Active Surveillance for Localized Renal Masses
abstract
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Access this abstract now Full Text Available for ClinicalKey SubscribersBACKGROUND
Active surveillance (AS) has gained acceptance as a management strategy for localized renal masses.
OBJECTIVE
To review our large single-center experience with AS.
DESIGN, SETTING, AND PARTICIPANTS
From 2000 to 2016, we identified 457 patients with 544 lesions managed with AS from our prospectively maintained kidney cancer database. A subset analysis was performed for patients with ≥5-yr follow-up without delayed intervention (DI).
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS
Linear growth rates (LGRs) were estimated using linear regression for the initial LGR (iLGR) AS interval and the entire AS period. Overall survival (OS) and cumulative incidence of DI were estimated with Kaplan-Meier methods utilizing iLGR groups, adjusting for covariates. DI was evaluated for association with OS in Cox models.
RESULTS AND LIMITATIONS
Median follow-up was 67 mo (interquartile range [IQR] 41-94 mo) for surviving patients. Cumulative incidence of DI (n=153) after 1, 2, 3, 4, and 5 yr was 9%, 22%, 29%, 35%, and 42%, respectively. Median initial maximum tumor dimension was 2.1cm (IQR 1.5-3.1cm). Median iLGR and overall LGR were 1.9 (IQR 0-7) and 1.9 (IQR 0.3-4.2) mm/yr, respectively. Compared with the no growth group, low iLGR (hazard ratio [HR] 1.25, 95% cumulative incidence [CI] 0.82-1.91), moderate iLGR (HR 2.1, 95% CI 1.31-3.36), and high iLGR (HR 1.87, 95% CI 1.23-2.84) were associated with DI (p=0.003). The iLGR was not associated with OS (p=0.8). DI was not associated with OS (HR 1.34, 95% CI 0.79-2.29, p=0.3). Five-year cancer-specific mortality (CSM) was 1.2% (95% CI 0.4-2.8%). Of 99 patients on AS without DI for >5 yr, one patient metastasized.
CONCLUSIONS
At >5 yr, AS±DI is a successful strategy in carefully managed patients. DI often occurs in the first 2-3 yr, becoming less likely over time. Rare metastasis and low CSM rates should reassure physicians that AS is safe in the intermediate to long term.
PATIENT SUMMARY
In this report, we looked at the outcomes of patients with kidney masses who elected to enroll in active surveillance rather than immediate surgery. We found that patients who need surgery are often identified early and those who remain on active surveillance become less likely to need surgery over time. We concluded that active surveillance with or without delayed surgery is a safe practice and that, when properly managed and followed, patients are unlikely to metastasize or die from kidney cancer.
Additional Info
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Active Surveillance for Localized Renal Masses: Tumor Growth, Delayed Intervention Rates, and >5-year Clinical Outcomes
Eur Urol 2018 Aug 01;74(2)157-164, AG McIntosh, BT Ristau, K Ruth, R Jennings, E Ross, MC Smaldone, DYT Chen, R Viterbo, RE Greenberg, A Kutikov, RG UzzoFrom MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
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As reflected in the current American Urological Association guidelines, active surveillance (AS) is being more widely accepted for the management of clinically localized small renal masses. One of the major criticisms of AS is the relatively short follow-up of most retrospective and prospective studies. The study by McIntosh and colleagues reports (median) 5-year outcomes for 457 patients in the Fox Chase AS program and addresses some of the concerns regarding longer-term follow-up in the AS literature. This study reinforces the findings of smaller studies, demonstrating slow rates of tumor growth and exceedingly low rates of kidney cancer metastases and death (1.2%). Importantly, this study reports a cumulative incidence of delayed intervention of 42% at 5 years. This highlights the need for intervention in the management of many patients undergoing AS, but also reinforces that the “therapeutic window” is preserved in a structured AS program.
In this article, McIntosh and colleagues describe their large (457 patients), single-center, 16-year experience with active surveillance for localized renal masses.
In their experience, the average linear growth rate was 1.9 mm/year. Overall, 42% of patients required delayed intervention by 5 years. Delayed intervention did not affect survival. In this group, the 5-year cancer-specific mortality rate was 1.2%. Of the 99 patients on active surveillance without delayed intervention over 5 years, 1 patient metastasized. The 5-year overall survival was 89%. Those who had delayed intervention didn’t have less chance of survival than those who continued on active surveillance.
Obviously, there are no randomized controlled trials of active surveillance vs ablative techniques vs surgical intervention. However, at this very low rate of metastasis and cancer-specific mortality with active surveillance with delayed intervention when needed, it is certainly a very viable management strategy. This strategy is likely underutilized, but this dataset and other datasets showing similar results support active surveillance as a very good strategy for patients with localized renal masses.