Mutations In Von Hippel-Lindau Gene Research Articles

A clinical analysis of multilocular cystic renal cell carcinoma and its correlation with mutation of the von Hippel-Lindau gene

Objective To discuss the diagnosis and surgical management of multilocular cystic renal cell carcinoma (MCRCC) and to evaluate the gene function of the mutation of von Hippel-Lindau (VHL) gene in MCRCC. Methods Seventeen MCRCC cases (11 men and 6 women) out of 512 cases of renal cell carcinoma from 2000 to 2010 were retrospectively analyzed. The mean age of the 17 patients was 46 years (37-61 years). Ultrasonography and CT were available in all 17 cases, and 1 case was misdiagnosed as parapelvic renal cyst. The mutation of VHL gene was detected by PCR in the specimens of can-cerous tissue and adjacent normal tissue from 11 cases of MCRCC. Results Three of 17 cases underwent nephron sparing surgery, the others underwent radical nephrectomy. One case underwent unroofing of parapelvic renal cyst, but the rapid frozen pathology of the cyst wall showed renal cell carcinoma of clear type. As a result, radical nephrectomy was eventually performed. All 17 cases were confirmed as MCRCC by eva-luating pathological characteristics, such as the cyst wall lined by single or several layers of clear tumor cells and the nuclei which were small and anachromasis. Clinical stages of all cases were T1N0M0, in which there were 14 cases with pathological T1G1 and 3 cases with pathological T1G2. All patients underwent a follow-up of 9 to 36 months (mean, 12 months) without recurrence or metastasis. Mutation of VHL gene was detected in 7 of 11 cases (64%), but all adjacent normal tissues were negative. Conclusions As a rare subtype of renal cell carcinoma, MCRCC is difficult to diagnose. CT is an essential measure in diagnosis of MCRCC preoperatively. Because of the good prognosis of reported cases, nephron sparing surgery for the treatment of MCRCC is recommended. VHL gene mutations may play an important role in the carcinogenesis of MCRCC. Key words: Kidney diseases, cystic; Carcinoma, renal cell; Hippel-Lindau disease; Genes; Mutation

Renal medullary carcinomas: histopathologic phenotype associated with diverse genotypes

Chromosomal abnormalities and gene mutations have become major determinants in the classification of kidney carcinomas. Most renal medullary carcinomas develop in patients with hereditary sickle cell disease, but sporadic cases unassociated with sickle cell disease have also been described, for which underlying genetic abnormality is unknown. We evaluated 3 patients with renal medullary carcinoma (1 patient with sickle cell disease and 2 patients without sickle cell disease) for germ line and somatic mutations in genes commonly involved in pathogenesis of renal carcinomas using denaturing high-performance liquid chromatography and direct sequencing. Chromosomal abnormalities were studied by the conventional cytogenetic and SNP arrays analysis. Expression of hypoxia-inducible factor 1α was examined using immunohistochemistry. Two new mutations in the gene for fumarate hydratase were identified in 1 case of medullary renal carcinoma without sickle cell disease: a germ line mutation in exon 6 (R233H) and an acquired (somatic) mutation in exon 8 (P374S). No fumarate hydratase mutations were identified in the other 2 patients. The second sporadic case of renal medullary carcinoma harbored double somatic mutations in von Hippel-Lindau gene, and renal medullary carcinoma in the patient with sickle cell disease showed von Hippel-Lindau gene promoter methylation (epigenetic silencing). No consistent pattern of chromosomal abnormalities was found between 2 cases tested. All 3 cases showed increased hypoxia-inducible factor 1α expression. Medullary renal carcinomas from patients with or without sickle cell disease show involvement of genes important in hypoxia-induced signaling pathways. Generalized cellular hypoxia (in sickle cell disease) or pseudohypoxia (in tumors with fumarate hydratase and von Hippel-Lindau mutations or epigenetic silencing) may act alone or in concert at the level of medullary tubular epithelium to promote development of this rare type of renal carcinoma, which could then be genetically reclassified as either fumarate hydratase-associated renal carcinomas or high-grade clear cell renal cell carcinomas.

