Optimizing management of small renal masses: a patient-centered approach to minimize overtreatment

Small renal masses (SRMs) usually have a favorable prognosis. Many studies have shown that cancer-specific survival (CSS) is comparable among various treatment options, such as partial nephrectomy, percutaneous thermal ablation, stereotactic body radiotherapy, and active surveillance (AS). Therefore, the choice of treatment should be based on patient background and tumor characteristics rather than on oncologic concerns alone. Important patient factors include age, comorbidities, renal function, and life expectancy. Tumor size, growth rate, and anatomical location also influence this decision. In older or frail patients, immediate intervention may represent overtreatment, as the risk of periprocedural complications and renal function loss may outweigh the limited oncological benefit. Recent AS studies have demonstrated excellent CSS and very low metastatic rates; however, many of these prospective cohorts included patients with limited life expectancies and relatively short follow-up periods, which limit their generalizability. This review summarizes the current evidence regarding local treatment options and surveillance strategies for SRMs, focusing on oncologic outcomes, renal function, and patient selection. Finally, we highlight the rationale and design of the ongoing JCOG2409 prospective comparative study in medically operable adults aged ≥75 years with a solitary renal mass that evaluates standardized AS versus upfront interventions.