Contemporary Management of Small Renal Masses

Corosolic acid inhibits metastatic response of human renal cell carcinoma cells by modulating ERK/MMP2 signaling

Corosolic acid (CA), a plant-derived pentacyclic triterpenoid, has potent anti-inflammatory, anti-metabolic, and anti-neoplastic actions against a variety of human cancers. However, the specific mechanism by which CA inhibits the progression of renal cell carcinoma (RCC) is yet unclear. We found that CA (≤8 μM) had no influence on either the growth or viability of RCC cell lines (786-O, ACHN, and Caki-1) or normal HK2 cells. However, in a dose-dependent manner, CA prevented the invasion and migration of RCC cells. Human protease array analysis showed that CA reduced MMP2 expression. At increasing concentrations of CA, the expression of MMP2 was dose-dependently reduced, as shown by western blot and RT-PCR analyses as well as immunofluorescence staining. CA also stimulated ERK1/2 phosphorylation in 786-O and Caki-1 cells. Transfection of CA-treated RCC cells with siRNA-ERK restored MMP2 protein expression and the motility and invasion capabilities of RCC cells. Molecular docking study results showed that CA and MMP2 interact strongly. These findings elucidate the mechanism by which CA prevents RCC cells from migrating and invading, and these findings indicate that CA may be a potential anti-metastatic therapy for RCC.

Perioperative, functional, and oncological outcomes after cryoablation or partial nephrectomy for small renal masses in solitary kidneys: a systematic review and meta-analysis

AIM

This study aims to compare the perioperative, functional, and oncological outcomes of cryoablation (CA) and partial nephrectomy (PN) for managing small renal masses in patients with solitary kidneys. The study seeks to assess the efficacy and safety of both interventions, evaluating their impact on kidney function and their ability to mitigate cancer recurrence.

METHODS

Searches were systematically conducted on PubMed, Scopus, EMBASE, SinoMed, and Google Scholar, identifying seven observational studies. Statistical analysis was performed using Stata v.12.0 and Review Manager version 5.2. Results for dichotomous variables are expressed using odds ratios, and weighted mean differences are used for continuous variables.

RESULTS

Our findings revealed that patients undergoing CA experienced significantly shorter operative time (p < 0.0001), reduced estimated blood loss (p < 0.00001), a shorter length of stay (p = 0.0001), and fewer postoperative complications (p = 0.02) compared to those undergoing PN. Although the CA group exhibited a lower transfusion rate (p = 0.69) compared with the PN group, the difference was not statistically significant. The combined data analysis demonstrated a significantly lower increase in serum creatinine levels after surgery in the CA group compared with the PN group (p = 0.003). Similarly, there was a noteworthy decrease in the estimated glomerular filtration rate after surgery in the PN group compared with the CA group (p < 0.0001). While not statistically significant, the CA group showed a lower postoperative dialysis rate (p = 0.11). Regarding oncological outcomes, the analysis revealed no significant differences between CA and PN concerning local recurrence (p = 0.2) and distant metastasis (p = 0.12), respectively.

CONCLUSIONS

Our analysis indicates comparable efficacy between PN and CA in controlling tumour recurrence and metastasis. However, CA is associated with superior preservation of renal function, significantly enhanced perioperative outcomes, and fewer postoperative complications. Based on our data, it can be inferred that the scope for applying CA might be expanded to encompass more patients seeking a less invasive treatment option.

Surgical Trends and Complications in Partial and Radical Nephrectomy: Results from the GRAND Study

BACKGROUND

We aimed to evaluate the current trends in renal cancer surgery, as well as to compare the perioperative outcomes of partial versus radical nephrectomy.

METHODS

We used the GeRmAn Nationwide inpatient Data (GRAND), provided by the Research Data Center of the Federal Bureau of Statistics (2005-2021). We report the largest study in the field, with 317,843 patients and multiple patient-level analyses.

RESULTS

Overall, 123,924 (39%) patients underwent partial and 193,919 (61%) underwent radical nephrectomy in Germany from 2005 to 2021. Of them, 57,308 (18%) were operated on in low-, 142,702 (45%) in intermediate-, and 117,833 (37%) in high-volume centers. A total of 249,333 (78%) patients underwent open, 44,994 (14%) laparoscopic, and 23,516 (8%) robotic nephrectomy. The number of patients undergoing renal surgery remained relatively stable from 2005 to 2021. Over the study period, the utilization of partial nephrectomy increased threefold, while radical nephrectomy decreased by about 40%. After adjusting for major risk factors in the multivariate regression analysis, radical nephrectomy was associated with 3.2-fold higher odds (95% CI: 3.2 to 3.9, p < 0.001) of 30-day mortality, longer hospitalization by 1.9 days (95% CI: 1.9 to 2, p < 0.001), and higher inpatient costs by EUR 1778 (95% CI: 1694 to 1862, p < 0.001) compared to partial nephrectomy. Furthermore, radical nephrectomy had a higher risk of in-hospital transfusion (p < 0.001), sepsis (p < 0.001), acute respiratory failure (p < 0.001), acute kidney disease (p < 0.001), acute thromboembolism (p < 0.001), surgical wound infection (p < 0.001), ileus (p < 0.001), intensive care unit admission (p < 0.001), and pancreatitis (p < 0.001).

CONCLUSIONS

More patients are offered partial nephrectomy in Germany. Patients undergoing radical nephrectomy present with a higher rate of concomitant risk factors and have increased perioperative morbidity and mortality, prolonged hospitalization, and increased in-hospital costs.

Renal Mass Imaging with MRI Clear Cell Likelihood Score: A User's Guide

Small solid renal masses (SRMs) are frequently detected at imaging. Nearly 20% are benign, making careful evaluation with MRI an important consideration before deciding on management. Clear cell renal cell carcinoma (ccRCC) is the most common renal cell carcinoma subtype with potentially aggressive behavior. Thus, confident identification of ccRCC imaging features is a critical task for the radiologist. Imaging features distinguishing ccRCC from other benign and malignant renal masses are based on major features (T2 signal intensity, corticomedullary phase enhancement, and the presence of microscopic fat) and ancillary features (segmental enhancement inversion, arterial-to-delayed enhancement ratio, and diffusion restriction). The clear cell likelihood score (ccLS) system was recently devised to provide a standardized framework for categorizing SRMs, offering a Likert score of the likelihood of ccRCC ranging from 1 (very unlikely) to 5 (very likely). Alternative diagnoses based on imaging appearance are also suggested by the algorithm. Furthermore, the ccLS system aims to stratify which patients may or may not benefit from biopsy. The authors use case examples to guide the reader through the evaluation of major and ancillary MRI features of the ccLS algorithm for assigning a likelihood score to an SRM. The authors also discuss patient selection, imaging parameters, pitfalls, and areas for future development. The goal is for radiologists to be better equipped to guide management and improve shared decision making between the patient and treating physician. © RSNA, 2023 Quiz questions for this article are available in the supplemental material. See the invited commentary by Pedrosa in this issue.

The Changing Role of Renal Mass Biopsy

The incidence and prevalence of small renal masses (SRMs) continues to rise and with increased detection comes increases in surgical management, although the probability of an SRM being benign is upward of 30%. An extirpative treatment first diagnose-later strategy persists and clinical tools for risk stratification such as renal mass biopsy remain severely underutilized. The overtreatment of SRMs has multiple detrimental effects including surgical complications, psychosocial stress, financial loss, and reduced renal function leading to downstream effects such as the need for dialysis and cardiovascular disease.

"Collecting duct carcinoma of the kidney: diagnosis and implications for management"

Collecting duct carcinoma of the kidney is a rare and aggressive subtype of renal cell carcinoma (RCC) arising from the distal convoluted tubules. At the time of diagnosis, patients are more frequently symptomatic, with advanced locoregional stage, and have metastatic disease. The 2016 WHO Classification of Tumours of the Urinary System defined diagnostic criteria for this entity. However, the diagnostic features continue to evolve, with typical, but not entirely specific, histologic and immunophenotypic characteristics. In addition, the lack of consistent molecular alterations makes collecting duct carcinoma a diagnosis of exclusion, with historical cases being re-classified as fumarate hydratase deficient RCC, ALK rearranged RCC, renal medullary carcinoma or high-grade urothelial carcinoma. The rarity and poor prognosis of the tumor makes it difficult to reach consensus guidelines to guide therapy. In this manuscript we review the clinicopathologic features of collecting duct carcinoma including pathologic diagnostic criteria, molecular characteristics and differential diagnosis, and their possible implications for management.

