Developments in the use of tyrosine kinase inhibitors in the treatment of renal cell carcinoma

Novel Prognosis and Therapeutic Response Model of Immune-Related lncRNA Pairs in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common type of renal carcinoma. It is particularly important to accurately judge the prognosis of patients. Since most tumor prediction models depend on the specific expression level of related genes, a better model therefore needs to be constructed. To provide an immune-related lncRNA (irlncRNAs) tumor prognosis model that is independent of the specific gene expression levels, we first downloaded and sorted out the data on ccRCC in the TCGA database and screened irlncRNAs using co-expression analysis and then obtained the differently expressed irlncRNA (DEirlncRNA) pairs by means of univariate analysis. In addition, we modified LASSO penalized regression. Subsequently, the ROC curve was drawn, and we compared the area under the curve, calculated the Akaike information standard value of the 5-year receiver operating characteristic curve, and determined the cut-off point to establish the best model to distinguish the high- or low-disease-risk group of ccRCC. Subsequently, we reassessed the model from the perspectives of survival, clinic-pathological characteristics, tumor-infiltrating immune cells, chemotherapeutics efficacy, and immunosuppressed biomarkers. A total of 17 DEirlncRNAs pairs (AL031710.1|AC104984.5, AC020907.4|AC127-24.4,AC091185.1|AC005104.1, AL513218.1|AC079015.1, AC104564.3|HOXB-AS3, AC003070.1|LINC01355, SEMA6A-AS1|CR936218.1, AL513327.1|AS005785.1, AC084876.1|AC009704.2, IGFL2-AS1|PRDM16-DT, AC011462.4|MMP25-AS1, AL662844.3I|TGB2-AS1, ARHGAP27P1|AC116914.2, AC093788.1|AC007098.1, MCF2L-AS1|AC093001.1, SMIM25|AC008870.2, and AC027796.4|LINC00893) were identified, all of which were included in the Cox regression model. Using the cut-off point, we can better distinguish patients according to different factors, such as survival status, invasive clinic-pathological features, tumor immune infiltration, whether they are sensitive to chemotherapy or not, and expression of immunosuppressive biomarkers. We constructed the irlncRNA model by means of pairing, which can better eliminate the dependence on the expression level of the target genes. In other words, the signature established by pairing irlncRNA regardless of expression levels showed promising clinical prediction value.

A Cluster of Metabolic-Related Genes Serve as Potential Prognostic Biomarkers for Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common type of renal cancer, characterized by the dysregulation of metabolic pathways. RCC is the second highest cause of death among patients with urologic cancers and those with cancer cell metastases have a 5-years survival rate of only 10–15%. Thus, reliable prognostic biomarkers are essential tools to predict RCC patient outcomes. This study identified differentially expressed genes (DEGs) in the gene expression omnibus (GEO) database that are associated with pre-and post-metastases in clear cell renal cell carcinoma (ccRCC) patients and intersected these with metabolism-related genes in the Kyoto encyclopedia of genes and genomes (KEGG) database to identify metabolism-related DEGs (DEMGs). GOplot and ggplot packages for gene ontology (GO) and KEGG pathway enrichment analysis of DEMGs with log (foldchange) (logFC) were used to identify metabolic pathways associated with DEMG. Upregulated risk genes and downregulated protective genes among the DEMGs and seven independent metabolic genes, RRM2, MTHFD2, AGXT2, ALDH6A1, GLDC, HOGA1, and ETNK2, were found using univariate and multivariate Cox regression analysis, intersection, and Lasso-Cox regression analysis to establish a metabolic risk score signature (MRSS). Kaplan-Meier survival curve of Overall Survival (OS) showed that the low-risk group had a significantly better prognosis than the high-risk group in both the training cohort (p < 0.001; HR = 2.73, 95% CI = 1.97–3.79) and the validation cohort (p = 0.001; HR = 2.84, 95% CI = 1.50–5.38). The nomogram combined with multiple clinical information and MRSS was more effective at predicting patient outcomes than a single independent prognostic factor. The impact of metabolism on ccRCC was also assessed, and seven metabolism-related genes were established and validated as biomarkers to predict patient outcomes effectively.

Role of 18F-FDG PET/CT in the assessment of therapy response and clinical outcome in metastatic renal cell carcinoma treated with tyrosine kinase inhibitors or immunotherapy

OBJECTIVE

This study aimed to determine the role and prognostic significance of 18F-FDG PET/CT on treatment response and survival outcomes in metastatic renal cell carcinoma patients treated with immunotherapy or tyrosine kinase inhibitors (TKIs).

PATIENTS AND METHODS

Forty patients scheduled for a standard treatment protocol with TKIs (n = 17; group-1) or PD-1 inhibitors (nivolumab, n = 23; group-2) were evaluated by 18F-FDG PET/CT. Peak standardized uptake value corrected for lean body mass (SULpeak) and maximum standardized uptake value (SUVmax) were calculated, and their relationship to treatment response was evaluated.

