Primary Renal Cell Carcinoma Research Articles

Cytoreductive nephrectomy in the current treatment algorithm.

The two recent prospective randomized trials CARMENA and SURTIME have changed the therapy paradigm of metastatic renal cell carcinoma. The CARMENA trial was conducted to investigate whether cytoreductive nephrectomy (CN) is required in the targeted therapy area, whereas SURTIME studied whether deferred CN in combination with sunitinib can be used to identify patients with inherent targeted therapy resistance. In the current review, we provide a comprehensive discussion of two randomized studies and the current evidence with up-do-date algorithms for treating primary metastatic clear-cell renal cell carcinoma in the era of targeted therapy and immune-checkpoint inhibition.

Aggressive management for metastatic renal cell carcinoma in the pancreas

Introduction: Metastatic cancer to the pancreas is rare and accounts for 2%∼5% of all pancreatic malignancies, metastasis from renal cell carcinoma is the most frequent. Pancreatic metastasis from renal cell carcinoma (RCC) can be only site of metastasis and can be surgically resectable. In this study, we report our six cases of metastatic renal cell carcinoma of the pancreas which underwent surgical treatment. Method: Between March 2016 to March 2019, eight patients (five men and three women of mean age 60.5±8.7 years) underwent pancreatic resection for RCC metastasis. We retrospectively reviewed clinicopathological data on those patients. Result: Pancreas metaststasis occurred metachronously in all patients, with a mean interval from primary renal cell carcinoma of 7.4±3.5 years. The mean length of hospital stay was 13.1±5.7 day. In-hospital mortality did not occur. Histological examination confirmed the location of a secondary RCC in all patients. Among the eight patients, 3 patients have multiple lesions of the pancreas and 5 patients were a solitary lesion. Median follow-up after pancreatectomy was 10.3 months (1-46 months). Eight patients were alive with no evidence of disease at 1, 1, 17, 19, and 24 months after resection. Three patients had recurrent disease but were still alive at 20, 31, and 46 months after resection. Conclusion: Localization of RCC metastasis to the pancreas is rare and it has a slow growing pattern. A hypervascular solid pancreatic tumor, in a patient who has previously undergone nephrectomy for RCC should be considered as suspicious metastasis. In selected patients, standard pancreatic resection might be an option can be associated good results.

"St. Peregrine tumor" with synchronous primary renal cell carcinoma.

"St. Peregrine tumor" with synchronous primary renal cell carcinoma.

"St. Peregrine tumor" with synchronous primary renal cell carcinoma.

"St. Peregrine tumor" with synchronous primary renal cell carcinoma.

GPI-80 as a Useful Index for Myeloid Cell Heterogeneity and a Potential Prognostic Biomarker for Metastatic Renal Cell Carcinoma.

Myeloid-derived suppressor cells (MDSCs), which include neutrophilic MDSCs and monocytic MDSCs, exhibit high immunosuppressive activity. Glycosylphosphatidylinositol-anchored 80 kD protein (GPI-80) is selectively expressed on mature neutrophils in healthy individuals. Increased GPI-80 expression on monocytes and variations in GPI-80 expression on neutrophils indicate the appearance of MDSCs in the peripheral blood of cancer patients. However, it is still unclear whether GPI-80 expression on myeloid cells, neutrophilic MDSCs and monocytic MDSCs, is correlated with the clinical outcomes of patients with cancer. In this study, we investigated the characteristics of myeloid cells expressing GPI-80 and the implication of GPI-80 expression in the clinical outcomes of patients with metastatic renal cell carcinoma (mRCC), in which primary renal cell carcinoma spreads from the kidney to other organs. The study included 20 patients with mRCC (a mean age of 66.0 years) and 16 healthy volunteers (a mean age of 47.8 years). To determine the heterogeneity of myeloid cells in peripheral blood samples, we performed the three-dimensional principal component analysis using the combination of GPI-80, CD16, and latency-associated peptide-1 (LAP), derived from the N-terminal region of transforming growth factor-β1 precursor. The results showed that myeloid cells in mRCC patients were widely distributed and clearly distinguishable from those in the healthy volunteers. The survival analysis revealed that GPI-80 expression on neutrophils and monocytes was correlated with poor prognostic outcomes of patients with mRCC. In conclusion, the expression of GPI-80 on myeloid cells, a useful index for the heterogeneity of MDSCs, serves as a potential prognostic biomarker for mRCC.

