Review of renal cell carcinoma and its common subtypes in radiology

High-grade eosinophilic renal tumor/eosinophilic vacuolar renal tumor: a case report and literature review

INTRODUCTION

Renal oncocytoma (RO) is an uncommon benign neoplasm of the kidney, while eosinophilic vacuolated tumor (EVT) represents a distinct subtype of renal oncocytoma characterized by specific morphological features. EVT is a rare eosinophilic renal neoplasm distinguished by its unique morphological, immunophenotypic, and molecular genetic attributes. Its biological behavior is generally indolent, and it is associated with a favorable prognosis.

CASE REPORT

This case report provides a comprehensive account of a 52-year-old female patient who presented to the hospital for a medical evaluation, revealing that her left kidney had been occupying space for over one month. Following an abdominal enhanced CT scan, a diagnosis of renal clear cell carcinoma was suspected, leading to the decision to perform a "robot-assisted laparoscopic partial left nephrectomy." During the surgical procedure, a mass measuring approximately 3.8 × 3.5 cm was identified adjacent to the renal hilum in the midsection of the left kidney. Subsequent pathological analysis classified the excised tumor as an eosinophilic vacuolar tumor of the kidney.

CONCLUSION

This case illustrates that EVT represents a novel solid neoplasm of the kidney, with occurrences being exceedingly uncommon. It is imperative for clinicians and pathologists to enhance their comprehension of these tumors and distinguish them effectively, thereby facilitating more precise classification of renal tumors and informing clinical management and prognostic assessment.

Intraoperative tumor capsule injury in patients with renal cell carcinoma receiving partial nephrectomy

OBJECTIVE

We investigated the impact of intraoperative tumor capsule injury (TCI) during robot-assisted partial nephrectomy (RAPN) or laparoscopic partial nephrectomy (LPN) on oncological outcomes, as well as underlying factors of intraoperative TCI for improving surgical outcomes.

METHODS

A total of 253 patients who underwent RAPN or LPN between 2010 and 2022 were retrospectively analyzed and were divided into two groups: non-TCI and TCI groups. The background was compared between two groups. We investigated the surgical records or video to evaluate TCI and seek the possible causes for TCI. Multivariate logistic regression analysis was performed to identify prognostic factors for cancer recurrence.

RESULTS

Of the 253 patients, 227 have renal cell carcinoma (RCC), with 29 patients having TCI. The TCI group had larger tumors, a lower rate of trifecta achievement, higher bleeding, higher T stage, and a lower rate of clear cell RCC (ccRCC) histological types as compared to non-TCI group. Disease recurrence rate was 13.8% with TCI and 1.0% with non-TCI (odds ratio 15.7; 95% confidence interval, 2.73-90.1; p = 0.003). Univariate and multivariate analyses confirmed TCI as an independent prognostic factor for disease-free survival. Compared with ccRCC, non-clear cell RCC (non-ccRCC) was found to have a higher probability of TCI and a significantly thinner capsule thickness on pathological evaluation.

CONCLUSION

TCI had a negative impact on oncological outcomes. Surgeons should consider thickness of tumor capsules, especially in cases with non-ccRCC, to minimize the risk of TCI during partial nephrectomy.

Value of Contrast-Enhanced Ultrasound in the Diagnosis of Clear Cell Renal Cell Carcinoma: A Meta-Analysis

This meta-analysis aims to evaluate the accuracy of contrast-enhanced ultrasound (CEUS) in diagnosing clear cell renal cell carcinoma (ccRCC). Literature published in five databases was searched. Twelve studies were included. The pooled results showed sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of CEUS were 79% (95% CI: 75%-83%), 84% (95% CI: 80%-88%), 4.97 (95% CI: 3.86-6.39), 0.24 (95% CI: 0.20-0.30), and 20.32 (95% CI: 13.84-29.84), respectively. The area under the summary receiver operating characteristic curve was 0.86. In conclusion, CEUS demonstrates high sensitivity and specificity in diagnosing ccRCC, showing good diagnostic accuracy.

Volatile Organic Metabolites as Potential Biomarkers for Genitourinary Cancers: Review of the Applications and Detection Methods

Cancer is one of the leading causes of death globally, and is ranked second in the United States. Early detection is crucial for more effective treatment and a higher chance of survival rates, reducing burdens on individuals and societies. Genitourinary cancers, in particular, face significant challenges in early detection. Finding new and cost-effective diagnostic methods is of clinical need. Metabolomic-based approaches, notably volatile organic compound (VOC) analysis, have shown promise in detecting cancer. VOCs are small organic metabolites involved in biological processes and disease development. They can be detected in urine, breath, and blood samples, making them potential candidates for sensitive and non-invasive alternatives for early cancer detection. However, developing robust VOC detection methods remains a hurdle. This review outlines the current landscape of major genitourinary cancers (kidney, prostate, bladder, and testicular), including epidemiology, risk factors, and current diagnostic tools. Furthermore, it explores the applications of using VOCs as cancer biomarkers, various analytical techniques, and comparisons of extraction and detection methods across different biospecimens. The potential use of VOCs in detection, monitoring disease progression, and treatment responses in the field of genitourinary oncology is examined.

Innovative Therapies Targeting Drug-Resistant Biomarkers in Metastatic Clear Cell Renal Cell Carcinoma (ccRCC)

A thorough study of Clear Cell Renal Cell Carcinoma (ccRCC) shows that combining tyrosine kinase inhibitors (TKI) with immune checkpoint inhibitors (ICI) shows promising results in addressing the tumor-promoting influences of abnormal immunological and molecular biomarkers in metastatic Clear Cell Renal Cell Carcinoma (ccRCC). These abnormal biomarkers enhance drug resistance, support tumor growth, and trigger cancer-related genes. Ongoing clinical trials are testing new treatment options that appear more effective than earlier ones. However, more research is needed to confirm their long-term safety use and potential side effects. This study highlights vital molecular and immunological biomarkers associated with drug resistance in Clear Cell Renal Cell Carcinoma (ccRCC). Furthermore, this study identifies a number of promising drug candidates and biomarkers that serve as significant contributors to the enhancement of the overall survival of ccRCC patients. Consequently, this article offers pertinent insights on both recently completed and ongoing clinical trials, recommending further toxicity study for the prolonged use of this treatment strategy for patients with metastatic ccRCC, while equipping researchers with invaluable information for the progression of current treatment strategies.

Low-grade oncocytic tumor of the kidney: imaging features of a novel tumor entity

PURPOSES

Low-grade oncocytic tumor (LOT) is a rare renal tumor that has emerged from the spectrum of eosinophilic/oncocytic renal tumors and poses a diagnostic challenge due to its similarity to chromophobe renal cell carcinoma (CHRCC) and renal oncocytoma (RO). The imaging features of this novel tumor entity have not yet been clearly described. The purpose of this study was to describe the imaging features of LOT with radiologic-pathologic correlation.

METHODS

We conducted a retrospective observational study involving two expert centers. We identified 12 pathologically proven LOT with preoperative imaging available, including at least computed tomography (CT) or magnetic resonance imaging (MRI), from the past 12 years. Three experienced radiologists performed the imaging analysis independently.

RESULTS

All tumors presented well-defined borders. Nine of the 12 LOT exhibited an early peripheral enhancement with complete or almost complete centripetal fill-in on nephrographic or delayed phases without any particular shape. Three showed a homogeneous contrast enhancement. Macroscopic fat and calcifications were not observed in any of the tumors.

CONCLUSION

Early peripheral enhancement with complete or almost complete centripetal fill-in on nephrographic or delayed phases without any particular shape suggests a LOT diagnosis. Further analyses involving larger studies are needed to fully confirm these imaging characteristics. To date, a percutaneous biopsy should be performed before considering management.

The Current State of the Diagnoses and Treatments for Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma is the most common form of kidney cancer, accounting for 75% of malignant kidney tumors, and is generally associated with poor patient outcomes. With risk factors including smoking, obesity, and hypertension, all of which have a high prevalence in the United States and Europe, as well as genetic factors including tuberous sclerosis complex and Von Hippel-Lindau syndrome, there is an increasing need to expand our present understanding. The current clear cell renal cell carcinoma knowledge is outdated, with obsolete diagnostic criteria and moderately invasive surgical treatments still prevailing, partially ascribed to its resistance to chemotherapy and radiation therapy. The standard of treatment relies on surgical intervention, including radical nephrectomy and partial nephrectomy, while more recent treatments target neoplastic growth pathways and immune regulation checkpoints.

