Management and outcomes of patients with renal medullary carcinoma: a multicentre collaborative study

Advances in non-clear cell renal cell carcinoma management: From heterogeneous biology to treatment options

Non-clear cell renal cell carcinoma (nccRCC) makes up nearly one quarter of all RCC subtypes, commonly impacts younger patients, and is often metastatic at presentation. Compared to clear-cell RCC (ccRCC), nccRCC typically has a worse prognosis in the metastatic setting, with overall survival durations that are ~10 months shorter. The nccRCC consists of a wide range of different histological subtypes, the majority of which are composed of papillary, chromophobe, renal medullary carcinoma, translocation RCC, collecting duct carcinoma and unclassified RCC. Most clinical trials have either excluded or only included small numbers of patients with nccRCC; owing to the lack of prospective studies focusing on this population, data on response rates and survival outcomes are lacking. NccRCC treatment is a nascent field with various therapeutic modalities and combinations under investigation, often based on data extrapolated from therapeutic studies in ccRCC. We herein review the use and outcomes of cytotoxic chemotherapy, various combination modalities of tyrosine kinase inhibitors and immune checkpoint inhibitors, and targeted agents. We discuss active ongoing clinical trials for patients with nccRCC and future directions in the treatment of this rare disease. Historically, treatment for nccRCC has been adopted from the standard of care for patients with ccRCC, although these treatments are less effective in the nccRCC population. As we begin to understand the underlying biology of these tumors, clinical trials have been able to slowly accrue and include more patients with various subtypes of nccRCC. There remains much room for improvement in this area of need, but there is hope on the horizon.

Renal Medullary Carcinoma: A Surveillance, Epidemiology, and End Results (SEER) Analysis

INTRODUCTION

Renal medullary carcinoma (RMC) is an aggressive and rare renal malignancy that predominantly affects Black patients but is also found in individuals of other ethnicities. To date, only a few hundred cases have been reported in the urologic literature. Due to this extreme rarity, the exact pathophysiology and optimal treatment have yet to be well described. This study aims to determine the predictors of mortality and overall survival outcomes in patients with RMC.

METHODS

We utilized the Surveillance, Epidemiology, and End Results Program (SEER) database 18 registries to retrieve demographic and clinical information on patients with RMC between 1996 and 2018. A multivariate analysis was performed to determine predictors of mortality in the study population. Kaplan-Meier survival curves were then created to display the differences in overall survival of Black versus non-Black patients diagnosed with renal medullary carcinoma during the study period.

RESULTS

We identified 100 patients diagnosed with renal medullary carcinoma using the SEER Database in the study period. The mean age was 28.0 ± 12.0 (95% confidence interval [CI] 25.7-30.4). Among the patients, 76% were male and 24% were female. Most RMC patients were Black (83%) with only 17% identifying as White. The mean survival in months was 13.8 ± 3.0 (95% CI 7.9-19.7). The majority (70%) of patients in this study presented with distant, metastatic disease at the time of diagnosis. Black patients with RMC were less likely to receive surgery and five times more likely to die in comparison to their White counterparts OR = 5.4 (95% CI 1.09-26.9, P = 0.04). Not only did Black patients have a lower survival rate at 12 mo compared to White patients, but they also continued to experience a sharp decline in survival to 10.2% at 24 mo (P < 0.05) and 7.6% at 48 mo (P < 0.05) following diagnosis of renal medullary carcinoma.

CONCLUSIONS

These data confirm that RMC is a rare disease that disproportionately affects Black patients. The prognosis appears to be substantially worse for Black subjects diagnosed with this cancer than non-Black patients. The worse outcomes seen in Black subjects are of an unclear etiology and are yet to be investigated.

A Phase 2 Trial of Talazoparib and Avelumab in Genomically Defined Metastatic Kidney Cancer

BACKGROUND

Although different kidney cancers represent a heterogeneous group of malignancies, multiple subtypes including Von Hippel-Lindau (VHL)-altered clear cell renal cell carcinoma (ccRCC), fumarate hydratase (FH)- and succinate dehydrogenase (SDH)-deficient renal cell carcinoma (RCC), and renal medullary carcinoma (RMC) are affected by genomic instability. Synthetic lethality with poly ADP-ribose polymerase inhibitors (PARPis) has been suggested in preclinical models of these subtypes, and paired PARPis with immune checkpoint blockade (ICB) may achieve additive and/or synergistic effects in patients with previously treated advanced kidney cancers.

OBJECTIVE

To evaluate combined PARPi + ICB in treatment-refractory metastatic kidney cancer.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a single-center, investigator-initiated phase 2 trial in two genomically selected advanced kidney cancer cohorts: (1) VHL-altered RCC with at least one prior ICB agent and one vascular endothelial growth factor (VEGF) inhibitor, and (2) FH- or SDH-deficient RCC with at least one prior ICB agent or VEGF inhibitor and RMC with at least one prior line of chemotherapy.

INTERVENTION

Patients received talazoparib 1 mg daily plus avelumab 800 mg intravenously every 14 d in 28-d cycles.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was objective response rate (ORR) by Immune Response Evaluation Criteria in Solid Tumors at 4 mo, and the secondary endpoints included progression-free survival (PFS), overall survival, and safety.

RESULTS AND LIMITATIONS

Cohort 1 consisted of ten patients with VHL-altered ccRCC. All patients had previously received ICB. The ORR was 0/9 patients; one patient was not evaluable due to missed doses. In this cohort, seven patients achieved stable disease (SD) as the best response. The median PFS was 3.5 mo (95% confidence interval [CI] 1.0, 3.9 mo). Cohort 2 consisted of eight patients; four had FH-deficient RCC, one had SDH-deficient RCC, and three had RMC. In this cohort, six patients had previously received ICB. The ORR was 0/8 patients; two patients achieved SD as the best response and the median PFS was 1.2 mo (95% CI 0.4, 2.9 mo). The most common treatment-related adverse events of all grades were fatigue (61%), anemia (28%), nausea (22%), and headache (22%). There were seven grade 3-4 and no grade 5 events.

