Comprehensive study of nine novel cases of TFEB-amplified renal cell carcinoma: an aggressive tumour with frequent PDL1 expression.

AIMS: First described in 2014, renal cell carcinoma (RCC) with TFEB amplification (6p21) is a rare molecular subgroup whose diagnosis is challenging. The prognosis and therapeutic implications remain unclear. METHODS: We report here the clinical, histological, immunohistochemical, and genetic features of nine novel cases. The pathological and immunohistochemical features were centrally reviewed by expert uropathologists. Fluorescence in situ hybridisation (FISH) confirmed the diagnosis and comparative genomic hybridisation (CGH) was performed to determine quantitative genomic alterations. We also performed an exhaustive review of the literature and compiled our data. RESULTS: TFEB-amplified RCC were locally advanced, with initial lymph node involvement in one case and liver metastasis in another case. They were high-grade eosinophilic tumours with papillary/pseudopapillary architecture, frequent positivity for melanocytic markers, and frequent PDL1 expression. FISH demonstrated high-level TFEB amplification in six cases. One case showed concomitant TFEB translocation. CGH analysis identified complex alterations with frequent losses of 1p, 2q, 3p, 6p, and frequent 6p and 8q gains. VEGFA coamplification was identified in all cases with a lower level than TFEB. The prognosis was poor, with five patients having lymph node or distant metastases. CONCLUSION: TFEB-amplified RCC is a rare molecular subgroup with variable morphology whose diagnosis is confirmed by FISH analysis. The complex alterations identified by CGH are consistent with an aggressive clinical behaviour. The coamplification of VEGFA and the expression of PDL1 could suggest a potential benefit from antiangiogenics and targeted immunotherapy in combination for these aggressive tumours.

Multiple metastatic clones assessed by an integrative multiomics strategy in clear cell renal carcinoma: a case study.

The dynamics of metastatic evolution in clear cell renal cell carcinoma (ccRCC) are complex. We report a case study where tumour heterogeneity resulting from clonal evolution is a frequent feature and could play a role in metastatic dissemination.We used an integrative multiomics strategy combining genomic and transcriptomic data to classify fourteen specimens from spatially different areas of a kidney tumour and three non-primary sites including a vein thrombus and two adrenal metastases.All sites were heterogeneous and polyclonal, each tumour site containing two different aggressive subclonal populations, with differentially expressed genes implicated in distinct biological functions. These are rare primary metastatic samples prior to any medical treatment, where we showed a multiple metastatic seeding of two subclonal populations.Multiple interdependent lineages could be the source of metastatic heterogeneity in ccRCC. By sampling metastases, patients with resistance to therapies could benefit a combination of targeted therapies based on more than one aggressive clone.

[Renal carcinoma with leiomyomatous stroma and osseous metaplasia from a patient diagnosed with a tuberous sclerosis complex]. / Carcinome rénal à stroma léiomyomateux avec métaplasie osseuse chez un patient porteur d'une sclérose tubéreuse de Bourneville.

Renal cell carcinoma with leiomyomatous stroma is a rare and poorly described histopathological entity. Here we report a unique case with osseous metaplasia, in a 31-year-old man recently diagnosed with a tuberous sclerosis complex (TSC2 gene mutation). Partial nephrectomy was performed. Histologically, the epithelial component was made up of papillary and alveolar structures with clear to eosinophilic cytoplasm, and basally located nuclei. The cells are surrounded by an abundant smooth muscle stroma with focally osseous metaplasia. The tumor was positive for carbonic anhydrase IX, cytokeratin 7, cytokeratin 20, and CD10, and negative for TFE3. This emerging entity is highly correlated to tuberous sclerosis complex, which justifies a screening for the syndrome when this diagnosis is made.

Association of AXL and PD-L1 Expression with Clinical Outcomes in Patients with Advanced Renal Cell Carcinoma Treated with PD-1 Blockade.