The Mainstay of Treatment will be Changed: Cytoreductive Nephrectomy Would Not be Required in Intermediate and Poor Risk Patients with Metastatic Renal Cell Carcinoma Cancer

To date, cytoreductive nephrectomy before systemic therapy is generally recommended in patients with a potentially surgically resectable primary renal cell carcinoma (RCC) and multiple metastases. Targeted therapy with tyrosine kinase inhibitors is widely used in the first-line treatment of metastatic renal cell carcinoma. The objective of CARMENA study was to determine whether cytoreductive surgery before the initiation of the targeted therapy in patients with metastatic renal cell carcinoma (mRCC) is required.

Comparison of Immediate vs Deferred Cytoreductive Nephrectomy in Patients With Synchronous Metastatic Renal Cell Carcinoma Receiving Sunitinib

In clinical practice, patients with primary metastatic renal cell carcinoma (mRCC) have been offered cytoreductive nephrectomy (CN) followed by targeted therapy, but the optimal sequence of surgery and systemic therapy is unknown. To examine whether a period of sunitinib therapy before CN improves outcome compared with immediate CN followed by sunitinib. This randomized clinical trial began as a phase 3 trial on July 14, 2010, and continued until March 24, 2016, with a median follow-up of 3.3 years and a clinical cutoff date for this report of May 5, 2017. Patients with mRCC of clear cell subtype, resectable primary tumor, and 3 or fewer surgical risk factors were studied. Immediate CN followed by sunitinib therapy vs treatment with 3 cycles of sunitinib followed by CN in the absence of progression followed by sunitinib therapy. Progression-free survival was the primary end point, which needed a sample size of 458 patients. Because of poor accrual, the independent data monitoring committee endorsed reporting the intention-to-treat 28-week progression-free rate (PFR) instead. Overall survival (OS), adverse events, and postoperative progression were secondary end points. The study closed after 5.7 years with 99 patients (80 men and 19 women; mean [SD] age, 60 [8.5] years). The 28-week PFR was 42% in the immediate CN arm (n = 50) and 43% in the deferred CN arm (n = 49) (P = .61). The intention-to-treat OS hazard ratio of deferred vs immediate CN was 0.57 (95% CI, 0.34-0.95; P = .03), with a median OS of 32.4 months (95% CI, 14.5-65.3 months) in the deferred CN arm and 15.0 months (95% CI, 9.3-29.5 months) in the immediate CN arm. In the deferred CN arm, 48 of 49 patients (98%; 95% CI, 89%-100%) received sunitinib vs 40 of 50 (80%; 95% CI, 67%-89%) in the immediate arm. Systemic progression before planned CN in the deferred CN arm resulted in a per-protocol recommendation against nephrectomy in 14 patients (29%; 95% CI, 18%-43%). Deferred CN did not improve the 28-week PFR. With the deferred approach, more patients received sunitinib and OS results were higher. Pretreatment with sunitinib may identify patients with inherent resistance to systemic therapy before planned CN. This evidence complements recent data from randomized clinical trials to inform treatment decisions in patients with primary clear cell mRCC requiring sunitinib. ClinicalTrials.gov identifier: NCT01099423.

Dissecting LncRNA Roles in Renal Cell Carcinoma Metastasis and Characterizing Genomic Heterogeneity by Single-Cell RNA-seq.

