Early Life Factors and Breast Cancer Risk

摘要

Introduction Breast development and structure is influenced most during the following stages of life - intrauterine, menarche, and pregnancy and lactation. The success of traditional breast cancer epidemiology has been to uncover the relationship of factors such as menarche, parity, and menopause on breast cancer risk. However, much of breast cancer risk is still unexplained perhaps because many investigations focus on exposures after critical breast development periods. In particular, studies examining the intrauterine period and later breast cancer risk are scan%t. In utem exposures may increase breast cancer risk by increasing the number of mammary cells and rate of cell division, increasing the number of in utero mutations, and/or through imprinting the fetal ovary. We hypothesize that early life factors are important to breast cancer risk, particularly premenopausal breast cancer, and also that they may %he'%lp to explain the higher breast cancer risk in African Americans as compared to whites in the premenopausal period. This %tudy is a prospective follow-up study of children who were part of a perinatal prospective cohort recruited during 1959-1963 in New York City. Specifically, we are examining associations between maternal exposures during fetal development, fetal growth and childhood growth with the following factors known to be important to breast cancer risk -- age at menarche, insulin-like growth factors, and mammographic density in a sample of 200 Hispanic, African Amencan and white, premenopausal women aged 38 to 42. After the first year of work, we have collected questionnaire information on 137 women. We are currently collecting blood and mammogram information and study recruitrnent is ongoing.