Integrative analysis of single-cell and bulk multi-omics data to reveal subtype-specific characteristics and therapeutic strategies in clear cell renal cell carcinoma patients

Background: Kidney renal clear cell carcinoma (KIRC) is the most prevalent subtype of malignant renal cell carcinoma and is well known as a common genitourinary cancer. Stratifying tumors based on heterogeneity is essential for better treatment options. Methods: In this study, consensus clusters were constructed based on gene expression, DNA methylation, and gene mutation data, which were combined with multiple clustering algorithms. After identifying two heterogeneous subtypes, we analyzed the molecular characteristics, immunotherapy response, and drug sensitivity differences of each subtype. And we further integrated bulk data and single-cell RNA sequencing (scRNA-Seq) data to infer the immune cell composition and malignant tumor cell proportion of subtype-related cell subpopulations. Results: Among the two identified consensus subtypes (CS1 and CS2), CS1 was enriched in more inflammation-related and oncogenic pathways than CS2. Simultaneously, CS1 showed a worse prognosis and we found more copy number variations and BAP1 mutations in CS1. Although CS1 had a high immune infiltration score, it exhibited high expression of suppressive immune features. Based on the prediction of immunotherapy and drug sensitivity, we inferred that CS1 may respond poorly to immunotherapy and be less sensitive to targeted drugs. The analysis of bulk data integrated with single-cell data further reflected the high expression of inhibitory immune features in CS1 and the high proportion of malignant tumor cells. And CS2 contained a large number of plasmacytoid B cells, presenting an activated immune microenvironment. Finally, the robustness of our subtypes was successfully validated in four external datasets. Conclusion: In summary, we conducted a comprehensive analysis of multi-omics data with 10 clustering algorithms to reveal the molecular characteristics of KIRC patients and validated the relevant conclusions by single-cell analysis and external data. Our findings discovered new KIRC subtypes and may further guide personalized and precision treatments.

Role of collateral vessels on contrast-enhanced computed tomography in predicting metastatic potential for small renal cell carcinoma

BACKGROUND

The presence of collateral vessels (CVs) on contrast-enhanced computed tomography is a poor prognostic factor in renal cell carcinoma (RCC), but its value in small RCC (sRCC; < 4 cm) remains unknown. In this study, we investigated whether presence of CVs is a predictor of high potential for metastasis in sRCC.

METHODS

We retrospectively reviewed clinical and imaging data of patients with pathologically confirmed sRCC evaluated at our institution between 2011 and 2021. All sRCCs were pathologically diagnosed by biopsy, metastasectomy, partial nephrectomy, or radical nephrectomy. CVs were defined as blood vessels of any diameter connecting the tumor with the surrounding perirenal tissues on contrast-enhanced computed tomography. The rate of metastasis-free survival (MFS), defined as the time from pathological diagnosis to confirmed metastasis, was compared among patients without CVs, those with one CV, and those with two or more CVs.

RESULTS

Of 141 patients, 4 (2.8%) had metastatic sRCC at initial diagnosis. In the 137 patients with nonmetastatic sRCC, the diagnosis was pathologically confirmed following radical surgery. The median follow-up period from pathological diagnosis was 73.9 months, and the overall 5-year MFS was 93.5%. The 5-year MFS was significantly poorer in patients with two or more CVs than in those with one CV (63.8% vs. 96.3%; p = 0.0003) and those without CVs (63.8% vs. 100%; p < 0.0001).

CONCLUSIONS

sRCCs with two or more CVs might have high potential for metastasis. Conversely, sRCCs without CVs might not be aggressive and be suitable for active surveillance.

Venous Tropism in Renal Cell Carcinoma: A Rare Imaging Presentation

Renal cell carcinoma (RCC) is one of the most prevalent malignancies in adults. Accurate staging and assessment of tumor extent are critical for effective management. RCC often demonstrates a tendency for venous invasion, commonly extending into the renal vein and inferior vena cava. However, RCC extending into the gonadal veins is an uncommon manifestation. In this report, we present the imaging features of a 62-year-old woman presented with left flank pain. The ultrasound examination revealed a large hyperechoic mass in the left renal fossa, replacing almost the entire left kidney with the contiguous extension of the tumor into the left renal vein and ovarian vein. Color Doppler showed the presence of flow within the thrombus, confirming the presence of a malignant thrombus. Contrast-enhanced CT examination revealed a large heterogeneously enhancing mass in the left kidney with the contiguous extension of tumor thrombus in the left renal vein, IVC, and into the left ovarian vein. This report highlights how imaging techniques can be instrumental in detecting and characterizing rare but significant tumor extensions, which can have crucial prognostic implications for overall patient management.

Uncertainty quantification in multi-class segmentation: Comparison between Bayesian and non-Bayesian approaches in a clinical perspective

BACKGROUND

Automatic segmentation techniques based on Convolutional Neural Networks (CNNs) are widely adopted to automatically identify any structure of interest from a medical image, as they are not time consuming and not subject to high intra- and inter-operator variability. However, the adoption of these approaches in clinical practice is slowed down by some factors, such as the difficulty in providing an accurate quantification of their uncertainty.

PURPOSE

This work aims to evaluate the uncertainty quantification provided by two Bayesian and two non-Bayesian approaches for a multi-class segmentation problem, and to compare the risk propensity among these approaches, considering CT images of patients affected by renal cancer (RC).

METHODS

Four uncertainty quantification approaches were implemented in this work, based on a benchmark CNN currently employed in medical image segmentation: two Bayesian CNNs with different regularizations (Dropout and DropConnect), named BDR and BDC, an ensemble method (Ens) and a test-time augmentation (TTA) method. They were compared in terms of segmentation accuracy, using the Dice score, uncertainty quantification, using the ratio of correct-certain pixels (RCC) and incorrect-uncertain pixels (RIU), and with respect to inter-observer variability in manual segmentation. They were trained with the Kidney and Kidney Tumor Segmentation Challenge launched in 2021 (Kits21), for which multi-class segmentations of kidney, RC, and cyst on 300 CT volumes are available. Moreover, they were tested considering this and other two public renal CT datasets.

RESULTS

Accuracy results achieved large differences across the structures of interest for all approaches, with an average Dice score of 0.92, 0.58, and 0.21 for kidney, tumor, and cyst, respectively. In terms of uncertainties, TTA provided the highest uncertainty, followed by Ens and BDC, whereas BDR provided the lowest, and minimized the number of incorrect certain pixels worse than the other approaches. Again, large differences were seen across the three structures in terms of RCC and RIU. These metrics were associated with different risk propensity, as BDR was the most risk-taking approach, able to provide higher accuracy in its prediction, but failing to assign uncertainty on incorrect segmentation in every case. The other three approaches were more conservative, providing large uncertainty regions, with the drawback of giving alert also on correct areas. Finally, the analysis of the inter-observer segmentation variability showed a significant variation among the four approaches on the external dataset, with BDR reporting the lowest agreement (Dice = 0.82), and TTA obtaining the highest score (Dice = 0.94).

CONCLUSIONS

Our outcomes highlight the importance of quantifying the segmentation uncertainty and that decision-makers can choose the approach most in line with the risk propensity degree required by the application and their policy.

The influence of sex hormones on renal cell carcinoma

Kidney cancer is a common malignancy that constitutes around 5% of all cancer cases. Males are twice as likely to acquire renal cell carcinoma (RCC) compared to females and experience a higher rate of mortality. These disparities indicate that sex hormone (SH)-dependent pathways may have an impact on the aetiology and pathophysiology of RCC. Examination of SH involvement in conventional signalling pathways, as well as genetics and genomics, especially the involvement of ribonucleic acid, reveal further insights into sex-related differences. An understanding of SHs and their influence on kidney cancer is essential to offer patients individualized medicine that would better meet their needs in terms of prevention, diagnosis and treatment. This review presents the understanding of sex-related differences in the clinical manifestation of kidney cancer patients and the underlying biological processes.

Fangchinoline targets human renal cell carcinoma cells through modulation of apoptotic and non‑apoptotic cell deaths

The process of apoptosis is one of the essential processes involved in maintenance of homeostasis in the human body. It can aid to remove misfolded proteins or cellular organelles. This sequence is especially necessary in cancer cells. However, specifically targeting already apoptotic pathways can induce drug resistance in cancer cells and hence drugs can induce cell death by alternative mechanism. We investigated whether fangchinoline (FCN) can target renal carcinoma cells by inducing multiple cell death mechanisms. Both paraptosis, autophagy, and apoptosis were induced by FCN through stimulation of diverse molecular signaling pathways. FCN induced ROS production with GSH/GSSG imbalance, and ER stress. In addition, formation of autophagosome and autophagy related markers were stimulated by FCN. Moreover, FCN induced cell cycle arrest and PARP cleavage. Except for blocking protein synthesis, these three cell death pathways were found to be complementarily working together with each other. FCN also exhibited synergistic effects with paclitaxel in inducing programmed cell death in RCC cells. Our data indicates that FCN could induce apoptotic cell death and non-apoptotic cell death pathways and can be con-tribute to development of novel cancer prevention or therapy.