Measurements of Plasma Methoxytyramine, Normetanephrine, and Metanephrine as Discriminators of Different Hereditary Forms of Pheochromocytoma

Pheochromocytomas are rare catecholamine-producing tumors derived in more than 30% of cases from mutations in 9 tumor-susceptibility genes identified to date, including von Hippel-Lindau tumor suppressor (VHL); succinate dehydrogenase complex, subunit B, iron sulfur (Ip) (SDHB); and succinate dehydrogenase complex, subunit D, integral membrane protein (SDHD). Testing of multiple genes is often undertaken at considerable expense before a mutation is detected. This study assessed whether measurements of plasma metanephrine, normetanephrine, and methoxytyramine, the O-methylated metabolites of catecholamines, might help to distinguish different hereditary forms of the tumor. Plasma concentrations of O-methylated metabolites were measured by liquid chromatography with electrochemical detection in 173 patients with pheochromocytoma, including 38 with multiple endocrine neoplasia type 2 (MEN 2), 10 with neurofibromatosis type 1 (NF1), 66 with von Hippel-Lindau (VHL) syndrome, and 59 with mutations of SDHB or SDHD. In contrast to patients with VHL, SDHB, and SDHD mutations, all patients with MEN 2 and NF1 presented with tumors characterized by increased plasma concentrations of metanephrine (indicating epinephrine production). VHL patients usually showed solitary increases in normetanephrine (indicating norepinephrine production), whereas additional or solitary increases in methoxytyramine (indicating dopamine production) characterized 70% of patients with SDHB and SDHD mutations. Patients with NF1 and MEN 2 could be discriminated from those with VHL, SDHB, and SDHD gene mutations in 99% of cases by the combination of normetanephrine and metanephrine. Measurements of plasma methoxytyramine discriminated patients with SDHB and SDHD mutations from those with VHL mutations in an additional 78% of cases. The distinct patterns of plasma catecholamine O-methylated metabolites in patients with hereditary pheochromocytoma provide an easily used tool to guide cost-effective genotyping of underlying disease-causing mutations.

Expression of the Hypoxia-Inducible Factors In the AML and MDS: Is Not Associated with the Von Hippel-Lindau Gene

AbstractAbstract 5114The hypoxia-inducible factor (HIF) is a transcriptional factor with important roles in tumor biology, which activates transcription of genes encoding glucose transporters, glycolytic enzymes, and vascular endothelial growth factor. The VHL (von Hippel-Lindau) gene normally regulates ubiquitin mediated proteolysis of HIF-1a. VHL inactivation blocks HIF-1 proteolysis, resulting in increased HIF-1 expression. In the previous study, the expression of HIF-1a was detected in children ALL and NHL. To clarify the possible involvement of the HIF-1a and VHL gene in the development and progression of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), we analyzed the mutation and methylation of the VHL gene in 98 patients (54 AML and 44 MDS). The mutations in VHL gene was examined by direct exons sequence and the methylation status of the promoter region was determined using methylation-specific polymerase chain reaction (MSP). In addition, we examined the expression of HIF-1a in 44 of these patients (25 AML and 18 MDS) through the immunoblotting. VHL mutations were identified only in one patient with AML. However, no mutation was detected in the coding region of the VHL gene in MDS. Meanwhile the methylation of VHL gene was not found in the AML and MDS. But the expression of HIF-1a was found in 10 (66.7%) of 25 patients with AML and 5 (38.5%) of 18 patients with MDS. There is no significant correlation between the expression of HIF-1a and the VHL gene. Our primary date support that the HIF-1a may be involved in the development and progression of AML and MDS, but is not associated with the VHL gene. Disclosures:No relevant conflicts of interest to declare.

Clinicopathologic and Molecular Genetic Study of Renal Cell Carcinoma Occurring in Teenagers

