Sarcomatoid renal cell carcinoma: a comprehensive review of the biology and current treatment strategies

FDG PET/CT and CT Findings of Renal Cell Carcinoma With Sarcomatoid Differentiation

OBJECTIVE. The purpose of this article is to investigate the value of ¹⁸F-FDG PET/CT and enhanced CT in the diagnosis of renal cell carcinoma (RCC) with sarcomatoid differentiation and the differential diagnosis of clear cell renal cell carcinoma (ccRCC). MATERIALS AND METHODS. Among patients with renal tumors confirmed by pathologic examination from September 2010 to August 2019, 29 patients with RCC with sarcomatoid differentiation and 82 patients with ccRCC who underwent FDG PET/CT, renal contrast-enhanced CT examination, or both, before surgery were studied. Features of the two groups on CT and PET/CT were retrospectively reviewed. RESULTS. The tumor size of RCC with sarcomatoid differentiation was larger than that of ccRCC (p = 0.0086). Cystic necrosis, peritumoral neovascularity, and metastasis were more common in RCC with sarcomatoid differentiation (p = 0.0052, p = 0.0008, p < 0.0001, respectively). The ratio of necrotic area to tumor diameter of RCC with sarcomatoid differentiation was statistically significantly larger than that of ccRCC (p = 0.0032). Three cases of RCC with sarcomatoid differentiation showed a large central necrotic area and dense intratu-moral neovascularity in the surrounding parenchyma, defined as the ring-of-fire sign, which was not found in ccRCC. The maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), and peak standardized uptake value (SUV_peak) of RCC with sarcomatoid differentiation were statistically significantly higher than those for ccRCC (all p < 0.0001), and the SUV_max, SUV_mean, and SUV_peak cutoff values of 5.4, 4.2, and 5.0, respectively, were helpful for discrimination. CONCLUSION. Imaging features including higher SUV_max, SUV_mean, and SUV_peak; a larger ratio of necrotic area to tumor diameter; the presence of peritumoral neovascularity; and metastasis are more commonly associated with RCC with sarcomatoid differentiation than with ccRCC. The ring-of-fire sign and SUV_max, SUV_mean, SUV_peak cutoff values of 5.4, 4.2, 5.0, respectively, may be helpful to indicate RCC with sarcomatoid differentiation.

Genomic profiling in renal cell carcinoma

The treatment landscape of metastatic renal cell carcinoma (RCC) has been revolutionized over the past two decades, bringing forth an era in which more than a dozen therapeutic agents are now available to treat patients. As a consequence, personalized care has become a critical part of developing effective treatment guidelines and improving patient outcomes. One of the most important emerging aspects of precision medicine in cancer is matching patients and treatments based on the genomic characteristics of an individual and their tumour. Despite the lack of a single genomic predictor of treatment response or prognostication feature in RCC, emerging research suggests that the identification of such markers remains promising. Mutations in VHL and alterations in its downstream pathways are the mainstay of RCC development and progression. However, the predictive value of VHL mutations has been questioned. Further research has examined mutations in genes involved in chromosome remodelling (for example, PBRM1, BAP1 and SETD2), DNA methylation and DNA damage repair, all of which have been associated with clinical outcomes. Here, we provide a comprehensive overview of genomic evidence in the context of RCC and its potential predictive and prognostic value.

A Population Study to Identify Candidates for Cytoreductive Nephrectomy in Patients with Metastatic Sarcomatoid Renal Cell Carcinoma from the Surveillance, Epidemiology, and End Results (SEER) Database

BACKGROUND This population study aimed to identify suitable candidates for cytoreductive nephrectomy in patients with metastatic sarcomatoid renal cell carcinoma (RCC) from the US Surveillance, Epidemiology, and End Results (SEER) database. MATERIAL AND METHODS Demographic and clinical data from 1,229 patients with metastatic sarcomatoid RCC were retrieved from the SEER database. Patients were divided into the cytoreductive nephrectomy group (n=937) and the no surgery group (n=292). Multivariate Cox regression analysis identified factors associated with overall survival (OS) and propensity score matching identified factors that significantly impacted the OS. Survival of propensity score-matched subgroups of patients with metastatic sarcomatoid RCC treated by cytoreductive nephrectomy or no surgery was determined by the Kaplan-Meier method and compared by the log-rank test. RESULTS Of the 1,229 patients with metastatic sarcomatoid RCC retrieved from the SEER database, age, tumor size, T stage, and N stage were independent risk factors for patient survival. There were no significant differences in age, N stage, and tumor size between the cytoreductive nephrectomy-treated and non-surgically treated T stage cases following propensity score matching. OS benefits were found in cases with stage T1 (12 months increase), T2 (7.5 months increase), T3a (2 months increase), and T4 (3 months increase), but not in the T3b or T3c subgroups treated by cytoreductive nephrectomy, compared with patients with no surgical treatment. CONCLUSIONS Data from the SEER database showed that cytoreductive nephrectomy improved OS in patients with T1 and T2 metastatic sarcomatoid RCC with a significant long-term survival benefit of >6 months.

Propensity-score matched comparison of partial versus radical nephrectomy for T1N0M0 sarcomatoid renal cell carcinoma

Background

Sarcomatoid renal cell carcinoma is a rare variant of renal cell carcinoma associated with poor clinical outcomes. Currently no reliable evidence indicates whether partial nephrectomy can be an effective treatment for patients with T1N0M0 sarcomatoid renal cell carcinoma. The present study was conducted to compare the overall and cancer-specific survival with partial and radical nephrectomy for such cases.

Methods

Data of sarcomatoid renal cell carcinoma were retrieved from Surveillance, Epidemiology, and End Results database. Factors independently associated with the overall or cancer-specific survival were identified by Cox regression analysis. The overall and cancer-specific survival of propensity-score matched T1N0M0 sarcomatoid renal cell carcinoma patients treated by partial and radical nephrectomy were estimated by the Kaplan-Meier method.

Results

The records of 452 T1N0M0 sarcomatoid renal cell carcinoma cases were retrieved. One hundred and fifty-five of these patients underwent partial nephrectomy, while the remaining 297 underwent radical nephrectomy. The median follow-up period in partial-treated group was 38 months (ranging from 2 to 132 months), while that in RN-treated was 39 months (ranging from 0 to 150 months). Age, sex, marital status and tumor size were independent risk factors for the overall and cancer-specific survival. There were no significant differences among age, sex, marital status and tumor size in the PN- and RN-treated T1N0M0 cases according to propensity-score matching. The estimated median overall survival of partial-treated group was 132 months, while that for RN-treated cases was 100 months (P=0.11). The median cancer-specific survival was not reached in both groups (P=0.092).

Conclusions

The overall and cancer-specific survival of T1N0M0 patients treated by partial nephrectomy was not inferior to that of patients treated by radical nephrectomy.

Sarcomatoid Renal Cell Carcinoma With Unusual Metastasis to the Small Intestine Manifesting as Perforated Appendicitis

BACKGROUND

Sarcomatoid renal cell carcinoma is a rare form of dedifferentiated carcinoma with a high metastatic rate and adverse prognosis. Common sites of metastasis include lymph nodes, lung, liver and bone. We report a case of sarcomatoid renal cell carcinoma with unusual metastasis to the small intestine in a 65-year-old female with a history of clear-cell renal cell carcinoma with focal sarcomatoid transformation.

CASE REPORT

The patient presented to the Emergency Department with worsening abdominal pain. Imaging showed perforated acute appendicitis, however, diagnostic laparoscopy found no evidence of appendicitis, but a small punctate perforation in the small intestine. Gross examination of the small intestine showed a 2 cm tan-white lobular firm lesion at the perforation site involving the full thickness of the wall. Histological examination revealed a high-grade spindle-cell neoplasm with hyperchromatic and pleomorphic nuclei, frequent mitotic figures, and necrosis. Immunohistochemically, the tumor cells were positive for CD10 and carbonic anhydrase 9, but negative for pan-cytokeratin, epithelial membrane antigen, paired box gene 8, renal cell carcinoma, desmin, smooth-muscle actin, c-KIT, discovered on gastrointestinal stromal tumor protein 1, CD34, and S100. Molecular studies showed that the tumor cells were microsatellite stable but harbored mutations in polybromo-1, telomerase reverse transcriptase, and von Hippel-Lindau genes, supporting renal cell carcinoma in nature. The patient received radiation therapy but unfortunately died after one month due to rapid disease progression.