RESULTS

Complete response (CR) in three patients, partial response (PR) in two patients and stable disease (SD) in eight patients were observed in group-1, and the results were as follows for group-2: PR in seven and SD in five patients. At a mean of 17.5-month observation period (range, 7-47), 35.2% of patients progressed, and 23.5% achieved a CR, and no recurrence was observed on PET/CT scans during follow-up. Among all patients enrolled in the study, the 5-year OS in patients with progressive disease (PD) was significantly shorter than patients with clinical benefit (CB = CR and PR and SD) (P = 0.016). Significant differences in both ΔSULpeak and ΔSUVmax were found between PD versus CB (P = 0.001 and P < 0.001, respectively).

CONCLUSION

18F-FDG-PET/CT can accurately assess therapy response and predict patient outcome in metastatic RCC. 18F-FDG PET/CT may facilitate patient management by evaluating the biological and immunological responses to treatment in patients treated with TKIs or ICIs.

18F-PSMA-1007 PET/CT for response assessment in patients with metastatic renal cell carcinoma undergoing tyrosine kinase or checkpoint inhibitor therapy: preliminary results

Introduction

Tyrosine kinase (TKI) and checkpoint inhibitors (CI) prolonged overall survival in metastatic renal cell carcinoma (mRCC). Early prediction of treatment response is highly desirable for the individualization of patient management and improvement of therapeutic outcome; however, serum biochemistry is unable to predict therapeutic efficacy. Therefore, we compared ¹⁸F-PSMA-1007 PET imaging for response assessment in mRCC patients undergoing TKI or CI therapy compared to CT-based response assessment as the current imaging reference standard.

Methods

¹⁸F-PSMA-1007 PET/CT was performed in mRCC patients prior to initiation of systemic treatment and 8 weeks after therapy initiation. Treatment response was evaluated separately on ¹⁸F-PSMA-PET and CT. Changes on PSMA-PET (SUV_mean) were assessed on a per patient basis using a modified PERCIST scoring system. Complete response (CR_PET) was defined as absence of any uptake in all target lesions on posttreatment PET. Partial response (PR_PET) was defined as decrease in summed SUV_mean of > 30%. The appearance of new, PET-positive lesions or an increase in summed SUV_mean of > 30% was defined as progressive disease (PD_PET). A change in summed SUV_mean of ± 30% defined stable disease (SD_PET). RECIST 1.1 criteria were used for response assessment on CT. Results of radiographic response assessment on PSMA-PET and CT were compared.

Results

Overall, 11 mRCC patients undergoing systemic treatment were included. At baseline PSMA-PET₁, all mRCC patients showed at least one PSMA-avid lesion. On follow-up PET₂, 3 patients showed CR_PET, 3 PR_PET, 4 SD_PET, and 1 PD_PET. According to RECIST 1.1, 1 patient showed PR_CT, 9 SD_CT, and 1 PD_CT. Overall, concordant classifications were found in only 2 cases (2 SD_CT + PET). Patients with CR_PET on PET were classified as 3 SD_CT on CT using RECIST 1.1. By contrast, the patient classified as PR_CT on CT showed PSMA uptake without major changes during therapy (SD_PET). However, among 9 patients with SD_CT on CT, 3 were classified as CR_PET, 3 as PR_PET, 1 as PD_PET, and only 2 as SD_PET on PSMA-PET.

Conclusion

On PSMA-PET, heterogeneous courses were observed during systemic treatment in mRCC patients with highly diverging results compared to RECIST 1.1. In the light of missing biomarkers for early response assessment, PSMA-PET might allow more precise response assessment to systemic treatment, especially in patients classified as SD on CT.

Emerging therapeutic agents for genitourinary cancers

The treatment of genitourinary malignancies has dramatically evolved over recent years. Renal cell carcinoma, urothelial carcinoma of the bladder, and prostate adenocarcinoma are the most commonly encountered genitourinary malignancies and represent a heterogeneous population of cancers, in both histology and approach to treatment. However, all three cancers have undergone paradigm shifts in their respective therapeutic landscapes due to a greater understanding of their underlying molecular mechanisms and oncogenic drivers. The advance that has gained the most recent traction has been the advent of immunotherapies, particularly immune checkpoint inhibitors. Immunotherapy has increased overall survival and even provided durable responses in the metastatic setting in some patients. The early success of immune checkpoint inhibitors has led to further drug development with the emergence of novel agents which modulate the immune system within the tumor microenvironment. Notwithstanding immunotherapy, investigators are also developing novel agents tailored to a variety of targets including small-molecule tyrosine kinase inhibitors, mTOR inhibitors, and novel fusion proteins to name a few. Erdafitinib has become the first targeted therapy approved for metastatic bladder cancer. Moreover, the combination therapy of immune checkpoint inhibitors with targeted agents such as pembrolizumab or avelumab with axitinib has demonstrated both safety and efficacy and just received FDA approval for their use. We are in an era of rapid progression in drug development with multiple exciting trials and ongoing pre-clinical studies. We highlight many of the promising new emerging therapies that will likely continue to improve outcomes in patients with genitourinary malignancies.