Long noncoding RNAs (lncRNA) have recently emerged as important regulators in cancer cell proliferation and metastasis. However, the role of lncRNAs in metastatic clear cell renal cell carcinoma (ccRCC) remains unclear. Here, single-cell RNA sequencing data were analyzed from primary renal cell carcinoma and paired metastatic renal cell carcinoma specimens, and characterized the expression profiles of over 10,000 genes, including 1,874 lncRNAs. Further analysis revealed that lncRNAs exhibit cancer type- and tissue-specific expression across ccRCC cells. Interestingly, a number of lncRNAs (n = 173) associated with ccRCC metastasis, termed ccRCC metastasis-associated lncRNAs (CMAL). Moreover, functional analysis based on a CMAL-PCG coexpression network revealed that CMALs contribute to cell adhesion, immune response, and cell proliferation. In combination with survival analysis, 12 CMALs were identified that participate in TNF and hypoxia-inducible factor 1 signaling to promote ccRCC metastasis. Further investigation on intratumoral heterogeneity showed that some CMALs are selectively expressed in different subpopulations. IMPLICATIONS: To explore ccRCC metastasis, the current study performed a global dissection of lncRNAs and a complex genomic analysis of ccRCC tumor heterogeneity. The data shed light on the discovery of potential lncRNA biomarkers and lncRNA therapeutic targets.

The side and the location of the primary tumor does not affect the probability of lymph node invasion in patients with renal cell carcinoma.

To evaluate the role of side and location of the primary renal cell carcinoma (RCC) on the risk of lymph node invasion (LNI) and/or nodal progression (NP) during follow-up. We evaluated 2485 patients with unilateral RCC, surgically treated in a single tertiary care referral center. Outcomes were LNI at surgery and/or NP during follow-up. We studied if RCC side (left vs. right) and location (upper vs. middle vs. hilar vs. lower area vs. more than one area) affected the probability of LNI and/or NP at follow-up. Overall, 43 and 15% of patients underwent lymph node dissection and had LNI at surgery, respectively. During follow-up, 2.2% of patients had NP. Higher rates of LNI and NP were observed for patients with primary tumor located in more than one anatomical kidney area relative to patients with tumor in a single area (upper 11% vs. middle 10% vs. hilar 0%, vs. lower 12% vs. more than one area 26%, p < 0.01). cM1, cN1, pT2/pT3/pT4 disease and Fuhrman grade 3/4 were independent predictors of the study outcome (all p ≤ 0.01). Neither the RCC side nor the location reached the independent predictor status (all p > 0.1). Patients with single-side and more than one anatomical kidney area affected by RCC have higher rate of LNI at surgery and/or NP at follow-up. Neither side nor location of primary RCC tumor is related to the risk of harboring LNI at surgery and/or developing NP at follow-up.

Multiregion Quantification of Extracellular Signal-regulated Kinase Activity in Renal Cell Carcinoma

To personalize treatment for renal cell carcinoma (RCC), it would be ideal to confirm the activity of druggable protein pathways within individual tumors. We have developed a high-resolution nanoimmunoassay (NIA) to measure protein activity with high precision in scant specimens (eg, fine needle aspirates [FNAs]). Here, we used NIA to determine whether protein activation varied in different regions of RCC tumors. Since most RCC therapies target angiogenesis by inhibiting the vascular endothelial growth factor (VEGF) receptor, we quantified phosphorylation of extracellular signal-regulated kinase (ERK), a downstream effector of the VEGF signaling pathway. In 90 ex vivo FNA biopsies sampled from multiple regions of 38 primary clear cell RCC tumors, ERK phosphorylation differed among patients. In contrast, within individual patients, we found limited intratumoral heterogeneity of ERK phosphorylation. Our results suggest that measuring ERK in a single FNA may be representative of ERK activity in different regions of the same tumor. As diagnostic and therapeutic protein biomarkers are being sought, NIA measurements of protein signaling may increase the clinical utility of renal mass biopsy and allow for the application of precision oncology for patients with localized and advanced RCC. Patient summaryIn this report, we applied a new approach to measure the activity of extracellular signal-regulated kinase (ERK), a key cancer signaling protein, in different areas within kidney cancers. We found that ERK activity varied between patients, but that different regions within individual kidney tumors showed similar ERK activity. This suggests that a single biopsy of renal cell carcinoma may be sufficient to measure protein signaling activity to aid in precision oncology approaches.

