Purpose: To estimate the cost-effectiveness of genetic testing strategies to identify Lynch syndrome among newly diagnosed patients with colorectal cancer and to offer targeted testing to relatives of patients with Lynch syndrome.
Methods: We calculated incremental costs per life-year saved for universal testing relative to no testing and age-targeted testing for strategies that use preliminary genetic tests (immunohistochemistry or microsatellite instability) of tumors followed by sequencing of mismatch repair genes. We also calculated incremental cost-effectiveness ratios for pairs of testing strategies.
Results: Strategies to test for Lynch syndrome in newly diagnosed colorectal tumors using preliminary tests before gene sequencing have incremental cost-effectiveness ratios of <or=$45,000 per life-year saved compared with no testing and <or=$75,000 per life-year saved compared with testing restricted to patients younger than 50 years. The lowest cost testing strategies, using immunohistochemistry as a preliminary test, cost <or=$25,000 per life-year saved relative to no testing and <or=$40,000 per life-year saved relative to testing only patients younger than 50 years. Other testing strategies have incremental cost-effectiveness ratios >or=$700,000 per life-year saved relative to the lowest cost strategies. Increasing the number of relatives tested would improve cost-effectiveness.
Conclusion: Laboratory-based strategies using preliminary tests seem cost-effective from the US health care system perspective. Universal testing detects nearly twice as many cases of Lynch syndrome as targeting younger patients and has an incremental cost-effectiveness ratio comparable with other preventive services. This finding provides support for a recent US recommendation to offer testing for Lynch syndrome to all newly diagnosed patients with colorectal cancer.