Management of non–clear cell renal cell carcinoma: Current approaches

Identification of an immune-related gene prognostic index for predicting survival and immunotherapy efficacy in papillary renal cell carcinoma

Despite considerable progress has been made in the understanding of the genetics and molecular biology of renal cell carcinoma (RCC), therapeutic options of patients with papillary renal cell carcinoma (PRCC) are limited. Immunotherapy based on immune checkpoint inhibitors (ICIs) has become a hot point in researching new drug for tumor and been tested in a number of human clinical trials. In this study, an immune-related gene prognostic index (IRGPI) was developed and provided a comprehensive and systematic analysis of distinct phenotypic and molecular portraits in the recognition, surveillance, and prognosis of PRCC. The reliability of the IRGPI was evaluated using independent datasets from GEO database and the expression levels of the genes in the IRGPI detected by real-time PCR. Collectively, the currently established IRGPI could be used as a potential biomarker to evaluate the response and efficacy of immunotherapy in PRCC.

Heterogeneity of tumor microenvironment is associated with clinical prognosis of non-clear cell renal cell carcinoma: a single-cell genomics study

Non-clear renal cell carcinomas (nccRCCs) are less frequent in kidney cancer with histopathological heterogeneity. A better understanding of the tumor biology of nccRCC can provide more effective treatment paradigms for different subtypes. To reveal the heterogeneity of tumor microenvironment (TME) in nccRCC, we performed 10x sing-cell genomics on tumor and normal tissues from patients with papillary renal cell carcinoma (pRCC), chromophobe RCC (chrRCC), collecting duct carcinoma (CDRCC) and sarcomatoid RCC (sarRCC). 15 tissue samples were finally included. 34561 cells were identified as 16 major cell clusters with 34 cell subtypes. Our study presented the sing-cell landscape for four types of nccRCC, and demonstrated that CD8+ T cells exhaustion, tumor-associated macrophages (TAMs) and sarcomatoid process were the pivotal factors in immunosuppression of nccRCC tissues and were closely correlated with poor prognosis. Abnormal metabolic patterns were present in both cancer cells and tumor-infiltrating stromal cells, such as fibroblasts and endothelial cells. Combined with CIBERSORTx tool, the expression data of bulk RNA-seq from TCGA were labeled with cell types of our sing-cell data. Calculation of the relative abundance of cell types revealed that greater proportion of exhausted CD8+ T cells, TAMs and sarRCC derived cells were correlated with poor prognosis in the cohort of 274 nccRCC patients. To the best of our knowledge, this is the first study that provides a more comprehensive sight about the heterogeneity and tumor biology of nccRCC, which may potentially facilitate the development of more effective therapies for nccRCC.

Targeting glycolysis with 2-deoxy-D-glucose sensitizes primary cell cultures of renal cell carcinoma to tyrosine kinase inhibitors

PURPOSE

To investigate the synergistic effect of glycolysis inhibition on therapy answer to tyrosine kinase inhibitors in renal carcinoma.

METHODS

Primary cell cultures from 33 renal tumors including clear cell RCC (ccRCC), papillary RCC and the rare subtype chromophobe RCC as well as two metastases of ccRCC were obtained and cultivated. The patient-derived cells were verified by immunohistochemistry. CcRCC cells were further examined by exon sequencing of the von Hippel-Lindau gene (VHL) and by RNA-sequencing. Next, cell cultures of all subtypes of RCC were exposed to increasing doses of various tyrosine kinase inhibitors (axitinib, cabozantinib and pazopanib) and the glycolysis inhibitor 2-deoxy-D-glucose, alone or combined. CellTiter-Glo^® Luminescence assay and Crystal Violet staining were used to assess the inhibition of glycolysis and the viability of the cultured primary cells.

RESULTS

The cells expressed characteristic tissue markers and, in case of ccRCC cultures, the VHL status of the tumor they derived from. An upregulation of HK1, PFKP and SLC2A1 was observed, while components of the respiratory chain were downregulated, confirming a metabolic shift towards aerobic glycolysis. The tumors displayed variable individual responses for the therapeutics. All subtypes of RCC were susceptible to cabozantinib treatment indicated by decreased proliferation. Adding 2-deoxy-D-glucose to tyrosine kinase inhibitors decreased ATP production and increased the susceptibility of ccRCC to pazopanib treatment.

