Long-term outcomes of CT-guided percutaneous cryoablation of T1a and T1b renal cell carcinoma

Primary tumor ablation in metastatic renal cell carcinoma

BACKGROUND

The role of primary tumor ablation (pTA) in metastatic renal cell carcinoma (mRCC) is unknown. We compared pTA-treated mRCC patients to patients who underwent no local treatment (NLT), as well as patients who underwent cytoreductive nephrectomy (CN).

METHODS

Within the Surveillance, Epidemiology, and End Results database (SEER, 2004-2020), we identified mRCC patients who underwent either pTA, NLT or CN. Endpoints consisted of overall survival (OM) and other-cause mortality (OCM). Propensity score 1:1 matching (PSM), multivariable cox regression models (OM), as well as, multivariable competing risk regressions (CRR) models (OCM) were used.

RESULTS

We identified 27,087 mRCC patients, of whom 82 (0.3%) underwent pTA, 17,266 (64%) NLT and 9,739 (36%) CN. In comparisons of pTA vs. NLT mRCC patients addressing OM, after 1:1 PSM, median survival was 19 months for pTA vs. 4 months for NLT patients (multivariable HR 0.3, 95% CI 0.22-0.47, P < 0.001). No statistically significant OCM differences were recorded in multivariable CRR (HR 1.13 95%, CI 0.52-2.44, P = 0.8). In comparisons of pTA vs. CN, after 1:1 PSM, no statistically significant differences in OM (HR 1.22, 95% CI 0.81-1.83, P = 0.32), as well as OCM (HR 1.4, 95% CI 0.56-3.48, P = 0.5) were recorded.

CONCLUSION

In mRCC patients, pTA is associated with significantly lower mortality compared to NLT. Interestingly, OM rates between pTA and CN mRCC patients do not exhibit statistically significant differences. This preliminary report may suggest that pTA may provide a comparable survival benefit to CN in highly selected mRCC patients.

Adjunctive techniques for renal cell carcinoma ablation: an update

Percutaneous ablation therapies currently play a major role in the management of T1a and T1b renal cell carcinoma (RCC). These therapies include thermal ablative technologies like radiofrequency (RFA), microwave (MWA) and cryoablation, as well as emerging techniques like irreversible electroporation (IRE) and high-intensity focused ultrasound (HIFU). These therapies are safe and effective, with their low complication rate being mostly related to the minimal invasive character. To increase the outcomes and safety of ablation, particularly in the setting of larger tumors, adjunctive techniques may be useful. These include pre-ablation trans-arterial embolization (TAE) and thermal protective measures. TAE is an endovascular procedure consisting of vascular access, catheterization and embolization of renal vessels supplying target tumor, with different embolic materials available. The purpose of combining TAE and ablation is manifold: to reduce vascularization and improve local tumor control, to reduce complications (including the risk of bleeding), to enhance tumor visibility and localization, as well as to improve cost-efficiency of the procedure. Thermal protective strategies are important to minimize damage to adjacent structures, requiring accurate knowledge of anatomy and proper patient positioning. In RCC ablation, strategies are needed to protect the adjacent nerves, as well as the visceral and muscular organs. These include placement of thermocouples, hydro- or gas-dissection, balloon interposition, pyeloperfusion and skin protection maneuvers. The purpose of this review article is to discuss the updated role of ablation in RCC management, to describe the status of adjunctive techniques for RCC ablation; in addition it will offer a review of the literature on adjunctive techniques for RCC ablation. and report upon future directions.

Comparative efficacy and safety of ablative therapies in the management of primary localised renal cell carcinoma: a systematic review and meta-analysis

BACKGROUND

Non-invasive and minimally invasive ablative treatments, including stereotactic body radiotherapy (SBRT), radiofrequency ablation, microwave ablation, and cryoablation, have emerged as key treatment options for managing renal cell carcinoma, especially for patients who are unsuitable for surgery. We aimed to compare the clinical efficacy and safety of these emerging treatment methods in patients with localised renal cell carcinoma.

