PURPOSE: A hospital-based case-control study was conducted to find out risk factors for developing breast cancer in Korea. MATERIALS AND METHODS: Histologically confirmed incident cases of breast cancer(n=280) were selected from inpatients 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 Department of Obstetrics and Gynecology of the same hospital during 1992 to 1994(n=930). Information on life-styles including reproductive factors were obtained by direct interview using questionnaire. Age- and education-adjusted odds ratio and 95% confidence interval were estimated by unconditional linear logistic regression. RESULTS: Based on the risk factors identified by both this study and other epidemiologic studies previously performed in Korea, high risk group for female breast cancer in Korea was established as follows. (1) women with age over 50, (2) women who have a family history of breast cancer, (3) women with age at menarche before 14-year old, (4) women with age at menopause after 50-year old, (5) women who were not experienced a full term pregnancy, (5) nulliparous women (6) women with age at her first fullterm pregnancy after 35-year old (7) women who were not experienced breast feeding, (8) women with body mass index more than 25 kg/m2 or with body weight more than 64 kg. CONCLUSION: Life-time risk of breast cancer, as an indicator of absolute risk, according to the risk factors should be pursued in further prospective studies with community population.
Adolescent ; Adult ; Body Mass Index ; Body Weight ; Breast Feeding ; Breast Neoplasms* ; Breast* ; Case-Control Studies ; Epidemiologic Studies ; Female* ; Gynecology ; Humans ; Inpatients ; Korea* ; Logistic Models ; Menarche ; Menopause ; Middle Aged ; Obstetrics ; Odds Ratio ; Pregnancy ; Surveys and Questionnaires ; Reproduction ; Risk Factors ; Seoul