CONCLUSION

This was a rare and challenging case of sarcomatoid renal cell carcinoma metastasis to the small intestine with loss of some renal cell carcinoma markers, reinforcing the aggressive nature of this entity and the importance of correlating findings with the prior history for reaching correct diagnosis.

Salvage ipilimumab associated with a significant response in sarcomatoid renal cell carcinoma

BACKGROUND

Metastatic sarcomatoid renal cell carcinoma (sRCC) is an aggressive variant of RCC with generally poor prognosis. Treatment with vascular endothelial growth factor inhibitors or chemotherapy generates only short-lived responses. Recent research has suggested a role for combination checkpoint inhibition as first line treatment for metastatic sRCC. This therapy consists of induction with cytotoxic T-lymphocyte-associated protein 4 inhibitor, ipilimumab, administered with programmed cell death protein 1 (PD-1) inhibitor, nivolumab. After completion of four cycles of combination therapy, single-agent maintenance nivolumab is recommended until progression. Patients who progress on maintenance nivolumab are switched to alternate therapy. Herein, we present a case of a patient with RCC who progressed on maintenance nivolumab who, on retreatment with ipilimumab, demonstrated a significant response In addition, we summarize important findings to support the role of salvage ipilimumab in patients with sRCC.

CASE PRESENTATION

A 46-year-old man presented with flank pain and hematuria, the work up of which noted a left kidney mass for which he underwent nephrectomy and was diagnosed with localized sRCC with 60% sarcomatoid differentiation. Within 3 months of nephrectomy, he presented with recurrent flank pain and was diagnosed with recurrence of disease. He was treated with ipilimumab 1 mg/kg and nivolumab 3 mg/kg for four doses and demonstrated a partial response. He was then transitioned to single agent nivolumab maintenance. After 3 months on maintenance therapy, he was noted to have progression of disease. Given prior response to immune check point combination, it was decided to rechallenge the patient with 1 mg/kg ipilimumab. After two doses of ipilimumab and nivolumab combination therapy, the patient was noted to have a partial response. He maintained a response for an additional 9 months and treatment was eventually discontinued due to grade 3 toxicity and progression.

CONCLUSIONS

This case report demonstrates the utility of retreatment with ipilimumab as a salvage option for patients progressing on maintenance PD-1 inhibitors in metastatic RCC. Further studies are needed to identify predictors of response and toxicity to this approach, as well as the optimal scheduling of ipilimumab with maintenance nivolumab.

Exceptional Response of Metastatic Chromophobe Renal Cell Carcinoma to Vascular Endothelial Growth Factor (VEGF) Inhibitors: Should Increased VEGF-C Expression Be Used to Guide Treatment?

There is sparse literature demonstrating effective treatments for metastatic chromophobe renal cell carcinoma (ChRCC). The tyrosine kinase inhibitor (TKI) sunitinib selectively inhibits the VEGF pathway and it is a standard care for metastatic clear cell renal cell carcinoma (ccRCC), although data supporting its use in ChRCC is much more limited. A 56-year-old underwent palliative nephrectomy for locally-advanced ChRCC with sarcomatoid differentiation. Tumor gene expression profiling using Affymetrix HG-U133 Plus 2.0 GeneChip platform demonstrated significantly elevated VEGF-C expression compared to normal renal tissue (n = 12) and other types RCC (n = 158). Adjuvant sunitinib was used to treat his residual unresectable retroperitoneal lymph nodes. He demonstrated an exceptional response and underwent complete surgical resection four months later. He has been managed with TKIs for nearly nine years with only minimal disease progression. Additional studies exploring treatment options for patients with non-clear cell RCC are needed; in their absence, we would recommend TKIs for patients whose tumors bear a similar molecular profile.

Cadmium and Lead Decrease Cell-Cell Aggregation and Increase Migration and Invasion in Renca Mouse Renal Cell Carcinoma Cells

Metastatic renal cell carcinoma (RCC) remains an important clinical issue; the 5-year survival rate of patients with metastasis is approximately 12%, while it is 93% in those with localized disease. There is evidence that blood cadmium and lead levels are elevated in RCC. The current studies were designed to assess the impact of cadmium and lead on the progression of RCC. The disruption of homotypic cell-cell adhesion is an essential step in epithelial-to-mesenchymal transition and tumor metastasis. Therefore, we examined the impact of cadmium and lead on the cadherin/catenin complex in Renca cells-a mouse RCC cell line. Lead, but not cadmium, induced a concentration-dependent loss of E-cadherin, while cadmium, but not lead, increased p120-catenin expression, specifically isoform 1 expression. Lead also induced a substantial increase in matrix metalloproteinase-9 levels. Both cadmium and lead significantly decreased the number of Renca cell aggregates, consistent with the disruption of the cadherin/catenin complex. Both metals enhanced wound healing in a scratch assay, and increased cell migration and invasion. These data suggest that cadmium and lead promote RCC progression.

Automated Renal Cancer Grading Using Nuclear Pleomorphic Patterns

PURPOSE

Nuclear pleomorphic patterns are essential for Fuhrman grading of clear cell renal cell carcinoma (ccRCC). Manual observation of renal histopathologic slides may lead to subjective and inconsistent assessment between pathologists. An automated, image-based system that classifies ccRCC slides by quantifying nuclear pleomorphic patterns in an objective and consistent interpretable fashion can aid pathologists in histopathologic assessment.

METHODS

In the current study, histopathologic tissue slides of 59 patients with ccRCC who underwent surgery at Singapore General Hospital were assembled retrospectively. An automated image classification pipeline detects and analyzes prominent nucleoli in ccRCC images to classify them as either low (Fuhrman grade 1 and 2) or high (Fuhrman grade 3 and 4). The pipeline uses machine learning and image pixel intensity-based feature extraction techniques for nuclear analysis. We trained classification systems that concurrently analyze different permutations of multiple prominent nucleoli image patches.

RESULTS

Given the parameters for feature combination and extraction, we present experimental results across various configurations for the classification of a given ccRCC histopathologic image. We also demonstrate that the image score used by the pipeline, termed fraction value, is correlated ( R = 0.59) with an existing multigene assay-based scoring system that has previously been demonstrated to be a strong indicator of prognosis in patients with ccRCC.

CONCLUSION

The current method provides an objective and fully automated way by which to process pathologic slides. The correlation study with a multigene assay-based scoring system also allows us to provide quantitative interpretation for already established nuclear pleomorphic patterns in ccRCC. This method can be extended to other cancers whose corresponding grading systems use nuclear pattern information.

The predictive role of preoperative and postoperative neutrophil-lymphocyte ratio in sarcomatoid renal cell carcinoma

OBJECTIVE

Preoperative inflammatory parameters are associated with outcome in renal cell carcinoma; however, their predictive value in tumors with sarcomatoid dedifferentiation (sRCC) is uncertain. We aimed to evaluate the association between preoperative and postoperative inflammatory parameters and the outcome of patients with locoregional and metastatic sRCC who underwent nephrectomy.

METHODS AND MATERIALS

After obtaining IRB approval, we identified 230 patients with sRCC treated between 1994 and 2018 with a complete blood count drawn ≤1 month before nephrectomy. Preoperative neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio, and platelet-lymphocyte ratio were evaluated as continuous variables. Postoperative NLR, 1 to 8 weeks after surgery, and percentage change in NLR were calculated. Cox regression models were used to identify predictors of outcome.

RESULTS

The study cohort included 105 metastatic patients and 112 patients with locoregional disease. Patients with metastatic disease had significantly higher preoperative NLR (4.31 vs. 3.29) and PLR (248 vs. 194), and lower preoperative LMR (2.6 vs. 3.23). Median follow-up for patients with locoregional and metastatic disease was 36 months and 20 months, respectively, and estimated 5-year cancer-specific survival (CSS) rates were 56% and 15%, respectively. Preoperative NLR was a significant predictor of CSS for both metastatic (HR = 1.23, 95% CI 1.1-1.37, P < 0.001) and locoregional (HR = 1.09, 95% CI 1-1.2, P = 0.049) patients. For metastatic patients, postoperative NLR was significantly associated with CSS on univariate analysis; however, change in NLR was not associated with outcome.

