Background
Prospective phase II observational study; 52 treatment-naive, asymptomatic metastatic RCC patients (IMDC: FAV 23%, INT 75%, POOR 2%). Radiographic assessment at baseline, q3mo x1yr, q4mo x2yr, then q6mo. Rationale: select patients may safely defer systemic therapy.
Interventions and follow up
Strategy: Active surveillance until disease progression triggered systemic therapy.
Primary endpoint: Time to initiation of systemic therapy.
mFollow up: 38.1 months.
Primary endpoint: Time to initiation of systemic therapy.
mFollow up: 38.1 months.
Results
Median time to treatment initiation: 14.9mo (95%CI 10.6–25.0).
Median time to progression: 9.4mo; among progressors 53% started systemic therapy, 47% continued surveillance.
12mo PFS: 41% (95%CI 27–55%).
18mo PFS: 22% (95%CI 11–34%).
24mo PFS: 17% (95%CI 8–30%).
mOS: 44.5mo.
Median time to progression: 9.4mo; among progressors 53% started systemic therapy, 47% continued surveillance.
12mo PFS: 41% (95%CI 27–55%).
18mo PFS: 22% (95%CI 11–34%).
24mo PFS: 17% (95%CI 8–30%).
mOS: 44.5mo.
Adverse events
Treatment-related toxicity: None during the surveillance period prior to systemic therapy (no drug exposure on study).
Psychosocial: Surveillance was not associated with increased anxiety or depression on patient-reported assessment.
Psychosocial: Surveillance was not associated with increased anxiety or depression on patient-reported assessment.
Conclusions
Active surveillance is a viable initial strategy in select patients with asymptomatic, favorable-risk clear cell m-RCC, deferring therapy with no toxicity and preserved quality of life.
Key Limitations
Small single-arm cohort (n=52) with no randomized comparator, predominantly favorable/intermediate IMDC risk, limiting generalizability to poor-risk disease; OS data immature.
Clinical Context
Supports ASCO/ESMO guidance permitting active surveillance in selected, asymptomatic favorable-risk metastatic clear cell RCC with low metastatic burden before initiating systemic therapy.