Percutaneous tumor ablation versus partial nephrectomy for small renal mass: the impact of histologic variant and tumor size

Impact of thermal ablation/cryoablation treatment on prognosis among patients with kidney cancer: a SEER database-based cohort study

BACKGROUND

Radiofrequency ablation (RFA) and cryoablation are minimally invasive treatments for renal cell carcinoma (RCC). However, their comparative efficacy remains under evaluation. This study aims to compare overall survival (OS) and cancer-specific survival (CSS) outcomes using data from the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

This retrospective cohort study included patients diagnosed with T1a-bN0M0 RCC from the SEER database (2004-2018). Propensity score matching was used to control for confounders, including age, sex, and tumor characteristics. Cox proportional hazards regression was applied to assess OS and CSS.

RESULTS

A total of 3768 patients were analyzed, including 3499 with T1a and 269 with T1b tumors. Patients aged > 65 years and those with T1b tumors exhibited significantly lower OS and CSS (P < 0.001). RFA was associated with reduced OS compared to cryoablation (P = 0.012). Multivariate analyses further confirmed that elderly patients, particularly those with T1b tumors, experienced worse OS (P = 0.0104) and CSS (P = 0.008) following RFA compared to cryoablation. Subgroup and competing risk analyses consistently demonstrated lower cumulative mortality in the cryoablation group.

CONCLUSIONS

Cryoablation offers superior survival outcomes compared to RFA for T1a and T1b RCC, particularly in elderly patients. These findings support cryoablation as the preferred minimally invasive treatment for early-stage kidney cancer.

Percutaneous ablation versus robotic‑assisted partial nephrectomy for cT1 renal cell carcinoma: an evidence-based analysis of comparative outcomes

This investigation sought to conduct a comprehensive meta-analysis to assess the comparative effectiveness and safety of percutaneous ablation (PCA) versus robotic-assisted partial nephrectomy (RAPN) among individuals diagnosed with cT1 renal tumors. This study rigorously followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to conduct a systematic review and meta-analysis. A systematic search was carried out in the PubMed, Embase, Web of Science, and Cochrane Library databases, focusing on studies published in English through February 2024. We focused on evaluating primary outcomes, specifically perioperative outcomes, functional outcomes, and oncological outcomes. In this analysis, data from 1534 patients across 13 studies were evaluated. PCA was found to have advantageous outcomes in comparison to RAPN regarding hospital stay durations, with a Weighted Mean Difference (WMD) of - 2.03 days (95% Confidence Interval [CI]: -3.78 to - 0.27; p = 0.02), operative times (WMD: -106.75 min; 95% CI: - 170.78 to - 42.72; p = 0.001), and overall complication rates (Odds Ratio [OR]: 0.61; 95% CI: 0.42 to 0.89; p = 0.01). Conversely, PCA showed a higher incidence of local recurrence compared to RAPN, with an OR of 3.20 (95% CI: 1.91 to 5.35; p < 0.00001). Moreover, there were no statistically significant differences between the two treatments in terms of major complications, declines in estimated glomerular filtration rates (eGFR), variations in creatinine levels, overall survival rates, and recurrence-free survival. While PCA exhibits higher local recurrence rates than RAPN, it also presents significant advantages, such as shorter hospital stays, decreased operative durations, and lower complication rates. This juxtaposition underscores the urgent need for further, more rigorous research to substantiate these findings.