CONCLUSIONS

The first clinical study of combination PARPi and ICB therapy in advanced kidney cancer did not show clinical benefit in multiple genomically defined metastatic RCC cohorts or RMC.

PATIENT SUMMARY

We conducted a study to look at the effect of two medications, talazoparib and avelumab, in patients with metastatic kidney cancer who had disease progression on standard treatment. Talazoparib blocks the normal activity of molecules called poly ADP-ribose polymerase, which then prevents tumor cells from repairing themselves and growing, while avelumab helps the immune system recognize and kill cancer cells. We found that the combination of these agents was safe but not effective in specific types of kidney cancer.

Renal Cell Carcinoma of Variant Histology: Biology and Therapies

The term variant histology renal cell carcinomas (vhRCCs), also known as non-clear cell RCCs, refers to a diverse group of malignancies with distinct biologic and therapeutic considerations. The management of vhRCC subtypes is often based on extrapolating results from the more common clear cell RCC studies or basket trials that are not specific to each histology. The unique management of each vhRCC subtype necessitates accurate pathologic diagnosis and dedicated research efforts. Herein, we discuss tailored recommendations for each vhRCC histology informed by ongoing research and clinical experience.

Systemic Treatment for Advanced and Metastatic Non-Clear Cell Renal Cell Carcinoma: Examining Modern Therapeutic Strategies for a Notoriously Challenging Malignancy

Non-clear cell renal cell carcinoma (nccRCC) is a heterogeneous group of malignancies that represents 25% of renal cell carcinoma (RCC) cases. Treatment for non-clear cell histologies is mostly based on evidence from small phase II clinical trials or extrapolated from successful therapies in clear cell RCC because of the low incidence of non-clear cell pathology. Advances in genomic profiling have improved clinicians' understanding of molecular targets for nccRCC, such as altered mesenchymal epithelial transition (MET) gene status and fumarate hydratase (FH) gene inactivation, but patient outcomes remain poor and optimal management of this disease remains unclear. This review assesses outcomes by histologic subtype from 27 prospective and 13 ongoing clinical trials to identify therapeutic strategies for advanced or metastatic nccRCC. Vascular endothelial growth factor tyrosine kinase inhibitors (TKI), such as sunitinib, and mammalian target of rapamycin (mTOR) inhibitors, such as everolimus, have demonstrated efficacy and remain viable treatment options, with a preference for sunitinib. However, everolimus is preferred in patients with chromophobe RCC because folliculin (FLCN) gene mutations upregulate the mTOR pathway. Novel TKIs, such as cabozantinib, show improved outcomes in patients with papillary RCC because of targeted MET inhibition. Platinum-based chemotherapy continues to be the recommended treatment strategy for collecting duct and medullary RCC. Clinically meaningful antitumor activity has been observed across all non-clear cell histologies for immune checkpoint inhibitors, such as nivolumab, pembrolizumab, and ipilimumab. Ongoing trials are evaluating novel tyrosine kinase inhibitor and immunotherapy combination regimens, with an emphasis on the promising MET-inhibitor cabozantinib and pembrolizumab plus lenvatinib.

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.

Obesity and renal cell carcinoma: Biological mechanisms and perspectives

Obesity, defined by body mass index (BMI), is an established risk factor for specific renal cell carcinoma (RCC) subtypes such as clear cell RCC, the most common RCC histology. Many studies have identified an association between obesity and improved survival after diagnosis of RCC, a potential "obesity paradox." Clinically, there is uncertainty whether improved outcomes observed after diagnosis are driven by stage, type of treatment received, or artifacts of longitudinal changes in weight and body composition. The biological mechanisms underlying obesity's influence on RCC are not fully established, but multiomic and mechanistic studies suggest an impact on tumor metabolism, particularly fatty acid metabolism, angiogenesis, and peritumoral inflammation, which are known to be key biological hallmarks of clear cell RCC. Conversely, high-intensity exercise associated with increased muscle mass may be a risk factor for renal medullary carcinoma, a rare RCC subtype that predominantly occurs in individuals with sickle hemoglobinopathies. Herein, we highlight methodologic challenges associated with studying the influence of obesity on RCC and review the clinical evidence and potential underlying mechanisms associating RCC with BMI and body composition.

A Phase II Clinical Trial of Pembrolizumab Efficacy and Safety in Advanced Renal Medullary Carcinoma

BACKGROUND

Renal medullary carcinoma (RMC) is one of most aggressive renal cell carcinomas and novel therapeutic strategies are therefore needed. Recent comprehensive molecular and immune profiling of RMC tissues revealed a highly inflamed phenotype, suggesting the potential therapeutic role for immune checkpoint therapies. We present the first prospective evaluation of an immune checkpoint inhibitor in a cohort of patients with RMC.

METHODS

A cohort of patients with locally advanced or metastatic RMC was treated with pembrolizumab 200 mg intravenously every 21 days in a phase II basket trial (ClinicalTrials.gov: NCT02721732). Responses were assessed by irRECIST. Tumor tissues were evaluated for PD-L1 expression and for tumor-infiltrating lymphocyte (TIL) levels. Somatic mutations were assessed by targeted next-generation sequencing.

RESULTS

A total of five patients were treated. All patients had advanced disease, with the majority of patients (60%) having metastatic disease at diagnosis. All patients had rapid disease progression despite pembrolizumab treatment, with a median time to progression of 8.7 weeks. One patient (patient 5) experienced sudden clinical progression immediately after treatment initiation and was thus taken off trial less than one week after receiving pembrolizumab.

