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

Renal Cell Carcinoma of Variant Histology: New Biologic Understanding Leads to Therapeutic Advances

Renal cell carcinoma (RCC) is one of the 10 most commonly diagnosed solid tumors. Most RCCs are histologically defined as clear cell, comprising approximately 75% of diagnoses. However, the remaining RCC cases are composed of a heterogeneous combination of diverse histopathologic subtypes, each with unique pathogeneses and clinical features. Although the therapeutic approach to both localized and metastatic RCCs has dramatically changed, first with the advent of antiangiogenic targeted therapies and more recently with the approval of immune checkpoint inhibitor (ICI)-based combinations, these advances have primarily benefited the clear cell RCC patient population. As such, there remains critical gaps in the optimization of treatment regimens for patients with non-clear cell, or variant, RCC histologies. Herein, we detail recent advances in understanding the biology of RCC with variant histology and how such findings have guided novel clinical studies investigating precision oncology approaches for these rare subtypes. Among the most common variant histology RCCs are papillary RCC, comprising approximately 15%-20% of all diagnoses. Although a histopathologically diverse subset of tumors, papillary RCC is canonically associated with amplification of the MET protooncogene; recently completed and ongoing trials have investigated MET-directed therapies for this patient population. Finally, we discuss the unique biology of RCC with sarcomatoid dedifferentiation and the recent clinical findings detailing its paradoxical sensitivity to ICIs.

Durable Remission with Immunotherapy in a Patient with Sarcomatoid Renal Cell Carcinoma

Sarcomatoid differentiation is a rare and aggressive histologic subtype with poor prognosis, seen in several malignancies. In sarcomatoid renal cell carcinoma (RCC), the degree of sarcomatoid differentiation and the stage at presentation determines the prognosis. Despite resection, chemotherapy and targeted therapy response is modest, with relapse usually occurring within a few months. We present a case of a gentleman with sarcomatoid RCC managed with pembrolizumab, who has had no evidence of recurrence for over 4 years since the last dose of immunotherapy. RCCs with sarcomatoid differentiation have a high presence of programmed cell death protein 1 and programmed cell death ligand 1 in T cells and tumor cells, respectively, making immunotherapy an attractive option in this setting. Clinical trials are ongoing to further define the benefit of immunotherapy in sarcomatoid RCC.

A case of multiple metastatic sarcomatoid renal cell carcinoma with complete response to nivolumab

Background

Sarcomatoid renal cell carcinoma (SRCC) is associated with poor prognosis. Although there is no standard treatment for SRCC, recent studies have reported the effectiveness of immune checkpoint inhibitors.

Case

An 82‐year‐old Japanese man presented to our hospital with an incidental right renal tumor. Abdominal computed tomography (CT) showed an exophytic tumor in the right kidney with suspected right iliopsoas muscle invasion. Laparoscopic right radical nephrectomy was performed. Histopathological diagnosis revealed a clear cell RCC with a spindle cell carcinoma component. CT performed 3 months after surgery revealed multiple bilateral lung metastases and local recurrence. Although the patient received tyrosine‐kinase inhibitors for treating multiple metastases, the lung metastases continued to gradually increase, and peritonitis carcinomatosis was observed. Thus, the patient was intravenously administered nivolumab once every 2 weeks. After nivolumab administration, lung metastases, local recurrence, and peritonitis carcinomatosis gradually reduced. After 20 months of nivolumab treatment, the patient achieved a complete response of multiple metastases on CT.

Conclusion

Nivolumab may be used as a treatment option for sarcomatoid renal cell carcinoma with multiple metastases.

Sarcomatoid renal cell carcinoma: biology, natural history and management

Sarcomatoid dedifferentiation is an uncommon feature that can occur in most histological subtypes of renal cell carcinomas (RCCs) and carries a decidedly poor prognosis. Historically, conventional treatments for sarcomatoid RCCs (sRCCs) have shown little efficacy, and median survival is commonly 6–13 months. Despite being first described in 1968, the mechanisms driving sarcomatoid dedifferentiation remain poorly understood, and information and treatment options available to physicians and patients are limited. When diagnosed at an early stage, surgical intervention remains the treatment of choice. However, preoperative identification through routine imaging or biopsy is unreliable and most patients present with advanced disease and systemic symptoms. For these patients, the role of cytoreductive nephrectomy is disputed. The expansion of immunotherapies approved for RCCs has generated a search for biomarkers that might be indicative of treatment response in sRCCs, although a proven effective systemic agent remains elusive. PDL1 expression is increased in sarcomatoid dedifferentiated renal tumours, which suggests that patients with sRCCs could benefit from PD1 and/or PDL1 immune checkpoint blockade therapy. Treatment outcomes for sarcomatoid tumours have remained relatively consistent compared with other RCCs, but further investigation of the tumour–immune cell microenvironment might yield insights into further therapeutic possibilities.

