Morphological classification of renal cancer

Plasma Kidney Injury Molecule-1 for Preoperative Prediction of Renal Cell Carcinoma Versus Benign Renal Masses, and Association With Clinical Outcomes

PURPOSE

Both clear cell and papillary renal cell carcinomas (RCCs) overexpress kidney injury molecule-1 (KIM-1). We investigated whether plasma KIM-1 (pKIM-1) may be a useful risk stratification tool among patients with suspicious renal masses.

METHODS

Prenephrectomy pKIM-1 was measured in two independent cohorts of patients with renal masses. Cohort 1, from the prospective K2 trial, included 162 patients found to have clear cell RCC (cases) and 162 patients with benign renal masses (controls). Cohort 2 included 247 patients with small (cT1a) renal masses from an academic biorepository, of whom 184 had RCC. We assessed the relationship between pKIM-1, surgical pathology, and clinical outcomes.

RESULTS

In Cohort 1, pKIM-1 distinguished RCC versus benign masses with area under the receiver operating curve (AUC-ROC, 0.81 [95% CI, 0.76 to 0.86]). In Cohort 2 (cT1a only), pKIM-1 distinguished RCC versus benign masses (AUC-ROC, 0.74 [95% CI, 0.67 to 0.80]) and the addition of pKIM-1 to an established nomogram for predicting malignancy improved the model AUC-ROC (0.65 [95% CI, 0.57 to 0.74] v 0.78 [95% CI, 0.72 to 0.85]). A pKIM-1 cutpoint identified using Cohort 2 demonstrated sensitivity of 92.5% and specificity of 60% for identifying RCC in Cohort 1. In long-term follow-up of RCC cases (Cohort 1), higher prenephrectomy pKIM-1 was associated with worse metastasis-free survival (multivariable MFS hazard ratio [HR] 1.29 per unit increase in log pKIM-1, 95% CI, 1.10 to 1.53) and overall survival (multivariable OS HR 1.31 per unit increase in log pKIM-1, 95% CI, 1.10 to 1.54). In long-term follow-up of Cohort 2, no metastatic events occurred, consistent with the favorable prognosis of resected cT1a RCC.

CONCLUSION

Among patients with renal masses, pKIM-1 is associated with malignant pathology, worse MFS, and risk of death. pKIM-1 may be useful for selecting patients with renal masses for intervention versus surveillance.

IFI16 promotes the progression of clear cell renal cell carcinoma through the IL6/PI3K/AKT axis

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is a common disease in the urinary system, with a high incidence and poor prognosis in advanced stages. Although γ-interferon-inducible protein 16 (IFI16) has been reported to play a role in various tumors, its involvement in ccRCC remains poorly documented, and the molecular mechanisms are not yet clear.

METHODS

We conducted bioinformatics analysis to study the expression of IFI16 in ccRCC using public databases. Additionally, we analyzed and validated clinical specimens that we collected. Subsequently, we explored the impact of IFI16 on ccRCC cell proliferation, migration, and invasion through in vitro and in vivo experiments. Furthermore, we predicted downstream molecules and pathways using transcriptome analysis and confirmed them through follow-up experimental validation.

RESULTS

IFI16 was significantly upregulated in ccRCC tissue and correlated with poor patient prognosis. In vitro, IFI16 promoted ccRCC cell proliferation, migration, and invasion, while in vivo, it facilitated subcutaneous tumor growth and the formation of lung metastatic foci. Knocking down IFI16 suppressed its oncogenic function. At the molecular level, IFI16 promoted the transcription and translation of IL6, subsequently activating the PI3K/AKT signaling pathway and inducing epithelial-mesenchymal transition (EMT).

CONCLUSION

IFI16 induced EMT through the IL6/PI3K/AKT axis, promoting the progression of ccRCC.

Sunitinib Treatment of VHL C162F Cells Slows Down Proliferation and Healing Ability via Downregulation of ZHX2 and Confers a Mesenchymal Phenotype

von Hippel-Lindau (VHL) disease, due to mutations of the tumor suppressor VHL gene, is a rare hereditary syndrome with a high risk of developing clear cell renal cell carcinoma (ccRCC). We asked whether the VHL-C162F mutation interferes with proliferation, migration, healing and forming colony ability by using wild-type VHL (WT VHL) and VHL-C162F reconstituted cells. We then analyzed the in vitro impact of the sunitinib treatment on VHL-C162F cells. We showed that VHL-C162F mutations have no impact on cell morphology, colony formation and migration ability but confer a significant higher healing ability than in WT VHL cells. RNA sequencing analysis revealed that VHL-C162F mutation upregulates genes involved in hypoxia and epithelial mesenchymal transition (EMT) pathways by comparison with VHL WT cells. We next showed a decrease in healing ability in VHL-C162F cells depleting on ZHX2, an oncogenic driver of ccRCC, highlighting the potential involvement of ZHX2 in aggressiveness of the VHL-C162F cells. Moreover, we found that sunitinib treatment inhibits ZHX2 expression and induces a reduced proliferation correlating with downregulation of P-ERK. Sunitinib treatment also conferred a more mesenchymal profile to VHL-C162F cells with significant downregulation of E-cadherin and upregulation of N-cadherin, Slug and AXL. Sunitinib therapy may therefore promote disease progression in VHL-C162F patients.

Exploring the role of natural bioactive molecules in genitourinary cancers: how far has research progressed?

The primary approaches to treat cancerous diseases include drug treatment, surgical procedures, biotherapy, and radiation therapy. Chemotherapy has been the primary treatment for cancer for a long time, but its main drawback is that it kills cancerous cells along with healthy ones, leading to deadly adverse health effects. However, genitourinary cancer has become a concern in recent years as it is more common in middle-aged people. So, researchers are trying to find possible therapeutic options from natural small molecules due to the many drawbacks associated with chemotherapy and other radiation-based therapies. Plenty of research was conducted regarding genitourinary cancer to determine the promising role of natural small molecules. So, this review focused on natural small molecules along with their potential therapeutic targets in the case of genitourinary cancers such as prostate cancer, renal cancer, bladder cancer, testicular cancer, and so on. Also, this review states some ongoing or completed clinical evidence in this regard.

Renal Cell Carcinoma Metastasizing to the Cricoid Cartilage Presenting With Subglottic Stenosis: A Case Report and Literature Review

A 72-year-old Japanese man with a 4-month history of hoarseness and 1-week history of difficulty breathing was admitted to our department. He underwent right total nephrectomy for primary clear cell-type renal cell carcinoma (RCC) 6 years ago and left partial nephrectomy for the metastasis 4 years ago. Flexible laryngeal fiberscope examination revealed bilateral subglottic stenosis without obvious mucosal lesions. Enhanced computerized tomography (CT) scan of the neck revealed that the cricoid cartilage had become bilaterally expansive and tumorous lesion exhibiting enhancement. We performed tracheostomy on the appointed day and biopsied the tumor in the cricoid cartilage via the skin incision. Results of histologic and immunohistologic examinations for AE1/AE3, CD10, and vimentin positivity were consistent with clear cell-type RCC. Chest and abdomen CT scans revealed a few tiny metastases in the upper lobe of the left lung but no recurrence in the abdomen. At 2 weeks from the day of tracheostomy, total laryngectomy was performed. Postoperatively, the patient was treated transorally with axitinib (10 mg/day) and as of 12 months he remains alive with unchanging lung metastasis. Next-generation sequencing of targeted regions using a surgical specimen from the tumor revealed a frameshift mutation in the von Hippel-Lindau gene (p.T124Hfs*35) and a missense mutation in the TP53 gene (p.H193R).

The Role of CT Imaging in Characterization of Small Renal Masses

Small renal masses (SRM) are increasingly detected incidentally during imaging. They vary widely in histology and aggressiveness, and include benign renal tumors and renal cell carcinomas that can be either indolent or aggressive. Imaging plays a key role in the characterization of these small renal masses. While a confident diagnosis can be made in many cases, some renal masses are indeterminate at imaging and can present as diagnostic dilemmas for both the radiologists and the referring clinicians. This review focuses on CT characterization of small renal masses, perhaps helping us understand small renal masses. The following aspects were considered for the review: (a) assessing the presence of fat, (b) assessing the enhancement, (c) differentiating renal tumor subtype, and (d) identifying valuable CT signs.