Downregulation of CLDN7 due to promoter hypermethylation is associated with human clear cell renal cell carcinoma progression and poor prognosis

BackgroundMetastasis is the primary cause of death in renal cell carcinoma (RCC). Loss of cell-to-cell adhesion, including tight junctions (TJs) is the initial step in the process of metastasis. Claudin-7 (CLDN7) is a major component of TJs. However, the clinical significance and its regulation of kidney tumorigenesis remain poorly understood.MethodsA total of 120 fresh clear cell RCC (ccRCC) specimens and 144 primary RCC and adjacent nonmalignant renal paraffin specimens were obtained from Department of Urology, Peking University First Hospital. Expression of CLDN7 in ccRCC tissues and cell lines were determined using bioinformatic data mining, quantitative real-time PCR (qRT-PCR), Western blotting and immunostaining. The clinical significance of CLDN7 expression and promoter DNA methylation status was analyzed in ccRCC patients from Peking University First Hospital and The Cancer Genome Atlas. Additionally, the methylation specific-PCR, bisulfite genomic sequencing and demethylation analysis of CLDN7 were performed. Biological functions of CLDN7 were investigated by examining cell proliferation using MTS assays and EdU incorporation assays, cell migration by in vitro wound healing assays and transwell migration assays, cell invasion by transwell invasion assays, and cell apoptosis by flow cytometry. Mouse model experiments were performed to confirm the effects of CLDN7 on tumor growth and metastasis in vivo. The molecular mechanism of CLDN7 function was investigated using gene-set enrichment analysis (GSEA) and high-throughput cDNA sequencing (RNA-Seq) and confirmed by qRT-PCR, Western blot and immunostaining in vitro and in vivo.ResultsOur findings revealed that CLDN7 is frequently downregulated via hypermethylation of its promoter in ccRCC. CLDN7 can help predict aggressive tumor status and poor prognosis in ccRCC patients. Interestingly, hypermethylation of the CLDN7 promoter was related to advanced ccRCC status and poor prognosis. Moreover, overexpression of CLDN7 induced cell apoptosis, suppressed proliferation, migration and invasion abilities of ccRCC cells both in vitro and in vivo. Additionally, GSEA and RNA-Seq results showed that CLDN7 had negative effects in cancer-associated signaling pathways and (epithelial-mesenchymal transition) EMT-related pathways. These results were validated by qRT-PCR, Western blot and immunostaining.ConclusionsWe have demonstrated a previously undescribed role of CLDN7 as a ccRCC suppressor and suggest that loss of CLDN7 potentiates EMT and tumor progression. CLDN7 may serve as a functional tumor suppressor in tumor progression and a potential biomarker and target in patients with ccRCC.

MTOR and mTOR phosphorylation status in primary and metastatic renal cell carcinoma tissue: differential expression and clinical relevance.

Impaired regulation of the Akt/mammalian target of rapamycin (mTOR) pathway has been implicated in mechanisms related to neoplastic transformation in renal cell cancer (RCC) through enhancement of cell proliferation and survival and mTOR activation has been reported to occur due to phosphorylation of mTOR. To further determine the relevance of mTOR expression and activation and to analyze their putative role as a biomarker for systemic treatment in metastatic RCC, we investigated the expression of mTOR and phospho(p)-mTOR in primary RCC and metastases and correlated levels with pathological variables and clinical outcome. Tissue microarrays (TMA) from paraffin-embedded tissue from 342 patients with primary clear cell renal cell carcinoma and 90 patients undergoing surgical resection for metastases were immunohistochemically stained for mTOR and p-mTOR and expression was quantified with immunoreactivity scores. Clinical patient characteristics and follow-up were recorded. Comparative evaluation of protein expression levels and association of expression with clinical variables and survival was performed. mTOR staining revealed differential expression in benign, primary and RCC metastasis (average staining score: 1.64, 0.78, and 1.44, respectively). Average staining of p-mTOR was 0.99 in benign kidney tissue, 0.73 in primary RCC and 1.14 in RCC metastasis tissue. Elevated mTOR expression in primary RCC tissue was associated with the presence of tumor necrosis, while a high level of p-mTOR was significantly correlated with advanced T-stage, high Fuhrman grade, the presence of tumor necrosis and sarcomatoid features. An elevated ratio of p-mTOR/mTOR was significantly correlated with advanced stage and sarcomatoid histology. mTOR expression was not predictive of overall survival (OS), while high p-mTOR levels were associated with impaired OS (p = 0.0046) and cancer-specific survival (p = 0.0067). In univariate analysis, advanced stage (HR 3.78), high Fuhrman grade (HR 4.0), the presence of tumor necrosis (HR 1.99), and sarcomatoid features (HR 5.12) were significant predictors of OS. Moreover, elevated levels of p-mTOR (HR 1.67) and an elevated ratio of p-mTOR/mTOR ratio (HR 1.73) were significantly predictive of OS. In the multivariate regression model only the presence of locally advanced tumors (HR 2.44) was of independent prognostic value for OS, while there was a trend for impaired OS for patients with a high p-mTOR (HR 1.27, p = 0.21). Phosphorylated mTOR is differentially expressed in localized RCC and metastasis. Elevated phosphorylation of mTOR is associated with aggressive pathologic features and unfavorable outcome. Whether these findings portend to relevance for mTOR inhibition treatment for metastatic RCC should be objective of further investigations.