METHODS

In this systematic review and meta-analysis, we searched PubMed (MEDLINE), Embase, and the Cochrane Library for publications between Jan 1, 2000, and March 1, 2024. Eligible articles were observational studies and randomised controlled trials including at least five adult patients (age ≥18 years) with primary and localised renal cell carcinoma treated with SBRT, radiofrequency ablation, microwave ablation, or cryoablation and that reported on local control outcomes. Two reviewers independently screened titles and abstracts and then full texts of eligible studies were independently evaluated by the same reviewers, with disagreements resolved via discussion or consultation with a third reviewer. Summary estimates were extracted from published reports manually using a standardised data extraction form. The primary endpoint was local control rate at 1 year, 2 years, and 5 years after start of treatment. A meta-analysis was conducted using a DerSimonian and Laird model to summarise local control rates. Publication bias was evaluated using funnel plots and Egger's test. We also recorded the frequency and severity of adverse events after treatment on the basis of the Common Terminology Criteria for Adverse Events (version 5.0) and Clavien-Dindo complication index. The study protocol was prospectively registered with PROSPERO, CRD42024511840.

FINDINGS

We identified 6668 records, of which 330 were assessed via full-text review, and 133 were included in our systematic review and meta-analysis. The eligible studies included data for 8910 patients (mean age 67·9 years [SD 7·3], 2518 [31·4%] of 8018 patients with available data were female and 5500 [68·6%] were male). Local control rates for SBRT were 99% (95% CI 97-100; I2=6%) at 1 year, 97% (95-99; I2=0%) at 2 years, and 95% (89-98; I2=42%) at 5 years; for radiofrequency ablation were 96% (94-98; I2=73%) at 1 year, 95% (92-98; I2=77%) at 2 years, and 92% (88-96; I2=78%) at 5 years; for microwave ablation were 97% (95-99; I2=74%) at 1 year, 95% (92-98; I2=77%) at 2 years, and 86% (75-94; I2=66%) at 5 years; and for cryoablation were 95% (93-96; I2=61%) at 1 year, 94% (91-96; I2=69%) at 2 years, and 90% (87-93; I2=74%) at 5 years. The proportion of patients who reported grade 3-4 adverse events was 3% (121 of 3726) after cryoablation, 2% (39 of 2503) after radiofrequency ablation, 1% (22 of 2069) after microwave ablation, and 2% (11 of 612) after SBRT. Risk of bias was moderate in most studies (70 [53%] of 133) and no publication bias was observed.

INTERPRETATION

All investigated ablative methods continue to represent effective treatment choices in renal cell carcinoma, and these findings support multi-disciplinary discussions of these treatment methods, along with surgery and surveillance, to individualise treatment decisions in these patients. Future research should aim to conduct randomised controlled trials across larger patient populations to further elucidate the long-term oncological and survival outcomes associated with these treatments.

FUNDING

None.

Cryoprobe Placement Using Electromagnetic Navigation System (IMACTIS® CT-Navigation™) for Cryoablation Treatment of Upper Kidney Pole Lesions and Adrenal Metastases: Experience from a Single-Center, 4-Year Study

The aim of this study is to evaluate the safety and efficacy of the use of the IMACTIS® CT-Navigation™-electromagnetic navigation system (EMNS) in cryoablation CT-guided procedures under local anesthesia for the treatment of upper kidney pole and adrenal lesions. We conducted a retrospective analysis of patients with upper kidney pole lesions and adrenal metastases who underwent cryoablation using the IMACTIS-CT®-EMNS between January 2019 and April 2023. The EMNS was used to guide the placement of the cryoprobes with CT guidance under local anesthesia. The primary outcome was technical success, defined as the successful placement of the cryoprobes in the target lesion. A total of 31 patients were studied, of whom, 25 patients were treated with cryoablation for upper pole kidney masses, and 6 patients underwent the cryoablation of adrenal metastases during the study period. The mean age was 60 years (range, 36-82 years), and 21 patients were male. All the upper kidney pole lesions were renal cell carcinomas, and regarding adrenal metastases, the primary cancer sites were the lungs (n = 3), breast (n = 2), and the colon (n = 1). The median size of the lesions was 3,8 cm (range, 1.5-5 cm). All procedures were technically successful, with the cryoprobes accurately placed in the target lesions under CT guidance using the EMNS, avoiding the penetration of any other organs using an oblique trajectory. No major complications were reported, and local tumor control was achieved in all cases. Our initial experience using the EMNS for cryoprobe placement during CT-guided interventional procedures under local anesthesia for the cryoablation treatment of upper pole kidney lesions and adrenal metastases showed that it is safe and effective.