Dual-Energy Computed Tomography in Urological Diseases: A Narrative Review

Dual-Energy computed tomography (DECT) with its various advanced techniques, including Virtual Non-Contrast (VNC), effective atomic number (Z-eff) calculation, Z-maps, Iodine Density Index (IDI), and so on, holds great promise in the diagnosis and management of urogenital tumours. In this narrative review, we analyze the current status of knowledge of this technology to provide better lesion characterization, improve the staging accuracy, and give more precise treatment response assessments in relation to urological tumours.

Targeting mTOR and survivin concurrently potentiates radiation therapy in renal cell carcinoma by suppressing DNA damage repair and amplifying mitotic catastrophe

BACKGROUND

Renal cell carcinoma (RCC) was historically considered to be less responsive to radiation therapy (RT) compared to other cancer indications. However, advancements in precision high-dose radiation delivery through single-fraction and multi-fraction stereotactic ablative radiotherapy (SABR) have led to better outcomes and reduced treatment-related toxicities, sparking renewed interest in using RT to treat RCC. Moreover, numerous studies have revealed that certain therapeutic agents including chemotherapies can increase the sensitivity of tumors to RT, leading to a growing interest in combining these treatments. Here, we developed a rational combination of two radiosensitizers in a tumor-targeted liposomal formulation for augmenting RT in RCC. The objective of this study is to assess the efficacy of a tumor-targeted liposomal formulation combining the mTOR inhibitor everolimus (E) with the survivin inhibitor YM155 (Y) in enhancing the sensitivity of RCC tumors to radiation.

EXPERIMENTAL DESIGN

We slightly modified our previously published tumor-targeted liposomal formulation to develop a rational combination of E and Y in a single liposomal formulation (EY-L) and assessed its efficacy in RCC cell lines in vitro and in RCC tumors in vivo. We further investigated how well EY-L sensitizes RCC cell lines and tumors toward radiation and explored the underlying mechanism of radiosensitization.

RESULTS

EY-L outperformed the corresponding single drug-loaded formulations E-L and Y-L in terms of containing primary tumor growth and improving survival in an immunocompetent syngeneic mouse model of RCC. EY-L also exhibited significantly higher sensitization of RCC cells towards radiation in vitro than E-L and Y-L. Additionally, EY-L sensitized RCC tumors towards radiation therapy in xenograft and murine RCC models. EY-L mediated induction of mitotic catastrophe via downregulation of multiple cell cycle checkpoints and DNA damage repair pathways could be responsible for the augmentation of radiation therapy.

CONCLUSION

Taken together, our study demonstrated the efficacy of a strategic combination therapy in sensitizing RCC to radiation therapy via inhibition of DNA damage repair and a substantial increase in mitotic catastrophe. This combination therapy may find its use in the augmentation of radiation therapy during the treatment of RCC patients.

Transient, Image-Guided Gel-Dissection for Percutaneous Thermal Ablation

Image-guided tumor ablative therapies are mainstay cancer treatment options but often require intra-procedural protective tissue displacement to reduce the risk of collateral damage to neighboring organs. Standard of care strategies, such as hydrodissection (fluidic injection), are limited by rapid diffusion of fluid and poor retention time, risking injury to adjacent organs, increasing cancer recurrence rates from incomplete tumor ablations, and limiting patient qualification. Herein, a "gel-dissection" technique is developed, leveraging injectable hydrogels for longer-lasting, shapeable, and transient tissue separation to empower clinicans with improved ablation operation windows and greater control. A rheological model is designed to understand and tune gel-dissection parameters. In swine models, gel-dissection achieves 24 times longer-lasting tissue separation dynamics compared to saline, with 40% less injected volume. Gel-dissection achieves anti-dependent dissection between free-floating organs in the peritoneal cavity and clinically significant thermal protection, with the potential to expand minimally invasive therapeutic techniques, especially across locoregional therapies including radiation, cryoablation, endoscopy, and surgery.

Can We Predict the Grade of Clear Cell Renal Cell Carcinoma from Houns-Field Unit of Renal Lesion on Computerized Tomography Scan, a Retrospective Cross-Sectional Study

Introduction

Renal cell carcinoma (RCC) is a type of urological malignancy that affects approximately 2% of the global population. Imaging modalities, especially computed tomography (CT) scanning, play a critical role in diagnosing RCC. In this study, we investigated whether there is a relationship between tumour grade of clear cell RCC and HU values of renal lesions on CT scan performed before operation.

Materials and Methods

We conducted a retrospective analysis of 123 patients who underwent radical or partial (open or laparoscopic) nephrectomy for clear cell RCC between January 2017 and January 2021. Post-operation histopathological grades were recorded according to World Health Organization (WHO)/International Society of Urological Pathology (ISUP) 2016 grading system and divided into low grade (includes grade 1 and 2) and high grade (grade 3 and 4), and their links to age, sex, smoking habits, tumour size, and HUs of renal lesions were evaluated.

Results

The mean age of the patients studied was 63.02 years old. About 56.9% of the patients were low grade (grade 1 or grade 2), while 43.1% were high grade (grade 3 or 4). The mean tumour size was 6.31 cm. There were no significant differences in tumour grade according to age, sex, or smoking habits. We found a significant relation between tumour grade and HU in the pre-contrast and nephrogenic phases, with p values of 0.001 and 0.037, respectively. On the other hand, there was no significant relation linking the tumour grade to the difference in HU between these phases, where there was a p value of 0.641.

Conclusion

HU in the pre-contrast and nephrogenic phases in addition to tumour size on CT scan have a significant relation to clear cell RCC grade.

A novel DNA methylation signature revealed GDF6 and RCC1 as potential prognostic biomarkers correlated with cell proliferation in clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) accounts for the majority (80%-90%) of renal cell carcinoma (RCC) patients at the time of diagnosis, and approximately 15% of ccRCC patients will develop distant metastasis or recurrence during their lifetime. Increasing number of studies have revealed that the aberrant DNA methylations is closely correlated with the tumorigenesis in ccRCC.

RESULTS

In this study, we utilized a LASSO (least absolute shrinkage and selection operator) model to identify a combination of 13 probes-based DNA methylation signature that associated with the progression-free survival (PFS) of ccRCC patients. First, differentially methylated regions (CpGs) related to PFS and phenotypes were identified. Next, prognostic DNA methylation probes were selected from the differentially methylated probes (DMPs) and calculated risk scores to stratify patients with ccRCC. The performance of this signature was validated in an independent testing set using various analyses, including Kaplan-Meier analysis for PFS and receiver operating characteristic (ROC) curve analysis. Based on our 13-DNA methylation probes signature, ccRCC patients were successfully stratified into high- and low-risk groups. Combining DNA methylation signature with clinical variables such as T stage, M stage and tumor grade could further improve the accuracy of prediction. Moreover, we highlight two molecular biomarkers (RCC1 and GDF6) corresponding to our probes. Invitro experiments showed that knockdown of RCC1 or GDF6 in ccRCC cell lines reduced cell proliferation, which indicated that both biomarkers are associated with tumorigenesis.

CONCLUSIONS

The 13-probes-based DNA methylation signature has the potential to serve as an independent tool for survival outcome improvement and treatment strategy selection for ccRCC patients. In addition, our findings suggest that RCC1 and GDF6 may serve as promising markers for ccRCC.

Assessment of Imaging Findings of Renal Carcinoma Subtypes with 3.0T MRI

BACKGROUND

The prevalence of renal masses has escalated as a result of the augmented utilization of cross-sectional imaging techniques. The approach to managing renal masses may exhibit variability contingent upon the subtype of renal cell carcinoma (RCC).

AIM

This research aimed to distinguish between clear cell and papillary RCCs, utilizing dynamic contrast magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

The study assessed the MR images of 112 patients with RCC. Two radiologists independently analyzed tumor size, vascular involvement, signal characteristics in T1- and T2-weighted sequences, the presence of hemosiderin, both microscopic and macroscopic fat content, enhancement patterns, and apparent diffusion coefficient (ADC) values derived from b-values of 1000 s/mm².

RESULTS

Seventy patients had clear cell RCC, and 42 had papillary. In the clear cell RCC, microscopic fat content was significantly higher than the papillary RCC (P < 0.001). However, in papillary RCC, hemosiderin content was substantially greater (P = 0.001). On T2-weighted MR images, clear cell RCCs were usually hyperintense, while papillary RCCs were hypointense (P < 0.001). Even though the rapid enhancement pattern was observed in clear cell RCCs, the progressive enhancement pattern was more prevalent in papillary RCCs (P < 0.001).

CONCLUSION

Hyperintensity on T2-weighted images, microscopic fat content, and rapid enhancement pattern may be indicative of clear cell RCC, whereas hypointensity on T2-weighted images, hemosiderin content, and a progressive contrast pattern may be diagnostic for papillary RCC.

