A study of the relationship between family history of breast cancer and knowledge of breast cancer genetic testing prerequisites

Abstract

Awareness of hereditary breast cancer genetic testing, of breast cancer risk factors, and of increased level of risk based on family history are necessary before women can seek out genetic services. The aim of this paper is to describe the relationships between family history of breast cancer and awareness of genetic testing, knowledge of breast cancer risk factors, and perceived lifetime risk of breast cancer. An anonymous survey was administered by mail to a random sample of 600 women, 200 from each of three breast cancer family history groups (none, intermediate, and strong), drawn from a population-based registry of 240,000 women enrolled in a mammography screening program in the Denver Metropolitan area in Colorado. Awareness of genetic testing for breast cancer risk assessment was found to be significantly associated with family history of breast cancer, increasing from 35% in the lowest family history risk group to 67% in the group with the strongest familial risk (p = 0.002). In all family history groups, nearly 70% of respondents viewed high-fat diet and smoking as being important in relation to breast cancer risk, but alcohol was seen as being only somewhat important or not important by almost half of all respondents. Having a mother or sister with breast cancer was reported as being extremely or very important by nearly all respondents, regardless of family history. As expected, perceived lifetime risk for developing breast cancer was associated with family history (p = 0.001), but the perception of the lifetime risk for breast cancer was much higher among all of the family history groups than their true risk. In conclusion, educational interventions are needed to heighten women's awareness of genetic testing, to clarify women's knowledge of breast cancer risk factors, especially alcohol, and to reassure many women that their actual breast cancer risk is lower than they might perceive.