CONCLUSIONS

This prospective evaluation showed no evidence of clinical activity for pembrolizumab in patients with RMC, irrespective of PD-L1 or TIL levels.

SMARCB1 regulates the hypoxic stress response in sickle cell trait

Renal medullary carcinoma (RMC) is an aggressive kidney cancer that almost exclusively develops in individuals with sickle cell trait (SCT) and is always characterized by loss of the tumor suppressor SMARCB1. Because renal ischemia induced by red blood cell sickling exacerbates chronic renal medullary hypoxia in vivo, we investigated whether the loss of SMARCB1 confers a survival advantage under the setting of SCT. Hypoxic stress, which naturally occurs within the renal medulla, is elevated under the setting of SCT. Our findings showed that hypoxia-induced SMARCB1 degradation protected renal cells from hypoxic stress. SMARCB1 wild-type renal tumors exhibited lower levels of SMARCB1 and more aggressive growth in mice harboring the SCT mutation in human hemoglobin A (HbA) than in control mice harboring wild-type human HbA. Consistent with established clinical observations, SMARCB1-null renal tumors were refractory to hypoxia-inducing therapeutic inhibition of angiogenesis. Further, reconstitution of SMARCB1 restored renal tumor sensitivity to hypoxic stress in vitro and in vivo. Together, our results demonstrate a physiological role for SMARCB1 degradation in response to hypoxic stress, connect the renal medullary hypoxia induced by SCT with an increased risk of SMARCB1-negative RMC, and shed light into the mechanisms mediating the resistance of SMARCB1-null renal tumors against angiogenesis inhibition therapies.

Neddylation inhibition sensitises renal medullary carcinoma tumours to platinum chemotherapy

BACKGROUND

Renal medullary carcinoma (RMC) is a highly aggressive cancer in need of new therapeutic strategies. The neddylation pathway can protect cells from DNA damage induced by the platinum-based chemotherapy used in RMC. We investigated if neddylation inhibition with pevonedistat will synergistically enhance antitumour effects of platinum-based chemotherapy in RMC.

METHODS

We evaluated the IC50 concentrations of the neddylation-activating enzyme inhibitor pevonedistat in vitro in RMC cell lines. Bliss synergy scores were calculated using growth inhibition assays following treatment with varying concentrations of pevonedistat and carboplatin. Protein expression was assessed by western blot and immunofluorescence assays. The efficacy of pevonedistat alone or in combination with platinum-based chemotherapy was evaluated in vivo in platinum-naïve and platinum-experienced patient-derived xenograft (PDX) models of RMC.

RESULTS

The RMC cell lines demonstrated IC50 concentrations of pevonedistat below the maximum tolerated dose in humans. When combined with carboplatin, pevonedistat demonstrated a significant in vitro synergistic effect. Treatment with carboplatin alone increased nuclear ERCC1 levels used to repair the interstrand crosslinks induced by platinum salts. Conversely, the addition of pevonedistat to carboplatin led to p53 upregulation resulting in FANCD2 suppression and reduced nuclear ERCC1 levels. The addition of pevonedistat to platinum-based chemotherapy significantly inhibited tumour growth in both platinum-naïve and platinum-experienced PDX models of RMC (p < .01).

CONCLUSIONS

Our results suggest that pevonedistat synergises with carboplatin to inhibit RMC cell and tumour growth through inhibition of DNA damage repair. These findings support the development of a clinical trial combining pevonedistat with platinum-based chemotherapy for RMC.

Renal Cell Carcinoma Unclassified with Medullary Phenotype in a Patient with Neurofibromatosis Type 2

We present, to our knowledge, the first reported case of germline neurofibromatosis Type 2 (NF2) associated with renal cell carcinoma unclassified with medullary phenotype (RCCU-MP) with somatic loss by immunohistochemistry of the SMARCB1 tumor suppressor gene located centromeric to NF2 on chromosome 22q. Our patient is a 15-year-old with germline neurofibromatosis Type 2 (NF2) confirmed by pathogenic mutation of c.-854-??46+??deletion. Her NF2 history is positive for a right optic nerve sheath meningioma, CNIII schwannoma requiring radiation therapy and post gross total resection of right frontotemporal anaplastic meningioma followed by radiation. At age 15 she developed new onset weight loss and abdominal pain due to RCCU-MP. Hemoglobin electrophoresis was negative for sickle hemoglobinopathy. Chemotherapy (cisplatin, gemcitabine and paclitaxel) was initiated followed by radical resection. Given the unique renal pathology of a high grade malignancy with loss of SMARCB1 expression via immunohistochemistry, and history of meningioma with MLH1 loss of expression and retained expression of PMS2, MSH2 and MSH6, further germline genetic testing was sent for SMARCB1 and mismatch repair syndromes. Germline testing was negative for mutation in SMARCB1. Therefore, this is the first reported case of RCCU-MP associated with germline NF2 mutation. This suggests the importance of closer surveillance in the adolescent and young adult population with NF2 with any suspicious findings of malignancy outside of the usual scope of practice with NF2.

[Collecting duct carcinoma and renal medullary carcinoma in the age of new therapies]

Collecting duct carcinoma (also known as Bellini tumour) and renal medullary carcinoma are two extremely rare and aggressive renal cancers. They are both less responsive to conventional treatments used in clear cell renal carcinoma. There are very few studies evaluating their optimal management and currently, at the metastatic stage, polychemotherapy based on platinum salts remains the most widely used. The emergence of new treatments such as anti-angiogenic TKIs, immunotherapy or treatments targeting specific genetic abnormalities, opens up a new field of possibilities in the management of these cancers. The evaluation of the response to these treatments is therefore essential. In this article, we will review the status of their management and the various studies that have evaluated recent treatments in these two cancers.