Perioperative and Oncological Outcomes of Percutaneous Radiofrequency Ablation versus Partial Nephrectomy for cT1a Renal Cancers: A Retrospective Study on Groups with Similar Clinical Characteristics

Over the recent years, progress in imaging techniques has led to an increased detection of kidney tumours, including small renal masses. While surgery is still the standard of care, there is a growing interest in minimally invasive methods. Ultrasound (US)-guided percutaneous ablation is particularly attractive because it is a safe and relatively simple procedure. In this study, we investigated the results of US-guided percutaneous radiofrequency ablation (RFA) and partial nephrectomy (PN) in the treatment of cT1a renal cancers. Between August 2016 and February 2022, 271 patients with renal tumours underwent percutaneous RFA as initial treatment in our institution. In the same period, 396 patients with renal tumours underwent surgical tumour excision. For the purpose of this study, only patients with confirmed renal cancer with matched age and tumour characteristics (size, location) were selected for both groups. Thus, a group of 44 PN patients and 41 RFA patients were formed with the same qualification criteria for both groups. Parameters such as procedure length, blood loss, hospital stay, analgesics used, and pre- and post-procedural serum creatinine were compared between these groups. Patients followed up with contrast-enhanced CT. There was no significant difference in age, tumour size, tumour location, and creatinine levels between these groups. All procedures were generally well tolerated. During a median follow-up of 28 months, two cases of recurrence/residual disease were found in each group. The overall survival was 100% in both groups, and all patients were disease-free at the end of observation. Percutaneous RFA was associated with a significantly shorter procedure length and hospital stay, lower blood loss, and lower analgesics used than PN. In the selected group of renal cancer patients, US-guided percutaneous RFA was associated with a shorter hospital stay, less analgesics used, and a shorter procedure length than PN, without differences in the oncological results or kidney function.

Clinical and Oncological Outcomes Following Percutaneous Cryoablation vs. Partial Nephrectomy for Clinical T1 Renal Tumours: Systematic Review and Meta-Analysis

Percutaneous cryoablation (PCA) can be an alternative to partial nephrectomy (PN) in selected patients with stage T1 renal tumours. Existing meta-analyses regarding ablative techniques compared both laparoscopic and PCA with PN. That is why we decided to perform a meta-analysis that focused solely on PCA. The aim of this study was to compare the complications and functional and oncological outcomes between PCA and PN. A systematic literature search was performed in January 2024. Data for dichotomous and continuous variables were expressed as pooled odds ratios (ORs) and mean differences (MDs), both with 95% confidence intervals (CIs). Effect measures for the local recurrence-free survival (LRFS), metastasis-free survival (MFS), cancer-specific survival (CSS) and overall survival (OS) were expressed as pooled hazard ratios with 95% CIs. Among 6487 patients included in the 14 selected papers, 1554 (23.9%) and 4924 (76.1%) underwent PCA and PN, respectively. Compared with the PN group, patients undergoing PCA had significantly lower overall and major postoperative complication rates. There was no difference in renal function between PCA and PN groups. When analysing collective data for cT1 renal carcinoma, PCA was associated with worse LRFS compared with PN. However, subgroup analysis revealed that in the case of PCA, LRFS was not decreased in patients with cT1a tumours. Moreover, patients undergoing robotic-assisted PN had improved LRFS compared with those undergoing PCA. No significant differences were observed between PCA and PN in terms of MFS and CSS. Finally, PCA was associated with worse OS than PN in both collective and subgroup analyses. In conclusion, PCA is associated with favourable postoperative complication rates relative to PN. Regarding LRFS, PCA is not worse than PN in cT1a tumours but has a substantially relevant disadvantage in cT1b tumours. Also, RAPN might be the only surgical modality that provides better LRFS than PCA. In cT1 tumours, PCA shows MFS and CSS comparable to PN. Lastly, PCA is associated with a shorter OS than PN.

Meta analysis of clinical prognosis of radiofrequency ablation versus partial nephrectomy in the treatment of early renal cell carcinoma

Objective

To systematically review the differences between radiofrequency ablation and partial nephrectomy in patients with early-stage renal cell carcinoma, and to provide evidence-based medical evidence for the choice of surgery for patients with early-stage renal cell carcinoma.

