Sunitinib re-challenge in advanced renal-cell carcinoma

Tumor Necrosis Factor Receptor-2 Signals Clear-Cell Renal Carcinoma Proliferation via Phosphorylated 4E Binding Protein-1 and Mitochondrial Gene Translation

Clear-cell renal cell carcinoma (ccRCC), a tubular epithelial malignancy, secretes tumor necrosis factor (TNF), which signals ccRCC cells in an autocrine manner via two cell surface receptors, TNFR1 and TNFR2, to activate shared and distinct signaling pathways. Selective ligation of TNFR2 drives cell cycle entry of malignant cells via a signaling pathway involving epithelial tyrosine kinase, vascular endothelial cell growth factor receptor type 2, phosphatidylinositol-3-kinase, Akt, pSer727-Stat3, and mammalian target of rapamycin. In this study, phosphorylated 4E binding protein-1 (4EBP1) serine 65 (pSer65-4EBP1) was identified as a downstream target of this TNFR2 signaling pathway. pSer65-4EBP1 expression was significantly elevated relative to total 4EBP1 in ccRCC tissue compared with that in normal kidneys, with signal intensity increasing with malignant grade. Selective ligation of TNFR2 with the TNFR2-specific mutein increased pSer65-4EBP1 expression in organ cultures that co-localized with internalized TNFR2 in mitochondria and increased expression of mitochondrially encoded COX (cytochrome c oxidase subunit) Cox1, as well as nuclear-encoded Cox4/5b subunits. Pharmacologic inhibition of mammalian target of rapamycin reduced both TNFR2-specific mutein-mediated phosphorylation of 4EBP1 and cell cycle activation in tumor cells while increasing cell death. These results signify the importance of pSer65-4EBP1 in mediating TNFR2-driven cell-cycle entry in tumor cells in ccRCC and implicate a novel relationship between the TNFR2/pSer65-4EBP1/COX axis and mitochondrial function.

YTHDC1 is downregulated by the YY1/HDAC2 complex and controls the sensitivity of ccRCC to sunitinib by targeting the ANXA1-MAPK pathway

BACKGROUND

Tyrosine kinase inhibitors (TKIs) such as sunitinib are multitarget antiangiogenic agents in clear cell renal cell carcinoma (ccRCC). They are widely used in the treatment of advanced/metastatic renal cancer. However, resistance to TKIs is common in the clinic, particularly after long-term treatment. YTHDC1 is the main nuclear reader protein that binds with m6A to regulate the splicing, export and stability of mRNA. However, the specific role and corresponding mechanism of YTHDC1 in renal cancer cells are still unclear.

METHODS

The Cancer Genome Atlas (TCGA) dataset was used to study the expression of YTHDC1 in ccRCC. Cell counting kit-8 (CCK-8), wound healing, Transwell and xenograft assays were applied to explore the biological function of YTHDC1 in ccRCC. Western blot, quantitative real time PCR (RT‒qPCR), RNA immunoprecipitation PCR (RIP-qPCR), methylated RIP-qPCR (MeRIP-qPCR) and RNA sequencing (RNA-seq) analyses were applied to study the YY1/HDAC2/YTHDC1/ANXA1 axis in renal cancer cells. The CCK-8 assay and xenograft assay were used to study the role of YTHDC1 in determining the sensitivity of ccRCC to sunitinib.

RESULTS

Our results demonstrated that YTHDC1 is downregulated in ccRCC tissues compared with normal tissues. Low expression of YTHDC1 is associated with a poor prognosis in patients with ccRCC. Subsequently, we showed that YTHDC1 inhibits the progression of renal cancer cells via downregulation of the ANXA1/MAPK pathways. Moreover, we also showed that the YTHDC1/ANXA1 axis modulates the sensitivity of tyrosine kinase inhibitors. We then revealed that HDAC2 inhibitors resensitize ccRCC to tyrosine kinase inhibitors through the YY1/HDAC2 complex. We have identified a novel YY1/HDAC2/YTHDC1/ANXA1 axis modulating the progression and chemosensitivity of ccRCC.