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.

Contemporary Drug Therapy for Renal Cell Carcinoma- Evidence Accumulation and Histological Implications in Treatment Strategy

Renal cell carcinoma (RCC) is a heterogeneous disease comprising a variety of histological subtypes. Approximately 70-80% of RCC cases are clear cell carcinoma (ccRCC), while the remaining subtypes constitute non-clear cell carcinoma (nccRCC). The medical treatment of RCC has greatly changed in recent years through advances in molecularly targeted therapies and immunotherapies. Most of the novel systemic therapies currently available have been approved based on ccRCC clinical trial data. nccRCC can be subdivided into more than 40 histological subtypes that have distinct clinical, histomorphological, immunohistochemical, and molecular features. These entities are listed as emerging in the 2022 World Health Organization classification. The diagnosis of nccRCC and treatments based on cancer histology and biology remain challenging due to the disease's rarity. We reviewed clinical trials focused on recent discoveries regarding clinicopathological features.

Molecular Characterization of the Tumor Microenvironment in Renal Medullary Carcinoma

Renal medullary carcinoma (RMC) is a highly aggressive disease associated with sickle hemoglobinopathies and universal loss of the tumor suppressor gene SMARCB1. RMC has a relatively low rate of incidence compared with other renal cell carcinomas (RCCs) that has hitherto made molecular profiling difficult. To probe this rare disease in detail we performed an in-depth characterization of the RMC tumor microenvironment using a combination of genomic, metabolic and single-cell RNA-sequencing experiments on tissue from a representative untreated RMC patient, complemented by retrospective analyses of archival tissue and existing published data. Our study of the tumor identifies a heterogenous population of malignant cell states originating from the thick ascending limb of the Loop of Henle within the renal medulla. Transformed RMC cells displayed the hallmarks of increased resistance to cell death by ferroptosis and proteotoxic stress driven by MYC-induced proliferative signals. Specifically, genomic characterization of RMC tumors provides substantiating evidence for the recently proposed dependence of SMARCB1-difficient cancers on proteostasis modulated by an intact CDKN2A-p53 pathway. We also provide evidence that increased cystine-mTORC-GPX4 signaling plays a role in protecting transformed RMC cells against ferroptosis. We further propose that RMC has an immune landscape comparable to that of untreated RCCs, including heterogenous expression of the immune ligand CD70 within a sub-population of tumor cells. The latter could provide an immune-modulatory role that serves as a viable candidate for therapeutic targeting.

Start of a New Era: Management of Non-Clear Cell Renal Cell Carcinoma in 2022

Purpose of Review

Historically, kidney cancer was diagnosed as either clear cell renal carcinoma (ccRCC) or non-clear cell renal carcinoma (nccRCC). With further research into the pathophysiology of nccRCC, multiple distinct subtypes have emerged creating distinct diagnosis, such as papillary renal cell carcinoma (PRCC), chromophobe renal cell carcinoma (crRCC), or unclassified carcinoma (cRCC). Many other kidney cancer subtypes are now included in the WHO classification system.

Recent Findings

The prognosis for each of the more frequently diagnosed types is discussed here along with treatment recommendations. The available clinical trial results and salient retrospective studies of each subtype are reviewed here to guide clinicians on the optimal treatment selection for patients with these rare histologic types or RCC.

Summary

Many nccRCC types are now recognized and each has unique molecular drivers which are different than ccRCC. The optimal treatment strategy is different for each subtype. The prognosis also differs based on the histology.

Kidney Cancer, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Kidney Cancer focus on the screening, diagnosis, staging, treatment, and management of renal cell carcinoma (RCC). Patients with relapsed or stage IV RCC typically undergo surgery and/or receive systemic therapy. Tumor histology and risk stratification of patients is important in therapy selection. The NCCN Guidelines for Kidney Cancer stratify treatment recommendations by histology; recommendations for first-line treatment of ccRCC are also stratified by risk group. To further guide management of advanced RCC, the NCCN Kidney Cancer Panel has categorized all systemic kidney cancer therapy regimens as "Preferred," "Other Recommended Regimens," or "Useful in Certain Circumstances." This categorization provides guidance on treatment selection by considering the efficacy, safety, evidence, and other factors that play a role in treatment selection. These factors include pre-existing comorbidities, nature of the disease, and in some cases consideration of access to agents. This article summarizes surgical and systemic therapy recommendations for patients with relapsed or stage IV RCC.

Association of High-Intensity Exercise with Renal Medullary Carcinoma in Individuals with Sickle Cell Trait: Clinical Observations and Experimental Animal Studies

Renal medullary carcinoma (RMC) is a lethal malignancy affecting individuals with sickle hemoglobinopathies. Currently, no modifiable risk factors are known. We aimed to determine whether high-intensity exercise is a risk factor for RMC in individuals with sickle cell trait (SCT). We used multiple approaches to triangulate our conclusion. First, a case-control study was conducted at a single tertiary-care facility. Consecutive patients with RMC were compared to matched controls with similarly advanced genitourinary malignancies in a 1:2 ratio and compared on rates of physical activity and anthropometric measures, including skeletal muscle surface area. Next, we compared the rate of military service among our RMC patients to a similarly aged population of black individuals with SCT in the U.S. Further, we used genetically engineered mouse models of SCT to study the impact of exercise on renal medullary hypoxia. Compared with matched controls, patients with RMC reported higher physical activity and had higher skeletal muscle surface area. A higher proportion of patients with RMC reported military service than expected compared to the similarly-aged population of black individuals with SCT. When exposed to high-intensity exercise, mice with SCT demonstrated significantly higher renal medulla hypoxia compared to wild-type controls. These data suggest high-intensity exercise is the first modifiable risk factor for RMC in individuals with SCT.

