The management of women at high risk of experiencing hereditary breast andovarian cancer - The Lahey guidelines

Most breast and ovarian cancers occur sporadically, but an estimated 5 to 1 0% of cases occur in women with hereditary predisposition to these cancers. Two genes, BRCA1 and BRCA2 have been identified, which, when altered, are thought to be responsible for most cases of hereditary breast and ovarian c ancer. Testing for mutations in these genes is now available for women who are at risk. At present, only a small percentage of women have been tested, and identification of high risk women is dependent on pedigree analysis an d application of empiric models. In the general population. the level of risk of hereditary cancer ranges fr om nonexistent to highly likely. A disease management approach requires ide ntification of the level of risk of each individual in the population, and the development of a specific management strategy of screening and consider ation of chemoprevention and prophylactic surgery commensurate with risk. T herefore. risk identification takes on an important role in the allocation of health resources. This article presents an approach to categorising women who are at increase d risk of experiencing hereditary breast or ovarian cancer, whether or not testing is accepted or feasible. An evidence-based approach to screening an d measures Fur prevention are outlined according to level of risk. Occasion s when genetic testing would appreciably enhance decisions regarding manage ment are noted. Clinically useful guidelines for risk assessment and management are intende d to reduce the incidence of and morbidity associated with hereditary breas t and ovarian cancer. Ongoing research with regard to clinical outcomes of carriers of the BRCA1 or BRCA2 mutation will help refine these strategies.