Percutaneous Cryoablation of Solitary, Sporadic Renal Cell Carcinoma: Outcome Analysis Based on Clear-Cell versus Papillary Subtypes

Stage IA papillary and chromophobe renal cell carcinoma: effectiveness of cryoablation and partial nephrectomy

OBJECTIVES

To evaluate the effectiveness of cryoablation compared to partial nephrectomy in patients with stage IA papillary and chromophobe renal cell carcinoma (pRCC; chRCC).

MATERIAL AND METHODS

The 2004-2016 National Cancer Database was queried for adult patients with stage IA pRCC or chRCC treated with cryoablation or partial nephrectomy. Patients receiving systemic therapy or radiotherapy, as well as those with bilateral RCC or prior malignant disease were excluded. Overall survival (OS) was assessed using Kaplan-Meier plots and Cox proportional hazard regression models. Nearest neighbor propensity matching (1:1 cryoablation:partial nephrectomy, stratified for pRCC and chRCC) was used to account for potential confounders.

RESULTS

A total of 11122 stage IA renal cell carcinoma patients were included (pRCC 8030; chRCC 3092). Cryoablation was performed in 607 (5.5%) patients, and partial nephrectomy in 10515 (94.5%) patients. A higher likelihood of cryoablation treatment was observed in older patients with non-private healthcare insurance, as well as in those with smaller diameter low-grade pRCC treated at non-academic centers in specific US geographic regions. After propensity score matching to account for confounders, there was no statistically significant difference in OS comparing cryoablation vs partial nephrectomy in patients with pRCC (HR = 1.3, 95% CI: 0.96-1.75, p = 0.09) and those with chRCC (HR = 1.38, 95% CI: 0.67-2.82, p = 0.38).

CONCLUSION

After accounting for confounders, cryoablation, and partial nephrectomy demonstrated comparable OS in patients with stage IA papillary and chromophobe RCC. Cryoablation is a reasonable treatment alternative to partial nephrectomy for these histological RCC subtypes when radiologically suspected or diagnosed after biopsy.

CRITICAL RELEVANCE STATEMENT

Cryoablation might be considered as an upfront treatment alternative to partial nephrectomy in patients with papillary and chromophobe stage IA renal cell carcinoma, as both treatment approaches yield comparable oncological outcomes.

KEY POINTS

The utilization of cryoablation for stage IA papillary and chromophobe RCC increases. In the National Cancer Database, we found specific patterns of use of cryoablation. Cryoablation and partial nephrectomy demonstrate comparable outcomes after accounting for confounders.

Safety, efficacy, and mid-term oncological outcomes of computed tomography-guided cryoablation of T1 renal cancer

BACKGROUND

Cryoablation is a promising minimally invasive, nephron-sparing treatment of small renal carcinoma (RCC) in co-morbid patients.

PURPOSE

To assess the safety, efficacy, and cancer-specific outcomes of computed tomography (CT)-guided cryoablation of stage T1 (RCC).

MATERIAL AND METHODS

A retrospective evaluation of 122 consecutive patients with 128 tumors treated with cryoablation during 2016-2017. All patients had biopsy-verified T1 RCC.

RESULTS

Median age was 69 years (IQR=59-76); 69% were male. Median tumor size was 26 mm (± 20-33); 9% were stage T1b. Mean follow-up time was 36.3±12.0 months. In total, 14 (11%) procedures led to complications, of which 4 (3%) were intraoperative, 5 (4%) appeared ≤30 days and 5 (4%) >30 days after treatment. Major complications arose after 4 (3%) procedures. Statistically significant associations were found between major complications and stage T1b (P = 0.039), RENAL score (P = 0.010), and number of needles used in cryoablation (P = 0.004). Residual tumor was detected after 4 (3%) procedures and 5 (4%) tumors had local tumor progression. Of 122 patients, 3 (2%) advanced to metastatic disease. Significant statistical associations were found between local tumor progression and T1b stage tumors and number of needles used in cryoablation (P = 0.05 and P = 0.004, respectively). For patients with T1a tumors, the one- and three-year disease-free survival was 98% and 95%, respectively, and for T1b 100% after one year and 75% after three years.

CONCLUSIONS

This study showed that cryoablation is a safe and effective treatment of stage T1 RCC and suggests that in selecting candidates for cryoablation of RCC, the tumor characteristics are more critical than patients' baseline health status.

Contrast-enhanced CT immediately following percutaneous microwave ablation of cT1a renal cell carcinoma: Optimizing cancer outcomes

OBJECTIVE

To evaluate the effect of intra-procedural contrast-enhanced CT (CECT) and same-session repeat ablation (SSRA) on primary efficacy, the complete eradication of tumor after the first ablation session as confirmed on first imaging follow-up, of clinically localized T1a (cT1a) renal cell carcinoma (RCC).