Predicting Oncologic Outcomes in Small Renal Tumors

BACKGROUND

Most patients diagnosed with renal cancer today present with small renal masses (SRMs). Although these patients have a low risk of dying from their disease and many are followed with active surveillance protocols, a small subset of renal cell carcinomas (RCCs) behave aggressively. Knowledge regarding features of aggressive behavior would enable better adoption of active surveillance strategies among these patients.

OBJECTIVE

We sought to improve prognostic models to predict metastasis-free survival after nephrectomy through focused analyses of clinicopathologic characteristics of SRMs associated with adverse outcomes.

DESIGN, SETTING, AND PARTICIPANTS

We identified consecutive patients with surgically resected SRMs (≤4 cm) at the University of Texas Southwestern Kidney Cancer Program between 1998 and 2020. In addition, we evaluated the ability of SRMs to form tumors when implanted in mice, an indicator of tumor aggressiveness.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We examined the clinicopathologic factors associated with metastasis including prospectively performed BAP1 immunohistochemistry at our Clinical Laboratory Improvement Amendments laboratory. Multivariable Cox proportional hazard regression was used to predict metastasis-free survival.

RESULTS AND LIMITATIONS

A total of 3900 evaluable nephrectomies (from 3674 ethnically diverse patients) were identified, of which 1984 (51%) were SRMs including 1720 RCC. Of these patients with RCC (SRMRCC), 1576 did not have synchronous or metachronous larger RCCs and among these, 37 (2%) developed metastases. SRMRCC that metastasized were significantly enriched for aggressive morphologic phenotypes and engrafted in mice at comparable rates as larger metastatic tumors. BAP1 loss remained significantly associated with metastasis-free survival after accounting for TNM (tumor-node-metastasis) stage and SSIGN (stage, size, grade, and necrosis) score in multivariable analysis.

CONCLUSIONS

We identified clinicopathologic features that influence metastasis-free survival for patients with SRMRCC. If validated independently, these data should assist with patient prognosis and help with active surveillance strategies.

PATIENT SUMMARY

We report the identification of features of aggressiveness in small renal tumors that influence the likelihood of metastases after surgery.

Using Competing Risk of Mortality to Inform the Transition from Prostate Cancer Active Surveillance to Watchful Waiting

BACKGROUND

For men on active surveillance (AS) for prostate cancer (PCa), disease progression and age-related changes in health may influence decisions about pursuing curative treatment.

OBJECTIVE

To evaluate the predicted PCa and non-PCa mortality at the time of reclassification among men on AS, to identify clinical criteria for considering a transition from AS to watchful waiting (WW).

DESIGN, SETTING, AND PARTICIPANTS

Patients enrolled in a large AS program who experienced biopsy grade reclassification (Gleason grade increase) were retrospectively examined. All patients who had complete documentation of medical comorbidities at reclassification were included.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

A validated model was used to assess 10- and 15-yr untreated PCa and non-PCa mortalities based on patient comorbidities and PCa clinical characteristics. We compared the ratio of predicted PCa mortality with predicted non-PCa mortality ("predicted mortality ratio") and divided patients into four risk tiers based on this ratio: (1) tier 1 (ratio: >0.33), (2) tier 2 (ratio 0.33-0.20), (3) tier 3 (ratio 0.20-0.10), and (4) tier 4 (ratio <0.10).

RESULTS AND LIMITATIONS

Of the 344 men who were reclassified, 98 (28%) were in risk tier 1, 85 (25%) in tier 2, 93 (27%) in tier 3, and 68 (20%) in tier 4 for 10-yr mortality. Fifteen-year risk tiers were distributed similarly. The 23 (6.7%) men who met the "transition triad" (age >75 yr, Charlson Comorbidity Index >3, and grade group ≤2) had a 14-fold higher non-PCa mortality risk and a lower predicted mortality ratio than those who did not (0.07 vs 0.23, p < 0.001). The primary limitations of our study included its retrospective nature and the use of predicted mortalities.

CONCLUSIONS

At reclassification, nearly half of patients had a more than five-fold and one in five patients had a more than ten-fold higher risk of non-PCa death than patients having a risk of untreated PCa death. Despite a more significant cancer diagnosis, a transition to WW for older men with multiple comorbidities and grade group <3 PCa should be considered.

PATIENT SUMMARY

Men with favorable-risk prostate cancer and life expectancy of >10 yr are often enrolled in active surveillance, which entails delay of curative treatment until there is evidence of more aggressive disease. We examined a group of men on active surveillance who developed more aggressive disease, and found, nevertheless, that the majority of these men continued to have a dramatically higher risk of death from non-prostate cancer causes than from prostate cancer based on a risk prediction tool. For men older than 75 yr, who have multiple medical conditions and who do not have higher-grade cancer, it may be reasonable to reconsider the need for curative treatment given the low risk of death from prostate cancer compared with the risk of death from other causes.

A Systematic Review and Meta-Analysis of Minimally Invasive Partial Nephrectomy Versus Focal Therapy for Small Renal Masses

Background

Minimally invasive partial nephrectomy (MIPN) and focal therapy (FT) are popular trends for small renal masses (SRMs). However, there is currently no systematic comparison between MIPN and FT of SRMs. Therefore, we systematically study the perioperative, renal functional, and oncologic outcomes of MIPN and FT in SRMs.

Methods

We have searched the Embase, Cochrane Library, and PubMed for articles between MIPN (robot-assisted partial nephrectomy and laparoscopic partial nephrectomy) and FT {radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation (CA), irreversible electroporation, non-thermal [irreversible electroporation (IRE)] ablation, and stereotactic body radiation therapy (SBRT)}. We calculated pooled mean difference (MD), odds ratios (ORs), and 95% confidence intervals (CIs) (CRD42021260787).

Results

A total of 26 articles (n = 4,420) were included in the study. Compared with MIPN, the operating time (OP) of FT had significantly lower (SMD, −1.20; CI, −1.77 to −0.63; I2 = 97.6%, P &lt; 0.0001), estimated blood loss (EBL) of FT had significantly less (SMD, −1.20; CI, −1.77 to −0.63; I2 = 97.6%, P &lt; 0.0001), length of stay (LOS) had shorter (SMD, −0.90; CI, −1.26 to −0.53; I2 = 92.2%, P &lt; 0.0001), and estimated glomerular filtration rate (eGFR) of FT was significantly lower decrease (SMD, −0.90; CI, −1.26 to −0.53; I2 = 92.2%, P &lt; 0.0001). However, FT possessed lower risk in minor complications (Clavien 1–2) (OR, 0.69; CI, 0.45 to 1.07; I2 = 47%, P = 0.023) and overall complications (OR, 0.71; CI, 0.51 to 0.99; I2 = 49.2%, P = 0.008). Finally, there are no obvious difference between FT and MIPN in local recurrence, distant metastasis, and major complications (P &gt; 0.05).

Conclusion

FT has more advantages in protecting kidney function, reducing bleeding, shortening operating time, and shortening the length of stay. There is no difference in local recurrence, distant metastasis, and major complications. For the minimally invasive era, we need to weigh the advantages and disadvantages of all aspects to make comprehensive choices.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier PROSPERO (CRD42021260787).

Mucinous tubular and spindle cell carcinoma with high-grade transformation: case report

Background

Mucinous tubular and spindle cell carcinoma (MTSCC) is a type of renal cell carcinoma (RCC) described as an entity with low-grade and low malignant potential. This report presents a high-grade transformation of MTSCC which is an uncommon finding in this subtype of RCC. Although most reported cases showed low malignant potential and good prognosis after surgical resection, a small subset of patients has been reported with aggressive phenotype and fatal outcome.

Case presentation

A case of a 23-year-old male is discussed with an incidental renal mass in the left kidney after a workup of bilateral flank pain. Morphologically, the tumor was composed of tubular structures lined by cuboidal cells mixed with spindle cells and sarcomatoid change was present in the tumor. Previously sarcomatoid change has been mostly reported along with conventional morphology in other common type of RCC with a worse prognosis.

Conclusions

The aim of this report is to draw the attention of pathologists and clinicians to the importance of high grade MTSCC owing to the unfavorable prognosis.