Clinical Review on the Management of Metastatic Renal Cell Carcinoma

Renal cell carcinomas vary considerably in their tumor biology and disease course, which is reflected in the range of treatment paradigms in localized and metastatic renal cell carcinoma (mRCC). Active surveillance remains an important component of all renal cell carcinoma management. In mRCC, the rapid evolution from cytokine-based therapy to targeted therapy to immunotherapy with checkpoint blockade has revolutionized the field and drastically altered treatment outcomes. More recently, combination therapies have become a standard of care for most patients with mRCC. In this review, we highlight recent critical data that led to changes in treatment paradigms and provide a practical framework for the management of patients with mRCC.

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.

New developments in existing WHO entities and evolving molecular concepts: The Genitourinary Pathology Society (GUPS) update on renal neoplasia

The Genitourinary Pathology Society (GUPS) reviewed recent advances in renal neoplasia, particularly post-2016 World Health Organization (WHO) classification, to provide an update on existing entities, including diagnostic criteria, molecular correlates, and updated nomenclature. Key prognostic features for clear cell renal cell carcinoma (RCC) remain WHO/ISUP grade, AJCC/pTNM stage, coagulative necrosis, and rhabdoid and sarcomatoid differentiation. Accrual of subclonal genetic alterations in clear cell RCC including SETD2, PBRM1, BAP1, loss of chromosome 14q and 9p are associated with variable prognosis, patterns of metastasis, and vulnerability to therapies. Recent National Comprehensive Cancer Network (NCCN) guidelines increasingly adopt immunotherapeutic agents in advanced RCC, including RCC with rhabdoid and sarcomatoid changes. Papillary RCC subtyping is no longer recommended, as WHO/ISUP grade and tumor architecture better predict outcome. New papillary RCC variants/patterns include biphasic, solid, Warthin-like, and papillary renal neoplasm with reverse polarity. For tumors with 'borderline' features between oncocytoma and chromophobe RCC, a term "oncocytic renal neoplasm of low malignant potential, not further classified" is proposed. Clear cell papillary RCC may warrant reclassification as a tumor of low malignant potential. Tubulocystic RCC should only be diagnosed when morphologically pure. MiTF family translocation RCCs exhibit varied morphologic patterns and fusion partners. TFEB-amplified RCC occurs in older patients and is associated with more aggressive behavior. Acquired cystic disease (ACD) RCC-like cysts are likely precursors of ACD-RCC. The diagnosis of renal medullary carcinoma requires a negative SMARCB1 (INI-1) expression and sickle cell trait/disease. Mucinous tubular and spindle cell carcinoma (MTSCC) can be distinguished from papillary RCC with overlapping morphology by losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22. MTSCC with adverse histologic features shows frequent CDKN2A/2B (9p) deletions. BRAF mutations unify the metanephric family of tumors. The term "fumarate hydratase deficient RCC" ("FH-deficient RCC") is preferred over "hereditary leiomyomatosis and RCC syndrome-associated RCC". A low threshold for FH, 2SC, and SDHB immunohistochemistry is recommended in difficult to classify RCCs, particularly those with eosinophilic morphology, occurring in younger patients. Current evidence does not support existence of a unique tumor subtype occurring after chemotherapy/radiation in early childhood.

Efficacy and Safety of Bevacizumab Plus Erlotinib in Patients with Renal Medullary Carcinoma

Simple Summary

Renal medullary carcinoma (RMC) is a rare and highly aggressive renal cell carcinoma, with a median survival of 13 months. Platinum-based chemotherapy is the recommended standard of care for RMC, but no effective salvage regimens have been established to date. Previous comprehensive molecular characterization of RMC tissues revealed a reliance on aerobic glycolysis, suggesting that bevacizumab plus erlotinib may be an effective regimen against RMC. The aim of our retrospective study was to evaluate the efficacy and safety of bevacizumab plus erlotinib in patients with RMC. In ten patients, the combination was safe and effective, establishing bevacizumab plus erlotinib as a new salvage regimen in RMC.

Abstract

Purpose: To assess the efficacy and safety of bevacizumab plus erlotinib in patients with RMC. Methods: We retrospectively reviewed the records of patients with RMC treated with bevacizumab plus erlotinib at our institution. Results: Ten patients were included in the study. Two patients achieved a partial response (20%) and seven patients achieved stable disease (70%). Tumor burden was reduced in seven patients (70%) in total, and in three out of five patients (60%) that had received three or more prior therapies. The median progression-free survival (PFS) was 3.5 months (95% CI, 1.8–5.2). The median overall survival (OS) from bevacizumab plus erlotinib initiation was 7.3 months (95% CI, 0.73–13.8) and the median OS from diagnosis was 20.8 months (95% CI, 14.7–26.8). Bevacizumab plus erlotinib was well tolerated with no grade ≥4 adverse events and one grade 3 skin rash. Dose reduction was required in one patient (10%). Conclusions: Bevacizumab plus erlotinib is clinically active and well tolerated in heavily pre-treated patients with RMC and should be considered a viable salvage strategy for this lethal disease.

Systemic Therapies for the Management of Non-Clear Cell Renal Cell Carcinoma: What Works, What Doesn't, and What the Future Holds

Non-clear cell renal cell carcinoma (nccRCC) is a broad term that refers to a diverse group of tumors, each with its own distinct biologic and therapeutic profile. The management of nccRCCs is often based on extrapolating data from clinical trials in the more common clear cell renal cell carcinoma, but our emerging prospective and retrospective clinical experience in nccRCC allows us to make more precise recommendations tailored to each histology. The systemic therapy options for metastatic nccRCC include targeted therapies such as tyrosine kinase inhibitors, immune checkpoint inhibitors, and, for specific rare subtypes, cytotoxic chemotherapy. Each nccRCC histology may respond differently to these regimens, which makes accurate pathologic diagnosis imperative. In the present review, we discuss the available clinical and biological data that can help guide systemic therapy recommendations for specific nccRCC subtypes.