Efficacy and Safety of First-line Systemic Therapy for Metastatic Renal Cell Carcinoma: A Systematic Review and Network Meta-analysis

CONTEXT

Considerable advances have been made in the first-line treatment of metastatic renal cell carcinoma (mRCC), with immunotherapy-based combinations including immunotherapy-tyrosine kinase inhibitors (IO-TKIs) and dual immunotherapy (IO-IO) favored. A lack of head-to-head clinical trials comparing these treatments means that there is uncertainty regarding their use in clinical practice.

OBJECTIVE

To compare and rank the efficacy and safety of first-line systemic treatments for mRCC with a focus on IO-based combinations.

EVIDENCE ACQUISITION

MEDLINE (Ovid), EMBASE, Cochrane Library, Web of Science, and abstracts of recent major scientific meetings were searched to identify the most up-to-date phase 3 randomized controlled trials (RCTs) of first-line IO-based combinations for mRCC up to June 2021. A systematic review and network meta-analysis were completed using the Bayesian framework. Primary endpoints included overall survival (OS) and progression-free survival (PFS). Secondary endpoints included the objective response rate (ORR), complete response (CR), grade 3-4 treatment-related adverse events (TRAEs), treatment-related drug discontinuation (TRDD), and health-related quality of life (HRQoL). The analysis was performed for the intention-to-treat (ITT) population as well as by clinical risk group.

EVIDENCE SYNTHESIS

A total of six phase 3 RCTs were included involving a total of 5121 patients. Nivolumab plus cabozantinib (NIVO-CABO) had the highest likelihood of an OS benefit in the ITT population (surface under the cumulative ranking curve 82%). Avelumab plus axitinib (AVEL-AXI) had the highest likelihood of an OS benefit for patients with favorable risk (65%). Pembrolizumab plus AXI (PEMBRO-AXI) had the highest likelihood of an OS benefit for patients with intermediate risk (78%). PEMBRO plus lenvatinib (PEMBRO-LENV) had the highest likelihood of an OS benefit for patients with poor risk (89%). PEMBRO-LENV was associated with a superior PFS benefit across all risk groups (89-98%). Maximal ORR was achieved with PEMBRO-LENV (97%). The highest likelihood for CR was attained with NIVO plus ipilimumab (NIVO-IPI; 85%) and PEMBRO-LENV (83%). The highest grade 3-4 TRAE rate occurred with PEMBRO-LENV (95%) and NIVO-CABO (83%), but the latter was associated with the lowest TRDD rate (2%). By contrast, NIVO-IPI had the lowest grade 3-4 TRAE rate (6%) and the highest likelihood of TRDD (100%). HRQoL consistently favored NIVO-CABO (66-75%), PEMBRO-LENV (44-85%), and NIVO-IPI (65-93%) in comparison to the other treatments.

CONCLUSIONS

IO-TKI drug combinations are associated with consistent improvements in clinically relevant outcomes for all mRCC risk groups. This benefit may be at the cost of higher TRAE rates; however, lower TRDD rates suggest a manageable side-effect profile. Longer follow-up is required to determine if the benefits of IO-TKIs will be sustained and if they should be favored in the first-line treatment of mRCC.

PATIENT SUMMARY

Combination treatments based on immunotherapy agents continue to show meaningful benefits in the first-line treatment of metastatic kidney cancer. Our review and network meta-analysis shows that immunotherapy combined with another class of agents called tyrosine kinase inhibitors is promising. However, longer follow-up is needed for this treatment strategy to clarify if the benefits are long-lasting.

Immune Checkpoint Inhibitors for Genitourinary Cancers: Treatment Indications, Investigational Approaches and Biomarkers

Cancers of the genitourinary (GU) tract are common malignancies in both men and women and are a major source of morbidity and mortality. Immune checkpoint inhibitors (ICI) targeting CTLA-4, PD-1 or PD-L1 have provided clinical benefit, particularly in renal cell and urothelial carcinoma, and have been incorporated into standard of care treatment in both localized and metastatic settings. However, a large fraction of patients do not derive benefit. Identification of patient and tumor-derived factors which associate with response have led to insights into mechanisms of response and resistance to ICI. Herein, we review current approvals and clinical development of ICI in GU malignancies and discuss exploratory biomarkers which aid in personalized treatment selection.

The effectiveness of systemic therapies after surgery for metastatic renal cell carcinoma to the spine: a propensity analysis controlling for sarcopenia, frailty, and nutrition

OBJECTIVE

The effectiveness of starting systemic therapies after surgery for spinal metastases from renal cell carcinoma (RCC) has not been evaluated in randomized controlled trials. Agents that target tyrosine kinases, mammalian target of rapamycin signaling, and immune checkpoints are now commonly used. Variables like sarcopenia, nutritional status, and frailty may impact recovery from spine surgery and are considered when evaluating a patient's candidacy for such treatments. A better understanding of the significance of these variables may help improve patient selection for available treatment options after surgery. The authors used comparative effectiveness methods to study the treatment effect of postoperative systemic therapies (PSTs) on survival.

METHODS

Univariable and multivariable Cox regression analyses were performed to determine factors associated with overall survival (OS) in a retrospective cohort of adult patients who underwent spine surgery for metastatic RCC between 2010 and 2019. Propensity score-matched (PSM) analysis and inverse probability weighting (IPW) were performed to determine the treatment effect of PST on OS. To address confounding and minimize bias in estimations, PSM and IPW were adjusted for covariates, including age, sex, frailty, sarcopenia, nutrition, visceral metastases, International Metastatic RCC Database Consortium (IMDC) risk score, and performance status.

RESULTS

In total, 88 patients (73.9% male; median age 62 years, range 29-84 years) were identified; 49 patients (55.7%) had an intermediate IMDC risk, and 29 (33.0%) had a poor IMDC risk. The median follow-up was 17 months (range 1-104 months) during which 57 patients (64.7%) died. Poor IMDC risk (HR 3.2 [95% CI 1.08-9.3]), baseline performance status (Eastern Cooperative Oncology Group score 3 or 4; HR 2.7 [95% CI 1.5-4.7]), and nutrition (prognostic nutritional index [PNI] first tertile, PNI < 40.74; HR 2.69 [95% CI 1.42-5.1]) were associated with worse OS. Sarcopenia and frailty were not significantly associated with poor survival. PST was associated with prolonged OS, demonstrated by similar effects from multivariable Cox analysis (HR 0.55 [95% CI 0.30-1.00]), PSM (HR 0.53 [95% CI 0.29-0.93]), IPW (HR 0.47 [95% CI 0.24-0.94]), and comparable confidence intervals. The median survival for those receiving PST was 28 (95% CI 19-43) months versus 12 (95% CI 4-37) months for those who only had surgery (log-rank p = 0.027).

CONCLUSIONS

This comparative analysis demonstrated that PST is associated with improved survival in specific cohorts with metastatic spinal RCC after adjusting for frailty, sarcopenia, and malnutrition. The marked differences in survival should be taken into consideration when planning for surgery.

Modified Glasgow Prognostic Score associated with survival in metastatic renal cell carcinoma treated with immune checkpoint inhibitors

BACKGROUND

The modified Glasgow Prognostic Score (mGPS) is a composite biomarker that uses albumin and C reactive protein (CRP). There are multiple immune checkpoint inhibitor (ICI)-based combinations approved for metastatic renal cell carcinoma (mRCC). We investigated the ability of mGPS to predict outcomes in patients with mRCC receiving ICI.

METHODS

We retrospectively reviewed patients with mRCC treated with ICI as monotherapy or in combination at Winship Cancer Institute between 2015 and 2020. Overall survival (OS) and progression-free survival (PFS) were measured from the start date of ICI until death or clinical/radiographical progression, respectively. The baseline mGPS was defined as a summary score based on pre-ICI values with one point given for CRP>10 mg/L and/or albumin<3.5 g/dL, resulting in possible scores of 0, 1 and 2. If only albumin was low with a normal CRP, no points were awarded. Univariate analysis (UVA) and multivariate analysis (MVA) were carried out using Cox proportional hazard model. Outcomes were also assessed by Kaplan-Meier analysis.