Impact of Percutaneous Cryoablation on Renal Function in Patients with Stage I Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

PURPOSE

To assess the effect of cryoablation on renal function (measured by estimated glomerular filtration rate [eGFR] or serum creatinine) for treating Stage I renal cancer.

MATERIALS AND METHODS

The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were systematically searched from inception to May 1, 2023. Cohort studies that included data on change of eGFR and serum creatinine increase were included. Meta-analysis was performed by measuring the weighted mean difference and by fitting random-effect models.

RESULTS

Overall, 38 studies were included, comprising 3,202 participants. Percutaneous cryoablation was associated with an absolute eGFR reduction of -3.06 mL/min/1.73 m2 (95% CI, -4.12 to -2.01; P < .001) and serum creatinine increase of 0.05 mg/dL (95% CI, -0.02 to 0.11; P > .05). The weighted absolute mean difference of percutaneous cryoablation for treating Stage T1b renal cell carcinoma was estimated at -5.19 mL/min/1.73 m2 (95% CI, -11.1 to 0.72; P > .05). Lastly, when analyzing studies that included cohorts with solitary kidneys, the pooled weighted mean difference was estimated as -3.27 mL/min/1.73 m2 (95% CI, -6.79 to 0.25; P > .05).

CONCLUSIONS

Percutaneous cryoablation for Stage 1 renal cell carcinoma has minimal significant impact on renal function (measured by eGFR or serum creatinine). The same outcome was observed in patients with larger tumors (T1b) and those with solitary kidneys.

Combined therapy for managing a clear cell renal cell carcinoma in a horseshoe kidney: A case report

The upper urinary tract is the most common human organ system affected by congenital anomalies. A Horseshoe kidney is a fusion anomaly, it can be described as a fusion across the midline of 2 distinct functioning kidneys. The incidence of renal tumors in a Horseshoe kidney is higher than in the normal population. We present a 60-year-old male patient with a history of Horseshoe kidney and a diagnosis of clear cell renal cell carcinoma who underwent a combined therapeutic approach, guided by interventional radiology. This approach involved selective transarterial embolization and microwave ablation. Three months after surgery and with abdominal MRI follow-up, there is evidence of a non-viable tumor, indicating a favorable response to the intervention.

Long-term follow-up of CT-guided percutaneous radiofrequency ablation of T1 renal cell carcinoma

Background

Radiofrequency ablation (RFA) has an established role in effective treatment of renal cell carcinomas (RCCs), as most of RCCs are diagnosed incidentally in early stages. Long-term follow-up is however important to consolidate the technique. Most of the literature contains series of short-term follow-ups of periods shorter than 2 years. This study in hand demonstrates the results of longer-term follow-up than the previously published series.

Results

Data analysis of 31 patient records involved in this study demonstrated the high clinical efficacy of RFA for long term, 12-year follow-up, by following the absence of tumor recurrences, as shown on regular interval contrast enhanced computed tomography (CT) and or magnetic resonance imaging (MRI).

Conclusions

RFA continues to prove its competent role in treating RCCs on longer-term follow-ups; the smaller the size of a tumor and the more peripheral the tumor is, the more effective the therapy. Even in larger early stages tumors, repeating the ablative sessions results in complete ablation without the need for more invasive surgical interventions.

Focal Cryo-Immunotherapy with Intratumoral IL-12 Prevents Recurrence of Large Murine Tumors

