The Carolina Breast Cancer Study: integrating population-based epidemiology and molecular biology

Abstract

The integration of epidemiology and molecular biology provides a new strategy to identify additional risk factors for breast cancer and to better understand the role played by traditionally recognized risk factors. The Carolina Breast Cancer Study (CBCS) is a population-based, case-control study designed to identify causes of breast cancer among Caucasian and African-American women who are residents of a 24-county area of central and eastern North Carolina. Information on established and potential breast cancer risk factors is obtained by personal interviews. Blood samples are collected from all consenting participants. Medical record documentation and paraffin-embedded tumor specimens are obtained for all breast cancer patients. DNA from tumor tissue is tested for a variety of molecular alterations characteristic of breast cancer. Germline DNA from blood lymphocytes is evaluated for presence of alleles increasing susceptibility to breast cancer. Statistical analyses evaluate gene-environment interaction by exploring the associations between environmental/behavioral factors and breast cancer in relation to specific molecular alterations (germline and tumor). Results will help identify high-risk women, clarify causal pathways, and hopefully contribute to the prevention of breast cancer.

Population-Based Case-Control Study of Occupational Exposure to Electromagnetic Fields and Breast Cancer

“…Offset terms were incorporated into the logistic models in order to control for the different ageã nd race-specific sampling fractions utilized for cases and controls (19,21,22). The analysis of breast cancer risk in relation to duration of employment and cumulative indices of exposure was stratified by menopausal status·to evaluate effect measure modification.…”

“…Details of the study design and identification and characteristics of cases and controls in the first phase of the Carolina Breast Cancer Study (CBCS) have been published in detail elsewhere (19,20) and are briefly described here. The· CBCS is an ongoing population-based case-control study to identify genetic and environmental risk factors .…”

Adolescent reproductive events and subsequent breast cancer risk.

“…4 Women aged 20 to 74 years with a first invasive, primary breast cancer diagnosis between May 1993 and May 1996 were eligible; African American case patients and patients younger than 50 years at diagnosis were oversampled to increase the numbers in these subgroups. Sampling fractions and randomized recruitment techniques were used in selecting case patients.56 The same methods were used to sample controls from Division of Motor Vehicle records (if the individuals were younger than 65 years) and Medicare records (if the individuals were 65 years or older); these individuals were frequency matched to the case patient age-race distribution.…”

A polymorphism C3435T of the MDR-1 gene associated with smoking or high body mass index increases the risk of sporadic breast cancer in women

“…The polycyclic aromatic hydrocarbons including benzopyrene in tobacco smoke are mutagenic for the p53 suppressor gene in humans, and 7,12-dimethylbenzanthracene is an inductor of mammary tumors in animals (7). Previous studies showed increased risk of breast cancer for active or passive smokers (8,9).…”