CONCLUSIONS

Preoperative NLR is associated with CSS in locoregional and metastatic sRCC. NLR should be considered when establishing future predictive models for sRCC.

A Case of Sarcomatoid Renal Cell Carcinoma With Osseous Metaplasia and Papillary Renal Cell Carcinoma Metastasis

Sarcomatoid renal cell carcinoma is an uncommon and aggressive renal tumor with rapid disease progression. A median survival time is only 4-9 months after diagnosis. Osteogenic differentiation is a rare feature of the tumor. Here, we present a case of renal cell carcinoma with sarcomatoid feature and osteoid differentiation, and papillary renal cell carcinoma metastasis in a 58 year-old African-American male. This is the first reported renal cell carcinoma case with the combination of sarcomatoid feature, osteoid differentiation, and papillary renal cell carcinoma metastasis.

PD-L1 detection using 89Zr-atezolizumab immuno-PET in renal cell carcinoma tumorgrafts from a patient with favorable nivolumab response

Background

Programmed death-ligand 1 (PD-L1) expression in metastatic renal cell carcinoma (RCC) correlates with a worse prognosis, but whether it also predicts responsiveness to anti-PD-1/PD-L1 therapy remains unclear. Most studies of PD-L1 are limited by evaluation in primary rather than metastatic sites, and in biopsy samples, which may not be representative. These limitations may be overcome with immuno–positron emission tomography (iPET), an emerging tool allowing the detection of cell surface proteins with radiolabeled antibodies. Here, we report iPET studies of PD-L1 in a preclinical tumorgraft model of clear cell RCC (ccRCC) from a patient who had a favorable response to anti-PD-1 therapy.

Case presentation

A 49-year-old man underwent a cytoreductive nephrectomy in 2017 of a right kidney tumor invading into the adrenal gland that was metastatic to the lungs and a rib. Histological analyses revealed a ccRCC of ISUP grade 4 with extensive sarcomatoid features. IMDC risk group was poor. Within two hours of surgery, a tumor sample was implanted orthotopically into NOD/SCID mice. Consistent with an aggressive tumor, a renal mass was detected 18 days post-implantation. Histologically, the tumorgraft showed sarcomatoid differentiation and high levels of PD-L1, similar to the patient’s tumor. PD-L1 was evaluated in subsequently transplanted mice using iPET and the results were compared to control mice implanted with a PD-L1-negative tumor. We labeled atezolizumab, an anti-PD-L1 antibody with a mutant Fc, with zirconium-89. iPET revealed significantly higher ⁸⁹Zr-atezolizumab uptake in index than control tumorgrafts. The patient was treated with high-dose IL2 initially, and subsequently with pazopanib, with rapidly progressive disease, but had a durable response with nivolumab.

Conclusions

To our knowledge, this is the first report of non-invasive detection of PD-L1 in renal cancer using molecular imaging. This study supports clinical evaluation of iPET to identify RCC patients with tumors deploying the PD-L1 checkpoint pathway who may be most likely to benefit from PD-1/PD-L1 disrupting drugs.

Assessing Outcomes and Prognostic Factors for First-Line Therapy in Elderly Patients With Metastatic Renal Cell Carcinoma: Real-Life Data From a Single United Kingdom Institution

BACKGROUND

Elderly metastatic renal cell carcinoma (mRCC) patients are under-represented in clinical trials, whose results are therefore difficult to translate into routine management of older patients. We aimed at exploring treatment outcomes and prognostic factors in our real-life elderly mRCC cohort receiving first-line tyrosine kinase inhibitor (TKI) monotherapy.

PATIENTS AND METHODS

We retrospectively analyzed demographic and clinicopathological characteristics, and treatment data of elderly (≥ 70 years old at first-line start) mRCC patients starting either pazopanib or sunitinib as first-line treatment in our institution between March 2012 and April 2018. Baseline characteristics included age-adjusted Charlson comorbidity index (CCI).

RESULTS

In total, the records of 35 elderly mRCC patients were identified and retrospectively analyzed. Overall response rate, median progression-free survival, and median overall survival were 20%, 9.7 months, and 21.6 months, respectively. Karnofsky performance status ≤ 70%, sarcomatoid features, absolute neutrophil count greater than upper limit of normal, and treatment-related Grade 3 arterial hypertension were independently associated with survival after multivariate analysis. Age-adjusted CCI was significantly associated with survival in univariate analysis only. The overall incidence of Grade 3 to 5 toxicities was 74%. Seven patients (20%) received early crossover to either sunitinib or pazopanib because of toxicity. Dose reduction was applied in 24 (73%) of the 33 patients who completed at least 1 cycle.

CONCLUSION

First-line TKI monotherapy provided clinical benefit in our elderly mRCC cohort. Relatively frequent dose reductions helped to maintain an acceptable tolerability profile. Further research is warranted to explore the significance of prognostic factors in elderly mRCC patients.

Percentage grade 4 tumour predicts outcome for clear cell renal cell carcinoma

Heterogeneity of tumour grading is common in clear cell renal cell carcinoma (ccRCC). WHO/ISUP grading specifies that RCC should be graded based on the highest grade present in at least one high power field. This does not take into account the proportion of high grade tumour present in a cancer, which may itself influence outcome. Cases of ccRCC accessioned by Aquesta Uropathology, Brisbane, Australia, between 2008 and 2015, were reviewed and grading assigned according to WHO/ISUP criteria. For tumours classified as grade 3 (G3) and 4 (G4), the percentage of tumour showing G3 and G4 morphology was assessed for each case. Survival analysis, with time to the development of metastases as the clinical outcome, was performed for six grading subclasses (G3 <10%, G3 10-50%, G3 >50%, G4 <10%, G4 10-50%, G4 >50%). Of the 681 cases of ccRCC in the series, there were 153 cases classified as G3 (91 cases) and G4 (62 cases) for which follow-up was available. During the follow-up period of <1-89 months, 19 (20.9%) patients with G3 and 30 (48.3%) patients with G4 cancers developed metastatic disease. The three subgroups of <10%, 10-50% and >50% G3 tumour were not significant in predicting outcome (p=0.47). Separating G3 into two groups of ≤50% vs >50% was also not significantly associated with outcome (p=0.22). For the three subgroups of G4 ccRCC (<10%, 10-50% and >50% G4) a higher percentage of G4 correlated with time to the development of metastases (p=0.01). Even though G4 tumours as a whole had a significantly worse outcome than G3 tumours (p=0.0004), the difference between G4 <10% and G3 tumours was not significant (p=0.27). On multivariate analysis, that included pT staging category and tumour size, there was a significant difference in survival between G4<10% and G4>50% tumours (p=0.018). The results of the study suggest that for ccRCC, WHO/ISUP G4 category should incorporate the percentage of G4 tumour present.

Patterns of Presentation and Treatment Outcomes of Non-clear-cell Renal Cell Carcinoma and Sarcomatoid Renal Cell Carcinoma Patients in 2 Tertiary Referral Centers in Sydney, Australia

BACKGROUND

Non-clear-cell renal cell carcinoma (nccRCC) and renal cell carcinoma with sarcomatoid features (scRCC) are rare, and represent subtypes with less defined treatment strategies. The aim of this study is to describe the patterns of care and outcomes of these patients in 2 tertiary referral centers in South Western Sydney Local Health District over a 10-year period.

PATIENTS AND METHODS

Patients with RCC seen at South Western Sydney Local Health District from January 1, 2005 to December 31, 2015 were identified from electronic medical records. For each patient, we extracted details regarding demographics, tumor characteristics, treatment, recurrences, and survival, which was analyzed using the Kaplan-Meier method.

RESULTS

Of 178 patients with RCC identified between 2005 and 2015, 23% (n = 41) had nccRCC and 8% (n = 15) had scRCC. Twenty-five patients in total had de novo metastatic disease or disease recurrence. The median follow-up was 46 and 16 months for nccRCC and scRCC, respectively. The median overall survival for nccRCC with metastatic disease was 34 months (range, 14 months to not reached). Seventy percent of these patients received systemic therapy. By contrast, the median overall survival for scRCC with metastatic disease was 10 months (range, 1.6-89 months). Less than one-half of the patients with scRCC received systemic therapy in our cohort, with only 34% receiving no more than 1 line of treatment.