CONCLUSION

We identified a novel YY1/HDAC2/YTHDC1/ANXA1 axis modulating the progression and chemosensitivity of ccRCC.

Transforming growth factor-β1 enhances proliferative and metastatic potential by up-regulating lymphoid enhancer-binding factor 1/integrin αMβ2 in human renal cell carcinoma

Renal cell carcinoma (RCC) is a kind of malignant tumor with high recurrence, and it is urgent to find molecular markers for diagnosis and prognosis of RCC. Our study investigated the expression and function of integrin αMβ2 in RCC cells, aiming to understand the role of integrin αMβ2 in RCC and develop new therapeutic target for RCC. Overexpression and knockdown of lymphoid enhancer-binding factor 1 (LEF1) were performed using vector containing full-length cDNA and via siRNA technology, respectively. The expressions of mRNA and protein were detected by RT-PCR and Western blot, respectively. Proliferation of RCC cell was analyzed using WST-1 assay, and metastasis of RCC cell was evaluated using the transwell system. Our results demonstrated that LEF1 and integrin αMβ2 were up-regulated in RCC cells via TGF-β1-dependent mechanism, and LEF1 together with β-catenin directly increased integrin αMβ2 level. On the other hand, TGF-β1-induced proliferation, migration and invasion were suppressed by function-blocking antibody against integrin αMβ2 in RCC cells. In addition, integrin αMβ2 is crucial for LEF1 mediated cell invasion by regulating MMP-2, MMP-9 and calpain-2 secretion in RCC cells. LEF1/integrin αMβ2 expression was regulated by TGF-β1, and LEF1/integrin αMβ2 was involved in TGF-β1's improvement effects on the proliferation and metastasis of RCC. Blocking integrin αMβ2 activity could be a therapeutic option for patients with advanced RCC.

Retreatment with Vismodegib after Progression in Advanced Basal Cell Carcinoma: First-Time Report of a Single-Institution Experience

Retreatment with vismodegib in advanced basal cell carcinoma (BCC) patients who previously discontinued the drug due to disease progression (PD) has not been reported yet. The objective of our report is to determine whether vismodegib is still active when used in BCC patients who progressed during a first vismodegib course (FVC). We conducted a retrospective study on six advanced BCC patients enrolled in a clinical trial (STEVIE, NCT01367665) who discontinued vismodegib due to PD and were then retreated with the same drug. All patients underwent intercurrent therapies between the FVC and the second vismodegib course (SVC). Disease control (complete response, CR; partial response, PR; and stable disease) was achieved in 100% and 80% of cases in FVC and SVC, respectively. The overall response rate was 80% for FVC (50% of CR) and 50% for SVC (only PR). Median treatment duration of FVC and SVC was 19.5 months (range: 13-35) and 8 months (range: 3-14+), respectively. G3-G4 AEs were reported only during SVC (two cases), leading to permanent discontinuation in one case. The median interval between FVC and SVC was 21.5 months (range: 13-30). After a median follow-up of 54 months (range: 46-63) only one patient with metastatic disease had rapid progression, discontinued vismodegib, and died. All other patients are still alive and two are currently on therapy. We concluded that vismodegib rechallenge is feasible and potentially active in advanced BCC patients who previously discontinued the drug due to disease progression.

Sunitinib Rechallenge After Other Targeted Therapies in Metastatic Renal Cell Carcinoma Patients: A Single-Center, Retrospective Study

BACKGROUND

Sunitinib is still one of the standard therapies in metastatic renal cell carcinoma (mRCC). Despite the benefit of sunitinib resistance will develop in the majority of patients. Most of them receive multiple sequential therapies during the course of disease.

OBJECTIVES

To retrospectively investigate the efficacy and safety of rechallenged sunitinib in third or later line settings.

PATIENTS AND METHODS

Twenty-one mRCC patients were identified who received rechallenged sunitinib between March 2010 and April 2018. Patients received sunitinib in first or second line, then other tyrosine kinase and/or mTOR inhibitors were applied, then sunitinib was rechallenged. Patients' characteristics, tolerability, treatment modalities, and treatment outcomes were recorded. The primary end-point was progression-free survival (PFS) of rechallenged sunitinib.