To investigate clinicopathological features, molecular genetic characteristics, differential diagnoses and prognosis of renal cell carcinoma in teenagers. Microscopic and immunohistochemical features of 46 cases of renal cell carcinomas in teenagers were reviewed along with the clinical follow-up data. Loss of heterozygosity (LOH), analysis of von Hippel-Lindau (VHL) gene and screening for VHL gene mutations were performed in all of the tumors. There were 19 Xp11.2 translocations/TFE3 gene fusions renal clear cell carcinomas (Xp11 RCCs), 9 chromophobe renal cell carcinomas (CCRCCs), 17 papillary renal cell carcinomas (PRCCs), and 1 unclassified renal cell carcinoma (RCC). All of the 19 Xp11.2 translocation RCCs showed a moderate to strong immunoreactivity for TFE, however, no TFEB expression was obtained. There were 4 histological patterns in the Xp11 RCC cases including: 8 tumors possessing a nested to papillary architecture resembling to the t(X;17) ASPL-TFE3 phenotype; 6 tumors possessing a morphologic feature like the t(X;1) PRCC-TFE3 phenotype; 4 cases morphologically resembling to clear cell RCC; and 1 Xp11 RCC case, with a special morphologic feature not searched yet in the literature, including a ground glass appearance of the nuclei accompanying occasionally with grooves on the nuclear surface; nucleoli inconspicuous with accumulation of abundant mucin-like substance in the stroma. VHL gene analysis revealed deletions at 3p25-26 in one clear cell RCC and one papillary type 2 RCC. The papillary type 2 RCC had also a family history of VHL disease, with a germline G→C mutation at a splicing site of position 553+5. There were no VHL mutations detected in the remaining 45 RCCs. Statistical analysis of tumor stage and outcome revealed that TFE+ RCCs of teen-agers were more frequently associated with a higher pT3/pT4 stage and a poorer outcome than that of the TFE-RCCs (P < 0.05). RCCs of the teenagers have a different morphologic spectrum and genetic background from the RCCs seen in adults. Among RCCs of the teen-agers, Xp11.2 translocation tumors are the most common RCCs and have a poorer prognosis than that of the TFE-RCCs.

Body Mass Index and von Hippel-Lindau Gene Mutations in Clear-cell Renal Cancer: Results of the Netherlands Cohort Study on Diet and Cancer

Body mass index (BMI) is an important risk factor for clear-cell renal cancer (cc-RCC). A common molecular alteration in cc-RCC is loss-of-function of the von Hippel-Lindau (VHL) gene. We evaluated the association between BMI and VHL mutations in cc-RCC by using data from the Netherlands Cohort Study (NLCS), a prospective study, which comprises 120,852 persons. After 11.3 years of follow-up, 337 incident RCC cases were identified; 185 cc-RCC cases were included for analyses. A high BMI at baseline was associated with an increased risk of cc-RCC with or without VHL mutations (per 1 kg/m(2): hazard ratio [HR] = 1.09, 95% confidence interval [CI]: 1.02-1.16 and HR = 1.08, 95%CI: 1.01-1.15, respectively). BMI at age 20 was only associated with an increased risk of cc-RCC with VHL mutations (per 1 kg/m(2): HR =1.09, 95% CI: 1.03-1.16). In contrast, BMI gain since age 20 was only associated with an increased risk in VHL wild-type cases (per 1 kg/m(2): HR = 1.10, 95% CI: 1.03-1.19). Our findings indicate that BMI may be differently associated with subtypes of RCC based on VHL mutations.

A Unique Pair of Monozygotic Twins with Concordant Clear Cell Renal Cell Carcinoma: A Case Report

Genetic predisposition to clear cell renal cell carcinoma (ccRCC) has been linked to disorders such as von Hippel-Lindau (VHL) syndrome. While twin research is a classic approach for elucidating genetic and environmental contributions to disease, no monozygotic twin-pair concordant for ccRCC in the absence of VHL syndrome has been previously reported in the literature or in major twin registries. We describe a unique monozygotic twin-pair concordant for ccRCC, with discordant but early ages of onset of 25 and 38 respectively. Cytogenetic studies and direct sequencing for VHL gene mutations in the second twin proved unremarkable. This is the fi rst reported case of monozygotic twins concordant for ccRCC in the absence of VHL gene mutation. The early yet discordant, age of onset of disease in both twins suggests both genetic and environmental contributions to ccRCC.