RESULTS

156 patients were included with a median follow-up 24.2 months. The median age was 64 years and 78% had clear cell histology. Baseline mGPS was 0 in 36%, 1 in 40% and 2 in 24% of patients. In UVA, a baseline mGPS of 2 was associated with shorter OS (HR 4.29, 95% CI 2.24 to 8.24, p<0.001) and PFS (HR 1.90, 95% CI 1.20 to 3.01, p=0.006) relative to a score of 0; this disparity in outcome based on baseline mGPS persisted in MVA. The respective median OS of patients with baseline mGPS of 0, 1 and 2 was 44.5 (95% CI 27.3 to not evaluable), 15.3 (95% CI 11.0 to 24.2) and 10 (95% CI 4.6 to 17.5) months (p<0.0001). The median PFS of these three cohorts was 6.7 (95% CI 3.6 to 13.1), 4.2 (95% CI 2.9 to 6.2) and 2.6 (95% CI 2.0 to 5.6), respectively (p=0.0216). The discrimination power of baseline mGPS to predict survival outcomes was comparable to the IMDC risk score based on Uno's c-statistic (OS: 0.6312 vs 0.6102, PFS: 0.5752 vs 0.5533).

CONCLUSION

The mGPS is prognostic in this cohort of patients with mRCC treated with ICI as monotherapy or in combination. These results warrant external and prospective validation.

Single-Cell Sequencing to Identify Six Heat Shock Protein (HSP) Genes-Mediated Progression Subtypes of Clear Cell Renal Cell Carcinoma

Background

Heat shock proteins (HSPs) are widely involved in tumor occurrence and development and are prognostic markers for multiple tumors. However, the role of HSPs in clear cell renal cell carcinoma (ccRCC) remains unclear.

Methods

We used Cytoscape to identify hub genes in the ccRCC single-cell sequencing data set from the Gene Expression Omnibus (GEO) data repository. We identified subtypes, C1 and C2, of The Cancer Genome Atlas (TCGA) patients based on the expression of hub genes using unsupervised consensus clustering. Principal component analysis (PCA) was used to verify the clustering differences, and Kaplan-Meier (K-M) estimate was used to verify the survival differences between C1 and C2 patients. We used TIMER 2.0 and CIBERSORT to evaluate the immune cell infiltration of HSP genes and C1 and C2 patients. The R package "pRRophetic" was used to evaluate the sensitivity in C1 and C2 patients to the four first-line treatment drugs.

Results

We identified six hub genes (HSP90AA1, HSPH1, HSPA1B, HSPA8, and HSPA1A) encoding HSP, five of which were significantly downregulated in TCGA group, and four had a protective effect on prognosis (p <0.05). Survival analysis showed that C1 patients had a better overall survival (p <0.001). TIMER 2.0 analysis showed that three HSP genes were significantly correlated with the infiltration of CD4+ T cells and CD4+ Th1 cells (|cor|>0.5, p<0.001). CIBERSORT showed significant differences in multiple infiltrating immune cells between C1 and C2 patients. Meanwhile, the expression of PD1 was significantly lower in C1 patients than in C2 patients, and the expression of PDL1 is the another way around. Drug sensitivity analysis showed that C1 patients were more sensitive to sorafenib, pazopanib, and axitinib (p <0.001).

Conclusion

Our research revealed two molecular subtypes of ccRCC based on 6 HSP genes, and revealed significant differences between the two subtypes in terms of clinical prognosis, immune infiltration, and drug sensitivity.

Clinical characteristics of renal cell carcinoma in patients under the age of 40

BACKGROUND

Renal cell carcinoma (RCC) most commonly afflicts older patients while those 40 years old or younger represent an uncommon population. We aim to describe the tumor characteristics and treatment patterns for young kidney cancer patients utilizing the National Cancer Database.

METHODS

The National Cancer Database Participant User File for RCC was queried from 2004 to 2016. Demographics and treatment trends were analyzed and compared between a young cohort, those aged 40 and younger vs. a conventional cohort, those older than 40. Pathology analyzed included clear cell, papillary, chromophobe, RCC not otherwise specified, and miscellaneous uncategorized. Subanalysis was performed for patients with localized disease and treatment type.

RESULTS

Amongst the 514,879 patients diagnosed with RCC, 4.7% were ≤40 years old. RCC for individuals ≤40 has a higher proportion of female gender, non-Caucasian race, and chromophobe pathology, relative to the conventional cohort. Younger patients more often presented with cT1 disease with decreased rates of metastasis. Risk of 30-day readmission after surgery was similar between cohorts. For patients with cT1-2N0M0 disease, there was a decreasing rate of radical nephrectomy and increasing rate of partial nephrectomy; however, the conventional cohort had an increasing rate of percutaneous ablation while this remained stable in the younger cohort.

CONCLUSION

Young RCC patients had a higher proportion of female gender, chromophobe histology, and favorable tumor characteristics. Partial nephrectomy has seen a dramatic increase in application regardless of age while percutaneous ablation increased only in the conventional cohort.

Uncontrolled Confounders May Lead to False or Overvalued Radiomics Signature: A Proof of Concept Using Survival Analysis in a Multicenter Cohort of Kidney Cancer

Purpose

We aimed to explore potential confounders of prognostic radiomics signature predicting survival outcomes in clear cell renal cell carcinoma (ccRCC) patients and demonstrate how to control for them.

Materials and Methods

Preoperative contrast enhanced abdominal CT scan of ccRCC patients along with pathological grade/stage, gene mutation status, and survival outcomes were retrieved from The Cancer Imaging Archive (TCIA)/The Cancer Genome Atlas-Kidney Renal Clear Cell Carcinoma (TCGA-KIRC) database, a publicly available dataset. A semi-automatic segmentation method was applied to segment ccRCC tumors, and 1,160 radiomics features were extracted from each segmented tumor on the CT images. Non-parametric principal component decomposition (PCD) and unsupervised hierarchical clustering were applied to build the radiomics signature models. The factors confounding the radiomics signature were investigated and controlled sequentially. Kaplan-Meier curves and Cox regression analyses were performed to test the association between radiomics signatures and survival outcomes.

Results

183 patients of TCGA-KIRC cohort with available imaging, pathological, and clinical outcomes were included in this study. All 1,160 radiomics features were included in the first radiomics signature. Three additional radiomics signatures were then modelled in successive steps removing redundant radiomics features first, removing radiomics features biased by CT slice thickness second, and removing radiomics features dependent on tumor size third. The final radiomics signature model was the most parsimonious, unbiased by CT slice thickness, and independent of tumor size. This final radiomics signature stratified the cohort into radiomics phenotypes that are different by cancer-specific and recurrence-free survival; HR (95% CI) = 3.0 (1.5-5.7), p <0.05 and HR (95% CI) = 6.6 (3.1-14.1), p <0.05, respectively.

Conclusion

Radiomics signature can be confounded by multiple factors, including feature redundancy, image acquisition parameters like slice thickness, and tumor size. Attention to and proper control for these potential confounders are necessary for a reliable and clinically valuable radiomics signature.

[Histological subtypes of renal cell carcinoma : Overview and new developments]

BACKGROUND

The classification of renal cell carcinoma (RCC) has changed remarkably in recent years.

OBJECTIVES

This is a short overview of the classification of RCC, focusing on new developments.

MATERIALS AND METHODS

A literature search was performed resulting in an overview of the classification of RCC. Emerging entities were discussed in detail.

RESULTS

Apart from the RCC subtypes in the WHO classification of 2016, several emerging entities came up over the last few years that are characterized by typical morphology, immunophenotype, and especially specific genetic alterations.

CONCLUSION

Precise classification of RCC is the key to better prognostic assessment with potential tumor-specific therapy and plays an important role in the recognition of possible association with hereditary tumor syndromes.

Update on First-Line Combination Treatment Approaches in Metastatic Clear-Cell Renal Cell Carcinoma

OPINION STATEMENT

The treatment for metastatic renal cell carcinoma (mRCC) has significantly evolved in recent years with a deeper understanding of the molecular make-up of the disease and the clinical development of therapies with novel mechanisms of action. While some patients with more indolent disease may benefit from local therapy such as metastasectomy or cytoreductive nephrectomy, others may safely embark on an active surveillance program or be offered targeted therapy. Yet, a combination regimen including an ICI is the most effective regimen and should be considered in most mRCC cases. Ongoing studies will help determine which factors can be further used to optimize treatment selection and personalize disease management.