Identifying Potential Predictors of Late Renal Toxicity after Stereotactic Body Radiation Therapy for Primary Renal Cell Carcinoma: A Prospective Cohort Study

Identifying Potential Predictors of Late Renal Toxicity after Stereotactic Body Radiation Therapy for Primary Renal Cell Carcinoma: A Prospective Cohort Study

Somatic mutations in renal cell carcinomas from Chinese patients revealed by whole exome sequencing

BackgroundWhile the somatic mutation profiles of renal cell carcinoma (RCC) have been revealed by several studies worldwide, the overwhelming majority of those were not derived from Chinese patients. The landscape of somatic alterations in RCC from Chinese patients still needs to be elucidated to determine whether discrepancies exist between Chinese patients and sufferers from other countries and regions.MethodsWe collected specimens from 26 Chinese patients with primary RCC, including 15 clear cell renal cell carcinoma (ccRCC) samples, 5 papillary renal cell carcinoma (PRCC) samples and 6 chromophobe renal cell carcinoma (ChRCC) samples. Genomic DNAs were isolated from paired tumor-normal tissues and subjected to whole exome sequencing (WES). Immunohistochemistry analysis was performed to detect the programmed death ligand 1 (PD-L1) expression in tumor tissues.ResultsA total of 1920 nonsynonymous somatic variants in exons and 86 mutations at splice junctions were revealed. The tumor mutation burden of ccRCC was significantly higher than that of ChRCC (P < 0.05). For both ccRCC and PRCC, the most frequent substitution in somatic missense mutations was T:A > A:T, which was different from that recorded in the COSMIC database. Among eight significantly mutated genes in ccRCC in the TCGA database, six genes were verified in our study including VHL (67%), BAP1 (13%), SETD2 (13%), PBRM1 (7%), PTEN (7%) and MTOR (7%). All the mutations detected in those genes had not been reported in ccRCC before, except for alterations in VHL and PBRM1. Regarding the frequently mutated genes in PRCC in our study, DEPDC4 (p.E293A, p.T279A), PNLIP (p.N401Y, p.F342L) and SARDH (p.H554Q, p.M1T) were newly detected gene mutations predicted to be deleterious. As the most recurrently mutated gene in ChRCC in the TCGA dataset, TP53 (p.R81Q) was somatically altered only in one ChRCC case in this study. The HIF-1 signaling pathway was the most affected pathway in ccRCC, while the PI3K-Akt signaling pathway was altered in all of the three RCC types. Membranous PD-L1 expression was positive in tumor cells from 6/26 (23%) RCC specimens. The PD-L1-positive rate was higher in RCC samples with the somatically mutated genes CSPG4, DNAH11, INADL and TMPRSS13 than in specimens without those (P < 0.05).ConclusionsUsing WES, we identified somatic mutations in 26 Chinese patients with RCC, which enriched the racial diversity of the somatic mutation profiles of RCC subjects, and revealed a few discrepancies in molecular characterizations between our study and published datasets. We also identified numerous newly detected somatic mutations, which further supplements the somatic mutation landscape of RCC. Moreover, 4 somatically mutated genes, including CSPG4, DNAH11, INADL and TMPRSS13, might be promising predictive factors of PD-L1-positive expression in RCC tumor cells.