Renal Cell Carcinoma in Children and Young Adults: Clinicopathological, Immunohistochemical, and VHL Gene Analysis of 46 Cases With Follow-up

To further study the characteristics of renal cell carcinoma (RCC) in young patients and better define their biological features, 46 RCCs of patients younger than 25 years were morphologically and immunohistochemically characterized with follow-up. Loss of heterozygosity (LOH) analysis of the von Hippel-Lindau (VHL) gene region and screening for VHL gene mutations were performed in all tumors. Applying the 2004 WHO classification for RCC, there were 19 Xp11.2 translocation RCCs, 9 clear cell RCCs, 17 papillary RCCs, and 1 unclassified RCC. All 19 Xp11.2 translocation RCCs showed moderate to strong immunoreactivity for TFE3. None had TFEB immunoreactivity. One Xp11.2 translocation RCC had an unreported morphology with empty or ground glass nuclei, occasional nuclear grooves, inconspicuous nucleoli and abundant mucinous material in stroma.VHL gene analysis revealed deletions at 3p25-26 in 1 clear cell RCC and 1 papillary type 2 RCC. The papillary type 2 RCC was also presented with a family history of VHL disease and found a germline mutation G → C on a splicing site at position 553+5. The present case widens the spectrum of microscopic features to be found in VHL-associated RCC. There were no VHL mutations in the remaining 45 RCCs. Statistical analysis of stage and outcome revealed that TFE+ pediatric RCCs were significantly more frequently associated with a higher pTNM pT3/pT4 stage and a poorer outcome than TFE-RCCs (P < .05). Owing to the already known aggressive behavior of these Xp11.2 translocation RCCs, patients with TFE+ pediatric RCCs should benefit from a stricter follow-up.

Bilateral Pheochromocytoma as First Presentation of von Hippel-Lindau Disease in a Chinese Family

To investigate the clinical and genetic features of a Chinese family with von Hippel-Lindau (VHL) disease revealed by bilateral pheochromocytoma. The proband and other members in a Chinese family with familial pheochromocytoma were clinically evaluated and followed up. Genomic DNA extracted from the peripheral blood of 8 family members (including 3 patients) was amplified by polymerase chain reaction (PCR) and the PCR products were directly sequenced. The first presentation in the proband, his mother, and his sister was bilateral pheochromocytoma, and the missense mutation of 695G-A (Arg161Gln) in exon 3 of VHL gene was detected in the three patients. In the follow-up study, the proband and his mother were found to have other VHL tumors, induding retinal and cerebellar hemangioblastomas and pancreatic tumor. Neither clinical presentation of VHL disease nor gene mutation was found in other family members. VHL disease should be suspected in some patients with familial pheochromocytoma, and VHL gene screening helps to achieve early diagnosis of the disease.

Familial and genetic researches on three Chinese families with von Hippel-Lindau disease

Objective: Hemangioblastoma of the central nervous system (CNS) occur as sporadic tumors or as a part of von Hippel-Lindau (VHL) disease, an autosomal dominant hereditary tumor syndrome caused by germline mutation of the VHL tumor suppressor gene. This study shows the clinical characteristics of three large Chinese families with VHL disease and evaluates the consequence of the genetic test for the diagnosis of VHL disease and clinical screening of the family members.Methods: DNA is extracted from peripheral blood in 43 members from three large families with VHL disease and amplified by PCR to three exons of the VHL gene. The PCR products were directly sequenced and the mutations compared with the Human Gene Mutation Database.Results: The ages of the patients who are given the initial diagnosis ranged from 16 to 47 years (mean: 31 years), and the mean time was 17.3 months (2–30 months) from the emergence of the symptom to patients' first visit. Furthermore, the gender distribution was 20% female (4) and 80% male (16). Twenty VHL disease patients in the three families have the most common manifestation of CNS hemangioblastoma. The cytosine replaced the 716th guanine on four patients and three carriers of virulence gene from the first family, which made the 168th serine replaced by threonine. And no mutation was found on the 22 members of the second family. Meanwhile, it was also found that the guanine replaced the 559th cytosine on one patient and two carriers from the third family, which made the 116th leucine replaced by valine.Conclusion: The DNA analysis of VHL germline mutations is clearly superior to clinical information to diagnose VHL disease. The CNS hemangioblastoma is the early manifestation in VHL disease. It is recommended that every patient with CNS hemangioblastoma should be screened for VHL gene mutation. The test for the VHL gene plays a key role in the discovery of asymptomatic patients and the carriers of virulence gene.

