Medullary Renal Cell Carcinoma and Response to Therapy With Bortezomib

An Overview of Systemic Targeted Therapy in Renal Cell Carcinoma, with a Focus on Metastatic Renal Cell Carcinoma and Brain Metastases

The most commonly diagnosed malignancy of the urinary system is represented by renal cell carcinoma. Various subvariants of RCC were described, with a clear-cell type prevailing in about 85% of all RCC tumors. Patients with metastases from renal cell carcinoma did not have many effective therapies until the end of the 1980s, as long as hormonal therapy and chemotherapy were the only options available. The outcomes were unsatisfactory due to the poor effectiveness of the available therapeutic options, but then interferon-alpha and interleukin-2 showed treatment effectiveness, providing benefits but only for less than half of the patients. However, it was not until 2004 that targeted therapies emerged, prolonging the survival rate. Currently, new technologies and strategies are being developed to improve the actual efficacy of available treatments and their prognostic aspects. This article summarizes the mechanisms of action, importance, benefits, adverse events of special interest, and efficacy of immunotherapy in metastatic renal cell carcinoma, with a focus on brain metastases.

Surgical and oncological management of renal medullary carcinoma in a young patient: a case report

Renal medullary carcinoma (RMC) is a rare form of renal cell carcinoma that has a poor prognosis. It is known to be associated with sickle cell trait or disease, although the exact underlying mechanisms are still unclear. The diagnosis is made through immunochemical staining for SMARCB1 (INI1). In this report, we present a case of a 31-year-old male patient with sickle cell trait who was diagnosed with stage III right RMC. Despite the poor prognosis, the patient survived for a remarkable duration of 37 months. Radiological assessment and follow-up were primarily performed using 18F-FDG PET/MRI. The patient underwent upfront cisplatin-based cytotoxic chemotherapy before surgical removal of the right kidney and retroperitoneal lymph node dissection. Identical adjuvant chemotherapy was administered post-surgery. Disease relapses were detected in the retroperitoneal lymph nodes; these were managed with chemotherapy and surgical rechallenges. We also discuss the oncological and surgical management of RMC, which currently relies on perioperative cytotoxic chemotherapy strategies, as there are no known alternative therapies that have been shown to be superior to date.

Efficacy and safety of gemcitabine plus doxorubicin in patients with renal medullary carcinoma

INTRODUCTION

Renal medullary carcinoma (RMC) is a rare and lethal renal cell carcinoma characterized by the loss of tumor suppressor SMARCB1. Molecular profiling studies have suggested that RMC cells may be vulnerable to therapies that generate DNA damage, such as the combination of the nucleoside analog gemcitabine, and topoisomerase inhibitor doxorubicin.

PATIENTS AND METHODS

We retrospectively analyzed the records of patients with RMC treated with gemcitabine plus doxorubicin at our institution between January 2005 and September 2020. Best radiographic response and disease progression (RECIST v1.1) were assessed by a blinded radiologist.

RESULTS

Sixteen patients were included in the study. All but 1 patient (93.8%) received prior platinum-based chemotherapy. Gemcitabine was given intravenously at 900-1200 mg/m² and doxorubicin at 40-50 mg/m² intravenously every 2 weeks. Three patients (18.8%) achieved partial response and 7 (43.8%) patients achieved stable disease. The median progression-free survival was 2.8 months (95% CI, 0-6.0). Median overall survival (OS) from gemcitabine plus doxorubicin initiation was 8.1 months (95% CI, 4.6-11.7) and OS from diagnosis was 15.5 months (95% CI, 4.2-26.8 months). There were no grade ≥ 4 AEs; grade 3 AEs were cytopenias (18.8%), nausea (12.5%), fatigue (12.5%), and cardiotoxicity (6.2%). No somatic alterations were detected in the 9 patients tested by targeted next generation sequencing assays.

CONCLUSION

Gemcitabine plus doxorubicin was well tolerated and demonstrated clinical activity in patients with platinum-refractory RMC, with a subset of patients experiencing durable responses lasting longer than 6 months. Further investigation is warranted to determine biomarkers of sensitivity and target mechanisms of resistance.

Combination Therapy With Bortezomib in Renal Medullary Carcinoma: A Case Series

BACKGROUND

Renal medullary carcinoma (RMC) is a very rare, aggressive neoplasm occurring almost exclusively in adolescents and young adults with sickle cell trait. Given the rare nature of this tumor, accounting for less than 0.5% of all renal carcinomas, most of the published data on therapies is from case reports and small case series, and current treatments are insufficient, with most patients succumbing to their disease in months. We report our experience with a cytotoxic chemotherapy regimen consisting of platinum-based therapy, doxorubicin, and bortezomib.

METHODS

Three patients with metastatic RMC at a single institution were treated off-label with a perioperative chemotherapy regimen for 4 cycles of 2 alternating regimens: regimen A consisting of cisplatin, doxorubicin, and bortezomib; regimen B consisting of carboplatin, paclitaxel, and gemcitabine. A radical nephrectomy was performed on all patients. Surveillance imaging was performed on all patients to assess response and disease burden. Patients received up to 12 months of maintenance therapy with everolimus.

