Active Surveillance of Renal Cortical Neoplasms: A Contemporary Review

Abstract

For highly selected patients with RCN, AS is a reasonable treatment option. Age, surgical risk, comorbidities, and patient opinion must all factor into the final decision when considering a patient for AS.

Incompletely Characterized Incidental Renal Masses: Emerging Data Support Conservative Management

“…These data demonstrated that among non-fat-containing solid renal masses, the smaller the mass, the more likely they are benign (13). However, size alone is not diagnostic (15), nor are growth kinetics (16). Growth is not diagnostic of a malignancy, because some benign neoplasms grow; for example, renal oncocytomas can grow at a rate similar to that of RCC (17).…”

“…The evidence suggests that small masses present a low risk of developing metastases during follow-up, particularly those smaller than 3 cm (27,70). Metastases are also rare in the absence of growth (71) but occur in approximately 1.5% of patients undergoing active surveillance (15,20,27,31,72). In the context of active surveillance, a pooled analysis of 880 patients with 936 masses who underwent active surveillance demonstrated that the proportion of masses that progressed to metastasis was small; 18 that progressed to metastatic disease had a higher mean linear growth rate (0.8 cm per year) than nonprogressing masses (0.3 cm per year) and generally progressed after an extended period (mean time to metastases, 40.2 months).…”

“…In scenarios in which solid renal masses smaller than 1 cm are followed, active surveillance not only appears to be low risk but can be used to obtain an estimate of growth (9,11,12,(14)(15)(16)(17)(18)(19)(20)(21)(22)(69)(70)(71)(72).…”

Recommendations for the Management of the Incidental Renal Mass in Adults: Endorsement and Adaptation of the 2017 ACR Incidental Findings Committee White Paper by the Canadian Association of Radiologists Incidental Findings Working Group

“…For any flowchart, if prior studies are available for comparison, indeterminate masses with no change in imaging features for at least 5 years can usually be considered clinically insignificant [12,13]. Patient age and clinical status (particularly comorbidities, suitability as a surgical candidate, and life expectancy) should also be factored in to any management decisions.…”

Renal mass size

“…They examined 2651 patients who had undergone either partial or radical nephrectomy between 1990 and 2006. Several studies have examined the growth kinetics of small renal masses, which have reported a low rate of metastasis [8]. Each 1-cm increase in tumor size also increased the risk of death from renal cell carcinoma by 10%.…”