METHODS

398 consecutive patients with cT1a RCC were treated with cryoablation between 10/2003 and 12/2017, radiofrequency (RFA) or microwave ablation (MWA) between 1/2010 and 12/2017. SSRA was performed for residual tumor identified on intra-procedural CECT. Kruskal-Wallis and Pearson's chi-squared tests were performed to assess differences in continuous and categorical variables, respectively. Multivariate linear regression was used to determine predictors for primary efficacy and decline in estimated glomerular filtration rate.

RESULTS

347 consecutive patients (231 M, mean age 67.5 ± 9.1 years) were included. Median tumor diameter was smaller [2.5 vs 2.7 vs 2.6 (p = 0.03)] and RENAL Nephrometry Score (NS) was lower [6 vs 7 vs 7 (p = 0.009] for MWA compared to the RFA and cryoablation cohorts, respectively. Primary efficacy was higher in the MWA cohort [99.4% (170/171)] compared to the RFA [91.4% (85/93)] and cryoablation [92.8% (77/83)] cohorts (p = 0.001). Microwave ablation and SSRA was associated with higher primary efficacy on multivariate linear regression (p = 0.01-0.03).

CONCLUSION

MWA augmented by SSRA, when residual tumor is identified on intra-procedural CECT, may improve primary efficacy for cT1a RCC.

sABLATE: a simplified ABLATE score for prediction of complications and outcome in percutaneous thermal ablation of renal lesions

The aim of the study is to evaluate the performance of a simplified ABLATE score (sABLATE) in predicting complications and outcome with respect to RENAL, mRENAL, and ABLATE scores. This study included 136 renal lesions in 113 patients (M:F ratio = 2.5; mean age 70.8 years). 98 tumors underwent cryoablation at San Raffaele hospital between 01/2015 and 03/2020, while 37 underwent microwave ablation at San Paolo or Policlinico hospitals between 07/2016 and 03/2020. RENAL, mRENAL, ABLATE, and sABLATE scores were calculated using pre-procedural imaging. Data regarding complications and follow-up were registered. Mann-Whitney U test, ROC analyses, and logistic regression analyses were used for complications. Cox-regression analyses were performed for outcome. Mean tumor diameter was 23.2 mm. Mean and median RENAL, mRENAL, ABLATE, and sABLATE scores were 6.8 and 7, 6.9 and 7, 5.3, and 5, and 3.5 and 3, respectively. During a mean follow-up of 21.9 months (range 1-73), we registered 7 complications, 3 cases of residual disease, and 10 local tumor progressions. Mann-Whitney U test p values for complications for RENAL, mRENAL, ABLATE, and sABLATE were 0.51, 0.49, 0.66, and 0.056, respectively. ROC analyses for complications showed an AUC for RENAL, mRENAL, ABLATE, and sABLATE of 0.57, 0.57, 0.55, and 0.71, respectively. Regarding outcome, HR and p values of Cox-regression analyses were 1.30 and 0.36 for RENAL, 1.33 and 0.35 for mRENAL, 2.16 and 0.01 for ABLATE, 2.29 and 0.004 for sABLATE. sABLATE was the only score close to significance for complications, representing a progress even if not definitive. Regarding outcome, ABLATE confirmed its value, and sABLATE maintained validity despite being a simplification.

External Validation of the Renal Ablation-Specific (MC)2 Risk Scoring System in Predicting Complications from Percutaneous Renal Cryoablation

PURPOSE

The (MC)2 score is a renal ablation-specific risk scoring system to predict major complications from percutaneous renal cryoablation (PRCA). However, it is untested in an external population of patients. The purpose of this study is to validate the ability of the (MC)2 score to predict major complications after PRCA in an external population.

MATERIALS AND METHODS

Retrospective review of patients who underwent PRCA from 2004 to 2019. Patient demographics, medical histories, and tumor characteristics were collected. The (MC)2 score was calculated and patients were assigned to low risk (< 5), moderate risk (5-8) and high-risk (> 8) groups. Complications were recorded. Major complications were classified according to CIRSE guidelines.

RESULTS

Two hundred and one patients [M = 116; F = 85; median age = 65 (range 27-90)] met inclusion criteria. Eleven patients (5.5%) developed major complications and 50 patients (24.9%) developed minor complications. Of patients with major complications, mean tumor diameter was 39 mm (± 10.4), seven patients (63.6%) had a central tumor, four patients (36.4%) had complicated diabetes, and one patient (9.1%) had a prior MI. Major complication rates were 2.1%, 14%, and 14.3% in the (MC)2 low risk, moderate risk, and high risk groups, respectively. The mean (MC)2 score for patients with major complications [6.2 (± 2.4)] was higher than the mean score for patients with minor complications [4.7 (± 2.4) (p = 0.07)] and no complications [3.9 (± 1.9) (p < 0.01)]. The area under the ROC curve to predict major complications was 0.78.