RESULTS

Three African American patients - 2 males and 1 female aged 14, 28, and 31 - with sickle cell trait and metastatic disease were treated with this regimen. The median follow-up was 18 months. All had resection of the primary tumor - 2 patients after receiving neoadjuvant therapy, and one patient underwent resection prior to referral. All 3 patients achieved complete responses based on imaging, 2 of which lasted for 12 months, and another is still in remission over 7 years after diagnosis.

CONCLUSIONS

This regimen of alternating cycles of platinum-based chemotherapy with bortezomib appeared to be active against RMC and was generally well-tolerated. Given the extremely rare nature of this disease and dismal prognosis, new treatment modalities should be pursued, and whenever possible, patients should be enrolled in a clinical trial. We propose that a multiinstitution clinical trial of this regiment may be warranted.

Targeting the Proteasome in Advanced Renal Cell Carcinoma: Complexity and Limitations of Patient-Individualized Preclinical Drug Discovery

Background: Systemic treatment options for metastatic renal cell carcinoma (RCC) have significantly expanded in recent years. However, patients refractory to tyrosine kinase and immune checkpoint inhibitors still have limited treatment options and patient-individualized approaches are largely missing. Patients and Methods: In vitro drug screening of tumor-derived short-term cultures obtained from seven patients with clear cell RCC was performed. For one patient, a patient-derived xenograft (PDX) mouse model was established for in vivo validation experiments. Drug effects were further investigated in established RCC cell lines. Results: The proteasome inhibitor carfilzomib was among the top hits identified in three of four patients in which an in vitro drug screening could be performed successfully. Carfilzomib also showed significant acute and long-term cytotoxicity in established RCC cell lines. The in vivo antitumoral activity of carfilzomib was confirmed in a same-patient PDX model. The cytotoxicity of carfilzomib was found to correlate with the level of accumulation of ubiquitinated proteins. Conclusions: In this proof-of-concept study, we show that patient-individualized in vitro drug screening and preclinical validation is feasible. However, the fact that carfilzomib failed to deliver a clinical benefit in RCC patients in a recent phase II trial unrelated to the present study underscores the complexities and limitations of this strategy.

Novel Patient Metastatic Pleural Effusion-Derived Xenograft Model of Renal Medullary Carcinoma Demonstrates Therapeutic Efficacy of Sunitinib

Background

Renal medullary carcinoma (RMC) is a rare but aggressive tumor often complicated by early lung metastasis with few treatment options and very poor outcomes. There are currently no verified RMC patient-derived xenograft (PDX) mouse models established from metastatic pleural effusion (PE) available to study RMC and evaluate new therapeutic options.

Methods

Renal tumor tissue and malignant PE cells from an RMC patient were successfully engrafted into 20 NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ (NSG) mice. We evaluated the histopathological similarity of the renal tumor and PE PDXs with the original patient renal tumor and PE, respectively. We then evaluated the molecular integrity of the renal tumor PDXs between passages, as well as the PE PDX compared to two generations of renal tumor PDXs, by microarray analysis. The therapeutic efficacy of sunitinib and temsirolimus was tested in a serially-transplanted generation of 27 PE PDX mice.

Results

The pathologic characteristics of the patient renal tumor and patient PE were retained in the PDXs. Gene expression profiling revealed high concordance between the two generations of renal tumor PDXs (RMC-P0 vs. RMC-P1, r=0.865), as well as between the first generation PE PDX and each generation of the renal tumor PDX (PE-P0 vs. RMC-P0, r=0.919 and PE-P0 vs. RMC-P1, r=0.843). A low number (626) of differentially-expressed genes (DEGs) was seen between the first generation PE PDX and the first generation renal tumor PDX. In the PE-P1 xenograft, sunitinib significantly reduced tumor growth (p<0.001) and prolonged survival (p=0.004) compared to the vehicle control.

Conclusions

A metastatic PE-derived RMC PDX model was established and shown to maintain histologic features of the patient cancer. Molecular integrity of the PDX models was well maintained between renal tumor and PE PDX as well as between two successive renal tumor PDX generations. Using the PE PDX model, sunitinib demonstrated therapeutic efficacy for RMC. This model can serve as a foundation for future mechanistic and therapeutic studies for primary and metastatic RMC.

Drug screening with a novel tumor-derived cell line identified alternative therapeutic options for patients with atypical teratoid/rhabdoid tumor

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare intracranial tumor occurring predominantly in young children. The prognosis is poor, and no effective treatment is currently available. To develop novel effective therapies, there is a need for experimental models for AT/RT. In this research, we established a cell line from a patient's AT/RT tissue (designated ATRT_OCGH) and performed drug screening using 164 FDA-approved anti-cancer agents, to identify candidates for therapeutic options. We found that bortezomib, a proteasome inhibitor, was among the agents for which the cell line showed high sensitivity, along with tyrosine kinase inhibitors, topoisomerase inhibitors, and histone deacetylase inhibitors, which are known to exert anti-AT/RT effects. Concomitant use of panobinostat potentiated the inhibitory effect of bortezomib on AT/RT cell proliferation. Our findings may provide a rationale for considering combination therapy of panobinostat and bortezomib for treatment of AT/RT.