Comprehensive genomic profiling of metastatic collecting duct carcinoma, renal medullary carcinoma, and clear cell renal cell carcinoma

INTRODUCTION AND OBJECTIVE

Unlike clear cell renal cell carcinoma (CCRCC), collecting duct carcinoma (CDC) and renal medullary carcinoma (RMC) are rare tumors that progress rapidly and appear resistant to current systemic therapies. We queried comprehensive genomic profiling to uncover opportunities for targeted therapy and immunotherapy.

MATERIAL AND METHODS

DNA was extracted from 40 microns of formalin-fixed, paraffin-embedded specimen from relapsed, mCDC (n = 46), mRMC (n = 24), and refractory and metastatic (m) mCCRCC (n = 626). Comprehensive genomic profiling was performed, and Tumor mutational burden (TMB) and microsatellite instability (MSI) were calculated. We analyzed all classes of genomic alterations.

RESULTS

mCDC had 1.7 versus 2.7 genomic alterations/tumor in mCCRCC ( = 0.04). Mutations in VHL (P < 0.0001) and TSC1 (P = 0.04) were more frequent in mCCRCC. SMARCB1 (P < 0.0001), NF2 (P = 0.0007), RB1 (P = 0.02) and RET (P = 0.0003) alterations were more frequent in mCDC versus mCCRCC. No VHL alterations in mRMC and mCDC were identified. SMARCB1 genomic alterations were significantly more frequent in mRMC than mCDC (P = 0.0002), but were the most common alterations in both subtypes. Mutations to EGFR, RET, NF2, and TSC2 were more frequently identified in mCDC versus mRMC. The median TMB and MSI-High status was low with <1% of mCCRC, mCDC, and mRMC having ≥ 20 mut/Mb.

CONCLUSION

Genomic alteration patterns in mCDC and mRMC differ significantly from mCCRCC. Targeted therapies for mCDC and mRMC appear limited with rare opportunities to target alterations in receptor tyrosine kinase and MTOR pathways. Similarly, TMB and absence of MSI-High status in mCDC and mRMC suggest resistance to immunotherapies.

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.

Renal medullary carcinoma involving serous cavity fluids: a cytomorphologic study of 12 cases

INTRODUCTION

Renal medullary carcinoma (RMC) is a highly lethal adenocarcinoma with a propensity for widespread metastatic disease in young patients. It is strongly associated with sickle cell trait and shows the loss of SMARCB1 (also known as INI1 or BAF47) protein expression. In the present study, we reviewed a series of 12 patients for whom the cytology specimens played a significant role in patient treatment.

MATERIALS AND METHODS

We performed a retrospective case review of patients with a history of RMC from 3 large tertiary care pathology practices.

RESULTS

A total of 12 patients were identified with histologically confirmed RMC who had had pleural, pericardial, or urine specimens involved by their disease or had undergone initial kidney fine needle aspiration. Patient age ranged from 13 to 37 years (median, 21.5 years). All 12 patients were black or of African descent, and 10 had a confirmed history of sickle cell trait. Of the 12 patients, 11 (92%) had fluid specimens involved by metastatic tumor at some point in their clinical course, and 4 (33%) had initially presented with pericardial and/or pleural effusions or urine specimens that were positive for malignancy. Cytologic examination predominantly showed fragments of 3-dimensional "tumor balls" with smooth borders, fine pale cytoplasm with vacuolization, and highly pleomorphic nuclei with irregular nuclear membranes and coarse to vesicular chromatin and single prominent nucleoli.

CONCLUSIONS

The cytomorphology of RMC involving serous fluids is nonspecific and in keeping with metastatic high-grade adenocarcinoma. In a young patient presenting with no history of malignancy and a pleural or pericardial effusion, triaging the material for ancillary studies and a nuanced assessment of patient history and radiologic findings will be critical.

Infiltrative Renal Malignancies: Imaging Features, Prognostic Implications, and Mimics

Infiltrative renal malignancies are a subset of renal masses that are morphologically characterized by a poorly defined interface with the renal parenchyma. Infiltrative renal malignancies are less common but more aggressive than more typical renal malignancies and carry an overall worse prognosis. Although an infiltrative renal process often represents a malignant neoplasm, infiltrative masses include a wide spectrum of diseases including primary renal cortical, medullary, and pelvic tumors; lymphoproliferative processes; metastases; and various infectious, inflammatory, immune-mediated, and vascular mimics. The imaging features of these masses are often nonspecific, but with the appropriate history, laboratory results, and clinical context, the radiologist can help narrow the diagnosis and guide further treatment. An invited commentary by Lee is available online.Online supplemental material is available for this article. ^©RSNA, 2021.

The Differential Diagnosis of Medullary-Based Renal Masses

CONTEXT.—

Renal malignancies can be divided into cortical- and medullary-based tumors, the latter of which classically infiltrate the renal parenchyma by extending between nonneoplastic structures. Although high-grade cortical tumors can rarely exhibit the same growth pattern, the infiltrative morphology should elicit a differential diagnosis to be considered in each case. However, these diagnoses can be challenging to distinguish, especially on small renal biopsy samples.

OBJECTIVE.—

To provide an overview of the clinical, gross, and microscopic findings; genetic and molecular alterations; and immunohistochemical evaluation of medullary-based renal tumors and other tumor types with overlapping morphologies and growth patterns.