Recurrent renal cell carcinoma to the breast and thigh soft tissues. A case report and review of the literature

The breast seldom harbors secondary malignant lesions and is rarer for the kidney to be the origin of the metastatic lesion. Keen Imaging analysis, as well as a high index of suspicion, are critical to differentiate a primary tumor from a metastatic lesion. We describe an unusual case of a recurrent RCC presenting as metastatic lesions to the breast and soft tissue of the right thigh in a 51-year-old patient referred to our breast-imaging unit 10 months after therapeutic surgery. An adequate and close follow-up accompanied by a thorough physical exam and appropriate imaging methods is essential to identify these types of cases.

Multi-energy computed tomography and material quantification: Current barriers and opportunities for advancement

Computed tomography (CT) technology has rapidly evolved since its introduction in the 1970s. It is a highly important diagnostic tool for clinicians as demonstrated by the significant increase in utilization over several decades. However, much of the effort to develop and advance CT applications has been focused on improving visual sensitivity and reducing radiation dose. In comparison to these areas, improvements in quantitative CT have lagged behind. While this could be a consequence of the technological limitations of conventional CT, advanced dual-energy CT (DECT) and photon-counting detector CT (PCD-CT) offer new opportunities for quantitation. Routine use of DECT is becoming more widely available and PCD-CT is rapidly developing. This review covers efforts to address an unmet need for improved quantitative imaging to better characterize disease, identify biomarkers, and evaluate therapeutic response, with an emphasis on multi-energy CT applications. The review will primarily discuss applications that have utilized quantitative metrics using both conventional and DECT, such as bone mineral density measurement, evaluation of renal lesions, and diagnosis of fatty liver disease. Other topics that will be discussed include efforts to improve quantitative CT volumetry and radiomics. Finally, we will address the use of quantitative CT to enhance image-guided techniques for surgery, radiotherapy and interventions and provide unique opportunities for development of new contrast agents.

Advanced renal cell carcinoma (RCC) management: an expert panel recommendation from the Latin American Cooperative Oncology Group (LACOG) and the Latin American Renal Cancer Group (LARCG)

PURPOSE

The outcome of RCC has improved considerably in the last few years, and the treatment options have increased. LACOG-GU and LARCG held a consensus meeting to develop guidelines to support the clinical decisions of physicians and other health professionals involved in the care of RCC patients.

METHODS

Eighty questions addressing relevant advanced RCC treatments were previously formulated by a panel of experts. The voting panel comprised 26 specialists from the LACOG-GU/LARCG. Consensus was determined as 75% agreement. For questions with less than 75% agreement, a new discussion was held, and consensus was determined by the majority of votes after the second voting session.

RESULTS

The recommendations were based on the highest level of scientific evidence or by the opinion of the RCC experts when no relevant research data were available.

CONCLUSION

This manuscript provides guidance for advanced RCC treatment according to the LACOG-GU/LARCG expert recommendations.

First-line Treatment of Metastatic Renal Cell Carcinoma in the Immuno-oncology Era: Systematic Review and Network Meta-analysis

Combination treatments with immuno-oncology (IO) agents and IO agents plus a vascular endothelial growth factor receptor tyrosine kinase inhibitor (VEGFR-TKI) have been approved for first-line treatment of patients with metastatic renal cell carcinoma (mRCC). No direct comparisons have been performed among these treatment options. We performed a systematic review and network meta-analysis to compare and rank the available regimens for first-line treatment in terms of survival benefit and efficacy. In accordance with the Preferred Reporting Items for Systematic Review statement, a systematic search of reported studies was performed in MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE up to May 31, 2019. Network meta-analysis models were adjusted using the Bayesian method. Four randomized clinical trials, with a total of 3758 patients, met the inclusion criteria. Considering systemic therapy, 1880 patients had received sunitinib and 550, 432, 442, and 454 patients had received ipilimumab plus nivolumab (ipi + nivo), pembrolizumab plus axitinib (pembro + axi), avelumab plus axitinib (avelu + axi), and atezolizumab plus bevacizumab (atezo + bev). No difference was found in overall survival between ipi + nivo and pembro + axi for the intention to treat population (hazard ratio [HR], 1.34; 95% credible interval [CrI], 0.92-1.97). No difference was found in progression-free survival among the treatments. The overall response rate (ORR) was superior with pembro + axi and avelu + axi compared with the ORR with the other treatments (atezo + bev vs. pembro + axi: HR, 0.66; 95% CrI, 0.52-0.84; ipi + nivo vs. pembro + axi: HR, 0.73; 95% CrI, 0.59-0.90; atezo + bev vs. avelu + axi: HR, 0.55; 95% CrI, 0.43-0.71; avelu + axi vs. ipi + nivo: HR, 1.66; 95% CrI, 1.31-2.12), with no differences across them (HR, 1.21; 95% CrI, 0.95-1.53). In the present indirect comparison, for an intention to treat population, we found no survival differences between pembro + axi and ipi + nivo. All treatments showed better progression-free survival compared with sunitinib that was similar among them. The combination of an IO agent (pembrolizumab or avelumab) and axitinib seemed to be the most effective therapy for the ORR.

Current Concepts of Non-Coding RNAs in the Pathogenesis of Non-Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a relatively rare malignancy of the urinary tract system. RCC is a heterogenous disease in terms of underlying histology and its associated underlying pathobiology, prognosis and treatment schedule. The most prevalent histological RCC subtype is clear-cell renal cell carcinoma (ccRCC), accounting for about 70-80% of all RCCs. Though the pathobiology and treatment schedule for ccRCC are well-established, non-ccRCC subtypes account for 20%-30% of RCC altogether, and their underlying molecular biology and treatment options are poorly defined. The class of non-coding RNAs-molecules that are generally not translated into proteins-are new cancer drivers and suppressors in all types of cancer. Of these, small non-coding microRNAs (miRNAs) contribute to carcinogenesis by regulating posttranscriptional gene silencing. Additionally, a growing body of evidence supports the role of long non-coding RNAs (lncRNAs) in cancer development and progression. Most studies on non-coding RNAs in RCC focus on clear-cell histology, and there is a relatively limited number of studies on non-ccRCC subtypes. The aim of this review is to give an overview of the current knowledge regarding the role of non-coding RNAs (including short and long non-coding RNAs) in non-ccRCC and to highlight possible implications as diagnostic, prognostic and predictive biomarkers.

Adjuvant Therapy in High-Risk Renal Cell Cancer: A Systematic Review and Meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating risk-benefit for adjuvant postoperative treatments in high-risk renal cell carcinoma by assessing reported disease-free survival (DFS), overall survival (OS), toxicity, and quality of life.

METHODS

A literature search was performed in PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials to identify relevant RCTs (from database inception through May 15, 2018). The results of the ATLAS trial were published while writing this manuscript, and the manuscript was updated accordingly. A generic variance-weighted random effects model was used to derive estimates for efficacy and common adverse effects. Heterogeneity was assessed using the Cochran Q statistic and was quantified using the I² test.

RESULTS

Adjuvant therapy with tyrosine kinase inhibitors compared with placebo was observed to have a DFS hazard ratio [HR] of 0.92 (95% CI, 0.83-1.01) and an OS HR of 1.01 (95% CI, 0.89-1.15) (4 RCTs; 4417 patients). Analysis of DFS for sunitinib compared with placebo (n=1909) in the adjuvant setting detected an HR of 0.90 (95% CI, 0.67-1.19). Increased risk of grade 3 or 4 adverse events (relative risk [RR]=2.6; 95% CI, 2.28-2.97), diarrhea (RR=9.89; 95% CI, 4.22-23.14), fatigue (RR=3.11; 95% CI, 1.86-5.18), hypertension (RR=3.63; 95% CI, 2.99-4.41), and palmar/plantar dysesthesia (RR=2.70; 95% CI, 2.47-2.96) was observed.

