SUO 2017: Results on Active Surveillance for Von Hippel-Lindau-Related Renal Tumors Using Size-Based Risk Stratification

Washington, DC ( Dr. Mark Ball and colleagues from the NCI presented their long-term results of active surveillance for von Hippel-Lindau (VHL) renal tumors. Renal cell carcinoma (RCC) develops in 25-60% of patients VHL patients. At the NCI, their practice has been to perform active surveillance for renal lesions less than 3-cm and surgical resection for lesions greater than 3-cm, based on early observations of low metastatic potential of small lesions. However, patients who are referred with larger tumors or who are lost to follow-up may not be managed exclusively by this guideline. The objective of this study was to evaluate the oncologic efficacy of the 3-cm size threshold in a large cohort with long-term follow-up.

The authors queried their prospective registry of 764 patients with VHL, identifying a subset of 440 (57.5%) patients with solid renal masses. The diameter of the largest solid tumor, length of follow-up, and development of metastatic disease was assessed. Patients were further subdivided into those who were managed exclusively by the 3-cm threshold and those who were not. The proportion of patients who developed metastatic disease at size thresholds beyond 3-cm was assessed in 1-cm increments. Metastasis-free survival (MFS) was defined as the interval from initial screening to the development of distant metastatic disease. Among these 440 patients, 417 (94.7%) had prior imaging reports available. Median follow-up was 103 months and metastatic disease developed in 42 patients (10.1%). No patients developed metastatic disease when the size of their largest tumor was < 3 cm. The proportion of patients who developed metastases by size of their largest tumor is as follows: <3 cm (0/148, 0%), 3-4 cm (4/139, 2.9%), 4-5 cm (8/62, 12.9%), 5-6 cm (7/27, 25.9%), 6-7 cm (6/12, 50%), 7-8 cm (7/13, 53.8%), 8-9 cm (2/5, 40%), 9-10 cm (3/4, 75%), >10 cm (5/6, 83.3%). MFS for patients managed with the 3-cm threshold was significantly longer compared to those who were not (p=0.007). MFS for patients managed by the 3-cm threshold was 100% compared, while the 5, 10 and 20-year MFS for patients not managed by the 3-cm threshold was 95.7%, 91.1%, and 69.5%, respectively.

Dr. Ball concluded that in a large cohort of patients with VHL, adherence to the 3-cm guideline was associated with superior MFS compared to those who were not. The NCI team advocates the use of this guideline in conjunction with other patient characteristics and surgical judgement.

Presented by: Mark Ball, NCI, Bethesda, MD
Co-Authors: Julie An, James Peterson, Maria Merino, Ramaprasad Srinivasan, Adam Metwalli, W. Marston Linehan

Written by: Zachary Klaassen, MD, Society of Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre @zklaassen_md at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC