Patients with anatomically "simple" renal masses are more likely to be placed on active surveillance than those with...

To determine if radiographically less complex renal lesions are deemed clinically less "worrisome" and therefore are more likely to be considered for active surveillance (AS).

We examined our prospective institutional database to identify and compare patients with localized renal cell carcinoma undergoing an initial period of AS or immediate surgery. Multivariate logistic regression was used to examine covariates associated with receipt of AS.

Of 1,059 patients with available anatomic complexity data, 195 underwent an initial period of AS (median duration of AS 25.6 mo [interquartile range: 11.8-52.8 mo]). Compared with patients undergoing immediate surgical treatment, patients selected for AS had lower overall nephrometry scores (NS) with tumors that were smaller, further from the sinus or urothelium, more often polar, and less often hilar (P<0.0015 all comparisons). After adjustment for age, largest tumor size, individual components of NS, total NS, and Charlson comorbidity index, total NS (odds ratio [OR] = 1.9 [CI: 1.4-2.5]), "R" score of 1 (OR = 5.2 [CI: 1.8-15.2]), "N" score of 1 (OR = 2.3 [CI: 1.5-3.6]), "L" score of 1 (OR = 1.4 [CI: 0.84-2.2]), and nonhilar tumor location (OR = 2.7 [CI: 1.2-5.8]) increased the probability of being selected for AS compared with immediate surgery. Findings remained significant in a subanalysis of T1a renal masses.

Lower tumor anatomic complexity was strongly associated with the decision to proceed with AS in patients with stage I renal mass. Not only may these data afford new insights into renal mass treatment trends, but the findings may also prove useful in the development of objective protocols to most appropriately select patients for AS.