Novel high-quality and reality biomaterial as a kidney surgery simulation model

Surgical training using live animals such as pigs is one of the best ways of achieving skilled techniques and fostering confidence in preclinical medical students and surgeon trainees. However, due to animal welfare ethics, laboratory animals’ usage for training should be kept to a minimum. We have developed a novel kidney organ model utilizing a simple procedure in which the kidney is first refluxed with N-vinyl-2-pyrrolidone (NVP) solution for 1 hour in its bath, followed by permeation for 23 hours, with a subsequent freshwater refluxed for 48 hours in the washing step. Surgical simulation of the prepared kidney model (NVP-fixed kidney) was compared with three types of other basic known simulation models (fresh kidney, freeze-thaw kidney, and FA-fixed kidney) by various evaluations. We found the NVP-fixed kidney to mimicked fresh kidney function the most, pertaining to the hardness, and strength of the renal parenchyma. Moreover, the NVP-fixed kidney demonstrated successful blood-like fluids perfusion and electrocautery. Further, we confirmed that surgical training could be performed under conditions closer to actual clinical practice. Our findings suggest that our model does not only contribute to improving surgical skills but also inspires the utilization of otherwise, discarded inedible livestock organs as models for surgical training.

Melatonin combined with sorafenib synergistically inhibit the invasive ability through targeting metastasis-associated protein 2 expression in human renal cancer cells

Objectives:

Materials and Methods:

Results:

Conclusion:

Propensity Score-Matched Analysis of Single Fraction Robotic Radiosurgery Versus Open Partial Nephrectomy in Renal Cell Carcinoma: Oncological Outcomes

Introduction High-dose local stereotactic robotic radiosurgery (RRS) is a non-invasive alternative to surgery in renal masses and selected patients. We have, so far, limited its use to the elderly and patients at high risk from surgery. In this study, we matched patients with renal tumors who were treated with single fraction RRS to patients who underwent open partial nephrectomy (OPN). Methods Between January 2009 and December 2017, we included 571 consecutive patients undergoing OPN and 99 patients who underwent RRS in this retrospective analysis. Patients had to have a follow-up of at least six months and we were able to match 35 with a propensity score. Matching criteria were Eastern Cooperative Oncology Group (ECOG) status, age, clinical tumor, nodes, and metastases (TNM), and tumor diameter. Tumor response, renal function, survival, and adverse events were evaluated every three months until progression or death. Results Median age was 65 years for RRS (range 58-75) and 71 (range 56-76) for OPN (p=0.131). Median diameter of renal tumors was 2.8 cm (range 2.4-3.9) for RRS and 3.5 cm (2.8-4.5) for OPN, p=0.104. Median follow-up was 28.1 months (range 6.0-78.3 months). Local tumor control nine months after RRS and OPN was 98% (95% CI: 89-99%). Renal function remained stable with a median creatinine clearance (Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)) at baseline of 76.8mlmin/1.73m² (range 25.3-126.3) and 70.3ml/min/1.73m² (range 18.6-127.3) at follow-up (p=0.89). Median overall survival was not reached. No difference in overall survival (OS) was seen in RRS compared to OPN (p=0.459). Conclusions Single fraction RRS is an alternative to OPN in patients unfit for surgery. Oncological and functional results are comparable to those of OPN. Further studies are needed to determine long-term results and limits of RRS in this setting and in younger patients.

A Statewide Quality Improvement Collaborative's Adherence to the 2017 American Urological Association Guidelines Regarding Initial Evaluation of Patients With Clinical T1 Renal Masses

OBJECTIVE

To evaluate MUSIC-KIDNEY's adherence to the American Urological Association (AUA) guidelines regarding the initial evaluation of patient's with clinical T1 (cT1) renal masses.

METHODS

We reviewed MUSIC-KIDNEY registry data for patients with newly diagnosed cT1 renal masses to assess for adherence with the 2017 AUA guideline statements regarding recommendations to obtain (1) CMP, (2) CBC, (3) UA, (4) abdominal cross-sectional imaging, and (5) chest imaging. An evaluation consisting of all 5 guideline measures was considered "complete compliance." Variation with guideline adherence was assessed by contributing practice, management strategy, and renal mass size.

RESULTS

We identified 1808 patients with cT1 renal masses in the MUSIC-KIDNEY registry, of which 30% met the definition of complete compliance. Most patients received care that was compliant with recommendations to obtain laboratory testing with 1448 (80%), 1545 (85%), and 1472 (81%) patients obtaining a CMP, CBC, and UA respectively. Only 862 (48%) patients underwent chest imaging. Significant variation exists in complete guideline compliance for contributing practices, ranging from 0% to 45% as well as for patients which underwent immediate intervention compared with initial observation (37% vs 23%) and patients with cT1b masses compared with cT1a masses (36% vs 28%).

CONCLUSION

Complete guideline compliance in the initial evaluation of patients with cT1 renal masses is poor, which is mainly driven by omission of chest imaging. Significant variation in guideline adherence is seen across practices, as well as patients undergoing an intervention vs observation, and cT1a vs cT1b masses. There are ample quality improvement opportunities to increase adherence and decrease variability with guideline recommendations.

Evaluation of radiomics and machine learning in identification of aggressive tumor features in renal cell carcinoma (RCC)

PURPOSE

The purpose of this study was to evaluate the use of CT radiomics features and machine learning analysis to identify aggressive tumor features, including high nuclear grade (NG) and sarcomatoid (sarc) features, in large renal cell carcinomas (RCCs).

METHODS

CT-based volumetric radiomics analysis was performed on non-contrast (NC) and portal venous (PV) phase multidetector computed tomography images of large (> 7 cm) untreated RCCs in 141 patients (46W/95M, mean age 60 years). Machine learning analysis was applied to the extracted radiomics data to evaluate for association with high NG (grade 3-4), with multichannel analysis for NG performed in a subset of patients (n = 80). A similar analysis was performed in a sarcomatoid rich cohort (n = 43, 31M/12F, mean age 63.7 years) using size-matched non-sarcomatoid controls (n = 49) for identification of sarcomatoid change.

RESULTS

The XG Boost Model performed best on the tested data. After manual and machine feature extraction, models consisted of 3, 7, 5, 10 radiomics features for NC sarc, PV sarc, NC NG and PV NG, respectively. The area under the receiver operating characteristic curve (AUC) for these models was 0.59, 0.65, 0.69 and 0.58 respectively. The multichannel NG model extracted 6 radiomic features using the feature selection strategy and showed an AUC of 0.67.

CONCLUSIONS

Statistically significant but weak associations between aggressive tumor features (high nuclear grade, sarcomatoid features) in large RCC were identified using 3D radiomics and machine learning analysis.

Feasibility and Outcomes of Renal Mass Biopsy for Anatomically Complex Renal Tumors

OBJECTIVE

To compare the feasibility and outcomes of renal mass biopsies (RMB) of anatomically complex vs non-complex renal masses.

METHODS

Our institutional renal tumor database was queried for patients who underwent RMB between 2005 and 2019 and with available nephrometry score. Complex masses were: (1) small (<2 cm), (2) entirely endophytic (nephrometry E=3), (3) hilar (h) or (4) partially endophytic (E=2) and anterior. Demographic and pathologic data were compared. Biopsies were deemed adequate if they resulted in a diagnosis. Concordance with surgical pathology was assessed. These were both presented using proportions. Factors associated with biopsy outcomes were identified using multivariable logistic regression. RMB sensitivity and specificity were calculated using contingency methods.

RESULTS

A total of 306 RBMs were included, 179 complex and 127 non-complex. A total of 199 (65%) had an extirpative procedure. Complex lesions were less likely to have an adequate biopsy (89% vs 96%, P = .03), and to be concordant with final surgical pathology from an oncologic standpoint (89% vs 97%, P = .03). There was no significant difference in concordance of histology (76% vs 86%, P = .10) or grade (48 vs 51%, P = .66). On multivariable analyses, only male gender was associated with biopsy adequacy (OR 3.31, 95% CI 1.28-8.55, P = .01). Our overall sensitivity was 93%, specificity 93%, and accuracy 93%. There were no significant differences over time in biopsy outcomes during the study period.