RESULTS

Median age of patients was 62 years at the start of sunitinib rechallenge. Sixty-seven percent of patients were male. All patients had prior nephrectomy. Upon rechallenge 4 patients achieved partial response and 12 stable disease. The median PFS of first sunitinib treatment was 22 (95% CI 17-26) months and for rechallenged sunitinib 14 (95% CI 6-20) months. No increased severity of prior toxicity or new adverse events was reported during rechallenged sunitinib. The median overall survival (OS) from the start of first sunitinib was 67 (95% CI 46-76) months. Multivariate Cox regression analysis revealed that younger age (< 57 years) at start of first sunitinib (HR = 0.24; 95% CI 0.07-0.79; p = 0.019) and longer (> 2 years) first sunitinib treatment (HR = 0.28; 95% CI 0.09-0.93; p = 0.038) were independent markers of longer OS.

CONCLUSION

Sunitinib rechallenge is a feasible and tolerable option with clinical benefit in selected mRCC patients.

Randomized Phase 2 Study of Trebananib (AMG 386) with or without Continued Anti-Vascular Endothelial Growth Factor Therapy in Patients with Renal Cell Carcinoma Who Have Progressed on Bevacizumab, Pazopanib, Sorafenib, or Sunitinib - Results of NCI/CTEP Protocol 9048

Background:

In renal cell carcinoma (RCC), angiopoietin (Ang) 2 is elevated at the time of progression on anti-vascular endothelial growth factor (VEGF) therapy and may contribute to resistance.

Objective:

We tested trebananib, an Ang 1 and 2 neutralizing peptibody in patients with RCC progressing on anti-VEGF treatment.

Methods:

Patients with measurable RCC progressing despite an anti-VEGF agent within 12 weeks, any number of prior treatments, and good PS were randomized to trebananib 15 mg/kg IV weekly without (Arm A) or with (Arm B) continuation of the prior anti-VEGF agent. The primary endpoint for each arm was tumor response (RECIST 1.1). Secondary endpoints included progression free survival and adverse events.

Results:

Of 41 enrolled patients, 35 were eligible and started treatment (17 Arm A, 18 Arm B) with median age 60 (46–76) and 3 prior treatments (1–8). Four died prior to documented progression and 27 progressed as their first event. Both arms were stopped after interim analysis, 2 responses (11%; 95% C.I. 1–35%) were observed in Arm B. Median PFS of 2.7 (95% C.I. 2.3–4.7) months in Arm A and 5.2 (95% C.I. 2.7–10.8) months in Arm B did not support continued study. Common adverse events including fatigue, nausea, and increased creatinine were generally grade 1–2 and numerically higher in Arm B. The most common grade 3 or higher adverse events were hypertension and dyspnea.

Conclusions:

While tolerable, trebananib either without or with continued anti-VEGF therapy did not show promising activity in RCC patients who recently progressed on anti-VEGF therapy alone.

Sunitinib rechallenge with dose escalation in progressive metastatic renal cell carcinoma: A case report and literature review

RATIONALE

We aimed to present a case of sunitinib rechallenge with dosage escalation after disease progression, hopefully, providing an optional approach to the personalized medication management of progressive metastatic renal cell carcinoma (mRCC).

PATIENT CONCERNS

The patient was admitted to hospital due to right kidney mass, with merged enlargement of retroperitoneal lymph nodes. Subsequent surgery and sunitinib treatment was administered.

DIAGNOSES

Postoperative pathologic diagnosis was type II papillary renal cell carcinoma (pRCC) (Fuhrman grade 3) with metastases of retroperitoneal lymph nodes (T1aN1M0).

INTERVENTIONS

The patient underwent cytoreductive nephrectomy followed by treatment of sunitinib standard therapy (4/2 schedule) and alternative schedules according to different disease status. The patient received alternative 2/1 schedule while experiencing grade 3/4 adverse events. Re-challenge with sunitinib upon disease progression and metastasectomy were given. After second disease progression, sunitinib rechallenge with dose escalation was administered. Around 2/1 schedule showed desirable efficacy and better tolerance.