Theranostic Lipid Nanoparticles for Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a common urological malignancy and represents a leading threat to healthcare. Recent years have seen a series of progresses in the early diagnosis and management of RCC. Theranostic lipid nanoparticles (LNPs) are increasingly becoming one of the focuses in this field, because of their suitability for tumor targeting and multimodal therapy. LNPs can be precisely fabricated with desirable chemical compositions and biomedical properties, which closely match the physiological characteristics and clinical needs of RCC. Herein, a comprehensive review of theranostic LNPs is presented, emphasizing the generic tool nature of LNPs in developing advanced micro-nano biomaterials. It begins with a brief overview of the compositions and formation mechanism of LNPs, followed with an introduction to kidney-targeting approaches, such as passive, active, and stimulus responsive targeting. With examples provided, a series of modification strategies for enhancing the tumor targeting and functionality of LNPs are discussed. Thereafter, research advances on applications of these LNPs for RCC including bioimaging, liquid biopsy, drug delivery, physical therapy, and gene therapy are summarized and discussed from an interdisciplinary perspective. The final part highlights the milestone achievements of translation medicine, current challenges as well as future development directions of LNPs for the diagnosis and treatment of RCC.

Characterization of tumor microenvironment and sensitive chemotherapy drugs based on cuproptosis-related signatures in renal cell carcinoma

Cuproptosis is a novel type of copper-induced cell death and is considered as a new therapeutic target for many cancers. Distant metastases occur in about 40% of patients with advanced renal cell carcinoma (RCC), with a poor 5-year prognosis of about 10%. Through a series of comprehensive analyses, four differentially expressed cuproptosis-related lncRNAs (DECRLs) were identified as candidate biomarkers for RCC. The risk model constructed by using these four DECRLs can better predict the prognosis of patients with RCC, which is determined by the receiver operating characteristic (Time dependent area under curve value at 1-year, 3-year, 5-year, and 10-year were 0.82, 0.80, 0.76, and 0.73 respectively). There were significant differences in immune status between high-risk and low-risk RCC patients. The differentially expressed gene enrichment terms between high- and low-risk patients was also dominated by immune-related terms. The risk score was also correlated with immunotherapy as measured by the tumor immune dysfunction and exclusion (TIDE) score. In addition, we also found that the sensitivity of many chemotherapy drugs varies widely between high- and low-risk patients. The sensitivity of the three chemotherapy drugs (AZD4547, Vincristine, and WEHI-539) varied among high- and low-risk patients, and was significantly negatively correlated with risk values, suggesting that they could be used as clinical treatment drugs for RCC. Our study not only obtained four potential biomarkers, but also provided guidance for immunotherapy and chemotherapy treatment of RCC, as well as new research strategies for the screening of other cancer biomarkers and sensitive drugs.

Berberine inhibits the progression of renal cell carcinoma cells by regulating reactive oxygen species generation and inducing DNA damage

BACKGROUND

Berberine is a natural isoquinoline alkaloid that has been shown to have antitumor properties in a growing number of studies. However, its role in renal cell carcinoma remains unclear. This study investigates berberine's effect and mechanism in renal cell carcinoma.

METHODS

The methyl-tetrazolium, colony formation, and lactate dehydrogenase assay were used to detect proliferation and cytotoxicity, respectively. Flow cytometry, caspase-Glo 3/7 assay, and adenosine triphosphate assay were used to detect apoptosis and the adenosine triphosphate levels. Wound healing and transwell assay were used to examine the migration ability of renal cell carcinoma cells. Besides, the level of reactive oxygen species (ROS) was explored using a DCFH-DA-based kit. Additionally, western blot and Immunofluorescence assay was taken to determine the levels of relative proteins.

RESULTS

In vitro, our findings indicated that the proliferation and migration of renal cell carcinoma cells treated with berberine in various concentrations were inhibited, while the level of ROS and apoptosis rate were increased. Furthermore, The results of western blot showed that the expression of Bax, Bad, Bak, Cyto c, Clv-Caspase 3, Clv-Caspase 9, E-cadherin, TIMP-1and γH2AX were up-regulated, while Bcl-2, N-cadherin, Vimentin, Snail, Rad51 and PCNA were down-regulated after treating with berberine with various concentration.

CONCLUSION

The result of this study revealed that berberine inhibits renal cell carcinoma progression via regulating ROS generation and inducing DNA break.

Magnetic Resonance Imaging Virtual Biopsy of Common Solid Renal Masses-A Pictorial Review

ABSTRACT

The expanded application of radiologic imaging resulted in an increased incidence of renal masses in the recent decade. Clinically, it is difficult to determine the malignant potential of the renal masses, thus resulting in complex management. Image-guided biopsies are the ongoing standard of care to identify molecular variance but are limited by tumor accessibility and heterogeneity. With the evolving importance of individualized cancer therapies, radiomics has displayed promising results in the identification of tumoral mutation status on routine imaging. This article discusses how magnetic resonance imaging features can guide a radiologist toward identifying renal mass characteristics.

VHL-HIF-2α axis-induced SEMA6A upregulation stabilized β-catenin to drive clear cell renal cell carcinoma progression

SEMA6A is a multifunctional transmembrane semaphorin protein that participates in various cellular processes, including axon guidance, cell migration, and cancer progression. However, the role of SEMA6A in clear cell renal cell carcinoma (ccRCC) is unclear. Based on high-throughput sequencing data, here we report that SEMA6A is a novel target gene of the VHL-HIF-2α axis and overexpressed in ccRCC. Chromatin immunoprecipitation and reporter assays revealed that HIF-2α directly activated SEMA6A transcription in hypoxic ccRCC cells. Wnt/β-catenin pathway activation is correlated with the expression of SEMA6A in ccRCC; the latter physically interacted with SEC62 and promoted ccRCC progression through SEC62-dependent β-catenin stabilization and activation. Depletion of SEMA6A impaired HIF-2α-induced Wnt/β-catenin pathway activation and led to defective ccRCC cell proliferation both in vitro and in vivo. SEMA6A overexpression promoted the malignant phenotypes of ccRCC, which was reversed by SEC62 depletion. Collectively, this study revealed a potential role for VHL-HIF-2α-SEMA6A-SEC62 axis in the activation of Wnt/β-catenin pathway. Thus, SEMA6A may act as a potential therapeutic target, especially in VHL-deficient ccRCC.

Imaging Recommendations for Diagnosis, Staging, and Management of Renal Tumors

Renal cell carcinomas accounts for 2% of all the cancers globally. Most of the renal tumors are detected incidentally. Ultrasound remains the main screening modality to evaluate the renal masses. A multi -phase contrast enhanced computer tomography is must for characterizing the renal lesions. Imaging plays an important role in staging, treatment planning and follow up of renal cancers. In this review , we discuss the imaging guidelines for the management of renal tumors.

The Emerging Role of PET/CT with PSMA-Targeting Radiopharmaceuticals in Clear Cell Renal Cancer: An Updated Systematic Review

BACKGROUND

Recent articles proposed the employment of positron emission tomography/computed tomography (PET/CT) with prostate-specific membrane antigen (PSMA)-targeting radiopharmaceuticals in clear cell renal cell carcinoma (ccRCC).

METHODS

The authors performed a comprehensive literature search of studies on the performance of PET/CT with PSMA-targeting radiopharmaceuticals in ccRCC. Original articles concerning this imaging examination were included in newly diagnosed ccRCC patients and ccRCC patients with disease recurrence.

RESULTS

A total of sixteen papers concerning the diagnostic performance of PSMA-targeted PET/CT in ccRCC (331 patients) were included in this systematic review. The included articles demonstrated an excellent detection rate of PSMA-targeting PET/CT in ccRCC.

CONCLUSIONS

PSMA-targeted PET/CT seems promising in detecting ccRCC lesions as well as in discriminating the presence of aggressive phenotypes. Prospective multicentric studies are warranted to strengthen the role of PSMA-targeting PET/CT in ccRCC.

Multiparametric magnetic resonance imaging for characterizing renal tumors: A validation study of the algorithm presented by Cornelis et al

Objectives

In the last decade, the incidence of renal cell carcinoma (RCC) has been rising, with the greatest increase observed for solid tumors. Magnetic resonance imaging (MRI) protocols and algorithms have recently been available for classifying RCC subtypes and benign subtypes. The objective of this study was to prospectively validate the MRI algorithm presented by Cornelis et al. for RCC classification.

Material and Methods

Over a 7-month period, 38 patients with 44 renal tumors were prospectively included in the study and received an MRI examination in addition to the conventional investigation program. The MRI sequences were: T2-weighted, dual chemical shift MRI, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced T1-weighted in wash-in and wash-out phases. The images were evaluated according to the algorithm by two experienced, blinded radiologists, and the histopathological diagnosis served as the gold standard.