CONCLUSION

RMB of complex lesions is associated with excellent diagnostic yield, albeit lower than non-complex lesions. RMB should not be deferred in cases of anatomically complex lesions where additional data could improve clinical decision-making.

Nephrectomy Delay of More than 10 Weeks from Diagnosis Is Associated with Decreased Overall Survival in pT3 RCC

In this study, we aimed to evaluate the impact of surgical wait time (SWT) on outcomes of patients with renal cell carcinoma (RCC), and to investigate risk factors associated with prolonged SWT. Using the National Cancer Database, we retrospectively reviewed the records of patients with pT3 RCC treated with radical or partial nephrectomy between 2004 and 2014. The cohort was divided based on SWT. The primary outcome was 5-year overall survival (OS). Logistic regression analysis was used to investigate the risk factors associated with delayed surgery. Cox proportional hazards models were fitted to assess relations between SWT and 5-year OS after adjusting for confounding factors. A total of 22,653 patients were included in the analysis. Patients with SWT > 10 weeks had higher occurrence of upstaging. Using logistic regression, we found that female patients, African-American or Spanish origin patients, treatment in academic or integrated network cancer center, lack of insurance, median household income of <$38,000, and the Charlson-Deyo score of ≥1 were more likely to have prolonged SWT. SWT > 10 weeks was associated with decreased 5-year OS (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.15-1.33). This risk was not markedly attenuated after adjusting for confounding variables, including age, gender, race, insurance status, Charlson-Deyo score, tumor size, and surgical margin status (adjusted HR, 1.13; 95% CI, 1.04-1.24). In conclusion, the vast majority of patients underwent surgery within 10 weeks. There is a statistically significant trend of increasing SWT over the study period. SWT > 10 weeks is associated with decreased 5-year OS.

Temporal improvements in renal surgery outcomes across surgical approaches

PURPOSE

To evaluate patient outcomes in a contemporary cohort of patients undergoing partial nephrectomy (PN) or radical nephrectomy (RN).

METHODS

The NSQIP database was used to identify patients undergoing PN or RN for renal neoplasms between 2010 and 2018. The SEER database was also queried to assess changes in tumor staging during the study period. Logistic regression was used to assess the independent relationship between surgery year and approach on postoperative complications.

RESULTS

Between 2010 and 2018, NSQIP captured 58,020 cases, including 26,745 (46%) PN and 31,275 (54%) RN. The proportion of PN increased annually, from 39.8% in 2010 to 48.7% in 2018. This rise in PN coincided with a decrease in the proportion of patients experiencing complications, irrespective of surgical approach (20.4% of total cases to 14.2% of total cases). While limited by a lack of information on tumor characteristics, multivariable analysis controlling for patient characteristics demonstrated that RN was associated with an increased risk of complications, OR 1.42 (95% CI 1.35-1.49).

CONCLUSION

Here, we report an 8.9% increase in the proportion of patients undergoing PN between 2010 and 2018, with no associated increase in perioperative morbidity/mortality. Given that there was no concurrent shift in stage or size of kidney tumors undergoing resection during the study period, these data therefore suggest markedly improved surgical technique and perioperative management nationally. Furthermore, the relative burden of complications has shifted from patients undergoing PN to those undergoing RN. Therefore PN, when technically feasible, should be increasingly considered.

Safety and efficacy of embolotherapy for severe hemorrhage after partial nephrectomy

BACKGROUND

Partial nephrectomy may be complicated by postoperative hemorrhage, which may be treated by transcatheter embolization.

PURPOSE

To assess the safety and efficacy of embolotherapy for hemorrhagic complications of partial nephrectomy and to analyze the potential correlation between multiple bleeding sites on angiography and surgical complexity.

MATERIAL AND METHODS

A cohort of 25 patients presenting with severe, postoperative bleeding after partial nephrectomy and treated with catheter-directed superselective embolization was included. Patients' demographics, radiological investigations before the embolization, and clinical outcome after embolization were analyzed. Mann-Whitney U test was used to analyze the potential difference in the RENAL score between patients with one or more bleeding sites in the resection area.

RESULTS

Selective renal angiography revealed multiple bleeding sites at the resection bed in 8 (32%) patients with amorphous contrast extravasation in 10 (40%) patients. Embolization with use of a microcatheter and microcoils was effective to stop the bleeding in all but one patient, the latter requiring a second embolization two days later. Transient decrease in renal function was noted in 3/25 (12%) patients with full recovery in two of the three. Patients with multiple bleeding sites did not show significantly different RENAL scores compared to patients with a single bleeding site (P = 0.148).

CONCLUSION

Embolotherapy for postoperative partial nephrectomy-related bleeding is safe and effective with a low rate of recurrent bleeding. The number of bleeding sites at the resection area did not correlate to the RENAL score.

Perioperative and Long-Term Outcomes of Robot-Assisted Partial Nephrectomy: A Systematic Review

Background

Adoption of the robotic surgical platform for small renal cancers has rapidly expanded, but its utility compared to other approaches has not been established. The objective of this review is to assess perioperative and long-term oncologic and functional outcomes of robot-assisted partial nephrectomy (RAPN) compared to laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN).

Methods

A search in PubMed, Embase, and Cochrane (2010-2019) was conducted. Of 3877 articles screened, 7 observational studies were included.

Results

RAPN was associated with 24-50 mL less intraoperative blood loss compared to LPN and 39-84 mL less than OPN. RAPN also demonstrated trends of other postoperative benefits, such as shorter length of stay and fewer major complications. Several studies reported better long-term functional kidney outcomes, but these findings were inconsistent. Recurrence and cancer-specific survival (CSS) were similar across groups. While RAPN had a 5-year CSS of 90.1%-97.9%, LPN and OPN had survival rates of 85.9%-86.9% and 88.5-96.3% respectively.

Conclusions

RAPN may be associated with a lower estimated blood loss and comparable long-term outcomes when compared to other surgical approaches. However, additional randomized or propensity matched studies are warranted to fully assess long-term functional kidney and oncologic outcomes.

Nephron-Sparing Robotic Radiosurgical Therapy for Primary Renal Cell Carcinoma: Single-Institution Experience and Review of the Literature

PURPOSE

We report our single-institution stereotactic body radiation therapy (SBRT) experience on stage I renal cancer with prospectively collected toxicity and efficacy data.

METHODS AND MATERIALS

A total of 21 patients with solitary renal tumors, including 14 surgical candidates who refused surgery (66%), were treated with SBRT. Histologic confirmation was obtained on all patients before treatment; 2 had transitional cell carcinoma and 19 had renal cell carcinoma. The median age was 71 years (range, 58-88). Nearly all patients received 48 Gy in 3 fractions.

RESULTS

The median follow-up was 78 months (range, 5-107). At 5 years post treatment, the local tumor control rate was 100%. Tumor size decreased by a median value of 5.3% at 1 year post treatment, 15.6% at 2 years post treatment, and 15.4% at 5 years post treatment. Glomerular filtration rate had decreased by a median value of 1.5% at 1 year post treatment, 7.0% at 2 years post treatment, and 14.2% at 5 years post treatment. Three patients experienced grade 1 toxicity; no other treatment-related adverse effects were reported.

CONCLUSIONS

SBRT is a promising noninvasive treatment in the management of primary renal cell carcinoma, with evolving clinical evidence demonstrating encouraging results with respect to local control and toxicity.

Visible near infrared reflectance molecular chemical imaging of human ex vivo carcinomas and murine in vivo carcinomas

SIGNIFICANCE

A key risk faced by oncological surgeons continues to be complete removal of tumor. Currently, there is no intraoperative imaging device to detect kidney tumors during excision.

AIM

We are evaluating molecular chemical imaging (MCI) as a technology for real-time tumor detection and margin assessment during tumor removal surgeries.

APPROACH

In exploratory studies, we evaluate visible near infrared (Vis-NIR) MCI for differentiating tumor from adjacent tissue in ex vivo human kidney specimens, and in anaesthetized mice with breast or lung tumor xenografts. Differentiation of tumor from nontumor tissues is made possible with diffuse reflectance spectroscopic signatures and hyperspectral imaging technology. Tumor detection is achieved by score image generation to localize the tumor, followed by application of computer vision algorithms to define tumor border.

