Cost effectiveness of surveillance for distant recurrence in extremity soft tissue sarcoma.

Abstract

11021 Background: Optimal surveillance strategies for extremity soft tissue sarcoma (STS) are unknown. We performed a cost-effectiveness analysis of competing imaging modalities performed at National Cancer Comprehensive Network guideline-specified intervals. Methods: We developed a Markov model simulating lifetime outcomes for 54-year-old patients after definitive treatment for Stage II-III extremity STS using four surveillance strategies: watchful waiting (WW), chest x-ray (CXR), chest computed tomography (CCT) and positron emission tomography-computed tomography (PET/CT) performed every 3-6 months for the first 3 years, every 6 months until year 5, and then annually. We used probabilities, utilities and costs extracted from the literature and Medicare claims to determine incremental cost-effectiveness ratios (ICER). Results: While the model showed that CCT is the most effective strategy, CXR is the most cost-effective strategy at a societal willing-to-pay (WTP) of $100,000/quality-adjusted life year (QALY). The ICER is $14,306/QALY for CXR versus $117,683/QALY for CCT while PET/CT is never cost effective (Table). Sensitivity analyses demonstrated CCT becomes the preferred imaging modality as the lifetime risk of DR increases beyond 38% or as the societal WTP increases beyond $130,000/QALY. Conclusions: Optimal DR surveillance imaging for Stage II-III extremity STS should be individualized based on patients’ risks for DR. CXR, or CCT at more protracted intervals, may be preferred for lower risk patients (i.e. DR risk less than 38%), whereas CCT may be preferred for higher risk patients (i.e. DR risk greater than 38%). These findings can help refine guidelines to reduce resource overutilization during surveillance of sarcoma patients. [Table: see text]