SS11 - Screening and Treating Asymptomatic Carotid Artery Stenosis among Patients Radiated for Head & Neck Cancer: Is It Worthwhile?

Objectives: Neck radiation is standard of care for squamous cell cancer of the head and neck (HNSCC) and is associated with a rapid progression of carotid artery stenosis. Among patients radiated for HPV-negative HNSCC, the more aggressive form of HNSCC that has a less than 70% 3-year survival, the benefit of screening for carotid artery stenosis has not been clearly delineated. We sought to perform a cost-effectiveness analysis comparing carotid screening versus no screening in order to determine the most cost-effective strategy to prevent strokes related to carotid stenosis in the HPV-negative HNSCC patient population.

Methods: A probabilistic Markov model was used to simulate the relative costs and outcomes (measured in quality-adjusted life-years, or QALYs) of two strategies for 100 hypothetical men one year after successful radiotherapy for HNSCC treatment: (strategy 1) no screening for carotid stenosis; or (strategy 2) screening with duplex ultrasound and treatment with transcarotid stent placement. The model incorporated clinical event rates (including development of severe carotid stenosis following radiation) and cost data from published literature on HNSCC.

Results: Compared to strategy 1 (no surveillance), strategy 2 resulted in an additional 426 ultrasound exams and 55 carotid stents for every 100 patients. The predicted stroke rate was 7.3 vs 1.7 per 100 patients in strategies 1 and 2, respectively, resulting in a number needed to treat of 18 for carotid stenting. Compared to strategy 1, strategy 2 cost an average of an additional 572,007 USD and yielded an average of 10.4 QALYs. Although parameter uncertainty resulted in a wide range of cost-effectiveness estimates, 24.9% of simulations predicted screening would result in cost-savings (improved outcomes at lower cost), and 81.9% of simulations below the 100,000 per QALY threshold.

Conclusions: Among patients treated with neck radiation for HPV-negative HNSCC, screening for carotid artery stenosis was cost-effective relative to not screening these patients given a willingness-to-pay threshold of $100,000/QALY. This data will help to inform conversations with HNSCC patients who present with treatment-related sequelae of high-grade carotid stenosis.