RESULTS

Performance of a partial least squares discriminant analysis (PLS-DA) model for kidney tumor in a 22-patient study is 0.96 for area under the receiver operating characteristic curve. A PLS-DA model for in vivo breast and lung tumor xenografts performs with 100% sensitivity, 83% specificity, and 89% accuracy.

CONCLUSION

Detection of cancer in surgically resected human kidney tissues is demonstrated ex vivo with Vis-NIR MCI, and in vivo on mice with breast or lung xenografts.

Role Of Robot-Assisted Partial Nephrectomy For Renal Cell Carcinomas In The Purpose Of Nephron Sparing

INTRODUCTION

Surgery remains the standard treatment for localized renal cell carcinomas, and partial nephrectomy is considered before radical nephrectomy with the aim of preserving renal function. This study aimed to compare robot-assisted and open partial nephrectomy for the purpose of nephron sparing.

MATERIALS AND METHODS

We retrospectively enrolled consecutive patients who received partial nephrectomy at a single tertiary medical center from January 2008 to January 2015. Medical records and radiographic images were reviewed. We analyzed the patients' general characteristics, underlying disease, complications, length of hospital stay, renal tumor complexity, surgery type, renal function, and specimen and tumor size. A comparison between open and robot-assisted nephrectomy groups was performed.

RESULTS

A total of 136 patients were enrolled, with a male to female ratio of 2:3 and a mean age of 57.8 years. Of these, 71 and 65 patients received open and robot-assisted surgery, respectively. Compared with the open group, patients who underwent robot-assisted surgery were significantly younger (56.0 versus 60.1 years old), had a longer operative time (303 versus 224 min), and a lower kidney ischemic time (33.4 versus 46.9 min). Given similar tumor sizes, the tumor-to-excision ratio was significantly higher in the robot-assisted group (51.7% versus 39.8%), and the excisional volume loss (EVL) was smaller (12.7 versus 19.6 mL). Preoperative glomerular filtration rate and EVL were significant predictors of long-term renal function preservation in the multivariate analysis.

CONCLUSION

When performing partial nephrectomy, a robot-assisted procedure could increase the accuracy of excision without increasing the risk of positive surgical margin. Lower EVL could assist in better long-term postoperative renal function preservation.

Review of methods and applications of attenuation coefficient measurements with optical coherence tomography

The optical attenuation coefficient (AC), an important tissue parameter that measures how quickly incident light is attenuated when passing through a medium, has been shown to enable quantitative analysis of tissue properties from optical coherence tomography (OCT) signals. Successful extraction of this parameter would facilitate tissue differentiation and enhance the diagnostic value of OCT. In this review, we discuss the physical and mathematical basis of AC extraction from OCT data, including current approaches used in modeling light scattering in tissue and in AC estimation. We also report on demonstrated clinical applications of the AC, such as for atherosclerotic tissue characterization, malignant lesion detection, and brain injury visualization. With current studies showing AC analysis as a promising technique, further efforts in the development of methods to accurately extract the AC and to explore its potential use for more extensive clinical applications are desired.

Can MRI be used to diagnose histologic grade in T1a (< 4 cm) clear cell renal cell carcinomas?

OBJECTIVE

To assess whether MRI can differentiate low-grade from high-grade T1a cc-RCC.

MATERIALS AND METHODS

With IRB approval, 49 consecutive solid < 4 cm cc-RCC (low grade [Grade 1 or 2] N = 38, high grade [Grade 3] N = 11) with pre-operative MRI before nephrectomy were identified between 2013 and 2018. Tumor size, apparent diffusion coefficient (ADC) histogram analysis, enhancement wash-in and wash-out rates, and chemical shift signal intensity index (SI index) were assessed by a blinded radiologist. Subjectively, two blinded Radiologists also assessed for (1) microscopic fat, (2) homogeneity (5-point Likert scale), and (3) ADC signal (relative to renal cortex); discrepancies were resolved by consensus. Outcomes were studied using Chi square, multivariate analysis, logistic regression modeling, and ROC. Inter-observer agreement was assessed using Cohen's kappa.

RESULTS

Tumor size was 24 ± 7 (13-39) mm with no association to grade (p = 0.45). Among quantitative features studied, corticomedullary phase wash-in index (p = 0.015), SI index (p = 0.137), and tenth-centile ADC (p = 0.049) were higher in low-grade tumors. 36.8% (14/38) low-grade tumors versus zero high-grade tumors demonstrated microscopic fat (p = 0.015; Kappa = 0.67). Microscopic fat was specific for low-grade disease (100.0% [71.5-100.0]) with low sensitivity (36.8% [21.8-54.6]). Other subjective features did not differ between groups (p > 0.05). A logistic regression model combining microscopic fat + wash-in index + tenth-centile-ADC yielded area under ROC curve 0.98 (Confidence Intervals 0.94-1.0) with sensitivity/specificity 87.5%/100%.

CONCLUSION

The combination of microscopic fat, higher corticomedullary phase wash-in and higher tenth-centile ADC is highly accurate for diagnosis of low-grade disease among T1a clear cell RCC.

Collagen organization of renal cell carcinoma differs between low and high grade tumors

Background

The traditional pathologic grading for human renal cell carcinoma (RCC) has low concordance between biopsy and surgical specimen. There is a need to investigate adjunctive pathology technique that does not rely on the nuclear morphology that defines the traditional grading. Changes in collagen organization in the extracellular matrix have been linked to prognosis or grade in breast, ovarian, and pancreatic cancers, but collagen organization has never been correlated with RCC grade. In this study, we used Second Harmonic Generation (SHG) based imaging to quantify possible differences in collagen organization between high and low grades of human RCC.

Methods

A tissue microarray (TMA) was constructed from RCC tumor specimens. Each TMA core represents an individual patient. A 5 μm section from the TMA tissue was stained with standard hematoxylin and eosin (H&E). Bright field images of the H&E stained TMA were used to annotate representative RCC regions. In this study, 70 grade 1 cores and 51 grade 4 cores were imaged on a custom-built forward SHG microscope, and images were analyzed using established software tools to automatically extract and quantify collagen fibers for alignment and density assessment. A linear mixed-effects model with random intercepts to account for the within-patient correlation was created to compare grade 1 vs. grade 4 measurements and the statistical tests were two-sided.

Results

Both collagen density and alignment differed significantly between RCC grade 1 and RCC grade 4. Specifically, collagen fiber density was greater in grade 4 than in grade 1 RCC (p < 0.001). Collagen fibers were also more aligned in grade 4 compared to grade 1 (p < 0.001).

Conclusions

Collagen density and alignment were shown to be significantly higher in RCC grade 4 vs. grade 1. This technique of biopsy sampling by SHG could complement classical tumor grading approaches. Furthermore it might allow biopsies to be more clinically relevant by informing diagnostics. Future studies are required to investigate the functional role of collagen organization in RCC.

Histologic Diagnosis of Renal Mass Biopsy

CONTEXT.—

Core biopsy has been increasingly used for clinical decision-making in the management of patients with renal masses. The sensitivity and specificity of histologic diagnoses of renal mass biopsies depend on many factors such as adequate sampling and tissue processing, diagnostic skill and experience, and appropriate use of ancillary techniques.

OBJECTIVE.—

To review the indications, emphasize the importance of obtaining adequate diagnostic material, and introduce a general diagnostic approach, in conjunction with immunohistochemistry, in diagnosis of renal mass biopsies.

DATA SOURCES.—

Literature review and personal experiences in daily practice and consultation diagnosis of renal masses in a large tertiary medical center.

CONCLUSIONS.—

For renal mass biopsies, it is critical to obtain adequate diagnostic material and establish a standard laboratory procedure in working with small biopsy specimens. The key for the diagnosis is to be familiar with different tumor entities with characteristic morphology and to understand the wide spectrum of tumor heterogeneity. By developing a systematic approach, one can categorize the tumor and create a sensible differential diagnosis based on the growth pattern and cellular morphology. Immunohistochemistry is particularly helpful for renal mass biopsy diagnosis in selected situations.

Cryoablation versus Partial Nephrectomy for Clinical Stage T1 Renal Masses: A Systematic Review and Meta-Analysis

Introduction: Cryoablation has been considered as the most efficacious ablative alternative to partial nephrectomy (PN) for selected patients. Our objective is to assess the existing evidence relating to the safety and efficacy of cryoablation compared with PN for clinical T1 renal masses.