OUTCOMES

After 4 months of sunitinib individualized treatment, a complete response with retroperitoneal metastases was achieved. Rechallenge with sunitinib after disease progression and also rechallenge with dose escalation after second disease progression were effective.

LESSONS

Cessation of sunitinib in patients with complete response is not suggested. Also, strategy of subsequently administered sunitinib after metastasectomy is seemed to be effective. What is more, sunitinib rechallenge with escalation to 62.5 mg probably possess value in progressive mRCC and has a well tolerance when sunitinib is rechallenged. Based on this case, we probe a feasible alternative strategy in personalized therapy of sunitinib, hoping for providing referable insights into the detailed strategies of individual treatment for patients with mRCC.

Immune consequences of anti-angiogenic therapyin renal cell carcinoma

Current therapies of renal cell carcinoma (RCC), a highly vascularised tumour, mostly rely on anti-angiogenic treatment options. These include tyrosine kinase inhibitors (TKIs) and anti-VEGF monoclonal antibodies. Although these strategies aim at restraining vascularisation to control tumour growth, the effects of such therapies are much wider, as affecting the vessel structure deeply modifies the microenvironment of the tumour mass. The aim of this review is to provide an overview of current knowledge on the global effects of anti-angiogenic treatment, mostly TKIs, on the shaping of the immune component of the RCC microenvironment. The data supporting the modification of immunity by anti-angiogenic therapies are collected to reveal the potential of angiogenesis modulation as a strategy for the adjuvant anti-cancer approach in immunotherapy.

The microRNA signature of patients with sunitinib failure: regulation of UHRF1 pathways by microRNA-101 in renal cell carcinoma

Molecular targeted therapy is a standard treatment for patients with advanced renal cell carcinoma (RCC). Sunitinib is one of the most common molecular-targeted drugs for metastatic RCC. Molecular mechanisms of sunitinib resistance in RCC cells is still ambiguous. The microRNA (miRNA) expression signature of patients with sunitinib failure in RCC was constructed using a polymerase chain reaction (PCR)-based array. Several miRNAs that were aberrantly expressed in RCC tissues from patients treated with sunitinib were identified in this analysis. MicroRNA-101 (miR- 101) was markedly suppressed in sunitinib treated RCC tissues. Restoration of miR-101 significantly inhibited cell migration and invasion in Caki-1 and 786-O cells. Ubiquitin-like with PHD and ring finger domains 1 (UHRF1) was directly suppressed by miR-101 in RCC cells, and overexpression of UHRF1 was confirmed in sunitinib-treated RCC tissues. The pathways of nucleotide excision repair and mismatch repair were significantly suppressed by knockdown of UHRF1. Our findings showed that antitumor miR-101- mediated UHRF1 pathways may be suppressed by sunitinib treatment.

Promising response to axitinib rechallenge for metastatic renal cell carcinoma after progression on prior axitinib: report of two cases

With the marked improvement in the prognosis of patients with metastatic renal cell carcinoma (mRCC) in the era of molecularly targeted therapy, sequential therapies using multiple targeted agents have been intensively performed for these patients. Despite being conducted targeting small cohorts, several studies showed efficacious findings on rechallenge with some targeted agents, such as sunitinib and sorafenib; however, there has not been any report describing axitinib rechallenge for patients with mRCC. Here, we report two cases of mRCC showing a significant response to axitinib rechallenge after progression on prior systemic treatment with multiple agents, including axitinib. These findings suggest that mRCC, once refractory to axitinib, can still show favorable disease control on rechallenge with this agent during sequential treatment with targeted agents.