Methods

According to the search strategy recommended by the Cochrane Collaboration, Chinese databases such as CNKI, VIP Chinese Science and Technology Periodicals Database (VIP), and Wanfang Full-text Database were searched with Chinese search terms. And PubMed and MEDLINE as databases for English literature retrieval. Retrieve the relevant literature on renal cell carcinoma surgical methods published before May 2022, and further screen radiofrequency ablation and partial nephrectomy in patients with renal cell carcinoma The relevant literature on the application is analyzed. RevMan5.3 software was used for heterogeneity test and combined statistical analysis, sensitivity analysis, and subgroup analysis. Analysis, and draw forest plot, using Stata software Begger quantitative assessment of publication bias.

Results

A total of 11 articles were involved, including 2958 patients. According to the Jadad scale, 2 articles were of low quality, and the remaining 9 articles were of high quality. Results of this study demonstrates the advantages of radiofrequency ablation in early-stage renal cell carcinoma. The results of this meta-analysis showed that compared with partial nephrectomy, there was significant difference in the 5-year overall survival rate between radiofrequency ablation and partial nephrectomy and there was a statistically significant difference between the two surgical methods in the 5-year relapse free survival rate of early renal cell carcinoma.

Conclusion

1. Compared with partial nephrectomy, the 5-year relapse-free survival rate, the 5-year cancer specific survival rate and the overall 5-year survival rate were higher in the radiofrequency ablation group. 2. Compared with partial nephrectomy, there was no significant difference in the postoperative local tumor recurrence rate of radiofrequency ablation. 3. Compared with partial resection, radiofrequency ablation is more beneficial to patients with renal cell carcinoma.

Effectiveness of Radiomic ZOT Features in the Automated Discrimination of Oncocytoma from Clear Cell Renal Cancer

Background: Benign renal tumors, such as renal oncocytoma (RO), can be erroneously diagnosed as malignant renal cell carcinomas (RCC), because of their similar imaging features. Computer-aided systems leveraging radiomic features can be used to better discriminate benign renal tumors from the malignant ones. The purpose of this work was to build a machine learning model to distinguish RO from clear cell RCC (ccRCC). Method: We collected CT images of 77 patients, with 30 cases of RO (39%) and 47 cases of ccRCC (61%). Radiomic features were extracted both from the tumor volumes identified by the clinicians and from the tumor’s zone of transition (ZOT). We used a genetic algorithm to perform feature selection, identifying the most descriptive set of features for the tumor classification. We built a decision tree classifier to distinguish between ROs and ccRCCs. We proposed two versions of the pipeline: in the first one, the feature selection was performed before the splitting of the data, while in the second one, the feature selection was performed after, i.e., on the training data only. We evaluated the efficiency of the two pipelines in cancer classification. Results: The ZOT features were found to be the most predictive by the genetic algorithm. The pipeline with the feature selection performed on the whole dataset obtained an average ROC AUC score of 0.87 ± 0.09. The second pipeline, in which the feature selection was performed on the training data only, obtained an average ROC AUC score of 0.62 ± 0.17. Conclusions: The obtained results confirm the efficiency of ZOT radiomic features in capturing the renal tumor characteristics. We showed that there is a significant difference in the performances of the two proposed pipelines, highlighting how some already published radiomic analyses could be too optimistic about the real generalization capabilities of the models.

Microwave versus cryoablation and radiofrequency ablation for small renal mass: a multicenter comparative analysis

BACKGROUND

Ablative techniques emerged as effective alternative to nephron-sparing surgery for treatment of small renal masses. Radiofrequency ablation (RFA) and cryoablation (CRYO) are the two guidelines-recommended techniques. Microwave ablation (MWA) represents a newer technology, less described. The aim of the study was to compare outcomes of MWA to those of CRYO and RFA.

METHODS

Retrospective investigation of patients who underwent MWA, CRYO, or RFA from seven high-volume US and European centers was performed. The first group included patients who underwent CRYO or RFA; the second MWA. We collected baseline characteristics, clinical, intraoperative, and postoperative data. Oncological data included technical success, local recurrence, and progression to metastasis. Multivariate analysis was performed to find predictors for postoperative complications. A composite outcome of "trifecta" was used to assess surgical, functional, and oncological outcomes.