CONCLUSION

The (MC)2 risk scoring system appropriately identifies patients at risk for major complications from PRCA in this external patient population.

LncRNA DGCR5 Isoform-1 Silencing Suppresses the Malignant Phenotype of Clear Cell Renal Cell Carcinoma via miR-211-5p/Snail Signal Axis

Long non-coding RNAs (lncRNAs) play important roles during the initiation and progression of cancer. We identified DiGeorge Syndrome Critical Region Gene 5 (DGCR5) as a clear cell renal cell carcinoma (ccRCC) cancer- and lineage-specific lncRNA. Agarose gel electrophoresis analysis and sanger sequencing verified two main isoforms of DGCR5 in ccRCC patient tissues and cell lines. Quantitative polymerase chain reaction further demonstrated that the expression level of DGCR5 major isoform (isoform-1) was higher in ccRCC tissues than that in papillary/chromophobe RCC and other multiple solid malignant tumors. We investigate the biological functions of DGCR5 isoform-1 in ccRCC and show that DGCR5 isoform-1 exerts a tumor-promoting effect in ccRCC. DGCR5 isoform-1 is localized in cytoplasm and shares the same binding sequence to the tumor-suppressive miR-211-5p with the epithelial-to-mesenchymal transition key component SNAI. Furthermore, cellular and molecular experiments demonstrate that DGCR5 isoform-1 could sequester miR-211-5p, leading to the elevation of Snail protein and downregulation of its downstream targets and further promoting ccRCC cell proliferation and migration. Thus, our study indicates that DGCR5 isoform-1 could contribute to ccRCC progression by sponging miR-211-5p through regulating the expression of Snail protein and could serve as a reliable diagnostic biomarker in ccRCC.

Papillary renal cell carcinoma: Review

Kidney cancer is the 13th most common malignancy globally, and the incidence is rising. Papillary renal cell carcinoma is the second most common subtype, comprising 10-15% of renal cell carcinomas. Though the histologic features of this subtype were initially described in the 1990's, our understanding of the genetic and molecular characteristics of this disease have rapidly evolved over the past decade. In this review, we summarize the contemporary understanding of the clinical, morphologic, radiographic, and genetic characteristics of papillary renal cell carcinoma, as well as clinical considerations, current options for management, and prognosis.

Intermediate to Long-Term Clinical Outcomes of Percutaneous Cryoablation for Renal Masses

PURPOSE

The purpose of this study was to evaluate the effectiveness and adverse outcomes of percutaneous cryoablation (CA) for treatment of renal masses in a large cohort of patients.

MATERIALS AND METHODS

This retrospective analysis included 299 CA procedures (297 masses in 277 patients) performed between July 2007 and May 2018 at a single institution. The mean patient age was 66.1 years (range, 30-93 years) with 65.8% being male. A total of 234 (78.8%) masses were biopsy-proven renal cell carcinoma (RCC). The mean maximal tumor diameter was 2.5 cm (range, 0.7-6.6 cm). Efficacy was assessed only for ablations of biopsy-proven RCC, whereas the evaluation of adverse events and renal function included all masses. Complications were graded according to the Society of International Radiology classification.

RESULTS

Major complications occurred in 3.0% of procedures (n = 9), none of which resulted in death or permanent disability. The mean imaging follow-up period was 27.4 months (range, 1-115) for the 199 RCC patients (204 ablated tumors) with follow-up imaging available. Complete response on initial follow-up imaging at mean 4.2 months (range, 0.3-75.6) was achieved in 195 of 204 tumors (95.6%) after a single session and in 200 of 204 tumors (98.0%) after 1 or 2 sessions. Of the RCC patients achieving complete response initially, local recurrence during the follow-up period occurred in 3 of 200 tumors (1.5%). Metastatic progression occurred in 10 of 193 (5.2%) RCC patients without prior metastatic disease during follow-up.

CONCLUSIONS

CA for renal masses is safe and remains efficacious through intermediate- and long-term follow-up.

Tumor location does not impact oncologic outcomes for percutaneous microwave ablation of clinical T1a renal cell carcinoma

OBJECTIVE

To evaluate the impact of anterior tumor location on oncologic efficacy, complication rates, and procedure duration for 151 consecutive biopsy-proven clinical T1a renal cell carcinoma (RCC) treated with percutaneous microwave (MW) ablation.