Tyrosine kinase inhibitors rechallenge in solid tumors: a review of literature and a case description with lenvatinib in thyroid cancer

INTRODUCTION

In the last decade tyrosine kinase inhibitors (TKIs) have been employed for a wide range of hematological and solid tumors and today they represent a valid therapeutic option for different neoplasms. Among them, both sorafenib and lenvatinib were approved for the treatment of radioactive iodine (RAI) refractory differentiated thyroid carcinoma (DTC). Unfortunately, in some cases the efficacy of TKIs is limited by the onset of drug resistance after the initial response. Areas covered: We report the case of a patient with a RAI refractory advanced DTC, treated with lenvatinib after surgery, multiple RAI administrations, traditional chemotherapy, and sorafenib. During treatment with lenvatinib, a noticeable response was detected by sequential computed tomography scans but, after 27 months, tumor progression became evident and led to lenvatinib interruption. In absence of any active treatment, a further disease progression was documented, and lenvatinib was re-administered obtaining a new objective response. Starting from this case report, we review available reports about the rechallenge with TKIs in solid tumors, discussing the possible mechanisms underlying the efficacy of this approach. Expert commentary: Rechallenge with TKIs in solid tumors could be a therapeutic option in subjects with advanced and metastatic DTC who experience a progressive disease after initial response to lenvatinib.

EZH2 Modifies Sunitinib Resistance in Renal Cell Carcinoma by Kinome Reprogramming

Acquired and intrinsic resistance to receptor tyrosine kinase inhibitors (RTKi) represents a major hurdle in improving the management of clear cell renal cell carcinoma (ccRCC). Recent reports suggest that drug resistance is driven by tumor adaptation via epigenetic mechanisms that activate alternative survival pathways. The histone methyl transferase EZH2 is frequently altered in many cancers, including ccRCC. To evaluate its role in ccRCC resistance to RTKi, we established and characterized a spontaneously metastatic, patient-derived xenograft model that is intrinsically resistant to the RTKi sunitinib, but not to the VEGF therapeutic antibody bevacizumab. Sunitinib maintained its antiangiogenic and antimetastatic activity but lost its direct antitumor effects due to kinome reprogramming, which resulted in suppression of proapoptotic and cell-cycle-regulatory target genes. Modulating EZH2 expression or activity suppressed phosphorylation of certain RTKs, restoring the antitumor effects of sunitinib in models of acquired or intrinsically resistant ccRCC. Overall, our results highlight EZH2 as a rational target for therapeutic intervention in sunitinib-resistant ccRCC as well as a predictive marker for RTKi response in this disease. Cancer Res; 77(23); 6651-66. ©2017 AACR.

Sunitinib in the treatment of renal cell carcinoma: an update on recent evidence

Sunitinib is a multitarget tyrosine kinase inhibitor endowed mainly by antiangiogenic effects, although an indirect inhibitory effect on tumor growth and, more recently, a complex activity on antitumor immune response has been described. From approval by the US Food and Drug Administration (FDA) in January 2006, sunitinib represents a key molecule in the treatment of metastatic renal cell carcinoma (mRCC) due to the peculiar molecular pathogenesis of this neoplasm. Over the past 10 years, clinical trials and real-world experiences helped clinicians to understand how, when and for how long to use sunitinib. Although a huge amount of data evidenced the relationship existing between sunitinib dose intensity and improved clinical outcome, the management of sunitinib-induced adverse events is often complex; thus, alternative schedules have been proposed over time which allow increased tolerability, without decreased daily sunitinib exposure, leading to improved clinical outcomes. To date, combinations of sunitinib with other approved targeted agents did not demonstrate any significant benefit over its single-agent use, mainly due to tolerability issues. Sunitinib has also been tested in the adjuvant setting, within the ASSURE and S-TRAC trials, with opposite results; indeed, equivocal risk-stratification criteria, as well as immature overall survival (OS) data prevent any definitive conclusion on this important issue. Despite being on the market for a long time, sunitinib still plays a role as the 'comparator arm' of a number of trials in the field of mRCC. Combinations with immune checkpoint inhibitors and vaccines look promising; once again, sunitinib can help us to optimize mRCC management.