RESULTS

739 patients underwent CRYO or RFA and 50 MWA. CRYO/RFA group had significantly longer operative time (P<0.001), but no difference in LOS, postprocedural Hb mean, intraprocedural complications (P=0.180), overall postprocedural complication rates (P=0.126), and in the 30-day re-admission rate (P=0.853) were detected. No predictive parameter of postprocedural complications was found. Concerning functional outcome, no differences were detected in terms of eGFR at 1 year (P=0.182), ΔeGFR at 1 year (P=0.825) and eGFR at latest follow-up (P=0.070). "Technical success" was achieved in 98.6% of the cases (MWA=100%, CRYO/RFA=98.5%; P=0.775), and there was no significant difference in terms of 2-year recurrence rate (P=0.114) and metastatic progression (P=0.203). Trifecta was achieved in 73.0% of CRYO/RFA vs. 69.6% of MWA cases (P=0.719).

CONCLUSIONS

MWA is a safe and effective treatment option for small renal masses. Compared with CRYO/RFA, it seems to offer low complication rates, shorter operation time, and equivalent surgical and functional outcomes.

Long-term comparative outcomes of partial nephrectomy and cryoablation in patients with solitary kidneys: a single-center analysis

BACKGROUND

Patients with solitary kidneys are amenable to postoperative acute kidney injury (AKI) after PN. We compared the functional and oncological outcomes of cryoablation (CA) and PN in patients with a solitary kidney and a cT1a renal mass.

METHODS

From a single-institution series, we analyzed 74 patients (31 PN, 43 CA) with a solitary kidney who underwent treatment for a cT1a renal mass. The functional outcomes were AKI and estimated glomerular filtration rate (eGFR) preservation. Oncological outcomes were recurrence and death. Linear mixed-effects and logistic regression models were used for functional outcomes analysis, whereas oncological outcomes were analyzed using the Kaplan-Meier method.

RESULTS

Median follow-up was 63.9 months. PN group had lower median age (59 years vs. 68, P<0.001) and larger median tumor size (2.80 cm vs. 2.0, p =0.003). AKI was more common in the PN group on postoperative day 1 (58% vs. 2.8%, P<0.001). However, only one patient in the PN group required temporary dialysis in the perioperative period. eGFR preservation was similar at postoperative 3 months (89% vs. 90%, P=0.083), or 12 months (85% vs. 94%, P=0.2) follow-up. CA group had higher recurrence rate (29% vs. 3.2%, P=0.005), and worse recurrence-free survival (P=0.027). Overall survival (OS) was comparable (P=0.31).

CONCLUSIONS

In a solitary kidney setting, CA is associated with a lower risk of AKI at postoperative day 1 compared to PN. Functional outcome is comparable upon longer follow-up. The local recurrence rates are significantly higher in the CA group with no significant difference in OS.

The Clinical and Molecular Features in the VHL Renal Cancers; Close or Distant Relatives with Sporadic Clear Cell Renal Cell Carcinoma?

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited cancer syndrome caused by germline mutations in the VHL tumor suppressor gene, characterized by the susceptibility to a wide array of benign and malign neoplasms, including clear-cell renal cell carcinoma. Moreover, VHL somatic inactivation is a crucial molecular event also in sporadic ccRCCs tumorigenesis. While systemic biomarkers in the VHL syndrome do not currently play a role in clinical practice, a new promising class of predictive biomarkers, microRNAs, has been increasingly studied. Lots of pan-genomic studies have deeply investigated the possible biological role of microRNAs in the development and progression of sporadic ccRCC; however, few studies have investigated the miRNA profile in VHL patients. Our review summarize all the new insights related to clinical and molecular features in VHL renal cancers, with a particular focus on the overlap with sporadic ccRCC.