Materials and Methods: A comprehensive search of PMC, EMBASE, and the Cochrane Library was conducted to identify studies containing comparison of cryoablation and PN. By utilizing those included studies, a systematic review and cumulative meta-analyses were performed to assess the safety and efficacy between cryoablation and PN for T1 renal masses.

Results: 17 retrospective studies providing available data were included in our study. Significant differences were found about all oncological variables including all-cause death, cancer-specific death, metastasis and local-recurrence (p < 0.001, p = 0.03, p < 0.001, and p < 0.001, respectively) between the PN group and the cryoablation group. The mean difference between two groups for percent estimated glomerular filtration rate decrease and creatinine increase was -4.84 and 0.15 respectively (p < 0.001 and p = 0.006, respectively). The incidences of overall and postoperative complications in the PN group were significantly higher than that in the cryoablation group (p = 0.001 and p < 0.001, respectively), but the result about intraoperative complications didn't show a significant difference between the two groups (p = 0.53).

Conclusions: Comparing with PN, cryoablation for clinical T1 renal tumors is associated with poorer oncological outcomes, but the existing disadvantages are accompanied by lower rate of overall and postoperative complications and superior renal functional preservation. For patients with imperative indications for nephron-sparing surgery who can't risk more invasive PN, cryoablation could be an attractive option. Owing to the inherent limitations of eligible studies, conclusions drawn from our meta-analyses should be interpreted cautiously and be confirmed further with well-designed randomized controlled trials with extensive follow-up length.

Trends in the incidence and mortality of kidney cancer in Lithuania from 1993 to 2012

Background.

The aim of this paper is to analyse trends of kidney cancer incidence and mortality in Lithuania during the period of 1993 to 2012 using joinpoint regression models with special attention to changes in the distribution of stages.

Materials and methods.

The study was based on all cases of kidney cancer reported to the Lithuanian Cancer Registry between 1993 and 2012. Age group-specific rates and standardized rates were calculated for each sex, using the direct method (world standard population). The joinpoint regression model was used to provide the estimated annual percentage change and to detect points in time where significant changes in the trends occur.

Results.

During the study period the age-standardized incidence rates increased from 16.89/100,000 in 1993 to 27.77/100,000 in 2012 in males, and from 7.95/100,000 to 13.44/100,000 in females. During this period, annual percentage changes in the age-standardized rates were 2.33% and 1.81% for males and females, respectively. The joinpoint analysis by stage of disease showed the highest increase in stage I kidney cancer, with statistically significant trend change in 2002 for males and in 2001 for females. During the study period, age-standardized mortality rates decreased from 10.42/100,000 in 1993 to 8.96/100,000 in 2012 in males, and from 4.54/100,000 to 3.9/100,000 in females.

Conclusions.

The kidney cancer incidence rate in Lithuania rose during the period of 1993 to 2012. The detailed analysis by stage showed the most significant increase in organ-confined incidence of kidney cancer. A stable mortality trend for males and a decreasing mortality trend for females along with increased incidence of early stage kidney cancer indicate that both earlier detection and modern treatment modalities may contribute to the reduction of mortality.

Quantitative multiparametric MR analysis of small renal lesions: correlation with surgical pathology

PURPOSE

The purpose of the study is to evaluate the utility of apparent diffusion coefficient (ADC), chemical shift signal intensity index (SII), and contrast enhancement in distinguishing between benign lesions and renal cell carcinoma (RCC) and between subtypes of renal lesions.

METHODS

This retrospective study included 98 renal lesions (≤ 3 cm) on MRI with correlative surgical pathology. Scanner field strength, lesion location, and size were recorded. Two readers blinded to surgical pathology independently measured ADC ratio (ADC lesion/ADC non-lesion kidney), SII, and absolute/relative enhancement in the corticomedullary and nephrographic phases of contrast.

RESULTS

There were 76 malignant and 22 benign lesions. 42 RCC were clear cell (ccRCC), 19 papillary (pRCC), 5 chromophobe (cbRCC). Benign lesions included both solid and cystic lesions. Interreader agreement for all variables was good-excellent (ICC 0.70-0.91). There was no difference in ADC or SII between benign and malignant lesions. There was greater absolute corticomedullary enhancement of benign versus malignant lesions (150.0 ± 111.5 vs. 81.1 ± 74.8, p = 0.0115), which did not persist when excluding pRCC. For lesion subtype differentiation, ADC_ratio for pRCC was lower than benign lesions (0.74 ± 0.35 vs. 1.03 ± 0.46, p = 0.0246). ccRCC demonstrated greater SII than other RCC (0.09 ± 0.22 vs. 0.001 ± 0.26, p = 0.0412). Oncocytomas and angiomyolipoma (AML) showed greater absolute corticomedullary enhancement than ccRCC and pRCC (145.6 ± 65.2 vs. 107.2 ± 85.3, p = 0.043 and 186.2 ± 93.9 vs. 37.6 ± 35.3, p = 0.0108), respectively.

CONCLUSIONS

While corticomedullary-phase enhancement was a differentiating feature, quantitative metrics from diffusion and chemical shift imaging cannot reliably differentiate benign from malignant lesions. Quantitative assessment may be useful in differentiating some benign and malignant lesion subtypes.

Urologic Pathology: Key Parameters from a Urologist's Perspective

Prostate cancer, bladder cancer, and kidney cancer represent the 3 most common urologic malignancies, and form a heterogenous group of disease processes, with a wide range of pathologic features. As a urologist, a strong understanding of the pathologic features of urologic malignancies is essential to prognosticate and counsel patients and to determine the most effective course of treatment. This review discusses the pathologic features of prostate, bladder, and kidney cancer, and examines how detailed pathologic reporting is critical to today's practicing urologist.

Adult Renal Neoplasms: Cytology, Immunohistochemistry, and Cytogenetic Characteristics

Tissue sampling of renal masses is traditionally performed using percutaneous sonographic or CT guidance core biopsy (CB) with or without touch preparation cytology and/or fine-needle aspiration cytology (FNAC). The combined used of CB and FNAC is expanding in clinical practice, especially in small renal masses and plays a pivotal role in therapeutic decision making. Grouping the renal neoplasms in differential diagnostic groups helps in choosing specific immunohistochemical markers and reaching an accurate diagnosis.

Intraoperative mannitol during robotic-assisted-laparoscopic partial nephrectomy

Mannitol is routinely used during partial nephrectomies due to its renoprotective properties. With minimally invasive techniques, the need for mannitol has been questioned. Robotic-assisted laparoscopic partial nephrectomy (RALPN) has been shown to decrease warm ischemia time, which may potentially minimize the benefit of mannitol. To date, no prospective, randomized, controlled trials have investigated the use of mannitol in only robotic procedures. We hypothesize that the intraoperative mannitol use during RALPN provides no statistically significant benefit for post-operative renal function outcomes. We conducted a randomized, controlled, double-blinded, single surgeon, prospective study to assess renal function after RALPN. Patients were randomized into a control group with intravenous normal saline infusion prior to clamping of the vessels or to an experimental group with an infusion of mannitol. Estimated glomerular filtration rate (eGFR) were obtained prior to the surgery as well as post operatively at 24 h, 1 week, and 30 days. Preoperative eGFR showed no statistical differences between the groups and evaluation of median percent change in eGFR after surgery did not indicate a statistical difference between the groups after RALPN. After prospective analysis of the change in post-operative renal function of randomized groups who received 12 g of mannitol following RALPN, we determined that infusion of mannitol does not provide significant improvement of maintenance of renal functions after RALPN. Based on our results, we recommend discontinuing routine use of mannitol during RALPN.

Is Cryotherapy a Genuine Rival to Robotic-assisted Partial Nephrectomy in the Management of Suspected Renal Malignancy? A Systematic Review and Meta-analysis

We systematically reviewed the world literature and compare oncological outcomes, morbidity, renal function, and perioperative outcome between cryotherapy and robotic-assisted partial nephrectomy (RAPN) for suspected renal malignancy. There was a statistically significant difference in "recurrence rates" between the 2 techniques, favoring the RAPN cohort. There was no statistically significant difference in overall and ≥Clavien 3a complication rates between the 2 techniques. The quality of evidence for recurrence rates, overall complication, and ≥Clavien 3a were "moderate", "low," and "very low," respectively, on GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. If a nephron sparing approach is indicated, RAPN should be the approach of choice.