In this Review, Blum et al. summarize the current knowledge on sarcomatoid renal cell carcinoma, a diagnosis characterized by the presence of sarcomatoid dedifferentiation and a poor prognosis. They discuss the origin, presentation, molecular biology and treatment of this disease.

Sarcomatoid dedifferentiation is not considered to be a unique histological subtype of renal cell carcinomas (RCCs); rather, it can be present within any subtype of RCCs.

Sarcomatoid dedifferentiation appears in ~4% of all RCCs, but is present in ~20% of all metastatic RCCs. According to WHO guidelines, any RCC with sarcomatoid dedifferentiation is a WHO–International Society of Urological Pathology grade 4 lesion.

Sarcomatoid dedifferentiation is often heterogeneously present within RCCs, making routine imaging and biopsy unreliable for preoperative detection. Surgical resection for localized disease is the standard of care, with subsequent close monitoring of patients following surgery.

In patients with metastatic disease, conventional therapies such as surgery and systemic agents have been ineffective and overall 5-year survival remains at 23.5–33%.

Previous genomic analyses have failed to identify definitive mutational drivers of disease. However, sarcomatoid RCCs (sRCCs) have been shown to have higher PD1 and PDL1 expression than other subtypes of RCCs. Newer combinations of immune checkpoint inhibitor immunotherapies could yield improved responses and outcomes.

Studies investigating sRCCs are limited by patient numbers owing to the low incidence of sRCCs and their advanced stage at presentation. Multi-institutional efforts to establish a consensus on treatment recommendations based on highly powered data are essential.

Construct a circRNA/miRNA/mRNA regulatory network to explore potential pathogenesis and therapy options of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most representative subtype of renal cancer. CircRNA acts as a kind of ceRNA to play a role in regulating microRNA (miRNA) in many cancers. However, the potential pathogenesis role of the regulatory network among circRNA/miRNA/mRNA is not clear and has not been fully explored. CircRNA expression profile data were obtained from GEO datasets, and the differentially expressed circRNAs (DECs) were identified through utilizing R package (Limma) firstly. Secondly, miRNAs that were regulated by these circRNAs were predicted by using Cancer-specific circRNA database and Circular RNA Interactome. Thirdly, some related genes were identified by intersecting targeted genes, which was predicted by a web tool (miRWalk) and differentially expressed genes, which was obtained from TCGA datasets. Function enrichment was analyzed, and a PPI network was constructed by Cytoscape software and DAVID web set. Subsequently, ten hub-genes were screened from the network, and the overall survival time in patients of ccRCC with abnormal expression of these hub-genes were completed by GEPIA web set. In the last, a circRNA/miRNA/mRNA regulatory network was constructed, and potential compounds and drug which may have the function of anti ccRCC were forecasted by taking advantage of CMap and PharmGKB datasets. Six DECs (hsa_circ_0029340, hsa_circ_0039238, hsa_circ_0031594, hsa_circ_0084927, hsa_circ_0035442, hsa_circ_0025135) were obtained and six miRNAs (miR-1205, miR-657, miR-587, miR-637, miR-1278, miR-548p) which are regulated by three circRNAs (hsa_circ_0084927, hsa_circ_0035442, hsa_circ_0025135) were also predicted. Then 497 overlapped genes regulated by these six miRNAs above had been predicted, and function enrichment analysis revealed these genes are mainly linked with some regulation functions of cancers. Ten hub-genes (PTGER3, ADCY2, APLN, CXCL5, GRM4, MCHR1, NPY5R, CXCR4, ACKR3, MTNR1B) have been screened from a PPI network. PTGER3, ADCY2, CXCL5, GRM4 and APLN were identified to have a significant effect on the overall survival time of patients with ccRCC. Furthermore, one compound (josamycin) and four kinds of drugs (capecitabine, hmg-coa reductase inhibitors, ace Inhibitors and bevacizumab) were confirmed as potential therapeutic options for ccRCC by CMap analysis and pharmacogenomics analysis. This study implies the potential pathogenesis of the regulatory network among circRNA/miRNA/mRNA and provides some potential therapeutic options for ccRCC.