DATA SOURCES.—

Literature review and personal observations were used to compile the information in this review.

CONCLUSIONS.—

Collecting duct carcinoma is a prototypical medullary-based tumor, and although diagnostic criteria exist, it remains a diagnosis of exclusion, especially with ancillary techniques aiding the recognition of established as well as more recently described neoplasms. Other medullary-based malignancies included in the differential diagnosis include renal medullary carcinoma/renal cell carcinoma unclassified with medullary phenotype, fumarate hydratase-deficient renal cell carcinoma, and upper tract urothelial carcinoma. Moreover, other rare entities should be excluded, including metastatic carcinoma, lymphoma, and melanoma. In addition to potential prognostic differences, accurate diagnoses can have important surgical and clinical management implications.

Individualizing Systemic Therapies in First Line Treatment and beyond for Advanced Renal Cell Carcinoma

Therapeutic options for treating advanced renal cell cancer (RCC) are rapidly evolving. Vascular endothelial growth factor (VEGF)-directed therapy, predominantly VEGF receptor (VEGFr) tyrosine kinase inhibitors (TKIs) had been the most effective first line treatment since 2005 irrespective of International Metastatic RCC Database Consortium (IMDC) risk stratification. However, immune checkpoint inhibitors (ICI) have recently changed the treatment paradigm for advanced RCC particularly as the first-line systemic treatment modality. The combination of Ipilimumab and Nivolumab provides better disease control and long-term outcomes compared with the anti-VEGFr TKI Sunitinib for IMDC intermediate- to poor-risk patients and we now have the option of using ICI with TKI upfront for all IMDC risk groups. This poses a challenge for physicians, both to select the most suitable first line regimen and the most suitable subsequent therapy given the lack of data about sequencing in this setting. This treatment landscape is expected to become more complex with the emerging treatment options. Moreover, these therapeutic options cannot be generalized as significant variability exists between individual's disease biologies and their physiologies for handling treatment adverse effects. Notable efforts are being made to identify promising predictive biomarkers ranging from neo-antigen load to gene expression profiling. These biomarkers need prospective validation to justify their utility in clinical practice and in treatment decision making. This review article discusses various clinicopathological characteristics that should be carefully evaluated to help select appropriate treatment and discusses the current status of biomarker-based selection.

Unusual Presentation of Renal Medullary Carcinoma With Undiagnosed Sickle Cell Trait

Renal medullary carcinoma (RMC) is an extremely rare malignancy that has been described in younger male patients of African descent with a history of sickle cell disease or trait. We describe a rather unique case of RMC in an older male patient who initially presented with acute on chronic urinary retention and concern for infection. Further investigation revealed a history of hematuria and long-standing microcytic anemia, and the patient was found to have sickle cell trait (SCT) as part of a workup for malignancy of unknown primary. Imaging findings initially interpreted as hydronephrosis later characterized a mass in the renal pelvis concerning for a genitourinary malignancy, later biopsy-proven RMC. RMC typically presents in its advanced stages, with associated poor prognosis, and treatment options are limited and have been extrapolated from standard regimens for other genitourinary malignancies. Therefore, early clinical suspicion in patients with microcytic anemia, flank pain, hematuria, and urinary symptoms, can aid in the diagnosis of RMC and allow for prompt intervention.

Molecular hallmarks of renal medullary carcinoma: more to c-MYC than meets the eye

Renal medullary carcinoma (RMC) is a lethal disease that predominantly afflicts young individuals with sickle cell trait. Our recently reported molecular profiling of primary untreated RMC tissues elucidated distinct genomic and immune hallmarks of RMC, and identified MYC-induced replication stress as a targetable vulnerability for this disease.

Genomic profiling in renal cell carcinoma

The treatment landscape of metastatic renal cell carcinoma (RCC) has been revolutionized over the past two decades, bringing forth an era in which more than a dozen therapeutic agents are now available to treat patients. As a consequence, personalized care has become a critical part of developing effective treatment guidelines and improving patient outcomes. One of the most important emerging aspects of precision medicine in cancer is matching patients and treatments based on the genomic characteristics of an individual and their tumour. Despite the lack of a single genomic predictor of treatment response or prognostication feature in RCC, emerging research suggests that the identification of such markers remains promising. Mutations in VHL and alterations in its downstream pathways are the mainstay of RCC development and progression. However, the predictive value of VHL mutations has been questioned. Further research has examined mutations in genes involved in chromosome remodelling (for example, PBRM1, BAP1 and SETD2), DNA methylation and DNA damage repair, all of which have been associated with clinical outcomes. Here, we provide a comprehensive overview of genomic evidence in the context of RCC and its potential predictive and prognostic value.

Comprehensive Molecular Characterization Identifies Distinct Genomic and Immune Hallmarks of Renal Medullary Carcinoma

Renal medullary carcinoma (RMC) is a highly lethal malignancy that mainly afflicts young individuals of African descent and is resistant to all targeted agents used to treat other renal cell carcinomas. Comprehensive genomic and transcriptomic profiling of untreated primary RMC tissues was performed to elucidate the molecular landscape of these tumors. We found that RMC was characterized by high replication stress and an abundance of focal copy-number alterations associated with activation of the stimulator of the cyclic GMP-AMP synthase interferon genes (cGAS-STING) innate immune pathway. Replication stress conferred a therapeutic vulnerability to drugs targeting DNA-damage repair pathways. Elucidation of these previously unknown RMC hallmarks paves the way to new clinical trials for this rare but highly lethal malignancy.

Redefining the Role of Surgical Management of Metastatic Renal Cell Carcinoma

PURPOSE OF REVIEW

The treatment landscape for metastatic renal cell carcinoma (mRCC) continues to evolve with ongoing advancements in systemic therapy, raising further questions about the optimal role of surgery in the management of mRCC. Herein, we provide a context and review of the recent evidence concerning the role of surgical therapy for patients with mRCC including cytoreductive nephrectomy and distant metastatectomy.

