BODY-SIZE AS A FACTOR IN DIFFERENT AGES AND BREAST-CANCER RISK IN TAIWAN

A matched case-control study was done on 175 pathologically proven new cases of female breast cancer from National Taiwan University Hospita l from February 1993 to June 1994 and 457 hospital controls individual ly matched for age and date of admission Height and weight during one year before the first full-term pregnancy and one year before admissio n were collected from a questionnaire interview. Body mass index (BMI) (kg/m(2)) was derived accordingly. Demographic and reproductive chara cteristics, and family history of breast cancer were collected and adj usted as potential confounders Conditional multiple logistic regressio n analysis was used to estimate the effect for each risk factor regard ing body size of different ages. After adjustment for potential confou nders, higher weight and BMI during one year before first full-term pr egnancy were associated with a moderately lower risk of breast cancer especially in the premenopausal group. The heaviest group (greater tha n or equal to 65 kg) during one year before admission also had a moder ately lower breast cancer ride Height did not show any significant ass ociation with breast cancer risk. Weight and BMI gain were associated with an elevated breast cancer risk in the postmenopausal group but wi th wide confidence limits. The results of this study imply that adipos e tissue may interfere with ovarian endocrine in the younger age group , and that there is increased hormonal production after obvious weight gain.