Results

Of 44 tumors in 38 patients, only 8 tumors (18.2%) received the same MRI diagnosis according to the algorithm as the histopathological diagnosis. MRI diagnosed 16 angiomyolipoma, 14 clear cell RCC (ccRCC), 12 chromophobe RCC (chRCC), and two papillary RCC (pRCC), while histopathological examination diagnosed 24 ccRCC, four pRCC, one chRCC, and one mixed tumor of both pRCC and chRCC. Malignant tumors were statistically significantly larger than the benign (3.16 ± 1.34 cm vs. 2.00 ± 1.04 cm, P = 0.006).

Conclusion

This prospective study could not reproduce Cornelis et al.'s results and does not support differentiating renal masses using multiparametric MRI without percutaneous biopsy in the future. The MRI algorithm showed few promising results to categorize renal tumors, indicating histopathology for clinical decisions and follow-up regimes of renal masses are still required.

Evaluation of Apoptosis, Cell Proliferation and Cell Cycle Progression by Inactivation of the NEAT1 Long Noncoding RNA in a Renal Carcinoma Cell Line Using CRISPR/Cas9

Background

Long noncoding RNAs (lncRNAs) play an important role in cellular mechanisms including transcription, translation, and apoptosis. NEAT1 is one of the essential types of lncRNAs in humans that can bind to active genes and modify their transcription. NEAT1 upregulation in various forms of cancer such as kidney cancer has been reported. Kidney cancer accounts for approximately 3% of all cancers worldwide and occurs almost twice as often in men as in women.

Objectives

This study has been performed to knockout the NEAT1 gene using the CRISPR/Cas9 technique in the Renal Cell Carcinoma ACHN cell line and to evaluate its effects on cancer progression and apoptosis.

Material and Methods

Two specific (single guide RNA (sgRNA) sequences for the NEAT1 gene were designed by CHOPCHOP software. These sequences were then cloned into plasmid pSpcas9, and recombinant vectors PX459-sgRNA1 and PX459-sgRNA2 were generated. ACHN cells were transfected using recombinant vectors carrying sgRNA1 and sgRNA2. The expression level of apoptosis-related genes was assessed by real-time PCR. Annexin, MTT and cell scratch tests were performed to evaluate the survival, proliferation, and migration of the knocked out cells, respectively.

Results

The results have shown successful knockout of the NEAT1 gene in the cells of the treatment group. Expressions of P53, BAK, BAX and FAS genes in the cells of the treatment group (NEAT1 knockout) showed significant increases in expression compared to the cells of the control group (P <0.01). Additionally, decreased expression of BCL2 and survivin genes was observed in knockout cells compared to the control group (p <0.05). In addition, in the cells of the treatment group compared to control cells, a significant decrease in cell viability, ability to migrate and cell growth and proliferation was observed.

Conclusion

Inactivation of the NEAT1 gene in ACHN cell line using CRISPR/Cas9 technology elevated apoptosis and reduced cell survival and proliferation which makes it a novel target for kidney cancer therapeutics.

Immunohistochemical Expression of CD44, MMP-2, MMP-9, and Ki-67 as the Prognostic Markers in Non-Clear Cell Renal Cell Carcinomas-A Prospective Cohort Study

CD44 is the most frequently reported marker of the cancer stem cells in renal cell carcinoma (RCC). Matrix metalloproteinases MMP-2 and MMP-9 are key regulators of tumor invasion and metastasis. The aim of this study was to investigate the clinicopathologic and prognostic values of the immunohistochemical expression of CD44, MMP2, MMP9, and Ki-67 in papillary and chromophobe RCCs. In the case of papillary RCC, MMP-2 expression was positively correlated with patient age (p < 0.05), while CD44 expression was positively correlated with tumor stage (τ = 0.26, p < 0.05). Moreover, CD44 expression positively correlated with MMP-9 (τ = 0.39, p < 0.05). In the case of chromophobe RCC, only Ki-67 expression was negatively correlated with tumor stage (τ = −0.44, p < 0.05). During follow-up, a death was documented in 6 patients with papillary RCC. In these patients, CD44 expression was not a significant factor affecting the overall survival of patients (p > 0.05), whereas there was a positive correlation between increased MMP-9 expression and shorter overall survival (p < 0.05). Taken together, carcinogenesis in papillary RCC is probably dependent on both cancer stem cells and metalloproteinases activity. Expression of CD44 and MMP-9 can significantly improve the prediction of papillary RCC prognosis in the future.

Renal cell carcinoma management: A step to nano-chemoprevention

Renal cell carcinoma (RCC) is one of the most common kidney cancers, responsible for nearly 90 % of all renal malignancies. Despite the availability of many treatment strategies, RCC still remains to be an incurable disease due to its resistivity towards conventional therapies. Nanotechnology is an emerging field of science that offers newer possibilities in therapeutics including cancer medicine, specifically by targeted delivery of anticancer drugs. Several phytochemicals are known for their anti-cancer properties and have been regarded as chemopreventive agents. However, the hydrophobic nature of many phytochemicals decreases its bioavailability and distribution, thus showing limited therapeutic effect. Application of nanotechnology to enhance chemoprevention is an effective strategy to increase the bioavailability of phytochemicals and thereby its therapeutic efficacy. The present review focuses on the utility of nanotechnology in RCC treatment and chemopreventive agents of RCC. We have also visualized the future prospects of nanomolecules in the prevention and cure of RCC.

Birt-Hogg-Dubé syndrome in apparent primary spontaneous pneumothorax patients; results and recommendations for clinical practice

Background

Birt-Hogg-Dubé syndrome (BHD) is an inherited disease caused by pathogenic variants in the FLCN gene. One of the characteristics is the increased risk for spontaneous pneumothorax, likely due to the presence of pulmonary cysts mainly distributed under the carina. Due to variable expression and lack of awareness, BHD is likely to be underdiagnosed. We aimed to examine the prevalence of BHD in patients presenting with an apparent primary spontaneous pneumothorax and to evaluate the contribution of chest CT in establishing the diagnosis.

Methods

Patients who presented with apparent primary spontaneous pneumothorax between 2004 and 2017 in a large Dutch teaching hospital were enrolled in this quantitative cross-sectional study. A questionnaire was sent to eligible patients. Patients who completed the questionnaire and consented to further participation were invited to visit the hospital for genetic testing and low dose, volumetric chest CT.

Results

Genetic testing was performed in 88 patients with apparent primary spontaneous pneumothorax. Three patients were found to have a pathogenic variant in the FLCN gene (3.4%). No variants of unknown significance were detected. Pulmonary cysts were detected in 14 out of 83 participants with an available chest CT, six had more than one cyst. All three patients with BHD had multiple pulmonary cysts.

Conclusions

Based on previous literature and the present study, we believe that performing a chest CT in every patient presenting with primary spontaneous pneumothorax is justified. Subsequent genetic testing of the FLCN gene should be considered when multiple pulmonary cysts are present.

Trial registration

The study was registered at clinicaltrials.gov with reference NCT02916992.

Summary at a glance

Three out of 88 patients with an apparent primary spontaneous pneumothorax were diagnosed with Birt-Hogg-Dubé syndrome in this study and all three had multiple pulmonary cysts. We believe that performing a chest CT in every patient with an apparent primary spontaneous pneumothorax is justified to identify underlying diseases.

Adhesion G protein-coupled receptor gluing action guides tissue development and disease

Phylogenetic analysis of human G protein-coupled receptors (GPCRs) divides these transmembrane signaling proteins into five groups: glutamate, rhodopsin, adhesion, frizzled, and secretin families, commonly abbreviated as the GRAFS classification system. The adhesion GPCR (aGPCR) sub-family comprises 33 different receptors in humans. Majority of the aGPCRs are orphan receptors with unknown ligands, structures, and tissue expression profiles. They have a long N-terminal extracellular domain (ECD) with several adhesion sites similar to integrin receptors. Many aGPCRs undergo autoproteolysis at the GPCR proteolysis site (GPS), enclosed within the larger GPCR autoproteolysis inducing (GAIN) domain. Recent breakthroughs in aGPCR research have created new paradigms for understanding their roles in organogenesis. They play crucial roles in multiple aspects of organ development through cell signaling, intercellular adhesion, and cell-matrix associations. They are involved in essential physiological processes like regulation of cell polarity, mitotic spindle orientation, cell adhesion, and migration. Multiple aGPCRs have been associated with the development of the brain, musculoskeletal system, kidneys, cardiovascular system, hormone secretion, and regulation of immune functions. Since aGPCRs have crucial roles in tissue patterning and organogenesis, mutations in these receptors are often associated with diseases with loss of tissue integrity. Thus, aGPCRs include a group of enigmatic receptors with untapped potential for elucidating novel signaling pathways leading to drug discovery. We summarized the current knowledge on how aGPCRs play critical roles in organ development and discussed how aGPCR mutations/genetic variants cause diseases.