Genetic detection and analysis of the VHL gene in patients with sporadic pheochromocytoma

To carry out a genetic detection and analysis of Von Hippel-Lindau (VHL) gene in Chinese patients with sporadic pheochromocytoma. DNA samples were extracted from peripheral blood cells and fresh pheochromocytoma specimens from 41 patients with sporadic pheochromocytoma were assayed by polymerase chain reaction and direct sequencing. The DNA samples of 50 healthy volunteers were extracted from peripheral blood as a control. The PCR products of exon 1, exon 2 and exon 3 were used for molecular analysis of the VHL gene. The genetic detection of family members of VHL gene mutations was also performed. One of mutations was located at nucleotide 572 (G-->C) in exon 2, presenting a codon 120 from arginine (R) to threonine (T). Tow small insertions were locatated at nucleotide 623T (TTTGTtG) in exon 2, leading to a frameshift mutation. There were also three carriers of G572C and three carriers of 623T (TTTGTtG) in family members of the three cases. There are some Chinese patients with sporadic pheochromocytoma with tumorigenic VHL gene mutations. It is recommended to use the genetic detection and analysis of VHL gene as a routine examination for patients with sporadic pheoehromoeytoma under the age of 50 years with questionable family history. The genetic detection and analysis of VHL gene may be useful as a marker for the diagnosis of hereditary pheochromocytoma.

Photodynamic therapy and vitrectomy for a large optic nerve hemangioma with neovascularization and retinal detachment: a clinicopathologic correlation.

To report the clinicopathologic correlation of a young man with a von Hippel-Lindau disease-associated peripapillary hemangioblastoma and its satisfactory response to a combination of photodynamic therapy (PDT) and vitrectomy. Clinicopathologic correlation. We studied the case of a 14-year-old boy with an optic nerve mass and large inferior exudative retinal detachment complicated by a significant tractional component from extensive secondary neovascularization over the lesion. A juxtapapillary hemangioblastoma with secondary neovascularization was documented by clinical examination, fundus photography, and optical coherence tomography. A von Hippel-Lindau gene mutation was detected. The patient responded satisfactorily to a combination of PDT and vitrectomy. A staged approach to treatment of peripapillary hemangioblastoma with a combination of PDT and vitrectomy may be favorable to therapy with one modality.

Von Hippel-Lindau Disease: delayed presentation as a cerebellar haemangioblastoma in an elderly patient

Cerebellar haemangioblastomas are rare in the elderly. Those associated with the von Hippel-Lindau (VHL) disease, usually present during the third decade of life. We report an unusually delayed presentation in an 80 year old obligate carrier of VHL gene mutation.

Von-Hippel-Lindau-Gen-Mutationstypen

The von-Hippel-Lindau (VHL) tumor suppressor is a multifunctional protein. VHL mutations are common in sporadic clear cell renal cell carcinoma (ccRCC). Different mutation types may specifically alter pVHL functions, which have significant impact on gene expression and, consequently, on the disease outcome. The aim of this study was to identify gene expression signatures that correlate with specific VHL gene mutation types in RCC.Total RNA and genomic DNA were extracted from 94 frozen clear cell (ccRCC) and 21 papillary RCC (pRCC) specimens from the tumor biobank of Zurich University Hospital. Transcriptome analysis was performed using Affymetrix HG U133A gene chips. All ccRCC tumors were subjected to VHL gene mutation analysis.By applying significance analysis of microarrays genes were identified, which were differentially regulated among the tumor subgroups. Hierarchical clustering based on the expression profile of the most differentially regulated genes resulted in a significant stratification between the two RCC populations. A total of 186 differentially expressed genes were identified by comparing the gene expression profiles of ccRCC with VHL loss-of-function mutations and ccRCC with no gene alterations.The results clearly argue for a significant influence of VHL mutations on gene expression profiles in RCC.

