Active Surveillance for Small Renal Masses

Abstract

Active surveillance (AS) is a safe and reasonable management strategy for many patients with small renal masses (SRM) suspicious for a clinical T1a renal cell carcinoma based on excellent metastasis-free and cancer-specific survival. However, the expansion of robotic extirpation of SRM has outpaced the adoption of AS, resulting in the possibility of overtreatment for select patients with SRM, especially the elderly and comorbid. In this review of AS for SRM, with a focus on the Delayed Intervention and Surveillance for Small Renal Masses (DISSRM) Registry, we detail the rationale behind AS, review lessons learned from the past decades of literature, and offer suggestions for appropriate patient selection and follow-up. An improved understanding of the data supporting AS will empower physicians and patients to more comfortably pursue AS to avoid over-treatment and provide individualized care to patients with SRM.

Keywords: Active surveillance; Chest imaging; Renal cell carcinoma; Renal mass biopsy; Small renal mass.

Figure 1.

Algorithm for management of patients with a small renal mass in the Delayed Intervention and Surveillance for Small Renal Mass (DISSRM) Registry. Axial imaging entails CT or MRI. CBC, complete blood count; CMP, comprehensive metabolic panel; PT/PTT, prothrombin time/partial thromboplastin time; QOL, quality of life. *Ultrasound is the preferred imaging modality; however, CT or MRI is typically used in an alternating fashion with ultrasound and may be used at the discretion of the physician in the case of uncertainty or changes in ultrasound findings. **Chest imaging (eg, chest radiograph) is no longer recommended on an annual basis without cause. Please refer to the body of the text and Figure 3.

Figure 2.

Examples of indications for percutaneous renal mass biopsy of small renal masses. (A) Determining initial management for whom the decision between active surveillance and primary intervention is unclear in a patient who would clearly choose intervention based on a histologic diagnosis. (B) To distinguish rapidly growing benign lesion (ie, oncocytoma) from malignant in a patient on active surveillance whose small renal mass grows > 0.5 cm/year. (C) Determining whether nephronsparing intervention or radical nephrectomy is appropriate in a patient for whom primary intervention is indicated but the benefits of both are unclear. For example, radical nephrectomy may be more justified in the setting of renal cell carcinoma than a benign entity. CBC, complete blood count; CMP, comprehensive metabolic panel; PT/PTT, prothrombin time/partial thromboplastin time; QOL, quality of life.

Figure 3.

Indications for annual chest imaging during active surveillance.