A Case-Control Study on Risk Factors of Benign Breast Disorders in Korea

Park, Sue Kyung; Yoo, Keun Young; Kang, Daehee; Kim, Sook Un; Lee, Sang Yun; Im, Hyung June; Kang, Hee Jun; Noh, Dong Young; Choe, Kuk Jin

Abstract

PURPOSE: A hospital-based case-control study was conducted to figure out the risk factors for benign breast disorders in Korea. MATERIALS AND METHODS: Histologically confirmed incident cases of benign breast disorders(n=54) were selected from inpatients with life-style information at the Department of General Surgery, Seoul National University Hospital during 1994 to 1997. Women with free of self-reporting past history of any malignancies were regarded as controls who were selected from the inpatients at the same department of the same hospital(n=180). Information on life-styles including reproductive factors were obtained by direct interview using questionnaire. Adjusted odds ratios and 95% confidence intervals were estimated by multivariate logistic regression model with matching variables. RESULTS: Overall, higher educational level, family history of breast cancer, alcohol drinking, and older age at first fullterm pregnancy related to the risk of benign breast disorders. For premenopausal women, older age, higher educational level, and family history of breast cancer increased the risk of benign breast disorders. For postmenopausal women, alcohol drinking, older age at first fullterm pregnancy, and more frequent experiences of fullterm pregnancy increased the risk. Elder age in postmenopausal women and the experience of breast feeding had, however, protective effect against benign breast disorders. CONCLUSIONS: Although the risk factors for benign breast disease may differ from those for breast cancer, these findings are consistent with the hypothesis of excessive circulating estrogen. The present data indicate some risk factors of benign breast disorders are confirmed as risk factors for breast cancer though a substantial agreement between the risk factors for (pathologically confirmed) benign and malignant breast disease.