Differential diagnosis and prognosis of small renal masses: association with collateral vessels detected using contrast-enhanced computed tomography

Background

Active surveillance (AS) is one of the treatment methods for patients with small renal masses (SRMs; < 4 cm), including renal cell carcinomas (RCCs). However, some small RCCs may exhibit aggressive neoplastic behaviors and metastasize. Little is known about imaging biomarkers capable of identifying potentially aggressive small RCCs. Contrast-enhanced computed tomography (CECT) often detects collateral vessels arising from neoplastic angiogenesis in RCCs. Therefore, this study aimed to evaluate the association between SRM differential diagnoses and prognoses, and the detection of collateral vessels using CECT.

Methods

A total of 130 consecutive patients with pathologically confirmed non-metastatic SRMs (fat-poor angiomyolipomas [fpAMLs; n = 7] and RCCs [n = 123]) were retrospectively enrolled. Between 2011 and 2019, SRM diagnoses in these patients were confirmed after biopsy or surgical resection. All RCCs were surgically resected. Regardless of diameter, a collateral vessel (CV) was defined as any blood vessel connecting the tumor from around the kidney using CECT. First, we analyzed the role of CV-detection in differentiating between fpAML and RCC. Then, we evaluated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of RCC diagnosis based on CV-detection using CECT. We also assessed the prognostic value of CV-detection using the Fisher exact test, and Kaplan-Meier method and the log-rank test.

Results

The sensitivity, specificity, PPV, NPV, and accuracy of CV-detection for the diagnosis of small RCCs was 48.5, 45.5, 100, 100, and 9.5% respectively. Five of 123 (4.1%) patients with RCC experienced recurrence. CV-detection using CECT was the only significant factor associated with recurrence (p = 0.0177). Recurrence-free survival (RFS) was significantly lower in patients with CV compared with in those without CV (5-year RFS 92.4% versus 100%, respectively; p = 0.005). In addition, critical review of the CT images revealed the CVs to be continuous with the venous vessels around the kidney.

Conclusions

The detection of CVs using CECT is useful for differentiating between small fpAMLs and RCCs. CV-detection may also be applied as a predictive parameter for small RCCs prone to recurrence after surgical resection. Moreover, AS could be suitable for small RCCs without CVs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09971-w.

Deep Learning Algorithm for Fully Automated Detection of Small (≤4 cm) Renal Cell Carcinoma in Contrast-Enhanced Computed Tomography Using a Multicenter Database

OBJECTIVES

Renal cell carcinoma (RCC) is often found incidentally in asymptomatic individuals undergoing abdominal computed tomography (CT) examinations. The purpose of our study is to develop a deep learning-based algorithm for fully automated detection of small (≤4 cm) RCCs in contrast-enhanced CT images using a multicenter database and to evaluate its performance.

MATERIALS AND METHODS

For the algorithmic detection of RCC, we retrospectively selected contrast-enhanced CT images of patients with histologically confirmed single RCC with a tumor diameter of 4 cm or less between January 2005 and May 2020 from 7 centers in the Japan Medical Image Database. A total of 453 patients from 6 centers were selected as dataset A, and 132 patients from 1 center were selected as dataset B. Dataset A was used for training and internal validation. Dataset B was used only for external validation. Nephrogenic phase images of multiphase CT or single-phase postcontrast CT images were used. Our algorithm consisted of 2-step segmentation models, kidney segmentation and tumor segmentation. For internal validation with dataset A, 10-fold cross-validation was applied. For external validation, the models trained with dataset A were tested on dataset B. The detection performance of the models was evaluated using accuracy, sensitivity, specificity, and the area under the curve (AUC).

RESULTS

The mean ± SD diameters of RCCs in dataset A and dataset B were 2.67 ± 0.77 cm and 2.64 ± 0.78 cm, respectively. Our algorithm yielded an accuracy, sensitivity, and specificity of 88.3%, 84.3%, and 92.3%, respectively, with dataset A and 87.5%, 84.8%, and 90.2%, respectively, with dataset B. The AUC of the algorithm with dataset A and dataset B was 0.930 and 0.933, respectively.

CONCLUSIONS

The proposed deep learning-based algorithm achieved high accuracy, sensitivity, specificity, and AUC for the detection of small RCCs with both internal and external validations, suggesting that this algorithm could contribute to the early detection of small RCCs.

Prognostic Relevance of ZNF844 and Chr 19p13.2 KRAB-Zinc Finger Proteins in Clear Cell Renal Carcinoma

BACKGROUND/AIM

Clear-cell renal cell carcinoma (ccRCC) is the most common and aggressive form of all urological cancers, with poor prognosis and high mortality. Despite growing evidence of involvement in carcinogenesis, the role of KRAB-ZFP in ccRCC has not been fully explored. KRAB Zinc finger proteins (KRAB-ZFPs) are the largest family of mammalian transcription regulators. They are differentially expressed in various tissues during cellular development and phenotypic differentiation.

MATERIALS AND METHODS

In this study, the levels of transcripts of ccRCC from The Cancer Genome Atlas (TCGA) dataset were used to identify prognostic biomarkers in this disease.

RESULTS

Using bioinformatics techniques, we demonstrate that approximately 60% of KRAB zinc finger proteins located on chromosome 19p13.2 are differentially expressed, with all but two being down-regulated in ccRCC. Moreover, ZNF844, a paralog of ZNF433, was the most down-regulated across all histological grades and pathological stages (p<0.001). In addition, the decrease in ZNF844 expression was associated with poor patient survival (HR=0.41; 95% CI=0.3-0.56; p<0.0001). Gene Set Enrichment Analysis of genes inversely co-expressed with ZNF844 revealed that enriched pathways were consistently related to immune and translation processes (p<0.05, FDR <0.05). Lastly, ZNF844 expression showed moderate, inverse correlation to Helper T-cell (CD4 or Th1) subtype 1 (R=-0.558, p=5.15×10^-39) infiltration and with the exhausted T-cell phenotype (R=-0.37; p=4.1×10^-21).

CONCLUSION

Down-regulation of KRAB-ZFPs at 19p13.2 may represent a signature for ccRCC. Moreover, ZNF844 is a prognostic marker for ccRCC and may serve as a putative immune-related tumor suppressor gene.

Clinicopathological features of non-conventional renal cell carcinoma histological subtypes: Learning points from a large contemporary series spanning over three decades

Purpose

To perform a retrospective review of the clinicopathological features of patients with conventional and non-conventional renal cell carcinoma (cRCC and ncRCC).

Materials and Methods

A large prospectively maintained uro-oncological registry was accessed to extract clinicopathological data of patients diagnosed with renal tumors who subsequently underwent nephrectomy from 1990–2019. Demographics and operative parameters were extracted. Analyses of overall survival (OS) and cancer-specific survival (CSS) were performed using the Kaplan–Meier method. Cox proportional-hazards analysis was used to identify risk factors which influenced survival.

Results

There were a total of 1,686 consecutive nephrectomies which was retrieved, with 1,286 cRCC and 400 ncRCC. The commonest ncRCC subtypes were papillary (n=198, 11.7%), clear cell papillary (n=50, 3.0%) and chromophobe (n=49, 2.9%) RCC. Kaplan–Meier estimates of OS were higher in cRCC (0.74; 95% confidence interval [CI], 0.71–0.78) than ncRCC (hazard ratio, 1.47; 95% CI, 1.16–1.87). Among individual subtypes, chromophobe RCC had the highest 5-year OS (0.90; 95% CI, 0.79–1.0). Among ncRCC subtypes, acquired cystic RCC demonstrated the highest association with end-stage renal failure and hypertension, with the highest CSS. MiT family translocation RCC had the youngest mean age at presentation (45.6±12.8 y) and excellent CSS. Factors associated with increased OS in the entire cohort included shorter operative time, partial nephrectomy and lower tumor stages.

Conclusions

This study provides a comprehensive contemporary overview of ncRCCs which are yet poorly characterized, in comparison to cRCCs. Data from this study would contribute towards tailored patient counseling and healthcare resource planning.

Renal Oncocytoma: The Diagnostic Challenge to Unmask the Double of Renal Cancer

Renal oncocytoma represents the most common type of benign neoplasm that is an increasing concern for urologists, oncologists, and nephrologists due to its difficult differential diagnosis and frequent overtreatment. It displays a variable neoplastic parenchymal and stromal architecture, and the defining cellular element is a large polygonal, granular, eosinophilic, mitochondria-rich cell known as an oncocyte. The real challenge in the oncocytoma treatment algorithm is related to the misdiagnosis due to its resemblance, at an initial radiological assessment, to malignant renal cancers with a completely different prognosis and medical treatment. Unfortunately, percutaneous renal biopsy is not frequently performed due to the possible side effects related to the procedure. Therefore, the majority of oncocytoma are diagnosed after the surgical operation via partial or radical nephrectomy. For this reason, new reliable strategies to solve this issue are needed. In our review, we will discuss the clinical implications of renal oncocytoma in daily clinical practice with a particular focus on the medical diagnosis and treatment and on the potential of novel promising molecular biomarkers such as circulating microRNAs to distinguish between a benign and a malignant lesion.