Strategies to overcome therapeutic resistance in renal cell carcinoma

BACKGROUND

Renal cell cancer (RCC) is a prevalent and lethal disease. At time of diagnosis, most patients present with localized disease. For these patients, the standard of care includes nephrectomy with close monitoring thereafter. While many patients will be cured, 5-year recurrence rates range from 30% to 60%. Furthermore, nearly one-third of patients present with metastatic disease at time of diagnosis. Metastatic disease is rarely curable and typically lethal. Cytotoxic chemotherapy and radiation alone are incapable of controlling the disease. Extensive effort was expended in the development of cytokine therapies but response rates remain low. Newer agents targeting angiogenesis and mTOR signaling emerged in the 2000s and revolutionized patient care. While these agents improve progression free survival, the development of resistance is nearly universal. A new era of immunotherapy is now emerging, led by the checkpoint inhibitors. However, therapeutic resistance remains a complex issue that is likely to persist.

METHODS AND PURPOSE

In this review, we systematically evaluate preclinical research and clinical trials that address resistance to the primary RCC therapies, including anti-angiogenesis agents, mTOR inhibitors, and immunotherapies. As clear cell RCC is the most common adult kidney cancer and has been the focus of most studies, it will be the focus of this review.

The Wide Experience of the Sequential Therapy for Patients with Metastatic Renal Cell Carcinoma

Sequential targeted therapies are the standard of care for patients with metastatic renal cell carcinoma (mRCC). Several drugs are available for patients whose disease progresses while they receive initial tyrosine kinase inhibitor (TKI) therapy; these include nivolumab (an inhibitor of PD-1 receptor), everolimus (an inhibitor of the mechanistic target of rapamycin) or additional TKIs. Until now, there has been no clinical evidence to support the use of one strategy versus another, so investigators and physicians rely on experience, judgement and findings from molecular analyses to select the appropriate treatment. However, with the arrival of nivolumab and cabozantinib that provide an overall survival higher than other alternative treatments, therapeutic strategies may have changed. Here, we discuss findings from preclinical and clinical studies that might help clinicians to choose the optimal treatment approach for patients with mRCC who progress to initial therapy.

The role of rechallenge with targeted therapies in metastatic renal-cell carcinoma

PURPOSE OF REVIEW

To explore the accumulating evidence and feasibility of rechallenge with agents targeting the vascular endothelial growth factor (VEGF) and mammalian target of rapamycin (mTOR) pathways for incorporation into the evolving management algorithm for metastatic renal-cell carcinoma (mRCC).

RECENT FINDINGS

The current standard of care after the development of resistance to first-line targeted therapies in mRCC is sequential treatment with subsequent lines of alternative anti-VEGF agents or mTOR inhibitors, with optimal sequencing being the focus of ongoing research. Recent evidence from case study and retrospective reports suggests that mRCC patients can achieve important clinical benefits from rechallenge at later lines of therapy with the same targeted therapy used for previous line treatment. Further, the results of REchallenge with SUnitinib in MEtastatic, the first study of sunitinib rechallenge to include a prospective component, reinforce the potential for prolonged survival with this treatment approach for mRCC patients.

SUMMARY

Rechallenge represents an important and feasible therapeutic option for the future treatment of mRCC patients. The results of ongoing prospective studies are expected to further evaluate the benefits of rechallenge and better inform wherein this approach fits in the treatment algorithm for mRCC.

Beyond evidence-based data: scientific rationale and tumor behavior to drive sequential and personalized therapeutic strategies for the treatment of metastatic renal cell carcinoma

The recent advances in identification of the molecular mechanisms related to tumorigenesis and angiogenesis, along with the understanding of molecular alterations involved in renal cell carcinoma (RCC) pathogenesis, has allowed the development of several new drugs which have revolutionized the treatment of metastatic renal cell carcinoma (mRCC).This process has resulted in clinically significant improvements in median overall survival and an increasing number of patients undergoes two or even three lines of therapy. Therefore, it is necessary a long-term perspective of the treatment: planning a sequential and personalized therapeutic strategy to improve clinical outcome, the potential to achieve long-term response, and to preserve quality of life (QOL), minimizing treatment-related toxicity and transforming mRCC into a chronically treatable condition.Because of the challenges still encountered to draw an optimal therapeutic sequence, the main focus of this article will be to propose the optimal sequencing of existing, approved, oral targeted agents for the treatment of mRCC using evidence-based data along with the knowledge available on the tumor behavior and mechanisms of resistance to anti-angiogenic treatment to provide complementary information and to help the clinicians to maximize the effectiveness of targeted agents in the treatment of mRCC.

