Su ZT, Patel HD, Huang MM, et al. Active surveillance versus immediate intervention for small renal masses: a cost-effectiveness and clinical decision analysis. J Urol. 2022;208(4)794-803.

Study Need and Importance

Patients with incidentally diagnosed small renal masses (SRMs) traditionally undergo immediate intervention, such as radical nephrectomy (RN), partial nephrectomy (PN), and thermal ablation (TA). Active surveillance (AS) as the initial management strategy with the possibility of delayed intervention (DI) is emerging as a safe alternative to immediate intervention for many patients with SRMs. However, limited comparative data exist to inform the most appropriate management strategy for SRMs.

What We Found

Using decision analytic Markov modeling to estimate the health outcomes and costs of 4 competing empirical management strategies for patients with an incidental SRM (AS with the possibility of DI, immediate PN, RN, or TA), we showed that the 10-year all-cause mortality for AS (22.6%) was similar to immediate PN (21.9%) and RN (22.4%), and lower than immediate TA (23.7%). At a willingness-to-pay threshold of $100,000 per quality-adjusted life year, AS was the most cost-effective management strategy. The cost-effectiveness analysis is robust to alternative input specifications. In particular, for the subset of patients harboring SRMs of likely very low metastatic potential, such as those SRMs <2 cm in size, AS may lead to better health utility outcomes than immediate intervention. Our modeling also demonstrated that the tumor’s metastatic potential and patient age, individual preferences, and health status were important factors influencing the optimal management strategy.

Limitations

The Markov model has inherent limitations, including the assumption that transition between health states only depends on the present but not the past. Our results may not be generalizable to all countries since we used data derived from patients in the United States. Our results were limited by data limitations, such as using certain data from retrospective studies, relying on some assumptions by clinical experts, and extrapolating some clinical event probabilities beyond original study durations.

Interpretation for Patient Care

Compared to immediate intervention, AS with timely DI offers a safe and cost-effective approach to managing patients with SRMs. For patients harboring tumors of very low metastatic potential, AS may lead to better patient outcomes than immediate intervention. Management decisions should be individualized based on the tumor’s metastatic potential and patient age, individual preferences, and health status.