Diagnostic performance of MRI, SPECT, and PET in detecting renal cell carcinoma: a systematic review and meta-analysis

Background

Renal cell carcinoma (RCC) is one of the most common malignancies worldwide. Noninvasive imaging techniques, such as magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET), have been involved in increasing evolution to detect RCC. This meta-analysis aims to compare to compare the performance of MRI, SPECT, and PET in the detection of RCC in humans, and to provide evidence for decision-making in terms of further research and clinical settings.

Methods

Electronic databases including PubMed, Web of Science, Embase, and Cochrane Library were systemically searched. The keywords such as “magnetic resonance imaging”, “MRI”, “single-photon emission computed tomography”, “SPECT”, “positron emission tomography”, “PET”, “renal cell carcinoma” were used for the search. Studies concerning MRI, SPECT, and PET for the detection of RCC were included. Pooled sensitivity, specificity, and the area under the summary receiver operating characteristic (SROC) curve (AUC), etc. were calculated.

Results

A total of 44 articles were finally detected for inclusion in this study. The pooled sensitivities of MRI, ¹⁸F-FDG PET and ¹⁸F-FDG PET/CT were 0.80, 0.83, and 0.89, respectively. Their respective overall specificities were 0.90, 0.86, and 0.88. The pooled sensitivity and specificity of MRI studies at 1.5 T were 0.86 and 0.94, respectively. With respect to prospective PET studies, the pooled sensitivity, specificity and AUC were 0.90, 0.93 and 0.97, respectively. In the detection of primary RCC, PET studies manifested a pooled sensitivity, specificity, and AUC of 0.77, 0.80, and 0.84, respectively. The pooled sensitivity, specificity, and AUC of PET/CT studies in detecting primary RCC were 0.80, 0.85, and 0.89.

Conclusion

Our study manifests that MRI and PET/CT present better diagnostic value for the detection of RCC in comparison with PET. MRI is superior in the diagnosis of primary RCC.

Identification of Five Ferroptosis-Related LncRNAs as Novel Prognosis and Diagnosis Signatures for Renal Cancer

Background: Ferroptosis is a novel regulated cell death that is characterized by iron-dependent oxidative damage. Renal cancer is the second most common cancer of the urinary system, which is highly correlated with iron metabolism. The aim of our present study was to identify suitable ferroptosis-related prognosis signatures for renal cancer.

Methods: We downloaded the RNA-seq count data of renal cancer from The Cancer Genome Atlas database and used the DESeq2, Survival, and Cox regression analyses to screen the prognosis signatures.

Results: We identified 5 ferroptosis-related differentially expressed lncRNAs (FR-DELs) (DOCK8-AS1, SNHG17, RUSC1-AS1, LINC02609, and LUCAT1) to be independently correlated with the overall survival (OS) of patients with renal cancer. The risk assessment model and diagnosis model constructed by those 5 FR-DELs could well predict the outcome and the diagnosis of renal cancer.

Conclusion: Our present study not only suggested those 5 FR-DELs could be used as prognosis and diagnosis signatures for renal cancer but also provided strategies for other cancers in the screening of ferroptosis-related biomarkers.

Comparison of cortico-medullary phase contrast-enhanced MDCT and T2-weighted MR imaging in the histological subtype differentiation of renal cell carcinoma: radiology-pathology correlation

Purpose

Renal cell carcinoma (RCC) subtype differentiation is of crucial importance in the management and prognosis of these patients. In this study, we investigated the usefulness of unenhanced and cortico-medullary phase contrast-enhanced multidetector-row computed tomography (MDCT) and T2-weighted fast spin-echo (FSE) magnetic resonance imaging (MRI) modalities in the discrimination of the 3 main subtype RCC patients in correlation with their histopathological findings.

Material and methods

A total of 80 pathologically proven RCC patients who had undergone either partial or total nephrectomy were retrospectively investigated in this study. Their histological subtypes were 54 clear cell renal cell carcinoma (ccRCC), 15 papillary renal cell carcinoma (pRCC), and 11 chromophobe renal cell carcinoma (cRCC), based on pathological evaluation. There were 62 male (77.5%) and 18 female (22.5%) patients. Among the 54 ccRCC patients, 29 patients had both non-contrast and cortico-medullary phase CT, 1 had only non-contrast CT, 5 only had cortico-medullary phase CT, and 38 had MRI examination. In the pRCC group, 10 patients had both non-contrast and cortico-medullary phase CT, 1 had only non-contrast CT, 1 had only cortico-medullary phase CT, and 12 had MRI. Finally, in the remaining 11 cRCC patients, 9 had both non-contrast and cortico-medullary phase CT, and only 5 had MRI. We calculated both tumour attenuation values as HU (Hounsfield units) on unenhanced and cortico-medullary phase MDCT images and also tumour mean signal intensity values on FSE T2-weighted MRI images by using the region of interest (ROI) including normal renal cortex measurements. Besides quantitative evaluation, we also performed qualitative visual assessment of tumours on contrast-enhanced MDCT and FSE T2-weighted MRI.

Results

There was no statistically significant difference among the attenuation values of the 3 tumour subtypes on pre-contrast CT images. ccRCC demonstrated a prominent degree of contrast enhancement compared to the chromophobe and papillary ones on cortico-medullary phase MDCT. We found no statistically significant difference between chromophobe and papillary subtypes, although chromophobe tumours showed slightly higher attenuation values compared to papillary ones. ccRCCs usually demonstrated a heterogenous contrast enhancement on cortico-medullary phase CT images, while the papillary subtype usually had a homogenous appearance on visual assessment. On FSE T2-weighted MR images, the signal intensity values of ccRCC patients were found to be significantly higher than both chromophobe and papillary subtypes. Although cRCC patients had a prominently lower T2 signal intensity than clear cell subtype, there was no statistically significant signal intensity difference between chromophobe and papillary subtypes. Regarding visual assessment, papillary subtype tumours showed a mostly homogenous appearance on T2-weighted images and a statistically significant difference was present. On the other hand, there was no significant difference of visual assessment of the clear cell and chromophobe subtypes.

Conclusions

The measurement of the attenuation values on cortico-medullary phase MDCT and the mean signal intensity values on FSE T2-weighted MRI can provide useful information in the differentiation of RCC main subtypes. Also, visual assessment of tumours on both modalities can contribute to this issue by providing additional imaging properties.

Multimodality imaging review of focal renal lesions

Background

Focal lesions of the kidney comprise a spectrum of entities that can be broadly classified as malignant tumors, benign tumors, and non-neoplastic lesions. Malignant tumors include renal cell carcinoma subtypes, urothelial carcinoma, lymphoma, post-transplant lymphoproliferative disease, metastases to the kidney, and rare malignant lesions. Benign tumors include angiomyolipoma (fat-rich and fat-poor) and oncocytoma. Non-neoplastic lesions include infective, inflammatory, and vascular entities. Anatomical variants can also mimic focal masses.

Main body of the abstract

A range of imaging modalities are available to facilitate characterization; ultrasound (US), contrast-enhanced ultrasound (CEUS), computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography (PET), each with their own strengths and limitations. Renal lesions are being detected with increasing frequency due to escalating imaging volumes. Accurate diagnosis is central to guiding clinical management and determining prognosis. Certain lesions require intervention, whereas others may be managed conservatively or deemed clinically insignificant. Challenging cases often benefit from a multimodality imaging approach combining the morphology, enhancement and metabolic features.

Short conclusion

Knowledge of the relevant clinical details and key imaging features is crucial for accurate characterization and differentiation of renal lesions.

Application of BOLDMRIbased radiomics in differentiating malignant from benign renal tumors

OBJECTIVES

Blood oxygen level dependent magnetic resonance imaging (BOLD-MRI) is a kind of non-invasive MRI technology which reflects the tissue blood oxyen levels. This stuy aims to explore the value of radiomics based on BOLD-MRI in differentiating malignant from benign renal tumors.