CONCLUSIONS

Our data confirm the rapid and aggressive course of scRCC, highlighting the need for more effective therapeutic strategies in this rare patient population.

Grading of renal cell carcinoma

Grading of renal cell carcinoma (RCC) has been recognised as a prognostic factor for almost 100 years. Numerous grading systems have been proposed, initially focusing upon a constellation of cytological features and more recently on nuclear morphology. It has been recommended that grading of RCC should be based upon nucleolar prominence/eosinophilia for grades 1-3, while grade 4 requires nuclear anaplasia (including tumour giant cells, sarcomatoid differentiation and/or rhabdoid morphology). The grading system was adopted formally by the International Society of Urological Pathology (ISUP) and subsequently by the World Health Organisation (WHO), being designated the WHO/ISUP grading classification in the fourth edition of the WHO classification tumours of the urinary system and male genital organs (2016). This grading system has been validated for both clear cell and papillary RCC. Validation studies for chromophobe RCC failed to demonstrate a correlation between grade and outcome for both the superseded Fuhrman grading system and the WHO/ISUP grading classification, and it has been recommended that these tumours not be graded. The WHO/ISUP system has been incorporated into the structured reports of the International Cancer Collaboration on Cancer Reporting for both clear cell and papillary RCC. It is also noted that other types of RCC may be graded, but it must be emphasised in the report that this is for descriptive and diagnostic purposes, and not outcome prediction. More recent studies have shown the incorporation of the presence of tumour necrosis into RCC grading to improve outcome prediction, and this has been validated in several studies.

TGF-β inducible epithelial-to-mesenchymal transition in renal cell carcinoma

Epithelial-to-mesenchymal transition (EMT) is a crucial step in cancer progression and the number one reason for poor prognosis and worse overall survival of patients. Although this essential process has been widely studied in many solid tumors as e.g. melanoma and breast cancer, more detailed research in renal cell carcinoma (RCC) is required, especially for the major EMT-inducer transforming growth factor beta (TGF-β). Here, we provide a study of six different RCC cell lines of two different RCC subtypes and their response to recombinant TGF-β1 treatment. We established a model system shifting the cells to a mesenchymal cell type without losing their mesenchymal character even in the absence of the external stimulus. This model system forms a solid basis for future studies of the EMT process in RCCs to better understand the molecular basis of this process responsible for cancer progression.

3D reconstruction of CT scans aid in preoperative planning for sarcomatoid renal cancer: A case report and mini-review

Contrast-enhanced multi-slice computed tomography (MSCT) is commonly used in the diagnosis of complex malignant tumours. This technology provides comprehensive and accurate information about tumour size and shape in relation to solid tumours and the affected adjacent organs and tissues. This case report demonstrates the benefit of using MSCT 3D imaging for preoperative planning in a patient with late-stage (T4) sarcomatoid renal cell carcinoma, a rare renal malignant tumour. The surgical margin on the liver was negative, and no metastases to veins, lungs or other organs were detected by abdominal and chest contrast-enhanced CT. Although sarcomatoid histology is considered to be a poor prognostic factor, the patient is alive and well 17 months after surgery. The MSCT imaging modality enables 3D rendering of an area of interest, which assists surgical decision-making in cases of advanced renal tumours. In this case, as a result of MSCT 3D reconstruction, the patient received justified surgical treatment without compromising oncological principles.

Prognostication in Kidney Cancer: Recent Advances and Future Directions

The most common type of cancer originating in the kidney is renal cell carcinoma (RCC). In both localized and advanced RCC, a number of clinical, pathologic, and molecular factors have been identified as having prognostic significance. In localized disease, risk stratification has traditionally involved the anatomic extent of disease, and several integrated scoring systems have been developed to help predict outcomes after definitive local therapy. In metastatic RCC, integrated prognostic models have also been established. These are used to stratify patients in contemporary clinical trials and to guide risk-directed treatment selection in clinical practice. Although many prognostic factors are common to both localized and advanced disease, there are some important distinctions. In both of these types of disease, the prognostic role of specific molecular and genomic alterations is an area of active investigation. In this review, we highlight the current staging systems and prognostic factors in localized and metastatic RCC. We also explore future directions in this area, including the expanding role of molecular biomarkers and their integration into the traditional prognostic models.

Uc.416 + A promotes epithelial-to-mesenchymal transition through miR-153 in renal cell carcinoma

Background

The transcribed ultraconserved regions (T-UCRs) are a novel class of non-coding RNAs that are absolutely conserved across species and are involved in carcinogenesis in some cancers. However, the expression and biological role of T-UCRs in renal cell carcinoma (RCC) remain poorly understood. This study aimed to examine the expression and functional role of Uc.416 + A and analyze the association between Uc.416 + A and epithelial-to-mesenchymal transition in RCC.

Methods

Expression of Uc.416 + A in 35 RCC tissues, corresponding normal kidney tissues and 13 types of normal tissue samples was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). We performed a cell growth and migration assay in RCC cell line 786-O transfected with negative control and siRNA for Uc.416 + A. We evaluated the relation between Uc.416 + A and miR-153, which has a complimentary site of Uc.416 + A.

Results

qRT-PCR analysis revealed that the expression of Uc.416 + A was higher in RCC tissues than that in corresponding normal kidney tissues. Inhibition of Uc.416 + A reduced cell growth and cell migration activity. There was an inverse correlation between Uc.416 + A and miR-153. Western blot analysis showed Uc.416 + A modulated E-cadherin, vimentin and snail. The expression of Uc.416 + A was positively associated with the expression of SNAI1, VIM and inversely associated with the expression of CDH1.

Conclusions

The expression of Uc.416 + A was upregulated in RCC and especially in RCC tissues with sarcomatoid change. Uc.416 + A promoted epithelial-to-mesenchymal transition through miR-153. These results suggest that Uc.416 + A may be a promising therapeutic target.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4863-y) contains supplementary material, which is available to authorized users.

Prevalence of PDL1 Amplification and Preliminary Response to Immune Checkpoint Blockade in Solid Tumors

Importance

Copy number alterations in programmed cell death ligand 1 (PDL1 or CD274), programmed cell death 1 ligand 2 (PDCD1LG2 or PDL2), and Janus kinase 2 (JAK2) genes (chromosome 9p24.1) characterize Hodgkin lymphoma, resulting in high response rates to programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) blockade. The prevalence and utility of PDL1 amplification as a response biomarker to PD-1/PD-L1 blockade are unknown in other tumors.

Objectives

To examine the prevalence of PDL1 amplification and its utility as a response biomarker to PD-1/PD-L1 blockade in solid tumors.

Design, Setting, and Participants

This retrospective study (October 1, 2012, to October 1, 2017) used a deidentified tumor database from a commercial company and annotated clinical records from a subset of patients treated at a university tertiary referral center. The study analyzed 118 187 tumors from the deidentified database, including a clinically annotated subgroup of 2039 malignant tumors.

Interventions

Comprehensive genomic profiling was performed on all samples to determine PDL1 amplification, microsatellite instability, and tumor mutational burden (TMB). A subset of patients was treated with PD-1/PD-L1 blockade.

Main Outcomes and Measures

The prevalence of PDL1 amplification was determined among 118 187 patient samples that underwent next-generation sequencing. Solid tumors treated with checkpoint blockade were evaluated for response and progression-free survival (PFS).

Results

Of the 118 187 deidentified tumor samples, PDL1 amplifications were identified in 843 (0.7%), including more than 100 types of solid tumors. Most PDL1-amplified tumors (84.8%) had a low to intermediate TMB. PDL1 amplification did not always correlate with high-positive PD-L1 expression by immunohistochemical analysis. Six of 9 patients (66.7%) from 1 center with PDL1-amplified solid tumors had objective responses after checkpoint blockade administration. The median PFS among all treated patients was 15.2 months. Responders included 1 patient with glioblastoma (PFS, ≥5.2 months), 2 patients with head and neck squamous cell cancer (PFS, ≥9 and 15.2 months), 2 patients with metastatic basal cell cancer (PFS, 3.8 and ≥24.1 months), and 1 patient with urothelial cancer (PFS, ≥17.8 months).

