Purpose: To assess the cost-effectiveness of epidermal growth factor receptor (EGFR) gene mutation testing to guide the selection of gefitinib as first-line therapy in patients with advanced non-small cell lung cancer (NSCLC) in Ontario.
Method: A decision analytic model was developed to conduct this cost-effectiveness analysis from the perspective of the Ontario Ministry of Health and Long-Term Care (MOHLTC). Under EGFR gene mutation testing strategy, tumour tissues from biopsy were assessed for EGFR gene mutation status. Patients with EGFR gene mutation would receive gefitinib as first-line therapy and conventional chemotherapy (platinum based chemotherapy and docetaxel (or pemetrexed)) before best supportive care (BSC). Patients without EGFR gene mutation would receive conventional chemotherapy and BSC. The other patients with undetermined EGFR gene mutation status would receive the same care as the patients under no testing strategy, who would receive conventional chemotherapy, erlotinib, and BSC. Literature review was conducted to estimate the epidemiology and natural history of advanced NSCLC, failure rate of EGFR gene mutation testing, and efficacy of treatments. A regression analysis on utility of patients with advanced NSCLC was applied to estimate utility variables. The estimation of cost variables was based on two Ontario cost studies for advanced NSCLC. Both benefits and costs were discounted at 5% per annum.
Result: Compared to no testing strategy, EGFR gene mutation testing strategy would need $46,021 for one additional life year or $81,071 for one additional quality adjusted life year (QALY). One-way sensitivity analysis indicated that the cost-effectiveness of EGFR gene mutation testing was highly sensitive to the efficacy and cost of gefitinib. Probabilistic sensitivity analysis suggested that the chance for EGFR gene mutation testing to be cost-effective would not be over 50% until willingness-to-pay (WTP) per QLAY increased to $93,340. Budget impact analysis predicted that the adaption of EGFR gene mutation testing would increase the annual direct medical costs by $4.6M, $7.0M, $7.9M, $8.1M, and $8.1M from 2011 to 2015 respectively on the Ontario health care system.
Conclusion: Applying EGFR gene mutation testing to guide the use of gefitinib as first-line therapy for patients with advanced NSCLC would not be considered cost-effective until WTP of MOHLTC was over $81,071 per QALY. The cost-effectiveness of EGFR gene mutation testing was highly sensitive to the efficacy and cost of gefitinib.