CONCLUSION

Adjuvant vascular endothelial growth factor tyrosine kinase inhibitors in high-risk renal cell carcinoma did not improve OS or DFS, and there was a significant increased risk of toxicity in greater than half of the patients, leading to a decline in quality of life.

Nonenhancing Component of Clear Cell Renal Cell Carcinoma on Computed Tomography Correlates With Tumor Necrosis and Stage and Serves as a Size-Independent Prognostic Biomarker

OBJECTIVES

This study aimed to quantify nonenhancing tumor (NT) component in clear cell renal cell carcinoma (ccRCC) and assess its association with histologically defined tumor necrosis, stage, and survival outcomes.

METHODS

Among 183 patients with ccRCC, multi-institutional changes in computed tomography attenuation of tumor voxels were used to quantify percent of NT. Associations of NT with histologic tumor necrosis and tumor stage/grade were tested using Wilcoxon signed rank test and with survival outcomes using Kaplan-Meier curves/Cox regression analysis.

RESULTS

Nonenhancing tumor was higher in ccRCC with tumor necrosis (11% vs 7%; P = 0.040) and higher pathological stage (P = 0.042 and P < 0.001, respectively). Patients with greater NT had higher incidence of cancer recurrence after resection (P < 0.001) and cancer-specific mortality (P < 0.001).

CONCLUSION

Nonenhancing tumor on preoperative computed tomographic scans in patients with ccRCC correlates with tumor necrosis and stage and may serve as an independent imaging prognostic biomarker for cancer recurrence and cancer-specific survival.

The true malignancy risk of Bosniak III cystic renal lesions: Active surveillance or surgical resection?

INTRODUCTION

We sought to evaluate the pathological results of renal masses in comparison with Bosniak III renal cystic lesions to determine the actual malignancy risk.

METHODS

A retrospective review of Bosniak III renal lesions identified by computed tomography (CT) or magnetic resonance imaging (MRI) were collected from our patients between August 1, 2013 and December 31, 2015 who underwent surgical excision. TNM stage, histology, Fuhrman grade, and maximum lesion size data was collected. Lesion size relationship with prevalence of malignancy was completed by two-tailed t-test, using the homogeneity hypothesis between malignant and benign groups.

RESULTS

Fifteen of 25 (60%) of Bosniak III lesions were determined to be malignant. All malignant lesions were classified as either Fuhrman grade 1 or 2 with no evidence of progression to Bosniak IV. Average size of malignant lesions was smaller than those of benign pathology (3.52±1.99 cm vs. 5.66±2.53 cm; p=0.041). Smaller lesions (size <4 cm) were more likely to be malignant than lesions of a larger size (p=0.047).

CONCLUSIONS

The malignancy risk of Bosniak III renal lesions was 60% in our study. All Bosniak III lesions were of low Fuhrman grade with no evidence of progression. No patient in this study developed metastatic disease within the three-year followup period. Smaller (<4 cm) Bosniak III cysts were more likely to be malignant and lesion size should be taken into consideration when considering management of complex cysts. Active surveillance may be a reasonable option for Bosniak III cystic lesions, regardless of overall size, based upon their universal low grade and no patient developing metastatic disease.

Plasma cytokine and angiogenic factors associated with prognosis and therapeutic response to sunitinib vs everolimus in advanced non-clear cell renal cell carcinoma

No biomarkers are available to predict relative clinical benefit from targeted therapies in patients with non-clear cell renal cell carcinoma (nccRCC). To identify candidate predictive markers, we investigated a set of cytokines and angiogenic factors (CAFs) in previously untreated patients with nccRCC participating in the phase II ESPN trial comparing first-line sunitinib to everolimus. Pre-treatment concentrations of 30 CAFs were measured in plasma from 37 patients treated with everolimus (n=16) or sunitinib (n=21), and associated with progression-free (PFS) and overall survival (OS) after adjusting for potential confounders. High (>median) concentrations of soluble glycoprotein 130 (sgp130) were predictive of a longer PFS with sunitinib compared with everolimus (HR = 0.30; 95% CI: 0.11-0.85; P = 0.024). Significantly shorter PFS was noted, independently of treatment arm, in patients with high (>median) levels of IL-8 (HR = 3.13; 95% CI: 1.41-6.92), IL-13 (HR = 3.36; 95% CI: 1.49-7.58), and soluble tumor necrosis factor receptor II (HR = 2.21; 95% CI: 1.04-4.72). High IL-8 levels were also associated with significantly shorter OS (HR = 3.55; 95% CI: 1.55-8.14). Thus, using CAF profiling we identified candidate prognostic and predictive circulating biomarkers that can be used to inform therapeutic decisions in nccRCC.

Conditional survival of metastatic renal cell carcinoma patients treated with high-dose interleukin-2

Conditional survival (CS) is a clinically useful prediction measure which adjusts a patient's prognosis based on their duration of survival since initiation of therapy. CS has been described in numerous malignancies, and recently described in patients with metastatic renal cell carcinoma (mRCC) who received vascular endothelial growth factor tyrosine kinase inhibitor (VEGFTKI) therapy. However, CS has been not reported in the context of mRCC treated with high-dose interleukin-2 therapy (HDIL-2). A total of 176 patients with histologically confirmed metastatic clear cell RCC (mccRCC) treated with HDIL-2 at the University of Utah Huntsman Cancer Institute from 1988-2012 were evaluated. Using the Heng/IMDC model, they were stratified by performance status and prognostic risk groups. Two-year CS was defined as the probability of surviving an additional two years from initiation of HDIL-2 to 18 months after the start of HDIL-2 at three-month intervals. The median overall survival (OS) was 19.9 months. Stratifying patients into favourable (n = 35; 20%), intermediate (n = 110; 63%), and poor (n = 31; 18%) prognostic groups resulted in median OS of 47.5 (HR 0.57, 95% CI 0.35-0.88, p = 0.0106 versus intermediate), 19.6 (HR 0.33, 95% CI 0.10-0.33, p < 0.0001 versus poor), and 8.8 (HR 5.34, 95% CI 3.00-9.62, p < 0.0001 versus favourable) months respectively. Two-year overall CS increased from 43% at therapy initiation to 100% at 18 months. These results have significant ramifications in prognostication. Furthermore, it is important when counseling patients with mccRCC who have completed treatment with HDIL-2 and are in active follow-up.

MicroRNA-148b enhances proliferation and apoptosis in human renal cancer cells via directly targeting MAP3K9

Increasing evidence revealed that miRNAs, the vital regulators of gene expression, are involved in various cellular processes, including cell growth, differentiation, apoptosis and progression. In addition, miRNAs act as oncogenes and/or tumor suppressors. The present study aimed to verify the potential roles of miR148b in human renal cancer cells. miR-148b was found to be downregulated in human renal cancel tissues and human renal cancer cell lines. Functional studies demonstrated that plasmid-mediated overexpression of miR-148b promoted cell proliferation, increased the S-phase population of the cell cycle and enhanced apoptosis in the 786-O and OS-RC-2 renal cancer cell lines, while it did not appear to affect the total number of viable cells according to a Cell Counting Kit-8 assay. Subsequently, a luciferase reporter assay verified that miR148b directly targeted mitogen-activated protein kinase (MAPK) kinase kinase 9 (MAP3K9), an upstream activator of MAPK kinase/c-Jun N-terminal kinase (JNK) signaling, suppressing the protein but not the mRNA levels. Furthermore, western blot analysis indicated that overexpression of miR148b in renal cancer cells inhibited MAPK/JNK signaling by decreasing the expression of phosphorylated (p)JNK. In addition, over-expression of MAP3K9 and pJNK was detected in clinical renal cell carcinoma specimens compared with that in their normal adjacent tissues. The present study therefore suggested that miR-148b exerts an oncogenic function by enhancing the proliferation and apoptosis of renal cancer cells by inhibiting the MAPK/JNK pathway.