Conclusions and Relevance

The results of this study suggest that PDL1 amplification occurs in a small subset of malignant tumors. Additional large-scale, prospective studies of PDL1-amplified cancers are warranted to confirm the responses to checkpoint blockade described herein, even in the absence of microsatellite instability, high PD-L1 expression, and a high TMB.

[The morphological and molecular genetic characteristics of sarcomatoid chromophobe renal cell carcinoma]

The paper describes a case of chromophobe renal cell carcinoma growing into the muscular layer of the descending colon and with metastases in 4 lymph nodes of paranephral tissue in a 66-year-old woman. The tumor had a zonal structure with an alternation of epithelioid and sarcomatoid structural sites and with the signs of grades I, II and III according to the grading system by Paner and et al. (2010). The sarcomatoid renal component occupied about 70.0% of the tumor. There was a pronounced immunohistochemical reaction with VEGF-A (5 scores), a high Ki-67 proliferation index (70%), and a large number of tumor cells with nuclear p53 expression (85%) in the areas with minimal differentiation and sarcomatoid elements (Grade III). These signs can serve as criteria for the aggressive behavior of the tumor. A large volume of the sarcomatoid carcinoma component and a strong reaction with VEGF-A are indications for targeted therapy with anti-VEGF drugs.

The prognostic value and clinicopathological features of sarcomatoid differentiation in patients with renal cell carcinoma: a systematic review and meta-analysis

Background and purpose

Numerous studies have demonstrated that sarcomatoid differentiation is linked to the risk of renal cell carcinoma (RCC). However, its actual clinicopathological impact remains inconclusive. Therefore, we undertook a meta-analysis to evaluate the pathologic and prognostic impacts of sarcomatoid differentiation in patients with RCC by assessing cancer-specific survival, overall survival, recurrence-free survival, progression-free survival, and cancer-specific mortality.

Materials and methods

In accordance with the preferred reporting items for systematic reviews and meta-analysis statement, relevant studies were collected systematically from PubMed, Embase, and Web of Science to identify relevant studies published prior to January 2018. The pooled effects (hazard ratios, odds ratios, and standard mean differences) and 95% confidence intervals were calculated to investigate the association of sarcomatoid differentiation with cancer prognosis and clinicopathological features.

Results

Thirty-five studies (N=11,261 patients [n=59-1,437 per study]) on RCC were included in this meta-analysis. Overall, the pooled analysis suggested that sarcomatoid differentiation was significantly associated with unfavorable cancer-specific survival (HR=1.46, 95% CI: 1.26-1.70, p<0.001), overall survival (HR=1.59, 95% CI: 1.42-1.78, p<0.001), progression-free survival (HR=1.61, 95% CI: 1.35-1.91, p<0.001), recurrence-free survival (HR=1.60, 95% CI: 1.29-1.99, p<0.001), and cancer-specific mortality (HR=2.36, 95% CI: 1.64-3.41, p<0.001) in patients with RCC. Moreover, sarcomatoid differentiation was closely correlated with TNM stage (III/IV vs I/II: OR=1.84, 95% CI: 1.12-3.03, p=0.017), Fuhrman grade (III/IV vs I/II: OR=8.37, 95% CI: 2.92-24.00, p<0.001), lymph node involvement (N1 vs N0: OR=1.88, 95% CI: 1.08-3.28, p=0.026), and pathological types (clear cell RCC-only vs mixed type: OR=0.48, 95% CI: 0.29-0.80, p=0.005), but was not related to gender (male vs female, OR=0.86, 95% CI: 0.58-1.28, p=0.464) and average age (SMD=-0.02, 95% CI: -0.20-0.17, p=0.868).

Conclusion

This study suggests that sarcomatoid differentiation in histopathology is associated with poor clinical outcome and advanced clinicopathological features in RCC and could serve as a poor prognostic factor for RCC patients.

Molecular and Metabolic Basis of Clear Cell Carcinoma of the Kidney

Renal cell carcinoma (RCC) is a heterogenous group of tumors, >70% of which belong to the category of clear cell carcinoma. In recent years, crucial advances have been made in our understanding of the molecular and metabolic basis of clear cell carcinoma. This tumor manifests significant alterations in the cellular metabolism, so that the tumor cells preferentially induce the hypoxia response pathway using aerobic glycolysis, rather than the normal oxidative phosphorylation for energy. Most of the clear cell carcinomas (sporadic as well as familial) have mutations and deletions in the VHL gene located at 3p (p3.25). Normally, pVHL plays a crucial role in the proteasomal degradation of hypoxia-inducible factors (HIF)1 and HIF2. Lack of a functioning pVHL owing to genetic alterations results in stabilization and accumulation of these factors, which promotes cell growth, cell proliferation, and angiogenesis, contributing to a neoplastic phenotype. Several other genes normally located adjacent to VHL (BAP1, SETD2, PBRM1) may also be lost. These are tumor suppressor genes whose loss not only plays a role in carcinogenesis but may also influence the clinical course of these neoplasms. In addition, interaction among a variety of other genes located at several different chromosomes may also play a role in the genesis and progression of clear cell carcinoma.

Quantification of sarcomatoid differentiation in renal cell carcinoma on magnetic resonance imaging

Background

Sarcomatoid differentiation in renal cell carcinoma (sRCC) is histologically characterized by anaplastic changes of renal cell carcinoma (RCC) subtypes, which has been associated with a poor prognosis. sRCC is managed more aggressively than RCC without sarcomatoid components, so pre-operative detection of sarcomatoid differentiation would significantly affect surgical management. The purpose of this study is to compare the quantification of sarcomatoid features in RCCs on pre-operative magnetic resonance imaging (MRI) to standard histological examination.

Methods

Patients who had nephrectomy at our institution between 2000 and 2015 with pathology proven RCC and pre-operative contrast enhanced MRI abdominal scans were retrospectively reviewed. A custom MATLAB routine calculated the portion of each manually segmented whole tumor with MRI signal suggestive of sarcomatoid involvement based on prior research (MRI%SARC). The primary endpoint compared MRI%SARC to percent sarcomatoid involvement estimated by histological examination (HIST%SARC) using Pearson correlation and Bland Altman analysis.

Results

A total of 17 patients with sRCC (10 males, age 60.3±11.1 years) and 17 consecutive control patients with clear cell RCC (ccRCC) without sarcomatoid components (10 males, age 64.5±7.6 years) were evaluated. Pearson correlation analysis revealed a strong association between MRI%SARC and HIST%SARC (r=0.782, P<0.001). Bland-Altman analysis demonstrated proportional bias, with a mean bias of 19.29 [95% confidence interval (CI): 9.79-28.79] and with 95% limits of agreement of -16.93 (95% CI: -33.38 to -0.48) to 55.51 (95% CI: 39.06-71.96), suggesting MRI%SARC underestimated values compared to HIST%SARC by 19%.

Conclusions

Multiparametric pre-operative MRI analysis to quantify sarcomatoid features in RCC correlates with standard histological examination but underestimates percent sarcomatoid involvement.

Sarcomatoid renal cell carcinoma: a case report and literature review

BACKGROUND

The poorly differentiated renal cell carcinoma (RCC) with rhabdomyosarcomatous sarcomatoid differentiation shows a severely aggressive biological behavior characterized by rapid disease progression. Preoperative identification of the subtype with the prognostic factors and imaging features of sarcomatoid renal cell carcinoma (SRCC) would be of great clinical significance.

CASE PRESENTATION

A 45-year-old male patient presented a nine day history of gross hematuria without any other symptoms. A computed tomography (CT) and a full-body fluorine-18 fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) - computed tomography (CT) scan urogram were performed. An initial diagnosis identified a space-occupying lesion of the right kidney, retroperitoneal and right renal hulum lymph node metastases, as well as a space-occupying lesion of the third thoracic vertebra (T3). A right radical nephrectomy was performed. Pathologic analysis revealed poorly differentiated RCC with rhabdomyosarcomatous sarcomatoid differentiation that extends into the renal sinus and the ureteral (T3N1M1). Five days later, the Magnetic Resonance imaging (MRI) evidenced a diffused osseous metastatic disease in the thoracic and lumbar vertebra and multiple retroperitoneal lymph node metastases. The disease progressed quickly to multiple organ dysfunction syndrome (MODS) in half a month and the patient died of respiratory failure two days later. The patient refused any chemoradiotherapy in the hospital.

