The cost-effectiveness of genetic testing strategies for Lynch syndrome among newly diagnosed patients with colorectal cancer.

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.