Image-guided tumor ablation showed no evidence of a difference in progression risk compared with surgical resection in patients with T1a renal cell carcinoma and was associated with shorter hospital stays and fewer postoperative hospital contacts in a nationwide Danish registry study.
Investigators analyzed data from 1,862 Danish adult patients diagnosed with T1a renal cell carcinoma between 2013 and 2021 who underwent tumor ablation, surgical resection, or nephrectomy. The primary outcome was progression, defined as either distant metastasis or local recurrence. Secondary outcomes included hospital length of stay and hospital contacts within 30 days posttreatment.
The patients in the cohort had a median age of 64 years and 70% of them identified as male. Treatment distribution included 540 patients undergoing ablation, 1,002 undergoing resection, and 320 undergoing nephrectomy.
After adjustment for age, sex, comorbidity, tumor morphology, tumor size, and tumor grade, the investigators found no evidence of a difference in progression risk between ablation and resection. Ablation was associated with a slightly higher risk of tumor progression compared with resection; however, the investigators noted that because of statistical uncertainty, this figure should be interpreted with caution.
Overall progression events were uncommon. Local recurrence occurred in 2% of patients undergoing ablation compared with 1% of those undergoing resection and 0% of those undergoing nephrectomy. Most recurrences following ablation were treated with additional ablation or surgical procedures.
The rates of distant metastasis were similar for ablation and resection, occurring in approximately 2% of the patients in each group, whereas metastasis occurred in 4% of patients undergoing nephrectomy.
Ablation was associated with shorter hospitalizations. For instance, the median hospital stay was 0 days for ablation compared with 2 days for both resection and nephrectomy. Ablation also resulted in fewer hospital contacts during the first 30 days following treatment, an indirect measure of postoperative complications.
Baseline characteristics differed between the treatment groups. Patients undergoing ablation were older and had more comorbidities compared with those undergoing resection. The median age was 67 years in the ablation group vs 62 years in the resection group, and 24% of the patients undergoing ablation had Charlson Comorbidity Index scores greater than 2 compared with 17% of those undergoing resection.
The investigators also identified tumor characteristics associated with progression risk. Tumors measuring 2 to 4 cm were associated with approximately three times the likelihood of progression compared with tumors measuring 0 to 2 cm, and Fuhrman grade 4 tumors were associated with nearly 14 times the likelihood of progression compared with grade 1 tumors.
Regional variation in treatment patterns was observed across Denmark. Ablation was used in 46.7% of cases in the southern region and 43% in the central region, compared with 10.6% in the capital region and 4.5% in the Zealand region. Despite these differences, progression rates didn't statistically differ across regions.
The investigators noted several limitations. The retrospective registry design introduced potential selection bias and unmeasured confounding. Tumor size data were missing for many patients undergoing ablation, and specific complication types weren't systematically recorded in the registries.
“Despite the higher local recurrence rate in the ablation group, [the] overall progression rate remained low across all treatment modalities, supporting that both ablation and resection are effective options for T1a [renal cell carcinoma],” wrote lead study author Johanne Ahrenfeldt, PhD, MScEng, of the Department of Molecular Medicine at Aarhus University Hospital in Denmark, and colleagues.
Full disclosures can be found in the study.
Source: Radiology