Novel renal medullary carcinoma cell lines, UOK353 and UOK360, provide preclinical tools to identify new therapeutic treatments

Renal medullary carcinoma (RMC) is a rare, aggressive disease that predominantly afflicts individuals of African or Mediterranean descent with sickle cell trait. RMC comprises 1% of all renal cell carcinoma diagnoses with a median overall survival of 13 months. Patients are typically young (median age—22) and male (male:female ratio of 2:1) and tumors are characterized by complete loss of expression of the SMARCB1 tumor suppressor protein. Due to the low incidence of RMC and the disease's aggressiveness, treatment decisions are often based on case reports. Thus, it is critical to develop preclinical models of RMC to better understand the pathogenesis of this disease and to identify effective forms of therapy. Two novel cell line models, UOK353 and UOK360, were derived from primary RMCs that both demonstrated the characteristic SMARCB1 loss. Both cell lines overexpressed EZH2 and other members of the polycomb repressive complex and EZH2 inhibition in RMC tumor spheroids resulted in decreased viability. High throughput drug screening of both cell lines revealed several additional candidate compounds, including bortezomib that had both in vitro and in vivo antitumor activity. The activity of bortezomib was shown to be partially dependent on increased oxidative stress as addition of the N‐acetyl cysteine antioxidant reduced the effect on cell proliferation. Combining bortezomib and cisplatin further decreased cell viability both in vitro and in vivo that single agent bortezomib treatment. The UOK353 and UOK360 cell lines represent novel preclinical models for the development of effective forms of therapy for RMC patients.

Phase II Study of Carfilzomib in Patients With Refractory Renal Cell Carcinoma

BACKGROUND

A von Hippel Lindau (VHL) mutation or functional inactivation occurs in the a large proportion of patients with clear-cell renal cell carcinoma (ccRCC), which results in the dysregulation of a number of key cellular functions. A high throughput screen and candidate compound assessment revealed that agents with proteasome inhibition properties were able to stabilize point-mutated VHL and restore some of its functions.

PATIENTS AND METHODS

Nine patients with histologically confirmed metastatic ccRCC with disease progression during at least 1 previous systemic therapy were treated with carfilzomib at a dose of 20 mg/m² over 30 minutes via intravenous (I.V.) infusion on days 1 and 2 and a dose of 56 mg/m² over 30 minutes via I.V. infusion on days 8, 9, 15, and 16 of each 4-week cycle.

RESULTS

The study was stopped after 9 patients were enrolled because of futility. Of the 9 patients treated in the study, all patients had disease progression within 4 months, with a median time of 1.8 months (95% confidence interval, 0.8-3.6 months). No patient showed a response according to Response Evaluation Criteria In Solid Tumors. Three patients showed a best response of stable disease. The most common side effects were musculoskeletal pain, elevated creatinine level, anemia, hyperkalemia, leukopenia, lymphopenia, and fatigue.

CONCLUSION

Although the negative safety and efficacy results of this study do not favor the use of carfilzomib for the treatment of ccRCC, previous studies have shown selected patients achieved partial or complete response to this class of agent. Further preclinical investigations to evaluate the molecular characteristics of the patients who respond to proteasome inhibitors will better characterize the underlying mechanism of response, and might allow for the selection of an appropriate patient population in future studies.

Pediatric renal cell carcinoma

PURPOSE OF REVIEW

To review the presentation, natural history and treatment of renal cell carcinoma in children and young adults with renal cell carcinoma (RCC).

RECENT FINDINGS

Complete resection of lymph nodes at the time of tumor resection can improve clinical outcomes and limit the need for adjuvant chemotherapy. Genetic alterations that lead to translocation tumors are a therapeutic target of receptor tyrosine kinase inhibitors.

SUMMARY

The incidence of RCC increases with age. Unlike adult patients, young patients with RCC present symptomatically and at higher stage and grade. Translocation tumors predominate RCC in children with biologic activity characterized by early spread to lymph nodes with small primary tumors. Preoperative imaging is poorly sensitive for positive lymph nodes; as such, surgeons should have a low threshold for lymph node sampling during tumor resection. Despite the advanced stage at presentation, the prognosis in children is more favorable than their adult counterparts. Complete resection of lymph nodes at the time of surgical resection improves patient prognosis. Chemotherapy targeting the PI3/AKT pathway has demonstrated clinical benefit.