Feasibility of salvage robotic partial nephrectomy after ablative treatment failure (UroCCR-62 study)

BACKGROUND

Ablative therapies (AT) are increasingly being offered to patients with kidney tumors. In cases of failure or local relapse, salvage surgery may be required. Such procedures often require an open approach, are difficult and have received little attention in the literature. We aim to evaluate the feasibility of salvage robot-assisted partial nephrectomy (sRAPN) after AT.

METHODS

We conducted a monocentric retrospective study of all patients who benefited from sRAPN. Clinical data were collected prospectively after written consent in the French UroCCR database.

RESULTS

Between 2013 and 2020, 724 RAPN were performed in our center; of these, 11 patients underwent salvage RAPN and four (36.4%) had an imperative indication for a solitary kidney. The median patient age was 54 (49-72) years, median preoperative glomerular filtration rate (GFR) was 65.5 (42.9-88.4) mL/min/1.73 m², and median tumor diameter was 34 (16-38) mm. Extensive perinephric fibrosis was present in 90.9% of cases. Postoperative complications occurred in 36.4% of patients, including major complications in 18.2%. The median GFR at three months (56.8 [45.9-63.9] mL/min/1.73 m²) and at last follow-up (52.1 [45.85-68.3] mL/min/1.73 m²) were not significantly different to the preoperative GFR (P=0.51 and P=0.65, respectively). During follow-up (median 12 months), three patients (all with Von Hippel Lindau disease) developed a recurrence, but none were on the sRAPN site.

CONCLUSIONS

Our series of sRAPN following AT failure confirms that such surgery is feasible with good functional and oncological results. However, these surgeries remain difficult, are associated with significant complication rate and should be performed in expert centers.

Impact of frailty on perioperative and oncologic outcomes in patients undergoing surgery or ablation for renal cancer: a systematic review

BACKGROUND

Frailty has been recognized as a major risk factor for adverse perioperative and oncological outcomes in patients with genitourinary malignancies. Yet, the evidence supporting such an association in patients with renal cell carcinoma (RCC) is still sparse. Herein we provide an updated comprehensive overview of the impact of frailty on perioperative and oncologic outcomes in patients undergoing surgery or ablation for RCC.

EVIDENCE ACQUISITION

A systematic review of the English-language literature was conducted using the MEDLINE (Via PubMed), Web of Science and the Cochrane Library databases according to the principles highlighted by the EAU Guidelines Office and the PRISMA statement recommendations. The review protocol was registered on PROSPERO (CRD42021242516). The overall quality of evidence was assessed according to GRADE recommendations.

EVIDENCE SYNTHESIS

Overall, 18 studies were included in the qualitative analysis. Most of these were retrospective single-centre series including patients undergoing surgery for non-metastatic RCC. The overall quality of evidence was low. A variety of measures were used for frailty assessment, including the Canadian Study of Health and Aging Frailty Index, the five-item frailty index, the Modified Rockwood's Clinical Frailty Scale Score, the Hopkins Frailty score, the Groningen Frailty Index, and the Geriatric nutritional risk index. Sarcopenia was defined based on the Lumbar skeletal muscle mass at cross-sectional imaging, the skeletal muscle index, the total psoas area, or the psoas muscle index. Overall, available studies point to frailty and sarcopenia as potential independent risk factors for worse perioperative and oncological outcomes after surgery or ablation for different RCC stages. Increased patient's frailty was indeed associated with higher risk of perioperative complications, healthcare resources utilization, readmission rates and longer hospitalization periods, as well as potentially lower cancer specific or overall survival.

CONCLUSIONS

Frailty has been consistently associated with worse outcomes after surgery for RCC, reinforcing the value of preoperative frailty assessment in carefully selected patients. Given the low quality of the available evidence (especially in the setting of tumour ablation), prospective studies are needed to standardize frailty assessments and to identify patients who are expected to benefit most from preoperative geriatric evaluation, aiming to optimize decision-making and postoperative outcomes in patients with RCC.