Defining the risk threshold for risk reducing salpingo-oophorectomy for ovarian cancer prevention in low risk postmenopausal women

Objective: To define risk thresholds for cost-effectiveness of risk-reducing salpingo-oophorectomy (RRSO) for ovarian cancer (OC) prevention in low/intermediate risk postmenopausal women.

Methods: A decision-analytic model compares lifetime costs-&-effects of offering 'RRSO' with 'no RRSO' to postmenopausal women ≥50years for different lifetime OC-risk thresholds: 2%, 4%, 5%, 6%, 8% and 10%. Well established data from the literature are used to estimate total costs, effects in terms of Quality-Adjusted-Life-Years(QALYs), cancer incidence, incremental cost-effectiveness ratio(ICER) and impact. Costs are reported at 2012 prices; costs/outcomes discounted at 3.5%. Deterministic/probabilistic sensitivity analysis (PSA) evaluate model uncertainty.

Results: RRSO does not save QALYs and is not cost-effective at the 2% general population lifetime OC-risk. At 4% OC-risk RRSO saves QALYs but is not cost-effective. At risk thresholds ≥5%, RRSO saves more life-years and QALYs and is highly cost-effective. The ICERs for OC-risk levels 5%, 6%, 8% and 10% are £15,247, £9958, £4584, and £1864 respectively. The gain in life-years from RRSO equates to 29.2, 40.1, 62.1 and 80.3days at risk thresholds of 5%, 6%, 8% and 10% respectively. The results are not sensitive to treatment costs of RRSO/OC/cardiovascular events but are sensitive to utility-scores for RRSO. On PSA, 67%, 80%, 84%, 91% and 94% of simulations at risk thresholds of 4%, 5%, 6%, 8% and 10% respectively are cost-effective for RRSO.

Conclusion: RRSO is highly cost-effective in postmenopausal women aged >50 with ≥5% lifetime OC-risk and increases life-expectancy by ≥29.2days. The results could have significant clinical implications given the improvements in risk prediction and falling costs of genotyping.