Harnessing the PD-1 pathway in renal cell carcinoma: current evidence and future directions

Programmed cell death-1 (PD-1) is a recognized immune checkpoint. It is frequently upregulated on the T cells that infiltrate tumors, providing an inhibitory signal, which may facilitate immune escape. Blocking antibodies have been developed to interrupt the interaction of PD-1 with its ligands PD-L1/PD-L2, with the goal of increasing the host antitumor immune response. Initial results have been encouraging, with durable responses in both treatment-naive and pretreated patients, along with an acceptable toxicity profile. This tolerability makes PD-1 blockade an excellent potential partner for combination strategies with the approved targeted agents, such as tyrosine kinase inhibitors (TKIs) and anti-vascular endothelial growth factor (anti-VEGF) antibodies, as well as other investigational immune checkpoint inhibitors or agonist antibodies that may costimulate an immune response. PD-L1 expression on tumor cells and tumor-infiltrating immune cells is also being evaluated as a predictive biomarker of response to treatment. This review summarizes the biological basis, preclinical studies, ongoing trials, and future challenges associated with targeting the PD-1 pathway in renal cell carcinoma.

Two cases of renal cell cancer during immunobiologic therapy for psoriasis

Immunobiologic therapy is indicated for severe forms of psoriasis, resistant to conventional therapy. There is growing concern about their safety profile and possible association with cancer development. This article documents two cases of renal cell cancer during treatment with biologic therapy, reviewing what is described in the literature . The risk of solid tumors as a complication of using TNF-alpha inhibitors is controversial. No conclusion can be drawn from the data in the literature, however, we believe that special attention should be given to those with known risk factors for a specific neoplasm.

Transient ischaemic attack secondary to paraneoplastic erythrocytosis

A 67-year-old woman with a history of hypertension and type 2 diabetes mellitus was admitted to the hospital due to aphasia and left-sided hemiparesis during the past 5 h with resolution of symptoms within 24 h. On admission laboratory analysis showed haemoglobin 19.2 g/dL and haematocrit 55.1%. Cerebral CT scan was also performed on admission revealing periventricular leucoaraiosis. Studies to investigate the cause of erythrocytosis were started and elevated erythropoietin levels were found. In order to investigate a secondary cause of erythrocytosis an abdominal ultrasound was conducted revealing a left renal mass. CT scans of thorax, abdomen and pelvis confirmed renal mass 8 × 8 cm of diameter, suggestive of neoplasm without associated lymphadenopathy or metastases. Radical nephrectomy was performed and a pathological diagnosis demonstrated clear cell renal cell carcinoma and was staged as T2aN0M0.

Solid renal masses: what the numbers tell us

OBJECTIVE

Solid renal masses are most often incidentally detected at imaging as small (≤ 4 cm) localized lesions. These lesions comprise a wide spectrum of benign and malignant histologic subtypes, but are largely treated with surgical resection given the limited ability of imaging to differentiate among them with consistency and high accuracy. Numerous studies have thus examined the ability of CT and MRI techniques to separate benign lesions from malignancies and to predict renal cancer histologic grade and subtype. This article synthesizes the evidence regarding renal mass characterization at CT and MRI, provides diagnostic algorithms for evidence-based practice, and highlights areas of further research needed to drive imaging-based management of renal masses.

CONCLUSION

Despite extensive study of morphologic and quantitative criteria at conventional imaging, no CT or MRI techniques can reliably distinguish solid benign tumors, such as oncocytoma and lipid-poor angiomyolipoma, from malignant renal tumors. Larger studies are required to validate recently developed techniques, such as diffusion-weighted imaging. Evidence-based practice includes MRI to assess renal lesions in situations where CT is limited and to help guide management in patients who are considered borderline surgical candidates.

MicroRNAs with prognostic potential for metastasis in clear cell renal cell carcinoma: a comparison of primary tumors and distant metastases

BACKGROUND

MicroRNAs (miRNAs) are regulators of gene expression in tumor development and progression. However, their influence on metastasis of clear cell renal cell carcinoma (ccRCC) is less understood. To determine the role of miRNAs in metastatic progression, miRNA expression in primary ccRCC was compared to distant metastases.

METHODS

Total RNA of 53 primary ccRCCs, 35 distant metastases from lung, bone, brain, and abdomen, as well as 17 normal kidney tissues was isolated from fresh frozen tissue and formalin-fixed paraffin-embedded (FFPE) samples. The miRNA microarrays were performed based on fresh frozen tissue. Results were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) on fresh frozen tissue and FFPE samples. Real-time cell analyses and transwell invasion assays were carried out after transient transfection of microRNA-30c (miR-30c) in cell line 786-O.

RESULTS

There were 14 miRNAs differently expressed in metastatic primary ccRCC and distant metastases compared to non-metastatic primary tumors. A strong correlation of miRNAs to progression-free- and cancer-specific 5-year-survival was determined. Specific miRNAs were differently expressed in distant metastases compared to primary ccRCC. A miRNA signature distinguished lung metastases from other metastatic sites. Overexpression of miR-30c increased adherence and decreased migration and invasion in the ccRCC cell line.

CONCLUSIONS

MiRNAs are deregulated in metastatic primary ccRCC and could be promising prognostic markers for an early prediction of metastasis. Alterations in miRNA expression characterize distant metastases of different metastatic sites. Furthermore, our study suggests a functional role of miR-30c in metastasis. The miRNAs could be a helpful tool for individual follow-up prediction and personalized therapy selection.

Metastases of renal cell carcinoma to the larynx and thyroid: Two case reports on metastasis developing years after nephrectomy

Renal cell carcinoma (RCC) has a high metastatic potential due to its hematogen and vascular features. It metastasizes frequently to the lungs, the bones, the liver, the lymph nodes and the brain. Metastasis of RCC to the head and neck region is quite rare. In this case report, two RCC patients with head and neck metastases are presented: one occurring after 5 years and the other occurring 17 years after diagnosis.

[Systemic treatment of renal cell carcinoma - recent update]

Renal cell cancer is the most common form of all malignant renal cancers. The most important exogenic risk factors are smoking and obesity. Most presentations are incidental and, when systemic symptoms occur they are often due to metastases. The mortality rate is still 30% in this disease. The only curative treatment option is surgery. Until recently interferon alpha and/or interleukin-2 were standard treatments in the palliative setting, but efficacy was limited. But in the last years advances could be made. Targeted therapies like sunitinib could demonstrate a significant improvement in progression free survival. Moreover, there are now treatment options even in second line palliative treatment. Nevertheless there are still enough questions to be answered: the optimal sequential therapy, how long should we treat our patients and can we combine theses targeted therapies? Studies to answer all these burning questions are already ongoing.

Specific miRNA signatures are associated with metastasis and poor prognosis in clear cell renal cell carcinoma

PURPOSE

MicroRNAs (miRNAs) play an important role as regulators of gene expression in tumourigenesis by controlling many biological processes in growth, development, differentiation and apoptosis. Previous studies have shown an altered expression of specific miRNAs in clear cell renal cell carcinoma (ccRCC). But the function in cancerogenesis and metastasis in this tumour type is almost unknown. We aimed at identifying specific miRNA expression patterns that are associated with metastasis and prognosis in ccRCC patients.

METHODS

MiRNA of 30 human ccRCC including ten non-metastatic tumours, four tumours with metastasis after 3 years or later and four tumours with primary metastasis was isolated. We analysed the miRNA expression by using microarrays and qRT-PCR.

RESULTS

We detected a miRNA signature that distinguishes between metastatic and non-metastatic ccRCC, including miR-451, miR-221, miR-30a, miR-10b and miR-29a. Furthermore, we identified a group of 12 miRNAs, such as let-7 family, miR-30c, miR-26a, which are decreased in highly aggressive primary metastatic tumours. We found also correlations between expression levels of specific miRNAs with progression-free survival and overall survival.

CONCLUSION

Our findings suggest that specific miRNAs are involved in metastasis and have an impact on the progression of the ccRCC. Furthermore, we identified specific miRNAs characterising very aggressive tumours with early metastasis. In addition, we determined candidate markers associated with survival of the patients. Thus, it seems possible to use miRNAs for prediction of progression to distant metastasis and prognosis analysing the primary tumour.