IMPACT OF TRANSCRIPTION FACTORS, VEGF AND PROTEASES ON KIDNEY CANCER PROGRESSION

Introduction.The efficacy of anticancer treatment depends on biological factors of tumor.The aimof the study was to determine the activity of proteasomes and calpains and to reveal their association with VEGF, HIF-1α and NF-κΒ expressions in normal, primary and metastatic renal cell carcinoma (RCC) tissues.Methods.Ninety-three patients with renal cell carcinoma were included into the study. The expression levels of transcription factor and VEGF were measured using ELISA kits. The levels of proteasome subunits were measured by Western Blotting. Proteasome and calpain activities were determined using specific fluorogenic substrates.Results.We revealed inactivation of proteolysis in patients with kidney cancer. Disease advance was associated with a significant depression of cellular proteolysis and increase in transcription and growth factor levels in primary kidney cancer tissues. The proteolysis activation was found in metastatic tissues.Conclusions.Our results suggest that NF-κΒ, HIF-1α and VEGF transcription factors and intracellular proteolytic systems are involved in kidney cancer progression.

Updated long-term outcomes after carbon-ion radiotherapy for primary renal cell carcinoma.

Long‐term oncological outcomes for primary renal cell carcinoma (RCC) treated with carbon‐ion radiotherapy (CIRT) are poorly understood. Patients with primary RCC were treated with 12 or 16‐fraction CIRT at The Hospital of the National Institute of Radiological Sciences outside of clinical trials. Outcome data were pooled and retrospectively analyzed for toxicity, local control, and disease‐free, cancer‐specific, and overall survival. From 1997 to 2014, 19 RCC patients (11 with T1aN0M0, 4 with T1bN0M0, and 4 with inoperable advanced stage [T4N0M0, T3aN1M0, and T1aN0M1]) were treated with CIRT and followed up for a median of 6.6 (range, 0.7‐16.5) years; 9 of these patients were inoperable because of comorbidities or advanced‐stage disease. Diagnoses were confirmed by imaging in 11 patients and by biopsy in the remaining 8. In 4 of 5 patients with definitive renal comorbidities, including diabetic nephropathy, sclerotic kidney or solitary kidney pre‐CIRT progressed to grade 4 chronic kidney disease (CKD). In contrast, the remaining 14 patients without definitive renal comorbidities did not progress to grade 3 or higher CKD. Furthermore, although 1 case of grade 4 dermatitis was observed, there were no other grade 3 or higher non‐renal adverse events. Local control rate, and disease‐free, cancer‐specific, and overall survival rates at 5 years of all 19 patients were 94.1%, 68.9%, 100%, and 89.2%, respectively. This updated retrospective analysis based on long‐term follow‐up data suggests that CIRT is a safe treatment for primary RCC patients without definitive renal comorbidities pre‐CIRT, and yield favorable treatment outcomes, even in inoperable cases.

Metastatic polyp of the gallbladder from renal cell carcinoma

Background: Gallbladder metastasis from renal cell carcinoma (RCC) is extremely rare. The purpose of this study is to clarify the characteristics of metastatic RCC to gallbladder. Methods: The pooled data for analysis were collected from gallbladder metastasis from RCC cases encountered by our institution along with sporadic cases reported in 35 English articles from 1991 to 2015. Results: A total of 50 cases of metastatic RCC to the gallbladder were recruited for study, including 49 from literature and 1 from our institution. 57% of the primary RCC was from the right kidney and 43% of the left. The median interval between diagnoses of primary and metastatic RCC to gallbladder was 36 months, with the longest duration up to 324 months. Most 70% were asymptomatic. The size of metastatic RCC to gallbladder ranged from 0.8 cm to 9 cm, with median of 2.6 cm. Majority (91%) of the metastatic RCCs presented as a polypoid mass with narrow stalk, and 82% were hypervascular lesion. The overall 1 year, 3 year and 5 year survival rate was 91.5%, 76.2% and 59.3% respectively, with a median of 26.5 months. Number of the metastatic site, timing of metastasis gallstone, symptom, tumor size and operation type of cholecystectomy seemed to have no impact on survival. Conclusions: Metastatic RCC to the gallbladder should be taken into account for a gallbladder polypoid mass with narrow hypervascular stalk during the diagnosis and/or follow-up of primary RCC.