METHODS

A total of 141 patients with renal tumors confirmed by pathology were retrospectively analyzed. Seventy-four men and sixty-seven women, aged 26-78 years, with a median age of 56, were included. In all patients, 118 with malignant tumors and 23 with benign tumors were confirmed. All the patients underwent renal T1 weighted imaging (T1WI), T2 weighted imaging (T2WI), and BOLD-MRI scan within 2 weeks before surgery. The patients were randomly assigned into a training group (benign, n=17; malignant, n=83) and a test group (benign, n=6; malignant, n=35). Two radiologists (A and B), who were blind to the pathological results, delineated the regions of interest (ROI) on the maximum axial slices of the tumors. Radiologist B delineated the ROI again at an interval of one month. The intra-class correlation coefficient (ICC) was used to evaluate inter-observer and intra-observer repeatability and ICC>0.75 represented as a good consistency. All the T2* Mapping images and the related ROI files were loaded into the Artificial Intelligence Kit software. A total of 396 texture features, which were calculated based on morphology, histogram, gray level co-occurrence matrix, gray-scale run length matrix, gray-scale area size matrix and gray-scale dependent matrix, were extracted from each ROI. The lowest redundancy and the highest correlation were filtered using minimum redundancy maximum relevance (mRMR) algorithm. Then least absolute shrinkage and selection operator (LASSO) algorithm was used to screened out the most predictive features. Multivariate logistic regression was performed to develop the prediction model after feature selection. The radiomics signature score (Radscore) of each case was calculated. The Wilcoxon test was used to compare the difference in the Radscore between benign and malignant renal tumors in the training and test groups. The diagnostic performance of the model in differentiating malignant from benign renal tumors was evaluated with receiver operating characteristic (ROC) curve and leave group out cross validation. The clinical application value of the model was evaluated by decision curve analysis (DCA).

RESULTS

There was significant difference in the age between the patients with benign and those with malignant tumors (t=4.383, P<0.001). There were no significant differences in gender composition and in the largest tumor diameter between the 2 groups (χ2=3.452, P=0.063; t=1.432, P=0.154). The ICC values of all the texture features for the inter-observer repeatability were ranged from 0.71 to 0.87, and the ICC values for the intra-observer repeatability were ranged from 0.76 to 0.91. Thirty features with the lowest redundancy and the highest correlation were screened out. The most predictive 12 features were filtered out. The Radscores of malignant tumors in the training and test groups were higher than those of benign tumors (P<0.001 and P=0.006, respectively). The areas under the ROC curve of the model developed by multivariable logistic regression for differentiating malignant from benign renal tumors in the training and test groups were 0.881 and 0.706, with the accuracy at 82.93% and 79.00%, the sensitivity at 82.86% and 77.11%, and the specificities at 83.33% and 88.24%, respectively. The results of decision curve analysis showed that the net benefit of the radiomics model was higher than that of "all malignant" or "all benign" when the threshold was higher than 0.3.

CONCLUSIONS

BOLD-MRI-based radiomics can be a reliable non-invasive approach for differentiating renal malignant tumors from benign tumors.

Serum markers change for intraocular metastasis in renal cell carcinoma

Objective: Renal cell carcinoma is prone to early metastasis. In general, intraocular metastasis (IOM) is not common. In the present study, we studied the relationship between different biochemical indicators and the occurrence of IOM in renal cancer patients, and identified the potential risk factors.

Methods: A retrospective analysis of the clinical data of 214 patients with renal cell carcinoma from October 2001 to August 2016 was carried out. The difference and correlation of various indicators between the two groups with or without IOM was analyzed, and binary logistic regression analysis was used to explore the risk factors of IOM in renal cancer patients. The diagnostic value of each independent related factor was calculated according to the receiver operating curve (ROC).

Results: The level of neuron-specific enolase (NSE) in renal cell carcinoma patients with IOM was significantly higher than that in patients without IOM (P<0.05). There was no significant difference in alkaline phosphatase (ALP), hemoglobin (Hb), serum calcium concentration, α fetoprotein (AFP), carcinoembryonic antigen (CEA), CA-125 etc. between IOM group and non-IOM (NIOM) group (P>0.05). Binary logistic regression analysis showed that NSE was an independent risk factor for IOM in renal cell carcinoma patients (P<0.05). ROC curve shows that the factor has high accuracy in predicting IOM, and the area under the curve (AUC) is 0.774. The cut-off value of NSE was 49.5 U/l, the sensitivity was 72.2% and the specificity was 80.1%.

Conclusion: NSE concentration is a risk factor for IOM in patients with renal cell cancer. If the concentration of NSE in the patient’s body is ≥49.5 U/l, disease monitoring and eye scans should be strengthened.

Concurrent Angiomyolipoma and Clear Cell Renal Cell Carcinoma in the Same Kidney: A Rare Finding in a Patient without Tuberous Sclerosis

Synchronous renal cell carcinomas (RCC) and angiomyolipomas (AML) occurring in the same kidney are rare. Cases in the setting of tuberous sclerosis (TS) have been reported in the literature. However, the association of these tumors in the same kidney without TS is even more rare. We report here a case of a clear cell renal cell carcinoma (CCRCC) associated with an AML in the same kidney in a 42 years old female lacking the TS diagnostic criteria. The patient underwent a radical nephrectomy. Six months after surgery, the patient is healthy without signs of tumor recurrence or distant metastasis.

The Identification of Zinc-Finger Protein 433 as a Possible Prognostic Biomarker for Clear-Cell Renal Cell Carcinoma

Clear-cell renal cell carcinoma (ccRCC) is the most common and aggressive form of all urological cancers, with poor prognosis and high mortality. At late stages, ccRCC is known to be mainly resistant to chemotherapy and radiotherapy. Therefore, it is urgent and necessary to identify biomarkers that can facilitate the early detection of ccRCC in patients. In this study, the levels of transcripts of ccRCC from The Cancer Genome Atlas (TCGA) dataset were used to identify prognostic biomarkers in this disease. Analyzing the data obtained indicated that the KRAB-ZNF protein is significantly suppressed in clear-cell carcinomas. Furthermore, ZNF433 is differentially expressed in ccRCC in a stage- and histological-grade-specific manner. In addition, ZNF433 expression was correlated with metastasis, with greater node involvement associated with lower ZNF433 expression (p < 0.01) and with a more unsatisfactory overall survival outcome (HR, 0.45; 95% CI, 0.33–0.6; p = 8.5 × 10⁻⁸). Since ccRCC is characterized by mutations in proteins that alter epigenetic modifications and /or chromatin remodeling, we examined the expression of ZNF433 transcripts in ccRCC with wildtype and mutated forms of BAP1, KDMC5, MTOR, PBRM1, SETD2, and VHL. Analysis revealed that ZNF433 expression was significantly reduced in ccRCC with mutations in the BAP1, SETD2, and KDM5C genes (p < 0.05). In addition, the ZNF433 promoter region was highly methylated, and hypermethylation was significantly associated with mRNA suppression (p < 2.2 × 10⁻¹⁶). In silico analysis of potential ZNF target genes found that the largest group of target genes are involved in cellular metabolic processes, which incidentally are particularly impaired in ccRCC. It was concluded from this study that gene expression of ZNF433 is associated with cancer progression and poorer prognosis, and that ZNF433 behaves in a manner that suggests that it is a prognostic marker and a possible tumor-suppressor gene in clear-cell renal cell carcinoma.

Contrast -Enhanced Ultrasound: State of the Art in North America

The Society of Radiologists in Ultrasound convened a panel of specialists in contrast-enhanced ultrasound (CEUS) to produce a white paper on noncardiac CEUS in North America. The panel met in Chicago, Illinois, on October 24 and 25, 2017. The recommendations are based on analysis of current literature and common practice strategies and are thought to represent a reasonable approach to introduce the advantages of this safe and noninvasive technique for the benefit of our patients. Characterization of liver nodules, and pediatric vascular and intravesicular applications comprise the approved indications for CEUS in the United States. They, along with the very successful off-label use of CEUS for the kidney, are included in this publication.Other off-label uses are presented with emphasis on their value and literature support in the online version.

Controlled ovarian stimulation therapy as a potential risk for the development and progression of renal cell carcinomas: A case report and literature review

Renal Cell Carcinoma (RCC) is the most common type of cancer in the kidney and is mostly asymptomatic. Previous studies have supported the important role of sex hormones in RCC pathophysiology and that targeted hormone receptor therapy, such as estrogen receptor targeting, is a promising treatment strategy. However, to the best of our knowledge, it remains unknown whether hormonal therapy, such as controlled ovarian stimulation for in vitro fertilization, serves a role in the development and progression of RCC. The present report describes a case of RCC developed after a fertility stimulation therapy and provides a summary of the known literature on the role of hormone receptors in the development and progression of RCC. A 35-year-old woman received fertility stimulation treatment with follitropin alfa 900 units, human chorionic gonadotropic hormone 5,000 units, injectable leuprolide 1 mg/0.2 ml and cetrotide 0.25 mg. The patient presented to the hospital with shortness of breath and weight loss. The patient had no known genetic predisposition or family history of malignancies and no exposure to chemicals. The patient never used tobacco, alcohol or recreational drugs. Imaging revealed a 17x19 mm, heterogeneously enhancing, and partially exophytic mass in the right kidney. After partial nephrectomy, the pathological evaluation confirmed the diagnosis of clear cell RCC. To the best of our knowledge, this was the first time that a case of ovarian stimulation therapy was associated with the development of RCC. This case raises concerns about the potential oncogenic effect of controlled ovarian stimulation therapy in RCC promotion, suggesting a need for systematic research to clarify the clinical significance of existing pre-clinical data.