Sarcomatoid Dedifferentiation in Renal Cell Carcinoma: From Novel Molecular Insights to New Clinical Opportunities

Sarcomatoid features in renal cell carcinoma (RCC) have long been associated with dismal prognosis and poor response to therapy, while biological mechanisms underpinning sarcomatoid dedifferentiation remained obscure. Several efforts have been conducted to break down the molecular profile of sarcomatoid RCC and investigate different targeted therapeutic approaches. Mutations enriched for in sarcomatoid RCC involve, notably, TP53, BAP1, cell cycle, and chromatin-remodeling genes. The immunological landscape of these tumors is also gradually being uncovered, showing frequent expression of programmed cell death ligand-1 (PD-L1) and high levels of tumor-infiltrating lymphocytes. These features may be major determinants for the activity of immune checkpoint inhibitors in this population, which has been confirmed by retrospective studies and subgroup analyses of large randomized phase 3 trials. Combinations based on PD-1/PD-L1 inhibition have demonstrated response rates and complete responses in >50% and >10% of patients in the first-line metastatic setting, respectively, with median overall survival exceeding two years. This remarkable improvement in outcomes effectively establishes immune checkpoint inhibitor combinations as a new standard of care in patients with sarcomatoid RCC. New research fields, including epigenetic regulations and tumor-microenvironment interactions, may further sharpen understanding of sarcomatoid RCC and advance therapeutic developments.

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.

Non-Clear Cell Renal Cell Carcinomas: From Shadow to Light

Non-clear cell renal cell carcinomas (RCCs) account for up to 25% of kidney cancers and encompass distinct diseases with distinct pathologic features, different molecular alterations, and various patterns of response to systemic therapies. Recent advances in molecular biology and large collaborative efforts helped to better define the oncogenic mechanisms at play in papillary, chromophobe, collecting duct, medullary, translocation, and sarcomatoid RCCs. Papillary RCCs are divided into several subsets of tumors characterized by distinct gene expression profiles, chromatin remodeling genes, cell cycle changes, and alterations of the MET pathway. Chromophobe RCC genomic analysis revealed mostly metabolic pathway alterations with mitochondrial dysfunctions. Translocation RCCs are characterized by MITF fusions and wide genomic reprogramming. Collecting duct carcinomas are distinct entities from upper tract urothelial carcinomas associated with high T-cell infiltration and metabolic alterations. Medullary RCCs present alterations of the INI1 gene and rhabdoid features at pathologic analysis. Finally, sarcomatoid RCCs represent sarcomatoid differentiation for any subsets of RCCs with specific alterations associated with mesenchymal dedifferentiation. From the standpoint of systemic therapy, more than a decade of using VEGF and mTOR inhibitors showed that they generally had limited efficacy in non-clear cell RCCs compared with clear cell RCCs. MET inhibitors are actively being developed for papillary RCC with a specific focus on MET-driven tumors. Other strategies under investigation include CDK4/6 inhibitors in tumors with cell cycle alterations and EZH2 inhibitors in RCCs with INI1 loss. The emergence of immune checkpoint inhibitors and combination strategies enlarges the spectrum of investigational treatments. Better understanding of driver and passenger alterations and better patient stratification along with dedicated clinical networks will be key to improving the management of these rare tumors.

Epidemiology, biology and treatment of sarcomatoid RCC: current state of the art

Long recognized to confer an extremely poor prognosis, sarcomatoid dedifferentiation of renal cell carcinoma (sRCC) is a tumor phenotype that is finally beginning to be better understood on the molecular and genetic levels. With an overall incidence that ranges from 1 to 32% depending on associated RCC subtype, the survival of sarcomatoid RCC patients rarely exceeds 2 years. The main reasons for its poor outcome include its aggressive biology, its tendency to present at an advanced or metastatic stage at the time of diagnosis, its high rate of tumor recurrence after nephrectomy, and its limited response to systemic therapies. Molecular pathology studies suggest that sarcomatoid dedifferentiation originates from a focal epithelial-mesenchymal transition (EMT) arising in the carcinomatous component of the tumor. It is hoped that the growing understanding of the molecular biology of sRCC will soon make it possible to adapt treatments based on the identification of actionable tumor alterations. The deliberate inclusion of these patients in the multicenter clinical trials of immune, targeted and combination therapies is a necessary next step in pioneering future treatment strategies.

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.