Olaparib targets the DNA repair pathways and has revolutionized the management of metastatic castration resistant prostate cancer (mCRPC). Treatment with the drug should be guided by genetic testing; however, published economic evaluations did not consider olaparib and genetic testing as codependent technologies. This study aims to assess the cost-effectiveness of BRCA germline testing to inform olaparib treatment in mCRPC.

We conducted a cost-utility analysis of germline BRCA testing-guided olaparib treatment compared to standard care without testing from an Australian health payer perspective. The analysis applied a decision tree to indicate the germline testing or no testing strategy. A Markov multi-state transition approach was used for patients within each strategy. The model had a time horizon of 5 years. Costs and outcomes were discounted at an annual rate of 5 percent. Decision uncertainty was characterized using probabilistic and scenario analyses.

Compared to standard care, BRCA testing-guided olaparib treatment was associated with an incremental cost of AU$7,841 and a gain of 0.06 quality-adjusted life-years (QALYs). The incremental cost-effectiveness ratio (ICER) was AU$143,613 per QALY. The probability of BRCA testing-guided treatment being cost effective at a willingness-to-pay threshold of AU$100,000 per QALY was around 2 percent; however, the likelihood for cost-effectiveness increased to 66 percent if the price of olaparib was reduced by 30 percent.

This is the first study to evaluate germline genetic testing and olaparib treatment as codependent technologies in mCRPC. Genetic testing-guided olaparib treatment may be cost-effective with significant discounts on olaparib pricing.

To assess the cost effectiveness from a Canadian perspective of index patient germline BRCA testing and then, if positive, family members with subsequent risk-reducing surgery (RRS) in as yet unaffected mutation carriers compared with no testing and treatment of cancer when it develops.

A patient level simulation was developed comparing outcomes between two groups using Canadian data. Group 1: no mutation testing with treatment if cancer developed. Group 2: cascade testing (index patient BRCA tested and first-/second-degree relatives tested if index patient/first-degree relative is positive) with RRS in carriers. End points were the incremental cost-effectiveness ratio (ICER) and budget impact.

There were 29,102 index patients: 2,786 ovarian cancer and 26,316 breast cancer (BC). Using the base-case assumption of 44 percent and 21 percent of women with a BRCA mutation receiving risk-reducing bilateral salpingo-oophorectomy and risk-reducing mastectomy, respectively, testing was cost effective versus no testing and treatment on cancer development, with an ICER of CAD 14,942 (USD 10,555) per quality-adjusted life-year (QALY), 127 and 104 fewer cases of ovarian and BC, respectively, and twenty-one fewer all-cause deaths. Testing remained cost effective versus no testing at the commonly accepted North American threshold of approximately CAD 100,000 (or USD 100,000) per QALY gained in all scenario analyses, and cost effectiveness improved as RRS uptake rates increased.

Prevention via testing and RRS is cost effective at current RRS uptake rates; however, optimization of uptake rates and RRS will increase cost effectiveness and can provide cost savings.