Systematic comparative protein expression profiling of clear cell renal cell carcinoma: a pilot study based on the separation of tissue specimens by two-dimensional gel electrophoresis

Proteome-based technologies represent powerful tools for the analysis of protein expression profiles, including the identification of potential cancer candidate biomarkers. Thus, here we provide a comprehensive protein expression map for clear cell renal cell carcinoma established by systematic comparative two-dimensional gel electrophoresis-based protein expression profiling of 16 paired tissue systems comprising clear cell renal cell carcinoma lesions and corresponding tumor-adjacent renal epithelium using overlapping narrow pH gradients. This approach led to the mapping of 348 distinct spots corresponding to 248 different protein identities. By implementing restriction criteria concerning their detection frequency and overall regulation mode, 28 up- and 56 down-regulated single target spots were considered as potential candidate biomarkers. Based on their gene ontology information, these differentially expressed proteins were classified into distinct functional groups and according to their cellular distribution. Moreover, three representative members of this group, namely calbindin, gelsolin, and heart fatty acid-binding protein, were selected, and their expression pattern was analyzed by immunohistochemistry using tissue microarrays. Thus, this pilot study provides a significant update of the current renal cell carcinoma map and defines a number of differentially expressed proteins, but both their potential as candidate biomarkers and clinical relevance has to be further explored in tissues and for body fluids like serum and urine.

Distribution of renal tumor growth rates determined by using serial volumetric CT measurements

PURPOSE

To retrospectively determine the distribution of growth rates across different sizes and subtypes of renal cortical tumors by assessing tumor volume and maximum tumor diameter at serial volumetric computed tomographic (CT) examinations.

MATERIALS AND METHODS

The institutional review board approved this retrospective, HIPAA-compliant study. Fifty-three of 2304 patients (34 men, 19 women; mean age, 67 years +/- 10 [standard deviation; range, 39-88 years) who underwent nephrectomy from 1989 to 2006 did not receive preoperative chemotherapy or radiation therapy and underwent at least two preoperative contrast material-enhanced CT examinations (at least 3 months apart) with identical section thickness that was no more than one-fifth of longitudinal tumor diameter. Tumor volume and maximum diameter were measured on CT scans. Reciprocal of doubling time (DT) (RDT) was calculated. Analysis of variance and Student t tests were performed.

RESULTS

Thirty-two clear cell carcinomas, 10 papillary carcinomas, six chromophobe carcinomas, four oncocytomas, and one angiomyolipoma were analyzed. Median tumor size was 2.9 cm (range, 1-12 cm). Seven tumors did not increase in volume. DT ranged from -78476.54 to 18057.43 days (mean, -1230.73 days; median, 590.51 days). [corrected] Growth rate determined by using maximum diameter ranged from -10.8 to 33.2 mm/y (mean, 5.1 mm/y; median, 3.5 mm/y). Faster-growing tumors were more likely to be clear cell carcinomas, those of higher grade had higher growth rates. No significant correlation was found between RDT and tumor initial volume, subtype, or grade. Small renal tumors (<or=3.5 cm) were similar to larger tumors in subtype and growth rate. Age at diagnosis correlated negatively with renal tumor growth rate (P = .03).

CONCLUSION

Growth rates in renal tumors of different sizes, subtypes, and grades represent a wide range and overlap substantially. Small renal tumors appear to be similar to larger ones in nature.

[Urological therapy of renal cell cancer]

Renal cell carcinomas, which originate within the renal cortex, constitute 80-85% of primary renal neoplasms. Patients can present with a range of symptoms due to the tumor itself (e.g., mass, pain), invasion of the urinary tract (e.g., hematuria), paraneoplastic syndromes, or the presence of metastases. Renal cell cancer is more frequently being diagnosed incidentally as a consequence of increased use of imaging procedures for other reasons. Surgery is curative in the majority of patients without metastatic disease and is therefore the preferred treatment for patients with stages I, II, and III disease. The five-year survival following the treatment correlates well with the anatomic extent of disease. Systemic therapy with molecularly targeted therapy or immunotherapy is the primary approach for patients with unresectable or recurrent disease.

Spontaneous occurrence of a distinctive renal tubule tumor phenotype in rat carcinogenicity studies conducted by the national toxicology program

The Toxicology Data Management System (TDMS) of the National Toxicology Program, National Institutes of Environmental Health Sciences, National Institutes of Health, was surveyed for occurrence and distribution of a distinctive renal tubule tumor type in rats. The hallmark features of this tumor included eosinophilic/amphophilic staining, large finely granular cells, and numerous vacuoles and/or minilumens. It is referred to here as the amphophilic-vacuolar (AV) variant of renal tubule tumor. Of 154 studies in which renal tubule tumors had been recorded in the standard single sections of kidney in the TDMS, there were collectively 1012 rats with renal adenomas, carcinomas, or adenocarcinomas, and of these, 100 displayed the distinctive AV morphology, representing 74 studies involving mostly the F344 rat, but also the Sprague-Dawley and Wistar strains. The AV tumors (mainly adenomas but also some carcinomas) occurred usually as solitary lesions in the affected animals. However, they were multiple and bilateral in a few cases. They were equally distributed between the sexes, did not metastasize (at least to the lung), and were not associated with chronic progressive nephropathy. The distribution of this renal tumor type was random across studies and dose groups, underscoring the likelihood that it was of spontaneous origin and not chemically induced. Accordingly, it is suggested that this distinctive renal tumor phenotype be recorded as a separate category from conventional RTT when assessing the carcinogenic potential of a test compound.

Solid renal cortical tumors: differentiation with CT

PURPOSE

To retrospectively determine if solid renal cortical tumors can be differentiated on computed tomographic (CT) images on the basis of their morphologic features and enhancement patterns.

MATERIALS AND METHODS

Institutional review board approval was obtained and the informed consent requirement was waived for this HIPAA-compliant study. Between January 2004 and September 2005, 193 consecutive patients (age range, 19-95 years; 112 men, 81 women) with renal masses underwent total or partial nephrectomy and preoperative renal CT. Two radiologists retrospectively reviewed CT studies in an independent and blinded fashion. The pattern and degree of enhancement, lesion contour, presence of neovascularity, and calcifications were evaluated. Fisher exact tests, Pearson chi(2) tests, multivariate logistic regression, and Wilcoxon rank sum tests were performed.

RESULTS

Of the 198 renal tumors (median size, 3.4 cm; range, 1.1-20.0 cm) included in this study, 108 (55%) were clear cell renal cell carcinomas (RCCs); 30 (15%), papillary lesions; 24 (12%), chromophobe adenomas; 14 (7%), oncocytomas; six (3%), lipid-poor angiomyolipomas; and 16 (8%), other or unclassified renal tumors. Clear cell RCC most commonly manifested with a mixed enhancement pattern of both hypervascular soft-tissue components and low-attenuation areas that corresponded to necrotic or cystic changes (reader 1, 88% of clear cell tumors; reader 2, 79% of clear cell tumors). This pattern was highly predictive of clear cell RCC (odds ratio of 22 and 54 for readers 1 and 2, respectively, for comparison with homogeneous pattern), whereas the homogeneous and peripheral enhancing patterns were more predictive of less aggressive papillary and chromophobe lesions. Clear cell RCCs and oncocytomas tended to be hypervascular, chromophobe lesions and angiomyolipomas tended to enhance moderately, and papillary lesions were mostly hypovascular.

CONCLUSION

Certain imaging features and the degree of enhancement may be helpful in differentiating subtypes of renal cortical tumors.

Significance of Peritumoral Vascularity on CT in Evaluation of Renal Cortical Tumor

PURPOSE

To investigate whether the presence and degree of peritumoral vascularity may provide any diagnostic information regarding the histological subtypes of renal tumors.

MATERIALS AND METHODS

Between January 2004 and March 2006, 214 patients (age, 19-94 years; 120 men, 94 women) with renal masses underwent total or partial nephrectomy and preoperative renal protocol computed tomography. Two radiologists retrospectively reviewed the computed tomographic exams in an independent and blinded fashion. The radiologists evaluated the presence of peritumoral vascularity and measured the largest vessel caliber. Fisher exact tests, multivariate logistic regression, and Wilcoxon rank-sum tests were performed for statistical analysis.