Stereotactic body radiation therapy (SBRT) on renal cell carcinoma, an overview of technical aspects, biological rationale and current literature.

Stereotactic body radiotherapy (SBRT) is characterized by the delivery of high doses of ionizing radiation in few fractions. It is highly effective in achieving local control, and, due to the high biological effective dose administered, it seems to overcome the radioresistance of renal cell carcinoma (RCC). Thus, SBRT could constitute a treatment option for the management of localized RCC in patients who are not surgical candidates. In this paper, we report an overview about data from the current evidence about SBRT in patients affected by localized RCC. A non-systematic review was performed, including data from both retrospective and prospective studies focusing on the use of SBRT for localized RCC and its biological rationale. Furthermore, ongoing trials on this issue are reported. Currently, SBRT might be considered a treatment alternative in inoperable patients affected by primary RCC. Currently, dose-escalation to 48 Gy in 3-4 fractions are effective and well tolerated. Emerging role of immune therapies in RCC patients warrant further studies to explore interactions between SBRT and immune response.

Diffusion weighted and dynamic contrast enhanced MRI as an imaging biomarker for stereotactic ablative body radiotherapy (SABR) of primary renal cell carcinoma

PurposeTo explore the utility of diffusion and perfusion changes in primary renal cell carcinoma (RCC) after stereotactic ablative body radiotherapy (SABR) as an early biomarker of treatment response, using diffusion weighted (DWI) and dynamic contrast enhanced (DCE) MRI.MethodsPatients enrolled in a prospective pilot clinical trial received SABR for primary RCC, and had DWI and DCE MRI scheduled at baseline, 14 days and 70 days after SABR. Tumours <5cm diameter received a single fraction of 26 Gy and larger tumours received three fractions of 14 Gy. Apparent diffusion coefficient (ADC) maps were computed from DWI data and parametric and pharmacokinetic maps were fitted to the DCE data. Tumour volumes were contoured and statistics extracted. Spearman’s rank correlation coefficients were computed between MRI parameter changes versus the percentage tumour volume change from CT at 6, 12 and 24 months and the last follow-up relative to baseline CT.ResultsTwelve patients were eligible for DWI analysis, and a subset of ten patients for DCE MRI analysis. DCE MRI from the second follow-up MRI scan showed correlations between the change in percentage voxels with washout contrast enhancement behaviour and the change in tumour volume (ρ = 0.84, p = 0.004 at 12 month CT, ρ = 0.81, p = 0.02 at 24 month CT, and ρ = 0.89, p = 0.001 at last follow-up CT). The change in mean initial rate of enhancement and mean Ktrans at the second follow-up MRI scan were positively correlated with percent tumour volume change at the 12 month CT onwards (ρ = 0.65, p = 0.05 and ρ = 0.66, p = 0.04 at 12 month CT respectively). Changes in ADC kurtosis from histogram analysis at the first follow-up MRI scan also showed positive correlations with the percentage tumour volume change (ρ = 0.66, p = 0.02 at 12 month CT, ρ = 0.69, p = 0.02 at last follow-up CT), but these results are possibly confounded by inflammation.ConclusionDWI and DCE MRI parameters show potential as early response biomarkers after SABR for primary RCC. Further prospective validation using larger patient cohorts is warranted.

Cytoreductive nephrectomy in metastatic renal cancer — less is more

CARMENA, a trial comparing the efficacy of sunitinib alone to that of nephrectomy followed by sunitinib in patients with primary metastatic renal cell carcinoma who require targeted therapy has demonstrated the non-inferiority of systemic therapy alone. The data provided by this and other studies argue for a lesser role of surgery in the management of these patients.