Sequence of treatment in locally advanced and metastatic renal cell carcinoma

The spectrum of drugs that have shown activity in advanced or metastatic renal cell carcinoma (RCC) has led to a debate on the optimal sequence of treatments. There is agreement on recommending targeted agents as the standard of care in this disease. Uncertainty, however, remains on the best first-line drug choice. Physicians and patients may select sunitinib, bevacizumab in combination with interferon-alpha (IFN-α), pazopanib, or-in poor risk patients-temsirolimus. There are also a variety of therapies with proven efficacy on hand in the second-line setting: sorafenib, pazopanib, axitinib, and everolimus. While most randomized RCC trials assessed progression free survival (PFS) as primary endpoint, some agents were shown to improve median overall survival (OS), and given in sequence they have extended the life expectancy of RCC patients from 13 months in the cytokine era to over 30 months. Despite the progress made, there are sobering aspects to the oncologic success story in RCC, as the new treatments do not obtain an objective response or disease stabilization (SD) in all patients. There are also as yet no predictors to select patients who might benefit and those who are primary resistant to specific drugs, and ultimately almost all patients will experience disease progression. Bearing inevitable treatment failure in mind, availability of further drugs and switching therapy while the patient is in a condition to continue pharmacotherapy is essential. Of note, depending on the setting, only 33-59% of patients receive second-line treatment. In this review we present data on first-, second-, and third-line treatment in RCC, and discuss the difficulties in their interpretation in the context of treatment sequence. We summarize biological aspects and discuss mechanisms of resistance to anti-angiogenic therapy and their implications for treatment selection.

Targeted therapy for renal cell carcinoma: focus on 2nd and 3rd line

INTRODUCTION

Second- and third-line treatments are more and more frequently administered to metastatic renal cell carcinoma (mRCC) patients.

AREAS COVERED

Here we discuss the various levels of evidence supporting presently available recommendations, trying to address a number of as yet unanswered issues, and also to take a glowing glance at the future. To do this, we interrogated the Medline database, as well as the proceedings of the main Oncological and Urological conferences for relevant studies.

EXPERT OPINION

Until recently, with regard to choosing the second line treatment after the failure of therapy with vascular endothelial growth factor receptors-tyrosine kinase inhibitors (VEGFR-TKIs), the continued inhibition of the VEGF/VEGR pathway, or else the switch to an mTOR inhibitor, is recommended. These two options are characterized by partly different targets, completely different toxicity profiles, but a comparable efficacy. This scenario will change soon, after the publication of two randomized, controlled, phase III trials in which cabozantinib and nivolumab proved to be superior as compared to everolimus. As regards third line treatment, where a sequence of two VEGFR-TKIs has been used beforehand, the choice is represented by the mTOR inhibitor everolimus, whilst if a VEGFR-TKI followed by everolimus has been chosen, a return to VEGF pathway inhibition is suggested.

Recent developments in receptor tyrosine kinases targeted anticancer therapy

Novel concepts and understanding of receptors lead to discoveries and optimization of many small molecules and antibodies as anti-cancerous drugs. Receptor tyrosine kinases (RTKs) are such a promising class of receptors under the investigation in past three decades. RTKs are one of the essential mediators of cell signaling mechanism for various cellular processes. Transformations such as overexpression, dysregulation, or mutations of RTKs may result into malignancy, and thus are an important target for anticancer therapy. Numerous subfamilies of RTKs, such as epidermal growth factor receptor, vascular endothelial growth factor receptor, fibroblast growth factor receptors, insulin-like growth factor receptor, and hepatocyte growth factor receptor, have been being investigated in recent years as target for anticancer therapy. The present review focuses several small molecules drugs as well as monoclonal antibodies targeting aforesaid subfamilies either approved or under investigation to treat the various cancers.

