Ethical and scientific considerations for chemoprevention research in cohorts at genetic risk for breast cancer.

Identification of cohorts at genetic risk for cancer offers unique research opportunities to explore the steps in carcinogenesis, from the inheritance of a predisposing mutation to the development of preinvasive lesions or overt malignancy, and to evaluate interventions to modulate the carcinogenic process. However, cancer prevention strategies for most inherited cancer predisposition syndromes are of unproven benefit, and the potential for adverse psychosocial effects and employment or insurance discrimination associated with genetic testing is substantial. Thus testing for genetic cancer risk remains highly controversial, and the National Center for Human Genome Research and the American Society of Human Genetics advise DNA testing for presymptomatic identification of cancer risk only in the setting of a carefully monitored research environment. The commercial availability of predictive genetic testing, particularly for inherited susceptibility to cancer, has focused attention not only on the urgent need for research in cancer prevention for cohorts at genetic cancer risk but also on ethical considerations surrounding clinical prevention research in genetic risk groups. This paper addresses the interrelationship of ethical and scientific issues in conducting chemoprevention research in these cohorts, especially for those studies which require presymptomatic testing for specific gene mutations as a study entry criterion or as a criterion for stratification. Practical approaches to study design and implementation issues for chemoprevention research in genetic risk cohorts are discussed, emphasizing the interactions of ethical and scientific considerations at all levels of the research process.