Renal medullary carcinomas depend upon SMARCB1 loss and are sensitive to proteasome inhibition

Renal medullary carcinoma (RMC) is a rare and deadly kidney cancer in patients of African descent with sickle cell trait. We have developed faithful patient-derived RMC models and using whole-genome sequencing, we identified loss-of-function intronic fusion events in one SMARCB1 allele with concurrent loss of the other allele. Biochemical and functional characterization of these models revealed that RMC requires the loss of SMARCB1 for survival. Through integration of RNAi and CRISPR-Cas9 loss-of-function genetic screens and a small-molecule screen, we found that the ubiquitin-proteasome system (UPS) was essential in RMC. Inhibition of the UPS caused a G2/M arrest due to constitutive accumulation of cyclin B1. These observations extend across cancers that harbor SMARCB1 loss, which also require expression of the E2 ubiquitin-conjugating enzyme, UBE2C. Our studies identify a synthetic lethal relationship between SMARCB1-deficient cancers and reliance on the UPS which provides the foundation for a mechanism-informed clinical trial with proteasome inhibitors.

Renal medullary carcinoma (RMC for short) is a rare type of kidney cancer that affects teenagers and young adults. These patients are usually of African descent and carry one of the two genetic changes that cause sickle cell anemia. RMC is an aggressive disease without effective treatments and patients survive, on average, for only six to eight months after their diagnosis.

Recent genetic studies found that most RMC cells have mutations that prevent them from producing a protein called SMARCB1. SMARCB1 normally acts as a so-called tumor suppressor, preventing cells from becoming cancerous. However, it was not clear whether RMCs always have to lose SMARCB1 if they are to survive and grow.

Often, diseases are studied using laboratory-grown cells and tissues that have certain features of the disease. No such models had been created for RMC, which has slowed efforts to understand how the disease develops and find new treatments for it. Hong et al. therefore worked with patients to develop new lines of cells that can be used to study RMC in the laboratory. These RMC cells started dying when they were given copies of the SMARCB1 gene, which supports the theory that RMCs have to lose SMARCB1 in order to grow.

Hong et al. then used a set of genetic reagents that can suppress or delete genes that are targeted by drugs, and followed this by testing a range of drugs on the RMC cells. Drugs and genetic reagents that reduced the activity of the proteasome – the structure inside cells that gets rid of old or unwanted proteins – caused the RMC cells to die. These proteasome inhibitor drugs also killed other kinds of cancer cells with SMARCB1 mutations.

Proteasome inhibitors are already used to treat different types of cancer. Potentially, a clinical trial could be run to see if they will treat patients whose cancers lack SMARCB1. Further work is also needed to determine the exact link between SMARCB1 and the proteasome.

Updated Recommendations on the Diagnosis, Management, and Clinical Trial Eligibility Criteria for Patients With Renal Medullary Carcinoma

Renal medullary carcinoma (RMC) is one of the most aggressive renal cell carcinomas. It predominantly afflicts young adults and adolescents with sickle cell trait and other sickle hemoglobinopathies, and is refractory to targeted and antiangiogenic therapies used in patients with clear-cell renal cell carcinoma. Platinum-based cytotoxic chemotherapy is the mainstay for RMC treatment. On the basis of recent advances in the diagnosis, management, and clinical trial development for RMC, a panel of experts met in October 2017 and developed updated consensus recommendations to inform clinicians, researchers, and patients. Because RMC often aggressively recurs while patients are still recovering from nephrectomy, upfront chemotherapy should be considered for most patients, including those with localized disease. After safety and dosing information has been established in adults, phase II and III trials enrolling patients with RMC should allow patients aged 12 years and older to be accrued. Patients with the very rare unclassified renal cell carcinoma with medullary phenotype variant should be included in RMC trials. Medical providers should be aware that RMC can afflict subjects of all races, and not only those of African descent, and that the presence of sickle cell trait, or of other sickle hemoglobinopathies, can affect drug responses and toxicity.

Renal medullary carcinoma: a nearly fatal malignancy specifically affecting patients with a so-called benign condition

Renal medullary carcinoma (RMC) is a highly aggressive and rare malignancy found almost exclusively in young patients with sickle cell trait (SCT). Metastatic disease is commonly present at diagnosis. There is very limited experience treating disseminated disease and the prognosis is dismal. We report the case of a young 9-year-old boy with SCT, who presented with 4 months' progression of abdominal pain, nausea and vomiting associated with cough spells, dysphagia, and weight loss. Upon evaluation, he was underweight, pale, and in mild respiratory distress. Cervical lymphadenopathy was evident and abdomen was diffusely tender. A whole-body CT scan showed a left kidney lesion with associated cervical, mediastinal, and retroperitoneal lymphadenopathy. Biopsy of a cervical lymph node revealed metastatic RMC. Patient was started on combination chemotherapy with paclitaxel, carboplatin, and gemcitabine followed by left adrenalectomy. In spite of having advanced disease, our patient achieved an excellent response with a progression-free survival of 17 months. Although SCT is thought to be a "benign" condition, RMC is one devastating complication associated with it. Considering its rarity, the near uniform associated fatality should prompt the question of whether clinical practice should change regarding proper counseling of these patients and raise awareness in the medical community.

Renal medullary carcinoma: A national analysis of 159 patients

BACKGROUND

Renal medullary carcinoma (RMC) is an aggressive malignancy seen predominantly in young males with sickle cell trait. RMC is poorly understood, with fewer than 220 cases described in the medical literature to date. We used a large national registry to define the typical presentation, treatments, and outcomes of this rare tumor.

