Disease progression in older patients with renal tumor assigned to an active surveillance protocol

ABSTRACT BACKGROUND Active surveillance (AS) is a validated option for the treatment of small renal masses (SMRs), especially in older patients. This study investigates the oncologic outcomes and competitive mortality of older patients prospectively assigned to AS. METHODS We conducted a monocentric study on patients ≥75 years treated between 2011 and 2016 for a SMR. Treatment modalities, biopsy data, survivals (overall, specific, cancer progression) and delayed interventions (DI) were analyzed. RESULTS Overall, 106 patients (median age 80.5 years) were included, of which 41 were managed by AS during a follow-up of 3.4 years [0-7.1]. Seven patients (17%) had a primary biopsy with 3 confirmed renal cell carcinomas. Fourteen patients (34.1%) presented with progression (29.2% local; 4.9% metastatic), 8 (19.5%) requiring DI (75% ablative therapy and 25% radical nephrectomy). Overall survival (OS) was 68.3% and cancer specific survival (CSS) was 95.1% during the study period. Competitive mortality was higher (84.6%) than cancer specific mortality (15.4%), p=0.001. CONCLUSION The growth rate of progression including 4.9% metastatic progression underlines the value of AS compared to simple watchful surveillance in the treatment of SMRs in older patients. Of note, the higher competitive mortality confirm that AS should be preferred to active intervention at the beginning of the management. MICROABSTRACT Management of small renal tumors in older patients is challenging. This study shows that older patients managed by active surveillance (AS) will mostly die from other causes than renal cancer, confirming the safety of AS. However, the significant progression rate under AS confirms the need of a careful and vigilant radiological follow-up rather than a simple watchful waiting surveillance.