CONCLUSION

This study presents a valuable tool to cultivate even uncommon and rare renal cancer subtypes and allows testing of targeted therapies as a personalized approach as well as testing new therapies such as glycolysis inhibition in an in vitro model.

Real-world evidence on first-line treatment for metastatic renal cell carcinoma with non-clear cell and sarcomatoid histologies: are sunitinib and pazopanib interchangeable?

INTRODUCTION

Non-clear cell renal cell carcinoma (nccRCC) and sarcomatoid renal cell carcinoma (sRCC) are underrepresented in clinical trials. Treatment approaches are frequently extrapolated from data of clear cell renal cell carcinoma, in which pazopanib is non-inferior to sunitinib. We aim to compare the effectiveness of first-line sunitinib and pazopanib for nccRCC and sRCC.

METHODS

We evaluated a retrospective cohort of patients with metastatic nccRCC and sRCC treated with first-line sunitinib or pazopanib at an academic cancer centre. Overall survival (OS), progression-free survival (PFS) and response rate were measured. Kaplan-Meier and log-rank analyses were used for time-to-event data. Cox regression was used for prognostic factors.

RESULTS

Fifty-three patients were included; 16 (30.1%) treated with sunitinib and 37 (69.9%) with pazopanib. Forty-six (86.8%) patients had nccRCC and 7 (13.2%) had sRCC. The majority had intermediate or poor International Metastatic Renal-Cell Carcinoma Database Consortium risk (93%).Median PFS was 6.6 months with sunitinib and 4.9 months with pazopanib (HR 1.75; P = 0.078). Treatment with pazopanib was associated with inferior OS in comparison with sunitinib (median OS: 30.4 months versus 8.7 months; HR 2.71, 95% CI 1.31-5.58, P = 0.007). These results were confirmed in subgroup analysis of patients with papillary, chromophobe and MiT family translocation histologies (median OS: 38.7 months versus 14.7 months; HR 3.16, 95% CI 1.20-8.29, P = 0.019). Unclassified and sarcomatoid histologies had inferior OS (median: 6.9 and 1.1 months, respectively) regardless of the treatment used.

CONCLUSION

In this patient cohort, pazopanib was associated with inferior OS in comparison with sunitinib for metastatic nccRCC. Larger trials are ideally warranted to confirm these results.

Temsirolimus in Asian Metastatic/Recurrent Non-clear Cell Renal Carcinoma

Purpose

Temsirolimus is effective in the treatment for metastatic non-clear cell renal cell carcinoma (nccRCC) with poor prognosis. We aim to investigate the efficacy and tolerability of temsirolimus in treatment of naïve Asian patients with metastatic/recurrent nccRCC.

Materials and Methods

From January 2008 to July 2017, data of treatment-naïve, metastatic/recurrent nccRCC patients, who were treated with temsirolimus according to the standard protocol, were collected. The primary end-point was progression-free survival (PFS). Secondary end points were overall survival (OS), objective response rate (ORR), and tolerability of temsirolimus.

Results

Forty-four metastatic/recurrent nccRCC patients, 10 from prospective and 34 from retrospective groups, were enrolled; 24 patients (54%) were papillary type, and other histology subtypes included 11 chromophobes (25%), two collecting ducts (5%), one Xp11.2 translocation (2%), and six others (14%). The median PFS and OS were 7.6 months and 17.6 months, res-pectively. ORR was 11% and disease control rate was 83%. Patients with prior nephrectomy had longer PFS (hazard ratio [HR], 0.16; 95% confidence interval [CI], 0.06 to 0.42; p < 0.001) and OS (HR, 0.15; 95% CI, 0.05 to 0.45; p < 0.001). Compared to favorable/intermediate prognosis group, poor prognosis group had shorter median PFS (4.7 months vs. 7.6 months [HR, 2.91; 95% CI, 1.39 to 6.12; p=0.005]) and median OS (9.2 months vs. 17.6 months [HR, 2.84; 95% CI, 1.23 to 6.56; p=0.015]).

Conclusion

Temsirolimus not only benefits poor-risk nccRCC patients, but it is also effective in favorable or intermediate-risk group in Asians. Temsirolimus was well-tolerated with manageable adverse events.