METHODS

This single-center retrospective study was performed under a waiver of informed consent. One hundred forty-eight consecutive patients (103 M/45 F; median age 67 years, IQR 61-73) with 151 cT1a biopsy-proven RCC (median diameter 2.4 cm, IQR 1.9-3.0) were treated with percutaneous MW ablation between March 2011 and August 2017. Patient and procedural data collected included Charlson comorbidity index (CCI), RENAL nephrometry score (NS), use of hydrodisplacement, MW antennas/generator output/time, and procedure time (PT). Data were stratified by anterior, posterior, and midline tumor location and compared with the Kruskal-Wallis or chi-squared tests. The Kaplan-Meier method was used for survival analyses.

RESULTS

Tumor size, NS, and use/volume of hydrodisplacement were similar for posterior and anterior tumors (p > 0.05). Patients with anterior tumors had a higher CCI (3 vs 4, p = 0.001). Median PT for posterior and anterior tumors was similar (100 vs 108 min, p = 0.26). Single session technical success and primary efficacy were achieved for all 151 tumors including 61 posterior and 67 anterior tumors. The 4 (3%) Clavien III-IV complications and 6 (4%) local recurrences were not associated with tumor location (p > 0.05). Three-year RFS, CSS, and OS were 95% (95% CI 0.87, 0.98), 100% (95% CI 1.0, 1.0), and 96% (95% CI 0.89, 0.98), respectively.

CONCLUSIONS

The safety and efficacy of percutaneous microwave ablation for anterior and posterior RCC are similar.

KEY POINTS

• The safety profile for percutaneous microwave ablation of anterior and posterior T1a renal cell carcinoma is equivalent. • Percutaneous microwave ablation of T1a renal cell carcinoma provides durable oncologic control regardless of tumor location. • Placement of additional microwave antennas and use of hydrodisplacement are associated with longer procedure times.

Safety of percutaneous renal cryoablation: an international multicentre experience from the EuRECA retrospective percutaneous database

OBJECTIVE

To investigate the safety profile of percutaneous cryoablation of renal tumours < 7 cm, utilising data extracted from an international multicentre registry.

MATERIALS AND METHODS

A retrospective review of all immediate and delayed complications from a multicentre database was performed and was categorised according to the Clavien-Dindo classification. Statistical analysis was performed for both overall complications (all Clavien-Dindo) and major complications (Clavien-Dindo 3 to 5). The following criteria were identified as potential predictive factors for complications: centre number, modality of image guidance, tumour size (≤ 4 cm vs. > 4 cm), number of tumours treated in the same session (1 vs. > 1) and tumour histology.

RESULTS

A total of 713 renal tumours underwent ablation in 647 individual sessions. In 596 of the cases, one tumour was treated; in the remaining 51 cases, several tumours were treated per session. Mean lesion size was 2.8 cm. Fifty-four complications (Clavien-Dindo 1 to 5) occurred as a result of the 647 procedures, corresponding to an overall complication rate of 8.3%. The most frequent complication was bleeding (3.2%), with 9 cases (1.4%) requiring subsequent treatment. The rate of major complication was 3.4%. The only statistically significant prognostic factor for a major complication was a tumour size > 4 cm.

CONCLUSION

Percutaneous renal cryoablation is associated with a low rate of complications. Tumours measuring more than 4 cm are associated with a higher risk of major complications.

KEY POINTS

• Percutaneous kidney cryoablation has a low rate of complications. • Bleeding is the most frequent complication. • A tumour size superior to 4 cm is a predictive factor of major complication.

Organ-sparing procedures in GU cancer: part 1-organ-sparing procedures in renal and adrenal tumors: a systematic review

PURPOSE

Organ-sparing surgery (OSS) for the kidney and adrenals has emerged as the need for preservation of function is paramount in patients with poor functional reserve. As reports increasingly showed that oncological outcomes were equivalent to radical excision, elective OSS became a viable alternative in patients with otherwise normal reserve. In this review, we summarize the current knowledge of OSS for adrenal and renal tumors.

MATERIALS AND METHODS

PubMed, Web of Science and Cochrane Library Central Search were searched for recently published articles up to December 2017. The following keywords were used; "partial adrenalectomy", "adrenal sparing", "partial nephrectomy", "nephron sparing", "kidney/renal cancer".

RESULTS

Partial adrenalectomy became an attractive alternative to total adrenalectomy avoiding adrenal insufficiency. Both minimally invasive surgery and ablative techniques were increasingly reported for adrenal OSS with adequate residual adrenal function and excellent oncological outcome. Radical nephrectomy remained for many years as the gold standard of treatment for organ-confined renal cell carcinoma. As the need to reduce the impact on renal function, more conservative approaches were utilized. Soon, the non-inferiority of nephron-sparing surgery to that of radical excision became evident and elective partial nephrectomy was gaining ground as the standard of care for small renal masses in patients with normal contralateral kidneys.

CONCLUSIONS

Herein, we present a comprehensive review of the current status of OSS in renal and adrenal tumors.