METHODS

The National Cancer Database was queried for patients under 40 years of age diagnosed with RMC from 1998 to 2011. An analysis of patient and tumor characteristics, treatment details, and overall survival (OS) was undertaken, and factors associated with mortality were identified using multivariable regression analysis.

RESULTS

In total, 159 patients with RMC were identified, of whom a majority were male (71%), African American (87%), and had metastatic disease (71%). Median tumor size was 6 cm and median survival was 7.7 months. Most patients underwent surgery (60%) and chemotherapy (65%). Few patients received radiation (12%). Patients with metastatic disease had a significantly worse median survival (4.7 vs. 17.8 months, P < 0.001) and were less likely to receive surgery (42% vs. 91%, P < 0.001). Age and tumor size did not appear to impact OS.

CONCLUSION

In the largest cohort to date of patients with RMC, we found a dismal median survival of less than 8 months. Age and tumor size were not associated with OS. Metastatic disease at presentation was the main negative prognostic indicator in RMC and was present in a majority of patients at the time of diagnosis.

Predictive role of PD-L1 expression in the response of renal Medullary carcinoma to PD-1 inhibition

Background

Renal medullary carcinoma is one of the rarest malignancies arising from the kidney. Despite various aggressive therapeutic regimens, mortality remains significantly high (95%) with a median overall survival of 5 months. Furthermore, the scarcity of this malignancy renders randomized clinical trials impossible. We examined the expression of programmed death ligand 1 (PD-L1) in two new renal medullary carcinoma cases, investigated their responses to the PD-L1 inhibitor nivolumab and explored the predictive role of the rate of PD-L1 expression in such response.

Case presentation

Two African-American patients (male and female) with sickle cell trait who presented to our center with hematuria and flank pain were diagnosed with metastatic renal medullary carcinoma. PD-L1 was expressed at rate of 25% and 60% in patient 1 and 2 respectively. Following nephrectomy, they were started on nivolumab. Patient 1 initially responded to the treatment with regression of metastatic lesions. However, following this early response, patient 1 who has been receiving nivolumab for more than 15 months, was noted to have a disease progression. Patient 2 had disease progression after 3 months of nivolumab therapy.

Conclusions

Although PD-L1 is expressed in these patients with renal medullary carcinoma, response to nivolumab was only observed in patient 1 whose tumor has the lowest rate of PD-L1 expression. This may suggest that in RMC, response to PD-L1 inhibition therapy may not correlate with the rate of PD-L1 expression.

Platinum plus bortezomib for the treatment of pediatric renal medullary carcinoma: Two cases

Renal medullary carcinoma (RMC) was first described over two decades ago as the seventh sickle nephropathy. Survival after diagnosis with metastatic disease still rarely extends beyond 1 year, with recent reports of median overall survival in patients treated with platinum therapy being just 10 months. We describe our experience using platinum-based chemotherapy plus the proteasome inhibitor bortezomib to treat metastatic RMC in two pediatric patients who had complete responses. One patient passed away 7 years after diagnosis, while another remains disease free nearly 2 years from diagnosis.

Genomic Characterization of Renal Medullary Carcinoma and Treatment Outcomes

BACKGROUND

Renal medullary carcinoma (RMC) is a rare and aggressive type of kidney cancer that primarily affects young adults with sickle cell trait; outcomes are poor despite treatment. Identifying molecular features of this tumor could provide biologic rationale for novel targeted therapies. The objective was to report on clinical outcomes with systemic therapy and characterize molecular features.

PATIENTS AND METHODS

This was a retrospective analysis on 36 patients given a pathologic diagnosis of RMC at one institution from 1995 to 2015. Tumors were analyzed for expression of SWI/SNF Related, Matrix Associated, Actin Dependent Regulator Of Chromatin, Subfamily B, Member 1 (SMARCB1) through immunohistochemistry and for genomic alterations with fluorescence in situ hybridization for SMARCB1, and targeted next-generation sequencing. Time from initiation of therapy to progression of disease and overall survival were calculated using the Kaplan-Meier method.

RESULTS

The median age in the cohort was 28 (range, 12-72) years, and all patients tested had sickle cell trait. Overall survival was 5.8 months (95% confidence interval [CI], 4.1-10.9) and for 12 patients who received platinum-based therapy, median progression-free survival was 2.5 months (95% CI, 1.2-not reached). A total of 10 available tumors underwent analysis with fluorescence in situ hybridization for SMARCB1; this revealed loss of heterozygosity with concurrent translocation in 8, and biallelic loss in 2. Next-generation targeted sequencing showed no recurring mutations.

CONCLUSIONS

Outcome was generally poor in this cohort of patients with RMC. Uniform loss of SMARCB1 is a key molecular feature in this tumor and mechanism of loss appears to be mostly through translocations and deletions.