Improved Identification of von Hippel-Lindau Gene Alterations in Clear Cell Renal Tumors

To provide a comprehensive, thorough analysis of somatic mutation and promoter hypermethylation of the von Hippel-Lindau (VHL) gene in the cancer genome, unique to clear cell renal cancer (ccRCC). Identify relationships between the prevalence of VHL gene alterations and alteration subtypes with patient and tumor characteristics. As part of a large kidney cancer case-control study conducted in Central Europe, we analyzed VHL mutations and promoter methylation in 205 well-characterized, histologically confirmed patient tumor biopsies using a combination of sensitive, high-throughput methods (endonuclease scanning and Sanger sequencing) and analysis of 11 CpG sites in the VHL promoter. We identified mutations in 82.4% of cases, the highest VHL gene mutation prevalence reported to date. Analysis of 11 VHL promoter CpG sites revealed that 8.3% of tumors were hypermethylated and all were mutation negative. In total, 91% of ccRCCs exhibited alteration of the gene through genetic or epigenetic mechanisms. Analysis of patient and tumor characteristics revealed that certain mutation subtypes were significantly associated with Fuhrman nuclear grade, metastasis, node positivity, and self-reported family history of RCC. Detection of VHL gene alterations using these accurate, sensitive, and practical methods provides evidence that the vast majority of histologically confirmed ccRCC tumors possess genetic or epigenetic alteration of the VHL gene and support the hypothesis that VHL alteration is an early event in ccRCC carcinogenesis. These findings also indicate that VHL molecular subtypes can provide a sensitive marker of tumor heterogeneity among histologically similar ccRCC cases for etiologic, prognostic, and translational studies.

Ocular von Hippel–Lindau disease: clinical update and emerging treatments

von Hippel-Lindau disease is an inherited, multisystemic cancer syndrome often involving the retina. This review will provide an update for the clinical characterization and treatment of ocular von Hippel-Lindau disease. A comprehensive and quantitative clinical characterization of ocular von Hippel-Lindau disease has been limited by small patient numbers and nonrepresentative sampling. Recently, a large population of patients with clinically and genetically defined von Hippel-Lindau disease was systemically characterized in a single center, enabling a quantitative evaluation of the ocular involvement of this syndrome. Correlations between the nature of von Hippel-Lindau gene mutations and the ocular phenotype were also examined, providing clues as to how disruptions in von Hippel-Lindau protein function may result in eye disease. This understanding may be relevant to the development of new therapies targeting the molecular biology of von Hippel-Lindau disease, some of which are presently being investigated. Quantitative studies enable a full characterization of the impact of von Hippel-Lindau disease on eye health and visual function. Establishing correlations between the genotype of the von Hippel-Lindau mutation and the phenotype of eye disease may inform us as to how ocular von Hippel-Lindau disease arises, and help guide molecular interventions in ocular von Hippel-Lindau disease.

Renal oncocytoma with and without intravascular extension into the branches of renal vein have the same morphological, immunohistochemical and genetic features

We attempted to investigate the clinicopathological correlation of renal oncocytoma (RO) with renal vein extension. We identified seven ROs with extension into the branches of renal vein. The age of seven patients ranged from 61 to 82 years. Five cases were identified; incidentally, two patients had gross hematuria. After surgery, all patients were alive and free of tumors with follow-up of 1 to 5 years (mean=3.6). Oncocytomas measured from 2.2 to 7.5 cm. Renal vein extension was grossly suspected in 5/7 cases and histologically confirmed in all seven cases. Tumor cells were positive for cytokeratins, mitochondrial antigen, epithelial membrane antigen, and parvalbumin; 5/7 tumors were focally positive for cluster of differentiation 117. Ultrastructurally, the cytoplasm was packed by mitochondria. Molecular genetic analysis did not detect abnormal numbers of chromosomes 1, 2, 6, 7, 10, 17, and XY by fluorescence in situ hybridization, loss of heterozygosity on 3p, and mutation of Von Hippel-Lindau gene in all cases. Array comparative genomic hybridization analysis of two cases did not show any major genetic changes. Conclusions are: (1) renal oncocytomas may have intravascular extension to the branches of the renal vein; (2) renal oncocytomas with intravascular extension to the branches of the renal vein have the same morphological, immunohistochemical, and cytogenetic findings as have their counterparts without evidence of intravascular invasion; (3) the absence of metastases suggests an overall benign behavior of this tumor, but this has to be substantiated by further studies with a long-term follow-up; (4) in a renal tumor with granular cytoplasm showing renal vein extension, it is necessary to carefully exclude renal cell carcinomas (RCC) such as chromophobe RCC, oncocytic variant of papillary RCC, and granular variant of clear cell RCC.