Comparisons of percutaneous versus retroperitoneoscopic cryoablation for renal masses

PURPOSE

Preserving renal function and controlling oncological outcomes are pertinent while managing renal tumours. We compared outcomes of percutaneous cryoablation (PCA) and retroperitoneoscopic cryoablation (RCA) in patients with renal neoplasms.

METHODS

We identified 108 patients with renal tumours at two medical centres, where 63 patients received PCA and 45 patients underwent RCA from August 2009 to July 2015, and they were followed up until February 2017. We compared preoperative and postoperative parameters, namely gender, systemic diseases, age, American Society of Anesthesiologists score, body mass index (BMI), haemoglobin, the estimated glomerular filtration rate, tumour size, operative time, tumour type, Clavien-Dindo classification of surgical complications, and tumour recurrence, by using an independent sample t test, Pearson's Chi-square test, Fisher's exact test, a Mann-Whitney test, and a generalised linear model.

RESULTS

Based on baseline characteristics, we found that the patients in the PCA group were older and had higher BMI than those in the RCA group, whereas the patients in the RCA group had more comorbidities than those in the PCA group. Retroperitoneoscopic and percutaneous methods had similar operative times, blood transfusion rates, postoperative fever episodes, and complication rates for either minor or major complications. However, the percutaneous method was associated with a shorter length of stay. No patient experienced deterioration in renal function until 2 years after both procedures. Impaired renal function was found in both groups in the 3-year follow-up. In both groups, tumour recurrence was significant for tumours > 4 cm.

CONCLUSIONS

Our results confirm that both cryoablation methods (PCA and RCA) are safe and effective for renal cell carcinoma. Favourable oncological control was achieved in both groups if the renal tumour size was ≤ 4 cm.

Demographic characteristics and complications of open and minimally invasive surgeries for renal cell carcinoma: a population-based case-control study in Taiwan

Introduction

Renal cell carcinoma (RCC) is one of the most lethal urological malignancies, and surgeries remain the mainstay for localized RCC. This study aimed to compare the selection of open surgery and minimally invasive kidney surgery for RCCs for the aspects of complication, medical costs, and patient preference.

Materials and methods

We conducted a population-based case-control study by using the National Health Insurance Research Database of Taiwan, which included data from 23 million Taiwanese residents. Patients newly diagnosed with RCC during 2006-2012 were included. We compared the general characteristics, underlying disease, complications, hospital stay, postoperative analgesic dosage, and medical costs between open group and minimally invasive group.

Results

A total of 3,172 patients who received radical nephrectomy (RN) or partial nephrectomy (PN) for RCC were included. The mean age was 61.1 years, with a male to female ratio of 1.88. In the minimally invasive groups, the mean hospital stay was significantly shorter than in open groups (12.4 days in open RN versus 10.3 days in minimally invasive RN, and 9.7 days in open PN versus 8.2 days in minimally invasive PN). There was no significant difference between the medical costs and the incidence of major bleeding complication between the open group and the minimally invasive group. Female patients and patients with higher monthly income were more likely to receive minimally invasive surgery.

Conclusion

During past decades, open RN has gradually been replaced by minimally invasive surgeries and PN. Compared to open surgeries, minimally invasive surgeries could lead to less postoperative pain and faster recovery. Economic status of the patients potentially hinders them from receiving minimally invasive surgeries, which may cost more.

Determinant factors for chronic kidney disease after partial nephrectomy

The objective of this review is to evaluate the factors that determine the development or deterioration of Chronic Kidney Disease (CKD) after partial nephrectomy (PN).

When current literature is reviewed, it is found that factors that influence renal function after partial nephrectomy, are multifactorial. Those are divided into pre-surgical factors, such as hypertension, diabetes mellitus, urolithiasis, obesity, metabolic syndrome among others; intra-surgical factors, like the surgical technique used, the remaining healthy tissue, the experience of the surgeon, the time and type of ischemia among others. Lastly, post-surgical factors, also impose some influence on the post-surgical renal performance.

It was also found that minimally invasive surgery, in addition to its known advantages, seems to offer a greater field of action in the future that will allow more nephrons preservation in any future surgical scenario.

Finally, the current trend is to perform PN on all patients, in whom surgery is technically feasible regardless of the approach used, without risking oncological outcomes, patient safety, and without being exposed to any additional complications.

Management of Small Renal Masses

With the ubiquitous use of cross-sectional abdominal imaging in recent years, the incidence of small renal masses (SRMs) has increased, and the evaluation and management of SRMs have become important clinical issues. Diagnosing a mass in the early stages theoretically allows for high rates of cure but simultaneously risks overtreatment. In the past 20 years, surgical treatment of SRMs has transitioned from radical nephrectomy for all renal tumors, regardless of size, to elective partial nephrectomy whenever technically feasible. Additionally, newer approaches, including renal mass biopsy, active surveillance for select patients, and renal mass ablation, have been increasingly used. In this chapter, we review the current evidence-based papers covering aspects of the diagnosis and management of SRMs.

Irreversible electroporation for locally advanced pancreatic cancer through a minimally invasive surgery supported by laparoscopic ultrasound

INTRODUCTION

Pancreatic cancer is one of the most lethal cancers worldwide, with 5-years survival rate as low as 6%. The majority of pancreatic cancer patients present locally advanced or metastatic disease at diagnosis. Typically, patients affected by locally advanced pancreatic cancer (LAPC) do not undergo radical surgery but are treated with focal ablative therapies. However, a high rate of morbidity due to the heat sink effect has limited the application of ablative techniques on a routine basis in LAPC patients. Irreversible electroporation (IRE) has proved to be a new method of LAPC ablation.

PRESENTATION OF THE CASE

A 69-year-old woman affected by LAPC with good response to systemic chemotherapy with FOLFIRINOX and residual 35 mm mass in the neck of the pancreas underwent to IRE through a minimally invasive surgical approach under laparoscopic ultrasound guide. The post-operative course was uneventful and the patient was discharged after 5 days. Six months after surgery she had no evidence of distant or recurrent disease.

DISCUSSION

IRE has previously shown promising results in the treatment of LAPC, with relatively acceptable morbidity rates and improvement of survival. We report on the application of IRE through a minimally invasive surgical approach supported by laparoscopic ultrasound.

CONCLUSION

In conclusion, we propose a novel technical approach that combines the benefits of IRE on the treatment of patients affected by LAPC with the advantages of laparoscopic surgery.

Glomerular loss after arteriovenous and arterial clamping for renal warm ischemia in a swine model

PURPOSE:

To evaluate the glomerular loss after arteriovenous or arterial warm ischemia in a swine model.

METHODS:

Twenty four pigs were divided into Group Sham (submitted to all surgical steps except the renal ischemia), Group AV (submitted to 30 minutes of warm ischemia by arteriovenous clamping of left kidney vessels), and Group A (submitted to 30 minutes of ischemia by arterial clamping). Right kidneys were used as controls. Weigh, volume, cortical volume, glomerular volumetric density (Vv[Glom]), volume-weighted glomerular volume (VWGV), and the total number of glomeruli were measured for each organ.

RESULTS:

Group AV showed a 24.5% reduction in its left kidney Vv[Glom] and a 25.4% reduction in the VWGV, when compared to the right kidney. Reductions were also observed when compared to kidneys of sham group. There was a reduction of 19.2% in the total number of glomeruli in AV kidneys. No difference was observed in any parameters analyzed on the left kidneys from group A.

CONCLUSIONS:

Renal warm ischemia of 30 minutes by arterial clamping did not caused significant glomerular damage, but arteriovenous clamping caused significant glomerular loss in a swine model. Clamping only the renal artery should be considered to minimize renal injury after partial nephrectomies.

Pathological heterogeneity in sporadic synchronous renal tumors: Is the histological concordance predictable?

OBJECTIVE

To evaluate the pathological concordance rate of multiple synchronous renal masses (MSRM) presumed to be sporadic and to analyze predictive factors of concordance.

MATERIAL AND METHODS

We identified from our institutional database patients with sporadic MSRM treated at our center between January 2000 and December 2015. All tumors were reviewed by a dedicated uropathologist. Pathological concordance rate was analyzed regarding clinical characteristics and preoperative imaging.