Clinical and computed tomography imaging features of renal medullary carcinoma: A report of six cases

Patients with renal medullary carcinoma (RMC) have a poor prognosis, usually due to late diagnosis. Computed tomography (CT) analysis may aid the differentiation between RMC and other types of renal cell carcinoma, in order to establish an accurate early diagnosis. There is a limited number of reports in the literature focusing on clinical and multi-slice CT (MSCT) imaging findings of RMC. Consequently, the present study aimed to characterize the clinical and MSCT imaging features of RMC. For this purpose, the MSCT imaging findings of 6 patients with RMC were retrospectively studied. The patients were subjected to MSCT in order to investigate the characteristics of the tumors, including location, size, density, calcification, cystic or solid appearance, capsule sign, enhancement pattern and presence of retroperitoneal lymph node metastasis. The tumors in the current study presented a mean diameter of 7.48±3.25 cm, and were observed to be solitary and heterogeneous with necrotic components. The majority of the tumors did not contain calcifications (5/6); displayed an ill-defined margin (4/6); were centered in the medulla; extended into the renal pelvis or peripelvic tissues (6/6); and did not exhibit a fibrous capsule. Localized caliectasis was observed in 3 of the 6 cases. The attenuation of the solid region of the RMC on unenhanced CT was equal to that of the renal cortex or medulla (42.3±2.7 vs. 40.7±3.6 and 41.2±3.9 Hounsfield units, respectively; P>0.05) while, on enhanced CT, the enhancement of the tumor was lower than that of the normal renal cortex and medulla during all phases (cortical phase, 52.6±4.8 vs. l99.5±9.7 and 72.7±6.4; medullary phase, 58.6±5.7 vs. 184.6±10.8 and 93.5±7.8; delayed phase, 56.8±6.1 vs. 175.7±8.5 and 96.5±7.9, respectively; P<0.05). In conclusion, RMC tends to be an infiltrative, ill-defined heterogeneous mass with intratumoral necrosis, which arises from the renal medulla, and displays lower enhancement than the renal cortex and medulla during all phases on enhanced CT. Despite its rarity in adults, RMC should be included in a differential diagnosis when CT imaging reveals these features.

Metastatic non-clear cell renal cell carcinoma: an evidence based review of current treatment strategies

Much progress has been made in the treatment of metastatic renal cell carcinoma (RCC) over the last decade, with the development of agents that block the vascular endothelial growth factor (VEGF) pathway or the mammalian target of rapamycin (mTOR) pathway. The incorporation of these agents into treatment algorithms has been the result of carefully conducted clinical trials leading to Food and Drug Administration (FDA) approval and subsequent adoption as the current standard of care. These trials, however, were dominated by patients with clear cell renal cell carcinoma (ccRCC), and little data are currently available on the treatment of non-clear cell renal cell carcinoma (nccRCC). nccRCC encompasses a biologically heterogeneous group of kidney tumors that portend very diverse prognoses and responses to therapy. This review is a pathway based approach that highlights the current systemic treatment strategies for metastatic nccRCC.

Characterization of adolescent and pediatric renal cell carcinoma: A report from the Children's Oncology Group study AREN03B2

BACKGROUND

The current study was conducted to characterize the epidemiology, histology, and radiographic features of as well as the surgical approach to pediatric and adolescent renal cell carcinoma (pRCC).

METHODS

pRCC cases prospectively enrolled on the Children's Oncology Group study AREN03B2 underwent central pathology, radiology, surgery, and oncology review.

RESULTS

As of June 2012, 120 of a total of 3250 patients enrolled on AREN03B2 (3.7%) were found to have unilateral RCC (median age, 12.9 years [range, 1.9-22.1 years]; 52.5% were female). Central review classified these as translocation morphology (56 patients), papillary (20 patients), renal medullary carcinoma (13 patients), chromophobe (4 patients), oncocytoma (1 patient), conventional clear cell (1 patient), and RCC not otherwise specified (25 patients). Lymph node (LN) involvement (N+) was found in 35 of 73 cases (47.9%) for which LNs were sampled, including 19 of 40 cases with primary tumors measuring <7 cm (47.5%). Using a size cutoff of 1 cm, imaging detection of LN involvement had a sensitivity of 57.14% (20 of 35 cases; 95% CI, 39.35%-73.68%) and a specificity of 94.59% (35 of 37 cases; 95% CI, 81.81%-99.34%). Distant metastases were present in 23 cases (19.2%). Initial surgery was radical nephrectomy in 88 patients (73.3%), nephron-sparing surgery in 18 patients (15.0%), and biopsy in 14 patients (11.7%). Compared with patients undergoing radical nephrectomy, those treated with nephron-sparing surgery were less likely to have LNs sampled (6 of 18 patients [33.3%] vs 65 of 88 patients [73.9%]; P = .002).

CONCLUSIONS

Translocation RCC is the most common form of pediatric and adolescent RCC. Lymph node disease is common and observed among patients with small primary tumors. Imaging has a high specificity but relatively low sensitivity for the detection of such lymph node disease. Failure to sample LNs results in incomplete staging and potentially inadequate disease control for younger patients with RCC.

