 95% CI, 1.03-7.38; p=0.039). Conclusions: malignant neoplasm of the breast is significantly associated with a second-degree family history of this disease.
Breast neoplasms; Risk factors; Heredity
