A study published in JAMA Network Open, finds that conventional colonoscopy remains the most cost-effective method for universal colorectal cancer (CRC) screening in average-risk adults in the US, compared to circulating tumor DNA-based methods (liquid biopsy).
Key points from the study include:
- Colonoscopy as the Most Cost-Effective Screening Tool: The study, led by first author Zainab Aziz and senior author Chin Hur, concludes that colonoscopy is more cost-effective than liquid biopsy-based tests for CRC screening. For liquid biopsy to be a viable option, it needs to become more affordable and improve in detecting early-stage cancers and pre-cancerous lesions.
- Low Screening Rates in the US: Despite recommendations for CRC screening starting at 45 years of age for average-risk individuals, the screening rates in the US are relatively low, around 60%.
- Study Methodology: The research used a Markov model-based economic analysis on a simulated cohort of 45-year-old individuals at average CRC risk. It compared life expectancy, total cost, and cost per life-year gained across different screening methods: colonoscopy, stool DNA testing (S-DNA), fecal immunochemical testing (FIT), liquid biopsy, and liquid biopsy post-colonoscopy refusal.
- Adherence Assumptions and Cost-Effectiveness Threshold: The study assumed 100% adherence to liquid biopsy and 60.6% adherence to other methods. Cost-effectiveness was based on a US willingness-to-pay threshold of $100,000 per life-year gained.
- Findings on Cost-Effectiveness: Colonoscopy showed the greatest cost-effectiveness with an incremental cost-effectiveness ratio of just over $28,000 per life-year gained. The combined colonoscopy-liquid biopsy method, used after refusal of colonoscopy, showed a higher life-year gain but was much less cost-effective, with over $377,500 per life year.
- Future Potential of Liquid Biopsy: The study acknowledges that as technology improves, liquid biopsy-based CRC screening could become more cost-effective.
- Concerns About Access and Disparities: The commentary by John Inadomi from the University of Utah highlights the importance of new technologies in cancer screening but cautions that higher costs of blood-based tests could increase barriers to screening, especially for uninsured individuals or those with high-deductible insurance plans.
The study underscores the current economic advantage of colonoscopy for CRC screening while acknowledging the potential future role of liquid biopsy as technology advances.