Renal medullary carcinoma: case report of an aggressive malignancy with near-complete response to dose-dense methotrexate, vinblastine, Doxorubicin, and Cisplatin chemotherapy

Renal medullary carcinoma (RMC) is a rare but aggressive malignancy affecting young individuals with sickle cell trait. Renal medullary carcinoma commonly presents with advanced or metastatic disease and is associated with a rapidly progressive clinical course and an extremely short overall survival measured in weeks to few months. Due to the rarity of RMC, there is no proven effective therapy and patients are often treated with platinum-based chemotherapy. We report near-complete radiological and pathological response in a patient treated with dose-dense MVAC (methotrexate, vinblastine, doxorubicin, and cisplatin) chemotherapy. The patient underwent consolidation nephrectomy and retroperitoneal lymph node dissection and had a 16-month progression-free survival, one of the longest reported in patients with RMC.

Renal medullary carcinoma in a white adolescent with sickle cell trait

Renal medullary carcinoma (RMC) is a rare neoplasm of the kidney that has been recently described. It is almost exclusive to young patients of African descent and associated with sickle cell hemoglobinopathy, mainly sickle cell trait and hemoglobin sickle cell disease. The prognosis of RMC is very poor because of the highly aggressive behavior of this neoplasm and its resistance to conventional chemotherapy. Metastatic disease is almost universal at the time of presentation, and the malignancy is minimally responsive to a variety of regimens and/or modalities, including surgery, radiotherapy, chemotherapy, and biological immune-modulation therapy. We report the seventh case of a left RMC occurring in a white child with sickle cell trait, but with a localization of the tumor in the left kidney, considered a nonpredominant side for this type of tumor.

Understanding pathologic variants of renal cell carcinoma: distilling therapeutic opportunities from biologic complexity

CONTEXT

Once believed to represent a uniform malignant phenotype, renal cell carcinoma (RCC) is now viewed as a diverse group of cancers that arise from the nephron.

OBJECTIVE

To review the pathologic characteristics, clinical behavior, molecular biology, and systemic therapy options of recognized RCC histologic subtypes.

EVIDENCE ACQUISITION

A systematic review of English-language articles was performed using the Medline and Web of Science databases. Manuscripts were selected with consensus of the coauthors and evaluated using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria.

EVIDENCE SYNTHESIS

The major findings of the evaluated manuscripts are discussed with an emphasis on the description of the pathologic features, clinical behavior, prognosis, and therapeutic strategies.

CONCLUSIONS

Classification schemes for kidney cancer have undergone dramatic changes over the past two decades. Improvements in these classification schemes are important, as pathologic variants differ not only in disease biology, but also in clinical behavior, prognosis, and response to systemic therapy. In the era of genomic medicine, further refinements in characterization of RCC subtypes will be critical to the progress of this burgeoning clinical space.

PATIENT SUMMARY

Kidney cancer can be subdivided into related but different cancers that arise from the kidney's tubules. In this article we review current classifications for kidney cancer, discuss their characteristics, and provide an overview of each subtype's clinical behavior and treatment. We stress that each subtype harbors unique biology and thus responds differently to available treatment strategies.

New drug therapies for advanced renal cell carcinoma

The incidence of renal cell cancer is increasing and surgery is the only curative treatment for patients presenting with localized disease at diagnosis. The treatment of metastatic renal cell cancer is palliative and, until recently, immunotherapy has been the standard treatment approach with response rates between 10 and 20%. An increase in the appreciation of the biology of this disease has resulted in a number of new 'targeted' therapies being developed. Most notable is the introduction of tyrosine kinase inhibitors with significant activity in both treatment-naive and cytokine-refractory renal cell cancer. Drugs targeting angiogenic pathways also appear promising. These agents are being rapidly introduced into clinical practice, but further studies are needed to establish their optimal place in the management of renal cell cancer and, in particular, the role of combination and/or sequential therapy.

Non-clear cell renal cancer: disease-based management and opportunities for targeted therapeutic approaches

A better understanding of the biology of renal cell carcinoma (RCC) has significantly changed the treatment paradigm of the disease. Several novel vascular endothelial growth factor (VEGF) and mammalian target of rapamycin (mTOR) inhibitors have been approved recently by the US Food and Drug Administration. Unfortunately, the vast majority of clinical trials conducted today have been aimed to include patients with clear cell RCC, which remains the most common histologic subtype of the disease. Non-clear cell RCC represents approximately 20%-25% of all RCC patients. Non-clear cell RCC is made up of multiple histologic subtypes, each with a different molecular printing profile. Although VEGF and TORC inhibitors are commonly used in the management of this cohort of patients, non-clear cell histologies do not appear to be related to the von Hippel-Lindau gene (VHL). As such, the clinical efficacy of the existing agents is quite limited. There is a need to develop more rational therapeutic approaches that specifically target the biology of each of the different subtypes of non-clear cell RCC. In this review, we discuss molecular and clinical characteristics of each of the non-clear cell RCC subtypes and describe ongoing efforts to develop novel agents for this subset of patients.

