A Case-Control Study of Breast Cancer (Part 1) : Analysis of Host Factors Stratified by Menopausal Status

A Case-control study was performed to investigate the risk factors for breast cancer of women in Hokkaido, Japan. These were 152 cases of patients treated between October 1986 and January 1989, in the Department of Surgery (Section 1), Sapporo Medical College. They were interviewed face-to-face. Controls were 304 women randomly selected from telephone directories. They were matched with index cases for age and menopausal status. Telephone interviews were conducted with them. For statistical analysis, t-test, Mantel-Haenszel method and conditional logistic regression analysis were employed. All of the analytical methods found the following risk factors to be significant. In pre-menopausal women, 1) single marital status, 2) no parity, 3) induced abortion, 4) mastopathy, and 5) being obese during puberty,; and in post-menopausal women, 1) single marital status, 2) miscarriage, 3) mastopathy, and 4) being lean during puberty, Considering the difference in risk factors for breast cancer between premenopausal women and postmenopausal women, it seems necessary to take menopausal status into account in studying its risk factors