Value for money of putting precision into practice: Germline genetic testing to guide olaparib treatment in HER2-negative metastatic breast cancer

Abstract

Aim: Genetic testing for germline BRCA mutation in women with HER2‐negative metastatic breast cancer (MBC) can guide targeted treatment with poly‐ADP‐ribose polymerase (PARP) inhibitors (eg olaparib) and inform cancer prevention strategies (eg risk‐reducing surgery) for family members of women who test positive. This study aimed to evaluate the cost‐effectiveness of BRCA testing in women with MBC to inform olaparib treatment and cascade testing of family members.

Methods: A cost‐effectiveness analysis was conducted using a decision analytic model from an Australian health‐payer perspective. Two scenarios were evaluated compared with no testing and standard chemotherapy: (a) BRCA testing of women with MBC followed by olaparib if the test is positive; and (b) BRCA testing of women with MBC followed by olaparib and cascade testing of first‐ and second‐degree family members if the test is positive. For each scenario, the incremental cost was compared with the quality‐adjusted life‐years (QALYs) gained to estimate the incremental cost‐effectiveness ratio (ICER). Decision uncertainty was characterised using probabilistic sensitivity analysis.

Results: Scenario 1 resulted in an incremental cost of AU$11 607 and 0.04 QALYs gained (ICER = AU$277 000/QALY), whereas Scenario 2 resulted in an incremental cost of AU$12 575 and 0.12 QALYs gained (ICER = AU$105 000/QALY). At a willingness‐to‐pay threshold of AU$100 000/QALY and at the listed price of olaparib, none of the scenarios were cost‐effective. Probability of being cost‐effective was 0% and 40% for Scenario 1 and Scenario 2, respectively. Nevertheless, if olaparib price is significantly reduced by 60%, the two scenarios would become cost‐effective, with Scenario 2 offering an additional AU$1100 in mean monetary benefit over Scenario 1.

Conclusions: Genetic testing for BRCA germline mutation to guide olaparib treatment in women with MBC is not cost‐effective unless the price of olaparib is significantly reduced. Extending BRCA testing to cover family members of mutation carriers would provide additional benefits compared with testing affected women only.