Renal medullary carcinoma response to chemotherapy: a referral center experience in Brazil

Renal medullary carcinoma (RMC) is rare, accounting for less than 1% of all renal neoplasms. Case reports suggest RMC is highly aggressive, poorly responsive to chemotherapy, often metastatic at diagnosis, affects young men with sickle cell trait, and median overall survival (mOS) is less than 12 months. We report the epidemiological characteristics, treatments performed, response rate to each treatment and mOS of five patients with RMC. All patients had sickle cell trait, four were male, three had metastatic disease at diagnosis and mean age at diagnosis was 25 years. Non-metastatic patients were submitted to nephrectomy. Two patients had partial response to first line chemotherapy including cisplatin and gemcitabine. There was no response to sunitinib or second line chemo - therapy; mOS was 6 months. Due to its rarity, case series are the only evidence available to discuss the treatment for RMC. In our experience, only cisplatin and gemcitabine based regimen offered response.

Systemic therapy for metastatic non-clear-cell renal cell carcinoma: recent progress and future directions

Insights into the biology of clear-cell renal cell carcinoma (CCRCC) have identified multiple pathways associated with the pathogenesis and progression of this cancer. This progress has led to the development of multiple agents targeting these pathways, including the tyrosine kinase inhibitors sorafenib, sunitinib, and pazopanib, the monoclonal antibody bevacizumab, and the mTOR inhibitors temsirolimus and everolimus. With the exception of temsirolimus, phase 3 trials tested these agents in patients with clear-cell histology; therefore, their efficacy in non-CCRCC is unclear. To date, there is no established effective therapy for patients with advanced non-CCRCC. This article focuses on treatment options for metastatic non-CCRCC.

Complete response to carboplatin, gemcitabine, and paclitaxel in a patient with advanced metastatic renal medullary carcinoma

Renal medullary carcinoma (RMC) is a rare and aggressive malignancy seen primarily in patients with sickle-cell trait. We report a complete response to carboplatin, paclitaxel, and gemcitabine in a patient with advanced metastatic RMC.

Renal medullary carcinoma: molecular, pathological and clinical evidence for treatment with topoisomerase-inhibiting therapy

STUDY TYPE

Aetiology (case series) Level of Evidence 4.

OBJECTIVE

To present the molecular rationale and potential clinical benefit of topoisomerase II (TopoII)-inhibiting therapy for renal medullary carcinoma (RMC), a rare but extremely lethal form of kidney cancer that classically afflicts young men with sickle-cell trait. The current therapeutic approach with these aggressive tumours is radical nephrectomy followed by systemic chemotherapy, but the prognosis remains dismal.

MATERIALS AND METHODS

The whole-genome expression was analysed in four RMC tumours. We also report a case of metastatic RMC in which a complete response was achieved for 9 months using a TopoII-inhibiting therapy.

RESULTS

Expanded whole-genome expression analysis showed increases of TopoII in all cases. There was also overall deregulation of DNA remodelling and repair, and an ontological association between RMC and urothelial carcinoma. Using a TopoII-inhibiting agent, there was a complete response for 9 months in a patient with metastatic RMC.

CONCLUSION

This report provides molecular evidence for the rational use of TopoII inhibitors in the treatment of RMC.

Present strategies in the treatment of metastatic renal cell carcinoma: an update on molecular targeting agents

The understanding of cellular processes underlying tumour biology has allowed the development of novel molecular-targeted drugs with optimistic results in renal cell carcinoma (RCC). Mutations in the von Hippel-Lindau gene are found in 75% of sporadic RCCs, which results in upregulation of several genes involved in angiogenesis, e.g. vascular endothelial growth factor and platelet-derived growth factor. Other activated pathways in RCC are the epidermal growth factor receptor and the mTOR pathway, which regulate survival and cell growth. In addition to temsirolimus (an mTOR inhibitor) two different strategies have been studied to inhibit these targets: monoclonal antibodies, e.g. bevacizumab, and small molecule tyrosine-kinase inhibitors such as sorafenib, sunitinib and AG 013736. Phase II studies with these drugs reported substantial clinical activity in advanced RCC. Survival benefit was reported with temsirolimus, sunitinib and sorafenib in randomized trials, which led to the accelerated approval of sorafenib and sunitinib for advanced RCC by regulatory authorities in the USA and Europe. Nevertheless, as new therapies develop, new challenges arise for the optimum use of these targeted drugs. We discuss the rationale and the clinical development of these novel molecular-targeted agents, with special emphasis on updated information presented at recent meetings because of the relevance of the data reported and the potential future impact in the management of patients with RCC.

Kidney cancer therapy: new perspectives and avenues

Immunotherapy with interleukin-2 and interferon-alpha has been the only viable option in metastatic renal cell cancer for almost two decades. In the last several years, significant advances in the understanding of the underlying biological and molecular mechanisms of renal cell carcinoma, particularly the role of tumour angiogenesis, have led to the identification of rational therapeutic targets and permitted the design of molecularly targeted therapeutics. At present, new compounds targeting specific signalling pathways are available and have successfully passed clinical testing. The use of small molecules, such as multitargeted tyrosine kinase inhibitors, the mTOR inhibitors and monoclonal antibodies, is dramatically changing the existing concepts of systemic treatment for metastatic kidney cancer.