RESULTS

We included 112 patients: 50 had unilateral synchronous renal masses and 62 bilateral synchronous renal masses. A total of 291 tumors were analyzed, with an average of 2.6 tumors per patient. Overall, the malignant concordance rate was 91.6%, the pathological concordance rate was 67.3% and the grade concordance rate was 62.5%. In univariate analysis, predictive factors of histological concordance were bilateral synchronous renal masses (odds ratio [OR] = 3.39; 95% CI: 1.06-10.8; P = 0.04), age<60 years (OR = 3.04; 95% CI: 1.2-7.7; P = 0.02) and ≥3 lesions (OR = 2.41; 95% CI: 1.03-5.68; P = 0.04). In multivariate analysis, age<60 remained significantly associated with histological concordance (OR = 3.84; 95% CI: 1.24-11.9; P = 0.02).

CONCLUSIONS

The histological concordance rate of MSRM is low. Age at diagnosis <60 years, bilateral lesions and ≥3 tumors are predictive factors of histological concordance, but the pathological diagnosis remains difficult to predict. This heterogeneity is important to take into account, particularly when choosing the treatment upon the renal biopsy results from a single lesion.

Management of the small renal mass

The increasing use of cross-sectional imaging has led to an increase in the diagnosis of incidental small renal masses (SRMs). About 20% of such masses are benign, while a significant proportion of malignant SRMs demonstrate slow growth kinetics and non-aggressive histologic features. Given these characteristics, lesions that were traditionally treated surgically are increasingly managed with less aggressive approaches. Further contributing to the evolving management paradigm is accumulating evidence supporting the safety of active surveillance and the efficacy of percutaneous renal mass biopsy in guiding management decisions. This review first discusses the epidemiology and diagnostic work-up of SRMs. The available management options are then examined, with emphasis placed on the clinical factors considered in selecting an appropriate approach. The existing evidence and long-term outcomes of each strategy are discussed. Finally, an overview of the current paradigm for the management of a patient with a SRM is provided. The goal is to provide physicians with the necessary understanding to appropriately manage this increasingly common condition.

Renal Tumor Invasion Depth and Diameter are the Two Most Accurate Anatomical Features Regarding the Choice of Radical Versus Partial Nephrectomy

BACKGROUND AND AIMS

To evaluate simple tumor characteristics (renal tumor diameter and parenchymal invasion depth) compared with more complex classifications, that is, Renal Tumor Invasion Index (RTII) and Preoperative Aspects and Dimensions Used for an Anatomical classification, in predicting the type of nephrectomy (radical vs partial) performed.

MATERIAL AND METHODS

A total of 915 patients who had undergone either partial nephrectomy ( n = 388, 42%) or radical nephrectomy ( n = 527, 58%) were identified from the Helsinki University Hospital kidney tumor database between 1 January 2006 and 31 December 2014. Tumor maximum diameter and depth of invasion into the parenchyma were estimated from computed tomography or magnetic resonance imaging images and compared with Preoperative Aspects and Dimensions Used for an Anatomical and Renal Tumor Invasion Index. Logistic regression and receiver operating curves were used to compare the parameters at predicting the type of nephrectomy.

RESULTS AND CONCLUSION

All the anatomical variables of receiver operating curve/area under the curve analyses were significant predictors for the type of nephrectomy. Parenchymal invasion (area under the curve 0.91; 95% confidence interval, 0.89-0.93), RTII (area under the curve 0.91; 95% confidence interval, 0.89-0.93), and diameter (area under the curve 0.91; 95% confidence interval, 0.89-0.93) performed significantly better than Preoperative Aspects and Dimensions Used for an Anatomical classification (area under the curve 0.88; 95% confidence interval, 0.85-0.89). In multivariable analysis, invasion depth was the best predictor of nephrectomy type (percentage correct, 85.6%). Addition of one anatomic parameter into the model of non-anatomical cofactors improved the accuracy of the model significantly, but the addition of more parameters did not. Parenchymal invasion depth and tumor diameter are the most accurate anatomical features for predicting the nephrectomy type. All potential anatomical classification systems should be tested against these two simple characteristics.

Statistical clustering of parametric maps from dynamic contrast enhanced MRI and an associated decision tree model for non-invasive tumour grading of T1b solid clear cell renal cell carcinoma

OBJECTIVES

To apply a statistical clustering algorithm to combine information from dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) into a single tumour map to distinguish high-grade from low-grade T1b clear cell renal cell carcinoma (ccRCC).

METHODS

This prospective, Institutional Review Board -approved, Health Insurance Portability and Accountability Act -compliant study included 18 patients with solid T1b ccRCC who underwent pre-surgical DCE MRI. After statistical clustering of the parametric maps of the transfer constant between the intravascular and extravascular space (K ^trans ), rate constant (K _ep ) and initial area under the concentration curve (iAUC) with a fuzzy c-means (FCM) algorithm, each tumour was segmented into three regions (low/medium/high active areas). Percentages of each region and tumour size were compared to tumour grade at histopathology. A decision-tree model was constructed to select the best parameter(s) to predict high-grade ccRCC.

RESULTS

Seven high-grade and 11 low-grade T1b ccRCCs were included. High-grade histology was associated with higher percent high active areas (p = 0.0154) and this was the only feature selected by the decision tree model, which had a diagnostic performance of 78% accuracy, 86% sensitivity, 73% specificity, 67% positive predictive value and 89% negative predictive value.

CONCLUSIONS

The FCM integrates multiple DCE-derived parameter maps and identifies tumour regions with unique pharmacokinetic characteristics. Using this approach, a decision tree model using criteria beyond size to predict tumour grade in T1b ccRCCs is proposed.

KEY POINTS

• Tumour size did not correlate with tumour grade in T1b ccRCC. • Tumour heterogeneity can be analysed using statistical clustering via DCE-MRI parameters. • High-grade ccRCC has a larger percentage of high active area than low-grade ccRCCs. • A decision-tree model offers a simple way to differentiate high/low-grade ccRCCs.

Positive surgical margins during partial nephrectomy for renal cell carcinoma: Results from Canadian Kidney Cancer information system (CKCis) collaborative

INTRODUCTION

We sought to determine the incidence, risk factors, and prognosis for patients with positive surgical margin (PSM) during partial nephrectomy (PN) for renal cell carcinoma (RCC).

METHODS

From the Canadian Kidney Cancer information system (CKCis) database, a historical cohort of PN patients with PSM were identified and compared to negative surgical margin (NSM). Risk factors for PSM were examined through multivariable logistic regression. Kaplan-Meier curves were used to compare progression-free survival.

RESULTS

Of 1103 patients, 972 (88.1%), 71 (6.4%), and 60 (5.4%) had NSM, PSM, and unknown status, respectively. Median patient age and tumour size were 61 years and 3.0 cm for both groups. From multivariable analysis, pathological stage ≥T3 (odds ratio [OR] 2.51; 95% confidence interval [CI] 1.13-5.60) and Fuhrman grade 4 (OR 5.35; 95% CI 1.11-25.72) were associated with PSM, whereas age, operative technique, and tumour size were not. Forty-nine (5.0%) patients from the NSM cohort and seven (9.9%) from the PSM cohort had a local/systemic progression of disease (adjusted hazard ratio [HR] 1.4; 95% CI 0.6-3.6). There were three (0.3%) cancer-related deaths in the NSM group and none in the PSM group. After median followup of 19 (interquartile range [IQR] 5-42) and 15 (IQR 7-30) months, 855 (91.4%) and 61 (89.7%) patients were alive in the NSM and PSM groups, respectively.

CONCLUSIONS

PSM occurred in 6.4% of PNs performed for RCC in this pan-Canadian cohort. Higher stage and grade are associated with a higher risk of positive margin. The small association between a PSM and progression suggests that complete nephrectomy is not necessary in patients with a PSM. The main study limitations are lack of nephrometry score and possible reporting bias.

Update on Renal Mass Biopsy

Renal masses are diagnosed with an increasing frequency. However, a significant proportion of these masses are benign, and the majority of malignant tumors are biologically indolent. Furthermore, renal tumors are often harbored by the elderly and comorbid patients. As such, matching of renal tumor biology to appropriate treatment intensity is an urgent clinical need. Renal mass biopsy is currently a very useful clinical tool that can assist with critical clinical decision-making in patients with renal mass. Yet, renal mass biopsy is associated with limitations and, as such, may not be appropriate for all patients.