Recent American Urological Association (AUA) guidelines commented on the preference for nephron-sparing approaches like partial nephrectomy, ablation, and active surveillance (AS) in the management of small renal masses (SRMs), but these recommendations were based on retrospective studies. A new prospective study by investigators at Johns Hopkins University in Baltimore validated and strengthened these recommendations.
“This study fills a major gap identified by the AUA [guidelines] committee by critically evaluating the statements in a prospective fashion, thereby strengthening the evidence behind the guidelines,” first author Ridwan Alam, MD, MPH, a urology resident, told Renal & Urology News. “While careful and expert patient selection remains crucial in the evaluation and management of SRMs, nephron-sparing approaches, including AS, have increasingly become accepted as the mainstay of treatment.”
Dr Alam and colleagues compared the effectiveness of partial nephrectomy (PN), radical nephrectomy (RN), ablation, and AS for SRMs among 638 patients. SRMs were defined as tumors 4 cm or small in diameter, and the median follow-up time was 3 years, with 158 patients (24.7%) followed for at least 5 years. They analyzed data using the prospectively-maintained Delayed Intervention and Surveillance for Small Renal Masses (DISSRM) database, which is supervised by Phillip Pierorazio, MD, the study’s senior author.
Results showed that cancer-specific survival at 7 years was 98.8% in the PN group and 100% in all of the other groups, as reported in the study published in BJU International. The AS group demonstrated significantly worse overall survival than the other groups, and this was likely due to older age and increased comorbidities at enrollment, according to the investigators.
The estimated glomerular filtration rate (eGFR) was lowest among the RN patients but comparable among the other groups. In multivariable mixed-effects logistic regression, RN was associated with significant 10.9-fold increased odds of clinically significant chronic kidney disease (CKD), defined as an eGFR below 45 mL/min/1.73 m2 (CKD stage 3B or higher), when compared with PN. Ablation and AS did not differ significantly from PN with respect to the risk of clinically significant CKD.
Importantly, this is one of the first studies to examine the effect of management strategy on quality of life scores in this patient population, according to the investigators. Using the Short Form 12 questionnaire, the authors found that quality of life (QOL) was lowest among AS patients due to lower physical health scores. Mental health scores, however, were comparable among the groups, and in fact, improved over time, possibly demonstrating increasing comfort with the chosen management strategy.
Although oncologic control remains the mainstay for treatment in patients with SRMs, secondary outcomes like renal function and patient QOL have gained increased attention within the urologic community, thus prompting the AUA guideline statements, according to Dr Alam.
Alam R, Patel HD, Osumah T, et al. Comparative effectiveness of management options for patients with small renal masses: a prospective cohort study. BJU Int. 2018; published online ahead of print.