Cost-Effectiveness of Active Surveillance for Incidentally Detected Early-Staged Papillary Thyroid Cancer: A Microsimulation Study

OBJECTIVES: Incidence of papillary thyroid cancer (PTC) has been increasing rapidly worldwide, with a large proportion being overdiagnosed and overtreated with radical thyroidectomy. Our previous study found that the upsurge of PTC was primarily driven by incidentally detected early-staged cancers, which manifested very low mortality risk. We aimed to estimate the cost-effectiveness among those low-risk patients of active surveillance (followed by intervention if progression is detected) compared to immediate surgery, the standard care recommended by the 2023 Chinese guidelines.

METHODS: We developed a Markov microsimulation model and the model-based evaluation was performed from a healthcare system perspective in China. We simulated 10,000 patients aged 40 years for 50 cycles. Probabilities of cancer progression, recurrence and death, together with direct medical costs and health utility values related to surgery, complications and active surveillance, were obtained from published literature and our previously established retrospective PTC cohort by detection route. The probabilities of dying from other causes were derived using the China life tables. Costs and quality-adjusted life years (QALYs) were discounted at a rate of 3%. Sensitivity analyses were conducted to assess the impact of parameter uncertainty in the model.

RESULTS: On average, active surveillance of the incidentally detected early-staged PTC followed by intervention if progression was detected yielded 18.0 QALYs per patient with a cost-effectiveness ratio (CER) of ¥1706/QALY, compared to 16.9 QALYs per patient and ¥4553/QALY associated with immediate surgery. The incremental cost-effectiveness ratio (ICER) was -¥41,524/QALY. Sensitivity analyses showed that the discounting rate, probabilities of cancer progress and recurrence after surgery, and the utility value after total thyroidectomy had large influence on ICER, but active surveillance remained cost-effective.

CONCLUSIONS: Active surveillance of incidentally detected early-staged PTC is likely cost-effective from a healthcare system perspective in China. This study provides continuing evidence of the de-escalation in low-risk thyroid cancer management.