TESTING FOR THE BRCA1 AND BRCA2 BREAST-OVARIAN CANCER SUSCEPTIBILITY GENES - A DECISION-ANALYSIS

Objective. The authors developed a Markov decision model to evaluate t he health implications of testing for mutations in the BRCA1 and BRCA2 breast-ovarian cancer susceptibility genes. Prophylactic measures con sidered included various combinations of immediate and delayed bilater al mastectomy and oophorectomy or taking no action. Methods. The model incorporated the likelihood of developing breast and/or ovarian cance r, survival, and quality of life. Parameter values were taken from pub lic databases, the published literature, and a survey of cancer expert s. Outcomes considered were additional life expectancy acid quality-ad justed life years (QALYs). Results are reported for 30-year-old cancer -free women at various levels of hereditary risk. Results and conclusi ons. The vast majority of women will not benefit from testing because their pre-test risks are low and surgical prophylaxis is undesirable. However, women who have family histories of early breast and/or ovaria n cancer may gain up to 2 QALYs by allowing genetic testing to inform their decisions.