Urology Resident at Maimonides Medical Center Maimonides Medical Center
Introduction: There currently remains debate about the need for intervention and surveillance in patients diagnosed with a renal angiomyolipoma (AML). Surveillance has typically been considered in masses =4cm and many still advocate for select intervention in large tumors, women of child-bearing age and patients with limited access to emergency care, however little empirical data supports these practices. The objective of this study is to report our institutional experience of patients with AMLs on active surveillance (AS). Methods: In this retrospective single-institution study at a large academic institution, we identified a cohort of patients with a radiographic diagnosis of AML. Many of these patients were placed on a surveillance protocol at the discretion of their physician. Patient demographics, tumor characteristics and intervention rates were captured. Additionally, we modeled the likelihood of requiring intervention while on surveillance using a Cox proportional hazard model. Results: The study included 163 patients with a radiographic diagnosis of AML from 1997 to 2021. In the cohort, 133 (81.6%) patients were placed on surveillance and the rest underwent upfront intervention. Most patients were women (n=141, 86.0%) and median age was 57. Patients who received upfront intervention (n=30) vs. surveillance (n=133) were more likely to be younger (51 vs. 59 years, p=0.02), have a smaller mass (1.6 vs. 2.1 cm, p=0.02) and be symptomatic on presentation (26.7% vs. 5.3%, p<0.01). Of the patients who received upfront intervention, 6 (20%) had pain and 2 (6.7%) had hematuria as their primary symptom. Median time on surveillance was 6.7 years (95%CI: 5.6-7.7) and patients who received an intervention on surveillance did so at median of 3.2 years (95%CI: 0.9-4.2). Of those on surveillance, 23 (17.3%) ultimately received an intervention, including 11 (47.8%) who had a mass > 4cm and 1 (4.4%) patient had an urgent intervention. Median yearly growth rate of AML was significantly different in those who received an intervention vs. those who did not (7.25% vs. 2.16%, p=0.01). Modeling likelihood of intervention while on surveillance, patients who had hematuria (HR: 9.15, p=0.04), mass size > 4cm (HR: 5.40, p<0.01) and higher growth rate (HR: 1.02, p<0.01) were more likely to receive an intervention. Conclusions: Many patients with an AML can be safely watched on active surveillance, however some patients may ultimately require intervention. Factors associated with increased likelihood of intervention on surveillance include hematuria, large mass size and rapid growth rate. SOURCE OF Funding: None