CONCLUSIONS

Our case presents a SRCC with severe, aggressive, and rapid disease progression. Classifying SRCC imaging features by CT, MRI as well as PET-CT techniques could potentially be helpful for preoperative identification of the subtype. The prognostic factors of SRCC would be of great clinical interest.

Genomic classifications of renal cell carcinoma: a critical step towards the future application of personalized kidney cancer care with pan-omics precision

Over the past 20 years, classifications of kidney cancer have undergone major revisions based on morphological refinements and molecular characterizations. The 2016 WHO classification of renal tumors recognizes more than ten different renal cell carcinoma (RCC) subtypes. Furthermore, the marked inter- and intra-tumor heterogeneity of RCC is now well appreciated. Nevertheless, contemporary multi-omics studies of RCC, encompassing genomics, transcriptomics, proteomics, and metabolomics, not only highlight apparent diversity but also showcase and underline commonality. Here, we wish to provide an integrated perspective concerning the future 'functional' classification of renal cancer by bridging gaps among morphology, biology, multi-omics, and therapeutics. This review focuses on recent progress and elaborates the potential value of contemporary pan-omics approaches with a special emphasis on cancer genomics unveiled through next-generation sequencing technology, and how an integrated multi-omics approach might impact precision-based personalized kidney cancer care in the near future. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Extensive Metastatic Sarcomatoid Renal Cell Carcinoma Evaluated by 18F-FDG PET/CT: a Case Report and Review of Literature

Sarcomatoid renal cell carcinoma (sRCC) is a highly aggressive form of dedifferentiated renal cell carcinoma. We report a 62-year-old man who presented with respiratory symptoms and a lung mass on chest computed tomography (CT). The patient underwent positron emission tomography/computed tomography (PET/CT) with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) and was found to have extensive metastatic disease. Based on the history and imaging findings, there were possible primary malignancies, including bronchogenic carcinoma, melanoma, or an aggressive lymphoma. An excisional biopsy surprisingly revealed a high-grade sarcomatoid carcinoma with no evidence of differentiation, and immunohistochemical (IHC) studies showed that the tumor cells were positive for markers of genitourinary origin (PAX-8 and vimentin). The histologic and IHC results, along with multiple FDG-avid exophytic lesions in both kidneys, were considered diagnostic of sRCC. Here we have highlighted the potential role of ¹⁸F-FDG-PET-CT in patients with sRCC, discussed the diagnostic challenges, and presented a brief review.

Sarcomatoid renal cell carcinoma: Biology and treatment advances

Sarcomatoid transformation in renal cell carcinoma, so called sacromatoid RCC (sRCC), is associated with an aggressive behavior and a poor prognosis. Current therapeutic approaches are largely ineffective. Recent studies looking into the genomic and molecular characterization of sRCCs have provided insights into the biology and pathogenesis of this entity. These advances in molecular signatures may help development of effective treatment strategies. We herein present a review of recent developments in the pathology, biology, and treatment modalities in sRCC.

Axitinib, cabozantinib, everolimus, nivolumab, sunitinib and best supportive care in previously treated renal cell carcinoma: a systematic review and economic evaluation

BACKGROUND

Several therapies have recently been approved for use in the NHS for pretreated advanced or metastatic renal cell carcinoma (amRCC), but there is a lack of comparative evidence to guide decisions between them.

OBJECTIVE

To evaluate the clinical effectiveness and cost-effectiveness of axitinib (Inlyta®, Pfizer Inc., NY, USA), cabozantinib (Cabometyx®, Ipsen, Slough, UK), everolimus (Afinitor®, Novartis, Basel, Switzerland), nivolumab (Opdivo®, Bristol-Myers Squibb, NY, USA), sunitinib (Sutent®, Pfizer, Inc., NY, USA) and best supportive care (BSC) for people with amRCC who were previously treated with vascular endothelial growth factor (VEGF)-targeted therapy.

DATA SOURCES

A systematic review and mixed-treatment comparison (MTC) of randomised controlled trials (RCTs) and non-RCTs. Primary outcomes were overall survival (OS) and progression-free survival (PFS). Secondary outcomes were objective response rates (ORRs), adverse events (AEs) and health-related quality of life (HRQoL). MEDLINE, EMBASE and The Cochrane Library were searched from inception to January and June 2016 for RCTs and non-RCTs, respectively. Two reviewers abstracted data and performed critical appraisals.

REVIEW METHODS

A fixed-effects MTC was conducted for OS, PFS [hazard ratios (HRs)] and ORR (odds ratios), and all were presented with 95% credible intervals (CrIs). The RCT data formed the primary analyses, with non-RCTs and studies rated as being at a high risk of bias included in sensitivity analyses (SAs). HRQoL and AE data were summarised narratively. A partitioned survival model with health states for pre progression, post progression and death was developed to perform a cost-utility analysis. Survival curves were fitted to the PFS and OS results from the MTC. A systematic review of HRQoL was undertaken to identify sources of health state utility values.

RESULTS

Four RCTs (n = 2618) and eight non-RCTs (n = 1526) were included. The results show that cabozantinib has longer PFS than everolimus (HR 0.51, 95% CrI 0.41 to 0.63) and both treatments are better than BSC. Both cabozantinib (HR 0.66, 95% CrI 0.53 to 0.82) and nivolumab (HR 0.73, 95% CrI 0.60 to 0.89) have longer OS than everolimus. SAs were consistent with the primary analyses. The economic analysis, using drug list prices, shows that everolimus may be more cost-effective than BSC with an incremental cost-effectiveness ratio (ICER) of £45,000 per quality-adjusted life-year (QALY), as it is likely to be considered an end-of-life treatment. Cabozantinib has an ICER of £126,000 per QALY compared with everolimus and is unlikely to be cost-effective. Nivolumab was dominated by cabozantinib (i.e. more costly and less effective) and axitinib was dominated by everolimus.

LIMITATIONS

Treatment comparisons were limited by the small number of RCTs. However, the key limitation of the analysis is the absence of the drug prices paid by the NHS, which was a limitation that could not be avoided owing to the confidentiality of discounts given to the NHS.

CONCLUSIONS

The RCT evidence suggests that cabozantinib is likely to be the most effective for PFS and OS, closely followed by nivolumab. All treatments appear to delay disease progression and prolong survival compared with BSC, although the results are heterogeneous. The economic analysis shows that at list price everolimus could be recommended as the other drugs are much more expensive with insufficient incremental benefit. The applicability of these findings to the NHS is somewhat limited because existing confidential patient access schemes could not be used in the analysis. Future work using the discounted prices at which these drugs are provided to the NHS would better inform estimates of their relative cost-effectiveness.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016042384.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

High-dose interleukin 2 in patients with metastatic renal cell carcinoma with sarcomatoid features

Background

High-dose interleukin-2 (HD IL-2) is used in the treatment of metastatic renal cell carcinoma (mRCC) and has an overall response rate (ORR) of 12–20% and a complete response rate (CR) of 8% in unselected populations with predominantly clear cell type renal cell carcinoma. Nearly 10–15% of patients with renal cell carcinoma exhibit sarcomatoid differentiation, a feature which correlates with a median overall survival (OS) of 9 months and overall poor prognosis. We report a single institution experience with 21 patients with mRCC with sarcomatoid features post-nephrectomy who were treated with HD IL-2.

Methods

Twenty one patients with mRCC with sarcomatoid features post-nephrectomy who underwent therapy with HD IL-2 were identified at the University of Pittsburgh Medical Center from 2004 to 2016. Baseline patient characteristics, HD IL-2 cycles, time to progression, and subsequent therapies were evaluated. OS and progression-free survival (PFS) in the cohort were calculated using the Kaplan-Meier method. Disease characteristics were evaluated for significance using the Fischer′s exact test and Wilcoxon rank sum test.

Results

Patients were predominantly Caucasian males with a median age of 54 years. A majority, 86% of these patients, had metastatic disease at time of initial presentation, primarily with lung and lymph node involvement. The ORR and CR with HD IL-2 was 10% and 5%, respectively. Initial localized disease presentation is the only variable that was significantly associated with response to HD IL-2 (p = 0.0158). Number of HD IL-2 doses did not correlate with response with a mean of 16.5 and 15.0 total doses in responders and non-responders, respectively (p = 0.53). Median PFS with HD IL-2 was 7.9 months (95% CI, 5.0–21.3). Median OS was 30.5 months (95% CI 13.3–57.66). Within the subset of patients who had progression on IL-2, median OS was 19.4 months (95% CI, 13.3–35.3). In patients who received second-line therapy, median PFS was 7.9 months (95% CI 2.4–10.2).

