Cost-effectiveness of microsatellite instability screening as a method for detecting hereditary nonpolyposis colorectal cancer.

BACKGROUND The National Cancer Institute has published consensus guidelines for universal screening for hereditary nonpolyposis colorectal cancer (HNPCC) in patients with newly diagnosed colorectal cancer. OBJECTIVE To determine the cost-effectiveness of screening compared with standard care in eligible patients with colorectal cancer and their siblings and children. DESIGN Cost-effectiveness analysis. DATA SOURCES National colorectal cancer registry data, the Creighton International Hereditary Colorectal Cancer Registry, Medicare claims records, and published literature. TARGET POPULATION Patients with newly diagnosed colorectal cancer and their siblings and children. TIME HORIZON Lifetime (varies depending on age at screening). PERSPECTIVE Societal. INTERVENTIONS Initial office-based screening to determine eligibility (based on personal and family cancer history), followed by tumor testing for microsatellite instability. Those with microsatellite instability were offered genetic testing for HNPCC. Siblings and children of patients with cancer and the HNPCC mutation were offered genetic testing, and those who were found to carry the mutation received lifelong colorectal cancer screening. MEASUREMENTS Life-years gained. RESULTS OF BASE-CASE ANALYSIS When only the patients with cancer were considered, cost-effectiveness of screening was $42 210 per life-year gained. When patients with cancer and their siblings and children were considered together, cost-effectiveness increased to $7556 per life-year gained. RESULTS OF SENSITIVITY ANALYSIS The model was most sensitive to the estimated survival gain from screening siblings and children, to the prevalence of HNPCC mutations among patients with newly diagnosed cancer, and to the discount rate. In probabilistic analysis, the 90% CI for the cost-effectiveness of screening patients with cancer plus their relatives was $4874 to $21 576 per life-year gained. CONCLUSION Screening patients with newly diagnosed colorectal cancer for HNPCC is cost-effective, especially if the benefits to their immediate relatives are considered.