Renal oncocytoma with and without intravascular extension into the branches of renal vein have the same morphological, immunohistochemical, and genetic features

We attempted to investigate the clinicopathological correlation of renal oncocytoma (RO) with renal vein extension. We identified seven ROs with extension into the branches of renal vein. The age of seven patients ranged from 61 to 82 years. Five cases were identified incidentally; two patients had gross hematuria. After surgery, all patients were alive and free of tumors with follow-up of 1 to 5 years (mean = 3.6). Oncocytomas measured from 2.2 to 7.5 cm. Renal vein extension was grossly suspected in five of seven cases and histologically confirmed in all seven cases. Tumor cells were positive for cytokeratins, mitochondrial-antigen (MIA), epithelial membrane antigen (EMA), and parvalbumin; five of seven tumors were focally positive for CD117. Ultrastructurally, the cytoplasm was packed by mitochondria. Molecular genetic analysis did not detect abnormal numbers of chromosomes 1, 2, 6, 7, 10, 17, and XY by fluorescence in situ hybridization, loss of heterozygosity on 3p and mutation of von Hippel-Lindau gene in all cases. Array comparative genomic hybridization analysis of two cases did not show any major genetic changes. Our conclusions are as follows: (1) renal oncocytomas may have intravascular extension to the branches of the renal vein; (2) renal oncocytomas with intravascular extension to the branches of the renal vein have the same morphological, immunohistochemical, and cytogenetic findings as have their counterparts without evidence of intravascular invasion; (3) the absence of metastases suggests an overall benign behavior of this tumor, but this has to be substantiated by further studies with a long-term follow-up; and (4) in a renal tumor with granular cytoplasm showing renal vein extension, it is necessary to carefully exclude renal cell carcinomas such as chromophobe RCC, oncocytic variant of papillary RCC, and granular variant of clear cell RCC.

Biomarkers in clear cell renal cell carcinoma

The treatment of advanced renal cell carcinoma (RCC) has evolved significantly following the identification of the von Hippel–Lindau (VHL) gene and the function of its protein, and subsequent development of antiangiogenic therapies. A series of clinical trials resulted in the approval of three new agents with significant activity in this disease. Additional studies are now underway to identify subsets of patients most likely to benefit. This article reviews the current therapy for advanced RCC and the development of biomarkers in RCC. This requires the identification of disease characteristics at a clinical, genetic and molecular level associated with response and/or surrogate measures of clinical benefit. Currently, a variety of prognostic factors (lactate dehydrogenase, performance status, disease-free interval, hemoglobin and calcium levels) are utilized to predict the survival of RCC patients. The use of validated biomarkers in either serum/plasma, urine or tissue could enhance this process, as well as define at the molecular and genetic levels, factors associated with response to therapy and/or the development of resistance. Examples include plasma VEGF levels, VHL gene mutation status and carbonic anhydrase IX levels in tumor tissue, among others. Validation of such biomarkers is crucial in order for them to be clinically useful.

Sorafenib With Interferon Alfa-2b As First-Line Treatment of Advanced Renal Carcinoma: A Phase II Study of the Southwest Oncology Group

This phase II study evaluated the activity of combined treatment with interferon alfa-2b and sorafenib, a Raf and multiple receptor tyrosine kinase inhibitor, in patients with advanced renal carcinoma. Eligible patients had metastatic or unresectable renal carcinoma with a clear-cell component, no prior systemic therapy, performance status 0 to 1, and measurable disease. Treatment consisted of interferon alfa-2b 10 x 10(6) U subcutaneously three times weekly and sorafenib 400 mg orally bid. The primary end point was confirmed Response Evaluation Criteria in Solid Tumors response rate. Twelve (19%) of 62 assessable patients achieved an objective confirmed response. An additional 31 (50%) had an unconfirmed partial response or stable disease as best response. The median progression-free survival was 7 months (95% CI, 4 to 11 months). The most common adverse events were fatigue, anorexia, anemia, diarrhea, nausea, rigors/chills, leukopenia, fever, and transaminase elevation. Von Hippel-Lindau gene mutations were detected in four (22%) of 18 archival tumor specimens. The confirmed response rate for the combination of sorafenib and interferon in advanced renal carcinoma is greater than expected with either interferon or sorafenib alone. The toxicity of this combination is dominated by adverse events common to interferon that limit further development of this regimen.