Conclusion

In patients with mRCC with sarcomatoid features, use of HD IL-2 was associated with a modest ORR and a higher survival compared to historical controls (patients with mRCC and sarcomatoid features). Thus, HD IL-2 may have a role in treating selected patients with mRCC with sarcomatoid features.

Sarcomatoid Renal Cell Carcinoma in an Adolescent with Sickle Cell Anaemia

Malignancies have been reported to occur in people with sickle cell disease. Renal medullary carcinoma (RMC), also tagged seventh sickle cell nephropathy, is an aggressive cancer seen almost exclusively in people with sickle cell disease with more than 160 cases reported worldwide, but only few cases were reported in patients with sickle cell anaemia (HBSS) and from Nigeria. Sarcomatoid renal cell carcinoma is a renal tumour of any histologic variant containing foci of high-grade malignant spindle cells. We report an adolescent girl with sickle cell anaemia (HBSS) who presented with left renal tumour, histology of which confirmed a diagnosis of sarcomatoid renal cell carcinoma (sRCC). Surgical debulking and palliative care with chemotherapy were given, and she demised 10 months after. The rarity of the case and challenges of managing a cancer in the background of a chronic haematologic disorder are highlighted.

Collision and composite tumors; radiologic and pathologic correlation

The terms composite and collision tumors have been used interchangeably throughout radiological literature. Both composite and collision tumors involve two morphologically and immunohistochemically distinct neoplasms coexisting within a single organ. However, collision tumors lack the histological cellular intermingling seen in composite tumors. Composite tumors often arise from a common driver mutation that induces a divergent histology from a common neoplastic source while collision tumors may arise from coincidental neoplastic change. The purpose of this review is to provide an overview of abdominal composite and collision tumors by discussing hallmark radiographic and pathological presentations of rare hepatic, renal, and adrenal case studies. A better understanding of the presentation of each lesion is imperative for proper recognition, diagnosis, and management of these unique tumor presentations.

Non-Clear Cell Renal Cell Carcinoma: Current Management and Best Practice

The treatment of metastatic renal cell carcinoma (mRCC) has evolved markedly over the past several decades; first with the introduction of targeted therapies and more recently with data supporting checkpoint inhibition. However, the vast majority of studies to date have explored the benefit of agents specifically in the context of clear cell disease. For the estimated 15-20% of patients with non-clear cell histology, there is little consensus around best practice. Herein, we discuss emerging datasets providing biologic characterization of non-clear cell RCC and identify trials that exploit this biology.

Texture analysis as a radiomic marker for differentiating renal tumors

PURPOSE

To evaluate the utility of texture analysis for the differentiation of renal tumors, including the various renal cell carcinoma subtypes and oncocytoma.

MATERIALS AND METHODS

Following IRB approval, a retrospective analysis was performed, including all patients with pathology-proven renal tumors and an abdominal computed tomography (CT) examination. CT images of the tumors were manually segmented, and texture analysis of the segmented tumors was performed. A support vector machine (SVM) method was also applied to classify tumor types. Texture analysis results were compared to the various tumors and areas under the curve (AUC) were calculated. Similar calculations were performed with the SVM data.

RESULTS

One hundred nineteen patients were included. Excellent discriminators of tumors were identified among the histogram-based features noting features skewness and kurtosis, which demonstrated AUCs of 0.91 and 0.93 (p < 0.0001), respectively, for differentiating clear cell subtype from oncocytoma. Histogram feature median demonstrated an AUC of 0.99 (p < 0.0001) for differentiating papillary subtype from oncocytoma and an AUC of 0.92 for differentiating oncocytoma from other tumors. Machine learning further improved the results achieving very good to excellent discrimination of tumor subtypes. The ability of machine learning to distinguish clear cell subtype from other tumors and papillary subtype from other tumors was excellent with AUCs of 0.91 and 0.92, respectively.

CONCLUSION

Texture analysis is a promising non-invasive tool for distinguishing renal tumors on CT images. These results were further improved upon application of machine learning, and support the further development of texture analysis as a quantitative biomarker for distinguishing various renal tumors.

Genomic and metabolic characterization of a chromophobe renal cell carcinoma cell line model (UOK276)

Chromophobe renal cell carcinoma (ChRCC) represents 5% of all RCC cases and frequently demonstrates multiple chromosomal losses and an indolent pattern of local growth, but can demonstrate aggressive features and resistance to treatment in a metastatic setting. Cell line models are an important tool for the investigation of tumor biology and therapeutic drug efficacy. Currently, there are few ChRCC-derived cell lines and none is well characterized. This study characterizes a novel ChRCC-derived cell line model, UOK276. A large ChRCC tumor with regions of sarcomatoid differentiation was used to establish a spontaneously immortal cell line, UOK276. UOK276 was evaluated for chromosomal, mutational, and metabolic aberrations. The UOK276 cell line is hyperdiploid with a modal number of 49 chromosomes per cell, and evidence of copy-neutral loss of heterozygosity, as opposed to the classic pattern of ChRCC chromosomal losses. UOK276 demonstrated a TP53 missense mutation, expressed mutant TP53 protein, and responded to treatment with a small-molecule therapeutic agent, NSC319726, designed to reactivate mutated TP53. Xenograft tumors grew in nude mice and provide an in vivo animal model for the investigation of potential therapeutic regimes. The xenograft pathology and genetic analysis suggested that UOK276 was derived from the sarcomatoid region of the original tumor. In summary, UOK276 represents a novel in vitro and in vivo cell line model for aggressive, sarcomatoid-differentiated, TP53 mutant ChRCC. This preclinical model system could be used to investigate the novel biology of aggressive, sarcomatoid ChRCC and evaluate the new therapeutic regimes.

Sarcomatoid Renal Cell Carcinoma and Collecting Duct Carcinoma: Discrimination From Common Renal Cell Carcinoma Subtypes and Benign RCC Mimics on Multiphasic MDCT

RATIONALE AND OBJECTIVES

To investigate whether imaging features on multiphasic multidetector computed tomography (MDCT) can help discriminate sarcomatoid renal cell carcinoma (RCC) and collecting duct carcinoma (CDC) from other solid renal masses.

MATERIALS AND METHODS

With institutional review board approval for this HIPAA-compliant study, we derived a cohort of 7 sarcomatoid RCCs, 4 CDCs, 165 clear cell RCCs, 56 papillary RCCs, 22 chromophobe RCCs, 49 oncocytomas, and 16 lipid-poor angiomyolipomas with preoperative multiphasic MDCT with up to four phases (unenhanced, corticomedullary, nephrographic, and excretory). Each lesion was reviewed for contour, spread pattern, pattern of enhancement, neovascularity, and calcification.

RESULTS

Sarcomatoid RCCs and CDCs were more likely than other solid renal masses to have an irregular contour (64% vs 2%, P < 0.001) and an infiltrative spread pattern, defined as infiltration into adjacent renal parenchyma, collecting system, or neighboring structures (82% vs 7%, P < 0.001). When used to discriminate sarcomatoid RCC and CDC from other solid renal masses, an infiltrative spread pattern had a specificity of 93% (287/308) and sensitivity of 82% (9/11), and an irregular contour had a specificity of 98% (303/308) and sensitivity of 64% (7/11).

CONCLUSIONS

Solid renal lesions with an irregular contour or an infiltrative spread pattern are suspicious for sarcomatoid RCC or CDC.

Sarcomatoid Renal Cell Carcinoma: The Apple Doesn't Fall Far from the Tree

The most comprehensive sequencing effort of sarcomatoid renal cell carcinoma (sRCC) to date reinforces the notion that the sarcomatoid component is closely related to the epithelial component of the cancer. This work also challenges the notion that sRCC evolves from low-grade RCC and identifies potential mediators of sarcomatoid differentiation. Clin Cancer Res; 23(21); 6381-3. ©2017 AACRSee related article by Wang et al., p. 6686.