RECENT FINDINGS

One randomized trial has been published in the targeted therapy era suggesting that initial systemic therapy is non-inferior to cytoreductive nephrectomy among patients with intermediate and poor-risk mRCC. Delaying cytoreductive nephrectomy until after systemic therapy may be a viable treatment approach, although a high level of evidence is lacking. Additional questions remain regarding the sequence of surgery with systemic therapy, utility of distant metastatectomy, as well as the application of these findings to the current generation of immunotherapy. Recent evidence challenges the need of upfront cytoreductive nephrectomy for unselected patients with mRCC. However, surgical therapy continues to play an important role in the management of the disease.

Renal medullary carcinoma masquerading as renal infection: a case report

Background

Renal medullary carcinoma is a rare and aggressive tumor and often seen in young adults with sickle cell hemoglobinopathies.

Case presentation

We report a case of renal medullary carcinoma in a 29-year old male patient with an occupying renal lesion who presented with fever, flank pain and hematuria. The patient received intensive antibiotics treatment, but no improvement was seen. The symptoms disappeared after laparoscopic radical left nephrectomy. Postoperative pathological study showed that the mass was renal medullary carcinoma.

Conclusions

Our case suggests that renal medullary carcinoma should be considered in differential diagnoses of patients with occupying renal lesions who have fever of unknown origin.

Renal medullary carcinoma and its association with sickle cell trait: a case report and literature review

Renal medullary carcinoma (rmc) is a rare and aggressive renal malignancy that usually presents at an advanced stage, has a poor prognosis, and is associated with sickle cell trait. We present a case of rmc including radiologic and pathology findings, treatment, and outcome. A review of the literature is also presented, with an emphasis on the association of rmc with sickle cell trait, which was an unknown diagnosis in our patient preoperatively.

Distinctive mechanisms underlie the loss of SMARCB1 protein expression in renal medullary carcinoma: morphologic and molecular analysis of 20 cases

Renal medullary carcinoma is a rare but highly aggressive type of renal cancer occurring in patients with sickle cell trait or rarely with other hemoglobinopathies. Loss of SMARCB1 protein expression, a core subunit of the switch/sucrose nonfermentable (SWI/SNF) chromatin remodeling complex, has emerged as a key diagnostic feature of these tumors. However, the molecular mechanism underlying this loss remains unclear. We retrospectively identified 20 patients diagnosed with renal medullary carcinoma at two institutions from 1996 to 2017. All patients were confirmed to have sickle cell trait, and all tumors exhibited a loss of SMARCB1 protein expression by immunohistochemistry. The status of SMARCB1 locus was examined by fluorescence in situ hybridization (FISH) using 3-color probes, and somatic alterations were detected by targeted next-generation sequencing platforms. FISH analysis of all 20 cases revealed 11 (55%) with concurrent hemizygous loss and translocation of SMARCB1, 6 (30%) with homozygous loss of SMARCB1, and 3 (15%) without structural or copy number alterations of SMARCB1 despite protein loss. Targeted sequencing revealed a pathogenic somatic mutation of SMARCB1 in one of these 3 cases that were negative by FISH. Tumors in the 3 subsets with different FISH findings largely exhibited similar clinicopathologic features, however, homozygous SMARCB1 deletion was found to show a significant association with the solid growth pattern, whereas tumors dominated by reticular/cribriform growth were enriched for SMARCB1 translocation. Taken together, we demonstrate that different molecular mechanisms underlie the loss of SMARCB1 expression in renal medullary carcinoma. Biallelic inactivation of SMARCB1 occurs in a large majority of cases either via concurrent hemizygous loss and translocation disrupting SMARCB1 or by homozygous loss.

Renal medullary carcinoma in a young mixed-race man in Japan

Renal medullary carcinoma (RMC) is a rare and aggressive cancer associated with the sickle cell trait. The diagnosis of RMC depends on recognition of its histologic features and immunohistochemical deficiency of INI1, but correct diagnosis is sometimes difficult, especially if a patient's information on race, past, and family medical history is unclear. At present, this is the first report on RMC in Japan.

Renal Medullary Carcinoma: a Report of the Current Literature

PURPOSE OF THE REVIEW

We present an updated report of renal medullary carcinoma (RMC), a rare and aggressive condition.

RECENT FINDINGS

There is a majority of male patients, of African descent, in the second or third decade of life. In differential diagnosis, other tumors, such as malignant rhabdoid tumor (MRT), vinculin-anaplastic lymphoma kinase (VCL-ALK) translocation renal cell carcinoma, and collecting duct carcinoma, may present difficulties. Abnormalities of tumor suppressor gene SMARCB1 have been found in RMC. Reported symptoms were hematuria, pain, weight loss, respiratory distress, palpable mass, cough, and fever. Most patients present with metastases at diagnosis. There is no definite recommended treatment, and protocols are extrapolated from other malignancies, with nephrectomy and systemic therapies being most frequently used. Response to treatment and prognosis remain very poor. RMC is a rare and aggressive tumor. Definitive diagnosis requires histological assessment and the presence of sickle-cell hemoglobinopathies.

Genitourinary Pathology Reporting Parameters Most Relevant to the Medical Oncologist

Pathologic variables play an important role in prognostication in urologic malignancies. Histologic subtype, histologic grade, and anatomic extent of disease (pathologic tumor and nodal staging) influence treatment decisions in both the adjuvant and metastatic settings. This article discusses treatment paradigms for the most common urologic malignancies, followed by the evidence base to support the relationship between pathologic assessment and decision making by the medical oncologist.

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.