Focal ablation technologies are routinely used in the clinical management of inoperable solid tumors but they often result in incomplete ablations leading to high recurrence rates. Adjuvant therapies, capable of safely eliminating residual tumor cells, are therefore of great clinical interest. Interleukin-12 (IL-12) is a potent antitumor cytokine that can be localized intratumorally through coformulation with viscous biopolymers, including chitosan (CS) solutions. The objective of this research was to determine if localized immunotherapy with a CS/IL-12 formulation could prevent tumor recurrence after cryoablation (CA). Tumor recurrence and overall survival rates were assessed. Systemic immunity was evaluated in spontaneously metastatic and bilateral tumor models. Temporal bulk RNA sequencing was performed on tumor and draining lymph node (dLN) samples. In multiple murine tumor models, the addition of CS/IL-12 to CA reduced recurrence rates by 30-55%. Altogether, this cryo-immunotherapy induced complete durable regression of large tumors in 80-100% of treated animals. Additionally, CS/IL-12 prevented lung metastases when delivered as a neoadjuvant to CA. However, CA plus CS/IL-12 had minimal antitumor activity against established, untreated abscopal tumors. Adjuvant anti-PD-1 therapy delayed the growth of abscopal tumors. Transcriptome analyses revealed early immunological changes in the dLN, followed by a significant increase in gene expression associated with immune suppression and regulation. Cryo-immunotherapy with localized CS/IL-12 reduces recurrences and enhances the elimination of large primary tumors. This focal combination therapy also induces significant but limited systemic antitumor immunity.

Prognostic significance of CKAP2L expression in patients with clear cell renal cell carcinoma

Background: Cytoskeleton-associated protein 2-like protein (CKAP2L) is thought to promote the progression of glioma, breast cancer, and ovarian cancer. However, the role of cytoskeleton-associated protein 2-like protein in clear cell renal cell carcinoma (ccRCC) is still unclear. The study aimed to investigate the roles and mechanisms of cytoskeleton-associated protein 2-like protein in clear cell renal cell carcinoma. Methods: The level of cytoskeleton-associated protein 2-like protein in tumors was explored by using UALCAN and Oncomine databases. Gene expression datasets of clear cell renal cell carcinoma from The Cancer Genome Atlas and Gene Expression Omnibus (GEO) were also used to validate the cytoskeleton-associated protein 2-like protein level in clear cell renal cell carcinoma. Survival analysis was performed to investigate the relationship between cytoskeleton-associated protein 2-like protein level and prognosis of clear cell renal cell carcinoma patients. Cox regression analysis was used for identifying the independent prognostic factors. Gene set enrichment analysis (GSEA), gene set variation analysis (GSVA), protein-protein interaction analysis, co-expression analysis, and immune infiltration analysis were used to explore the potential mechanisms of cytoskeleton-associated protein 2-like protein in clear cell renal cell carcinoma. Moreover, the levels of cytoskeleton-associated protein 2-like protein in clinical clear cell renal cell carcinoma tissues were also measured using RT-PCR, immunohistochemical analysis, and Western blotting. M1 macrophages and CD4⁺ T cells were also detected by immunohistochemistry between tumor and normal tissues. Results: The level of cytoskeleton-associated protein 2-like protein was upregulated in clear cell renal cell carcinoma according to multiple databases and experimental verification. Upregulated cytoskeleton-associated protein 2-like protein is an independent prognostic factor, which might activate the JAK-STAT signaling pathway, the P53 signaling pathway, the TGF-β signaling pathway, the WNT signaling pathway, etc., in clear cell renal cell carcinoma. Protein-protein interaction analysis and co-expression analysis suggest that cytoskeleton-associated protein 2-like protein might interact with some proliferation proteins. Immune infiltration analysis indicates that cytoskeleton-associated protein 2-like protein may affect the level of activated CD4⁺ memory T cells, M1 macrophages, CD8⁺ T cells, and neutrophils in clear cell renal cell carcinoma. More M1 macrophage infiltrations in tumor tissues with higher cytoskeleton-associated protein 2-like protein were validated by clear cell renal cell carcinoma tumor tissues. Conclusion: Cytoskeleton-associated protein 2-like protein is upregulated in clear cell renal cell carcinoma tissues, which may promote progression of the disease. Cytoskeleton-associated protein 2-like protein is a potential target for prognostic markers and a potential treatment target in clear cell renal cell carcinoma.

The Role of Focal Therapy and Active Surveillance for Small Renal Mass Therapy

Small and low-grade renal cell carcinomas have little potential for metastasis and disease-related mortality. As a consequence, the main problem remains the use of appropriately tailored treatment for each individual patient. Surgery still remains the gold standard, but many clinicians are questioning this approach and present the advantages of focal therapy. The choice of treatment regimen remains a matter of debate. This article summarizes the current treatment options in the management of small renal masses.