Differential expression of CD44 and CD24 markers discriminates the epitheliod from the fibroblastoid subset in a sarcomatoid renal carcinoma cell line: evidence suggesting the existence of cancer stem cells in both subsets as studied with sorted cells

Epithelioid and fibroblastoid subsets coexist in the human sarcomatoid renal cell carcinoma (sRCC) cell line, RCC52, according to previous clonal studies. Herein, using monoclonal antibodies to CD44 and CD24 markers, we identified and isolated these two populations, and showed that CD44^bright/CD24^dim and CD44^bright/CD24^bright phenotypes correspond to epithelioid and fibroblastoid subsets, respectively. Both sorted subsets displayed different levels of tumorigenicity in xenotransplantation, indicating that each harbored its own cancer stem cells (CSCs). The CD44^bright/CD24^bright subset, associated with higher expression of MMP-7, -8 and TIMP-1 transcripts, showed greater migratory/invasive potential than the CD44^bright/CD24^dim subset, which was associated with higher expression of MMP-2, -9 and TIMP-2 transcripts. Both subsets differentially expressed stemness gene products c-Myc, Oct4A, Notch1, Notch2 and Notch3, and the RCC stem cell marker, CD105 in 4-5% of RCC52 cells. These results suggest the presence of CSCs in both sRCC subsets for the first time and should therefore be considered potential therapeutic targets for this aggressive malignancy.

Phase 2 Trial of Capecitabine, Gemcitabine, and Bevacizumab in Sarcomatoid Renal-Cell Carcinoma

BACKGROUND

Patients with sarcomatoid renal-cell carcinomas (sRCC) have poor outcomes and limited treatment options. Preclinical and clinical data suggest susceptibility to cytotoxic agents and vascular endothelial growth factor-targeted therapies. We designed a phase 2 trial to evaluate the efficacy and safety of capecitabine, gemcitabine, and bevacizumab in sRCC.

PATIENTS AND METHODS

Patients with metastatic or unresectable sRCC were eligible for inclusion. Patients received oral capecitabine 800 mg/m2 twice daily on days 1 to 21 of a 28-day cycle, intravenous gemcitabine 900 mg/m2 on days 1 and 15, and intravenous bevacizumab 10 mg/kg on days 1 and 15. Primary end points were progression-free survival and time to treatment failure (TTF). Secondary end points were safety, objective response rate, and overall survival.

RESULTS

Thirty-four patients were enrolled onto the trial. One patient was excluded from survival analysis and 4 from response analysis as a result of missing data. Median progression-free survival was 5.5 months (95% confidence interval [CI], 3.4-7.7), median TTF was 4.2 months (95% CI, 2.4-6.0), and median overall survival was 12 months (95% CI, 10.6-13.4). Objective response rate was 20% (5 partial responses, 1 complete response), and disease control rate was 73%. Thirty-one (91%) of the 34 patients discontinued treatment. The most common reason for treatment discontinuation was progressive disease, which occurred in 24 patients (71%). The most common grade 3 toxicity was rash (including hand-foot syndrome) in 24% patients.

CONCLUSION

The combination of capecitabine, gemcitabine, and bevacizumab is an option for patients with sRCC; however, response rates are low. Novel therapies are needed to improve outcomes in patients with sRCC.

Sarcomatoid Renal Cell Carcinoma Has a Distinct Molecular Pathogenesis, Driver Mutation Profile, and Transcriptional Landscape

Purpose: Sarcomatoid renal cell carcinoma (SRCC) ranks among the most aggressive clinicopathologic phenotypes of RCC. However, the paucity of high-quality, genome-wide molecular examinations of SRCC has hindered our understanding of this entity.Experimental Design: We interrogated the mutational, copy number, and transcriptional characteristics of SRCC and compared these data with those of nonsarcomatoid RCC (RCC). We evaluated whole-exome sequencing, single-nucleotide polymorphism, and RNA sequencing data from patients with SRCC (n = 65) and RCC (n = 598) across different parent RCC subtypes, including clear-cell RCC, papillary RCC, and chromophobe RCC subtypes.Results: SRCC was molecularly discrete from RCC and clustered according to its parent RCC subtype, though with upregulation of TGFβ signaling across all subtypes. The epithelioid (E-) and spindled (S-) histologic components of SRCC did not show differences in mutational load among cancer-related genes despite a higher mutational burden in S-. Notably, sarcomatoid clear-cell RCC (SccRCC) showed significantly fewer deletions at 3p21-25, a lower rate of two-hit loss for VHL and PBRM1, and more mutations in PTEN, TP53, and RELN compared with ccRCC. A two-hit loss involving VHL predicted for ccRCC and a better prognosis, whereas mutations in PTEN, TP53, or RELN predicted for SccRCC and worse prognosis.Conclusions: SRCC segregates by parent subtype, and SccRCC has a fundamentally different early molecular pathogenesis, usually lacking the classic 3p21-25 deletion and showing distinctive mutational and transcriptional profiles. These features prompt a more precise molecular classification of RCC, with diagnostic, prognostic, and therapeutic implications. Clin Cancer Res; 23(21); 6686-96. ©2017 AACRSee related commentary by Bergerot et al., p. 6381.

Metastatic sarcomatoid renal cell carcinoma manifesting as a subcutaneous soft tissue mass

Metastases from visceral malignancies to subcutaneous soft tissues are relatively rare and their diagnosis requires a high level of suspicion. It is even more challenging if a metastatic lesion shows non-specific high-grade spindle cell morphology overlapping with various primary cutaneous and soft tissue tumors. We describe a unique case of subcutaneous metastasis of sarcomatoid renal cell carcinoma which was the first manifestation of the occult malignancy. The patient had a history of lipomas and dysplastic nevi and presented with an upper back mass. The mass, located superficially within the subcutis, was composed of atypical spindle cells arranged in a storiform pattern. By immunohistochemistry, the tumor cells were strongly diffusely positive for cytokeratin AE1/AE3 and vimentin and negative for Melan-A, S-100 protein, SOX10, melanoma cocktail, epithelial membrane antigen (EMA), p63, CK7, CK18, CK20, smooth muscle actin (SMA), desmin, CD34, TTF-1, CD21, CD99 and bcl-2. Scattered tumor cells were positive for MDM2 immunostain, but MDM2 amplification was not detected using fluorescent in situ hybridization (FISH). Co-expression of cytokeratin and vimentin by the tumor raised the possibility of metastatic renal cell carcinoma and positivity of the tumor for PAX8 supported this hypothesis. A large renal mass was detected radiologically and the subsequent nephrectomy specimen showed high-grade clear cell renal cell carcinoma with sarcomatoid features.

Manifestation of osteoblastic phenotypes in the sarcomatous component of epithelial carcinoma and sarcomatoid carcinoma

Epithelial carcinomas occasionally have sarcomatous components that consist primarily of spindle and cuboidal cells, which often resemble osteoblasts. Sarcomatoid carcinomas consist of similar cells. Recent studies have characterized these phenomena as a manifestation of epithelial-mesenchymal transition in carcinoma cells, but the mesenchymal phenotypes that manifest in sarcomatous cells of epithelial carcinomas are not well understood. Here, we examined the expression profiles of four osteoblastic differentiation biomarkers in the sarcomatous components of multiple carcinoma types, including five renal clear cell, four breast invasive ductal, two esophageal, one maxillary squamous cell, three larynx, three lung, one liver, and one skin sarcomatoid carcinoma. Expression was analyzed by immunohistochemistry using antibodies against cell adhesion molecule 1, a member of the IgCAM superfamily, osterix transcription factor (Osterix), cluster of differentiation 151, a transmembrane 4 superfamily member, and alkaline phosphatase. Immunostaining intensity was rated in scale 0 (negative), 0.5 (weak), and 1 (strong) for each marker, and the four scale values were summed to calculate osteoblastic scores. In all, 10 cases had a osteoblastic score ≥3, and all of these 10 cases were cell adhesion molecule 1- and Osterix-positive. Eight and five of the nine samples with a osteoblastic score <3 were negative for cell adhesion molecule 1 ( p < 0.0001) and Osterix ( p = 0.006), respectively. The other markers showed no statistical significance. These results indicate that osteoblastic differentiation can occur in carcinoma cells and that cell adhesion molecule 1 could be a useful marker for identifying this phenomenon in carcinoma tissues.