A Comparison of Percutaneous Ablation Therapy to Partial Nephrectomy for cT1a Renal Cancers: Results from the Canadian Kidney Cancer Information System

Abstract

Purpose:Percutaneous ablation therapy (AT) and partial nephrectomy (PN) are successful management strategies for T1a renal cancer. Our objective was to compare AT to PN with respect to recurrence-free survival (RFS) and overall survival (OS).Materials and Methods:Patients post PN or AT for cT1aN0M0 renal cancer from 2011 – 2021 were identified from the national Canadian Kidney Cancer Information System (CKCis). Inverse probability of treatment weighting (IPTW) using propensity scores (PS) was used. The primary outcomes, RFS and OS, were compared using Kaplan-Meier log rank test analyses and Cox proportional hazard regression models.Results:275 patients underwent AT and 2,001 underwent PN, with a median follow-up of 2.0 years (IQR 0.6-4.1 years). Covariates were well balanced between the AT and PN cohorts following PS matching. Two-year RFS following IPTW PS analysis for patients undergoing AT and PN was 88.1% and 97.4% (p<0.0001) respectively, while two-year OS was 97.4% and 99.0% (p=0.7), respectively. Five-year RFS following IPTW PS analysis for patients undergoing AT and PN was 86.0% and 95.1% respectively (p=0.003), while five-year OS was 94.2% and 95.1%, respectively (p=0.9). Following IPTW PS analysis, treatment modality (PN versus AT) was a predictor for disease recurrence (HR 0.36; p=0.003) but not for overall survival (HR 0.96; p=0.9).Conclusions:With short follow-up, PN offers better RFS than AT, although no significant difference in overall survival was detected following propensity score adjustments. Both modalities can be offered to appropriately selected patients while we await a prospective randomized data.

Cancer-specific Mortality After Cryoablation vs Heat-based Thermal Ablation in T1a Renal Cell Carcinoma

“…22 Nevertheless, 2 contemporary large-scale analyses with pathologically confirmed T1a RCC reported higher recurrence-free survival and lower CSM after partial nephrectomy vs local tumor destruction. 23,24 To the best of our knowledge, our findings regarding higher CSM after hTA vs CA in patients with tumor size 3.1-4 cm can only be partially compared with Palumbo et al (SEER 2004(SEER -2015 CA vs 217 hTA), who also reported higher CSM rates (7.6% vs 3.9%, P [ .02) after hTA vs CA. 5 The limitations in comparison between the 2 studies are based on several considerations.…”

“…22 Nevertheless, 2 contemporary large-scale analyses with pathologically confirmed T1a RCC reported higher recurrence-free survival and lower CSM after partial nephrectomy vs local tumor destruction. 23,24…”

“…Within the SEER database (2004-2018), we identified patients >18 years old with clinical T1a stage and histologically confirmed RCC (International Classification of Disease for Oncology site code C64.9) treated with CA (surgery codes 13,23) or hTA (surgery code 15). Histological subtypes according to the Heidelberg classification included clear cell, papillary, chromophobe and nonotherwise classified RCC (codes: 8310, 8260, 8317, 8312).…”

A Comparison of Percutaneous Ablation Therapy to Partial Nephrectomy for cT1a Renal Cancers: Results From the Canadian Kidney Cancer Information System. Letter.

“…To the Editor: We read with great interest the publication by Millan et al comparing percutaneous ablation therapy to partial nephrectomy as a treatment for cT1a renal cancers. 1 This national multicenter prospective cohort included 2,276 patients from the Canadian Kidney Cancer Information System from 2011 to 2021, and analyzed the recurrence-free survival and overall survival (OS) with propensity score techniques to adjust the differences between the groups. This publication provides more convincing evidence regarding the outcome of the treatment for cT1a renal cancers.…”

A Comparison of Percutaneous Ablation Therapy to Partial Nephrectomy for cT1a Renal Cancers: Results From the Canadian Kidney Cancer Information System. Reply.

“…Patients requiring systemic therapy (metastases) will likely have significantly worse prognoses than those with cT1a RCC; however, our data set is underpowered to comment on outcomes of patients subsequently requiring extirpative surgery after AT (13 in the AT cohort and 18 in the PN cohort). 1,7…”