Genetic mutations in breast cancer susceptibility genes BRCA1/2 are associated with an increased risk of breast/ovarian cancers. Cost-effective preventive measures are available for women who test positive. The objective of this study was to determine at what risk of mutation it is cost-effective to test women for BRCA1/2 mutations.
A semi-Markov model accrued costs and quality-adjusted life years (QALYs) annually from the societal perspective. The estimates of health-care costs, life expectancy, likelihood of obtaining a mastectomy or oophorectomy, and patient preferences for treatment and certainty about their BRCA1/2 status were based on the literature.
At a 10% probability of mutation (the current guideline), the test strategy generated 22.9 QALYs over the lifetime and cost $118k, while the no-test strategy generated 22.7 QALYs and cost $117k. The incremental cost-effectiveness ratio of the test strategy was $9k and the differences between costs and effects were not substantial. The test strategy remained cost-effective to a probability of mutation of 0%, as long as utility gained from a negative test result was 0.006 or greater. These results were sensitive to the frequency of inconclusive test results and utility gain from a negative test result.
The costs and effectiveness of both the test and no-test strategies are very similar even when there is a small probability of mutation. Current guidelines, which can be used by insurance companies to refuse coverage, could deny some women a cost-effective approach. Further research to decrease the frequency of inconclusive results could improve the cost-effectiveness of this test.