RESULTS

Of 219 renal tumors (median size, 3.5 cm; range, 0.9-20.0 cm) included in this study, 112 (51%) were clear cell renal cell carcinoma, 34 (16%) were papillary, 32 (15%) were chromophobe, 17 (8%) were oncocytomas, 6 (3%) were lipid-poor angiomyolipomas, and 18 (8%) were other or unclassified renal tumors. The presence of peritumoral vascularity was significantly associated with tumor size within each subtype. For both readers, peritumoral vascularity was more frequently identified in clear cell carcinomas than in papillary renal carcinomas of similar size (P = 0.019 and 0.008, respectively). For one of the readers, chromophobe carcinomas were also significantly less frequently associated with peritumoral vascularity than clear cell carcinomas of similar size (P = 0.014).

CONCLUSIONS

Clear cell carcinomas demonstrate peritumoral vascularity significantly more frequently than other malignant renal tumors of similar size. The presence of peritumoral vascularity may provide additional diagnostic information and improve therapeutic planning in some cases.

Pathways of Dysregulation in Renal Cell Carcinoma: Rational Approaches to Development of Novel Treatment

Recent developments have involved a series of novel agents that produce clinical benefit in patients with advanced clear-cell renal cell carcinoma (RCC). The molecular characteristics of RCC, pathways involved in growth and progression, and development of targeted therapeutic approaches have become the focus of many investigators in the past decade. A variety of genetic abnormalities, molecular markers and drugs that target these markers or alter the genetic expression of certain regulatory proteins, have been identified and might have clinical significance for prognosis and treatment. However, specific markers associated with RCC and further development of novel single or combination targeted therapies is now required. An understanding of the complicated and unique biologic behavior of RCC and its various histologic subtypes is crucial for the continued development of novel and targeted therapies.

Expression of vitamin D3 receptor in kidney tumors

The kidney is not only a primary vitamin D target organ but also is a key site of vitamin D metabolism. Recent studies have shown that vitamin D has important physiologic effects on proliferation and differentiation in a variety of benign and malignant cells. Our preliminary immunohistochemical study showed that vitamin D receptor (VDR) was highly expressed in renal distal tubules and collecting ducts, whereas the renal proximal tubules and glomeruli did not express VDR. These observations led us to study the expression of VDR in various kidney tumors to determine the possible diagnostic utility of VDR. Paraffin tissue microarray (TMA) blocks were constructed containing core cylinders from clear cell (52), papillary (35), chromophobe (20), sarcomatoid (20), and metastatic (59) renal cell carcinomas (RCCs). Oncocytomas (20), normal adult kidneys (12), and normal adult adrenals (6) were also included. In addition, 30 clear cell RCCs and 3 collecting duct carcinomas were also studied using conventional sections. Furthermore, VDR messenger RNA and protein expression was also quantified using real-time reverse transcriptase-polymerase chain reaction and Western blot analysis. Vitamin D receptor was strongly positive in collecting duct carcinomas (100% [3/3], cytoplasmic), papillary RCCs (94% [33/35], cytoplasmic), chromophobe RCCs (85% [17/20], membranous), and oncocytomas (90% [18/20], cytoplasmic with perinuclear accentuation). In contrast, VDR expression was focal/weak and present only in the peripheral regions of clear cell RCCs. Vitamin D receptor was weakly positive in sarcomatoid variant RCCs (88% [14/16]) regardless of the type of associated original RCC. Overall, VDR is a discriminative marker for renal cell tumors. The preferential expression of VDR in chromophobe RCCs, oncocytomas, and collecting duct carcinomas is in agreement with the concept that these tumors differentiate toward epithelium lining the distal convoluted tubules and collecting ducts. Considering the different VDR expression patterns, VDR is a useful ancillary tool in distinguishing chromophobe RCCs from oncocytomas. In addition, the focal and much weaker VDR expression in clear cell RCCs makes VDR valuable in distinguishing clear cell RCC from other types of RCCs.

Influence of polymorphisms of ABCB1 and ABCC2 on mRNA and protein expression in normal and cancerous kidney cortex

There is increasing evidence that polymorphisms of the adenosine 5' triphosphate membrane transporters ABCB1 (P-glycoprotein, MDR1) may affect expression and function, whereas less information is available about the impact of ABCC2 (multidrug resistance-associated protein (MRP2)) single-nucleotide polymorphisms . Particularly, their role in human kidney for drug elimination and in the etiology of renal cell carcinoma is poorly understood. ABCB1 and ABCC2 mRNA and protein expression levels were determined by real-time polymerase chain reaction or immunohistochemistry in kidney cancer and adjacent unaffected cortex tissue of 82 nephrectomized renal cell cancer (RCC) patients (63 clear-cell RCC (CCRCC), 19 non-CCRCC). The DNA of all patients was genotyped for ABCB1 -2352G>A, -692T>C, 2677G>T/A (Ala893Ser/Thr), and 3435C>T, and ABCC2 -24C>T, 1249G>A (Val417Ile) and 3972C>T. ABCB1 and ABCC2 were less expressed in CCRCC than in normal cortex on mRNA as well as on protein level. Although the overall genotype frequency distribution did not differ between the patients and a matched control group, ABCB1 2677T/A and 3435T genotypes were associated with higher (P=0.02 and P=0.04) and ABCC2 -24 T with lower mRNA levels in normal tissues (0.03). The expression of ABCB1 and ABCC2 was not related to genetic variants in RCC tissue. In a reporter gene assay in HepG2 cells, the ABCC2 -24T construct showed an 18.7% reduced activity (P=0.003). In conclusion, ABCB1 and ABCC2 genotypes modulate the expression in the unaffected renal cortex of RCC patients, possibly contributing to inter-individual differences in drug and xenobiotics elimination. Their role in RCC cancer susceptibility or chemotherapy resistance needs further elucidation.

Identification of fatty acid binding proteins as markers associated with the initiation and/or progression of renal cell carcinoma

Renal cell carcinoma (RCC) representing the most common neoplasia of the kidney in Western countries is a histologic diverse disease with an often unpredictable course. The prognosis of RCC is worsened with the onset of metastasis, and the therapies currently available are of limited success for the treatment of metastatic RCC. Although gene expression analyses and other methods are promising tools clarifying and standardizing the pathological classification of RCC, novel innovative molecular markers for the diagnosis, prognosis, and for the monitoring of this disease during therapy as well as potential therapeutic targets are urgently needed. Using proteome-based strategies, a number of RCC-associated markers either over-expressed or down-regulated in tumor lesions in comparison to the normal epithelium have been identified which have been implicated in tumorigenesis, but never linked to the initiation and/or progression of RCC. These include members of the fatty acid binding protein family, which have the potential to serve as diagnostic or prognostic markers for the screening of RCC patients.

Differentiation of renal cell carcinoma subtypes by multislice computerized tomography

PURPOSE

We differentiated renal cell carcinoma subtypes using multislice computerized tomography (CT).

MATERIALS AND METHODS

We reviewed the CT images of 87 patients with renal cell carcinoma. Three subtypes of renal cell carcinoma were noted, including clear cell in 37 cases, papillary in 26 and chromophobe in 24. Biphasic CT (unenhanced, corticomedullary and excretory phases) was done in all patients. We compared patient age and sex, tumor size, enhancement degree and pattern (homogeneous, heterogeneous and predominantly peripheral), the presence or absence of calcification or cystic degeneration (necrotic or hemorrhagic areas within the tumor) and tumor spreading patterns, including perinephric change, venous invasion and lymphadenopathy, in the 3 subtypes.

RESULTS

The degree of enhancement was significantly different among the 3 subtypes in the corticomedullary and excretory phases (p <0.001). Cystic degeneration was more evident in the clear cell subtype than in the other subtypes regardless of tumor size (p <0.001). A hypervascular pattern (higher tumor enhancement after contrast material injection due to higher vascularity) was noted in 48.6% of clear cell subtype in comparison to 15.4% of papillary and 4.2% of chromophobe subtypes (p <0.001). The chromophobe subtype showed homogeneous enhancement in 75% of cases in comparison to 45% and 65% of clear cell and papillary subtypes (p >0.05). Calcification was evident in 21.6%, 23.1% and 25% of clear cell, papillary and chromophobe subtypes, respectively (p >0.05).

CONCLUSIONS

To differentiate the subtypes of renal cell carcinoma the degree of enhancement is the most valuable parameter. The presence or absence of cystic degeneration, vascularity and enhancement patterns can serve supplemental role in differentiating renal cell carcinoma subtypes.