NDUFA4 expression in clear cell renal cell carcinoma is predictive for cancer-specific survival

Like other cancers, renal cell carcinoma (RCC) derives the essential energy for proliferation and survival from high rates of glycolysis rather than from oxidative phosphorylation of the mitochondrial respiration pathway. NDUFA4 (NADH Dehydrogenase (Ubiquinone) 1 Alpha Subcomplex, 4) is encoding a protein belonging to the respiratory chain of mitochondria. For a better understanding of the tumor biology and for identification of a potential new biomarker, we analyzed the regulation of NDUFA4 in RCC compared to normal tissue cells. Downregulation of NDUFA4 mRNA and protein was detected in RCC compared to normal renal tissues in quantitative real-time PCR as well as in western blot and immunohistochemical staining. Histological analysis revealed higher NDUFA4 expression in the distal tubules compared to the proximal tubules and the loop of Henle. A higher molecular weight of the NDUFA4 protein was discovered in RCC samples, possibly indicating a posttranslational modification. Moreover, NDUFA4 protein expression was predictive for cancer-specific survival. Our analysis revealed a potential new biomarker, but future studies are warranted to investigate the prognostic value of NDUF4A expression.

Predictive biomarker candidates to delineate efficacy of antiangiogenic treatment in renal cell carcinoma

Antiangiogenic therapy is currently considered as the cornerstone of treatment in metastatic kidney cancer. A monoclonal antibody against the vascular endothelial growth factor (VEGF) and several tyrosine kinase inhibitors targeting the VEGF receptors demonstrated, 7 years ago, to deeply impact the outcome of this tumor and became a model of integration of molecular knowledge into clinical practice. Unfortunately, no further improvement in survival has been made and 20-25 % of cases remain primary refractory to these drugs, with an overall dismal prognosis. Since biomarker predictors of activity are lacking, their development could highly help in the process of making clinical decisions when choosing the best option for every patient or prompting the inclusion in clinical trials. This unmet medical need could become even more relevant if new immunotherapy confirms its initial promising results in this pathology. In this article, we provide an insight of current state of the art regarding the prediction of antiangiogenic efficacy in kidney cancer and propose new strategies for the implementation of such markers in clinical practice.

Renal cell carcinoma with intramyocardial metastases

Background

Cardiac metastases from renal cell carcinoma without vena caval involvement are extremely rare with a limited number of cases reported in the worldwide literature until now. Nevertheless, this rare location of metastasis may significantly influence patient treatment and prognosis. Cooperation between oncology, cardiology, and urology teams are indispensable in cases of patients suffering from intramyocardial tumors. For these individuals, treatment guidelines based on large-scale studies are unavailable and only case/case series analysis may provide clinicians with decision assistance.

Case presentation

In this paper, we report a case of a 50-year-old Caucasian male diagnosed with a 10.2 × 10.3 × 10.0 cm lower pole left renal mass in January 2002. He was subsequently treated with immunochemotherapy, tyrosine kinase inhibitors (TKIs), and mTOR inhibitors (mTORIs) - that is sunitinib, everolimus, and sorafenib. In March 2012, contrast-enhancing tumors in the left myocardium (∅22 mm) and in the interventricular septum (∅26 mm) were seen on CT. Cardiology testing was conducted and the patient was treated with pazopanib with a profound response. Overall survival since the clear cell renal cell carcinoma (ccRCC) diagnosis was 11 years 2 months and since diagnosis of multiple heart metastases was 1 year.

Conclusions

Cardiac metastases present a unique disease course in renal cell carcinoma. Cardiac metastases may remain asymptomatic, as in the case of this patient at the time of diagnosis. The most common cardiac presentation of renal cell carcinoma is hypertension, but other cardiac presentations include shortness of breath, cough, and arrhythmias. Targeted systemic therapy with tyrosine kinase inhibitors may be useful for this group of patients, but necrosis in the myocardium can result in tamponade and death. Regular cardiac magnetic resonance imaging scans are required for treatment monitoring.