Thermal ablation vs. active surveillance for renal masses: a systematic review and network meta-analysis

Partial nephrectomy, thermal ablation and active surveillance are acceptable options for T1 stage renal tumor management. Currently, we lack sufficient information to make an accurate comparison of thermal ablation with active surveillance. The study objectives were to compare thermal ablation with active surveillance indirectly using partial nephrectomy as a reference.

We performed a systematic literature search using two databases (Scopus and Medline). The detailed search strategy is available at Prospero, CRD42021290055. The primary outcome was cancer-specific survival. Secondary outcomes included overall survival and metastasis-free survival.

The final sample comprised 33 articles. They included the ones that compare: partial nephrectomy to ablation (29 studies), partial nephrectomy to active surveillance (2 studies), and partial nephrectomy vs. active surveillance vs. ablation (2 articles). We assessed 3-year and 5-year cancer-specific survival, and 3-, 5- and 7-year overall survival. The surface under the cumulative ranking curve (SUCRA) treatment benefit ranking was: cancer-specific survival - 48.6% for thermal ablation and 1.6% for active surveillance (5-year follow-up); overall survival - 52% for thermal ablation and 0.6% for active surveillance (7-year follow-up). The results demonstrated a significantly higher 3-year cancer-specific survival (RR 1.55, P=0.02) and 3- and 7-year follow-up overall survival (RR 1.85, P=0.03) in thermal ablation compared to active surveillance. At 5-year follow-up, cancer-specific survival and overall survival were in favor of thermal ablation while no statistically significant difference was reported.

Thermal ablation offers a significantly higher cancer-specific survival and overall survival at mid-term follow-up in the management of T1 renal tumors compared to active surveillance. However, it is necessary to conduct further prospective randomized studies to validate the data.