Understanding criteria for surveillance of patients with a small renal mass.

OBJECTIVE: To better delineate which factors influence the decision to undergo active surveillance of small renal masses.
METHODS: We identified 204 consecutive patients at our institution with clinical Stage T1 renal masses from June 2009 through June 2010. A variety of demographic and clinical characteristics were measured. Based on our previous work, the "ideal" criteria for active surveillance included tumor size ≤ 4 cm, Charlson comorbidity index of ≥ 2, Eastern Cooperative Oncology Group (ECOG) performance status (PS) of ≥ 2, and estimated glomerular filtration rate <60 mL/min. We performed sensitivity analyses to identify the characteristics associated with choice of active surveillance and compared these with our "ideal" criteria.
RESULTS: Of the 204 patients, 73 (36%) and 131 (64%) underwent active surveillance and treatment, respectively. The patients undergoing active surveillance versus treatment differed with respect to distance from hospital >60 miles (P = .04), ECOG PS of ≥ 2 (P < .01), tumor size (P < .01), multifocality (P = .03), endophytic nature of lesion (P = .04), and whether the patient's surgeon generally used a robotic, laparoscopic, or open approach (P = .01). Neither the baseline estimated glomerular filtration rate (P = .91) nor the Charlson comorbidity index (P = .69) were significant factors. The combination of tumor size <3 cm, ECOG PS of ≥ 2, and an endophytic lesion were most predictive of active surveillance.
CONCLUSION: Patient, tumor, and surgeon characteristics all influence the choice of active surveillance. From the sensitivity analyses, active surveillance was driven by a tumor size <3 cm, poor PS (ie, ECOG PS of ≥ 2), and an endophytic lesion.