PURPOSE: A minority of patients currently respond to single-agent immune-checkpoint blockade (ICB), and strategies to increase response rates are urgently needed. AXL is a receptor tyrosine kinase commonly associated with drug resistance and poor prognosis in many cancer types, including in clear-cell renal cell carcinoma (ccRCC). Recent experimental cues in breast, pancreatic, and lung cancer models have linked AXL with immune suppression and resistance to antitumor immunity. However, its role in intrinsic and acquired resistance to ICB remains largely unexplored. EXPERIMENTAL DESIGN: In this study, tumoral expression of AXL was examined in ccRCC specimens from 316 patients who were metastatic receiving the PD-1 inhibitor nivolumab in the GETUG AFU 26 NIVOREN trial after failure of antiangiogenic therapy. We assessed associations between AXL and patient outcomes following PD-1 blockade, as well as the relationship with various markers, including PD-L1; VEGFA; the immune markers CD3, CD8, CD163, and CD20; and the mutational status of the tumor-suppressor gene von Hippel-Lindau (VHL). RESULTS: Our results show that high AXL-expression level in tumor cells is associated with lower response rates and a trend to shorter progression-free survival following anti-PD-1 treatment. AXL expression was strongly associated with tumor-PD-L1 expression, especially in tumors with VHL inactivation. Moreover, patients with tumors displaying concomitant PD-L1 expression and high AXL expression had the worst overall survival. CONCLUSIONS: Our findings propose AXL as candidate factor of resistance to PD-1 blockade, and provide compelling support for screening both AXL and PD-L1 expression in the management of advanced ccRCC.See related commentary by Hahn et al., p. 6619.

Renal cell carcinoma with leiomyomatous stroma in tuberous sclerosis complex: a distinct entity.

Renal cell carcinoma with leiomyomatous stroma (RCCLS) is an emerging entity frequently associated with tuberous sclerosis complex (TSC). We described herein a series of RCCLS in TSC patients at pathological and cytogenetic levels. Three male patients with TSC and RCCLS were identified between 2000 and 2019 at the University Hospital of Rennes. Histologically, the architecture was tubulo-papillary with thick bundles of smooth muscle cells. The tumor cells showed clear cytoplasm with eosinophilic globules. The immunohistochemical profile was identical with an intense positivity of CK7, CAIX, and CD10 and a heterogeneous positivity of CK20. SDHB was low but positive and TFE3 was not expressed. Comparative genomic hybridization (CGH) did not show any quantitative chromosome abnormality. No recurrence was observed with a median follow-up of 4 years. RCCLS in TSC patients has morphological, immunohistochemical, and cytogenetic distinct features that could constitute a distinct entity and a sentinel manifestation for the diagnosis of TSC.

Immunotherapy in Renal Cell Carcinoma: The Future Is Now.

Renal cell carcinoma is the third type of urologic cancer and has a poor prognosis with 30% of metastatic patients at diagnosis. The antiangiogenics and targeted immunotherapies led to treatment remodeling emphasizing the role of the tumour microenvironment. However, long-term responses are rare with a high rate of resistance. New strategies are emerging to improve the efficacy and the emerging drugs are under evaluation in ongoing trials. With the different treatment options, there is an urgent need to identify biomarkers in order to predict the efficacy of drugs and to better stratify patients. Owing to the limitations of programmed death-ligand 1 (PD-L1), the most studied immunohistochemistry biomarkers, and of the tumor mutational burden, the identification of more reliable markers is an unmet need. New technologies could help in this purpose.

Diagnosis of uncommon renal epithelial neoplasms: performances of fluorescence in situ hybridization.

Renal cell carcinomas (RCC) are divided in several subtypes, characterized by morphological and histological features, protein expression patterns and genetics criteria. The main subtypes include Clear cell renal cell carcinoma (CCRCC), Papillary RCC (PRCC), Chromophobe RCC (ChRCC), oncocytoma, TFE3 and TFEB Translocation renal cell carcinoma (TRCC). In most cases, RCC can be easily classified according to histological criteria and immunohistochemistry. Nevertheless, the subtyping process can be more complex in some cases: differential diagnosis (CCRCC or TFE3 TRCC, PRCC or TFE3 TRCC, oncocytic tumors corresponding to ChRCC or oncocytoma), molecular confirmation (TFEB TRCC) and unclassified RCC. Complementary analyses are required such as fluorescence in situ hybridization (FISH) for the detection of chromosomal abnormalities associated to each subtype. In this aim, this study assessed the performance of FISH analysis in the histological classification of 359 RCC exhibiting unusual histological characteristics and/or occurring in young people. FISH probes were selected according to the histological features of each tumor. FISH analysis contributed to the histological classification in 73% of the RCC (261/359). Conversely, FISH did not contribute to the diagnosis in 19% of the cases (69/359) and a hybridization failure was observed for the remaining tumors (8%; 29/359). Considering the different RCC subtypes, FISH analysis was highly efficient to confirm the histological diagnosis of CCRCC, PRCC, and TFE3 TRCC and to identify abnormalities of the TFEB gene. However, this strategy showed some limitations for the diagnosis of oncocytic tumors and unclassified RCC, suggesting that additional molecular assays should be evaluated in these cases.

Targeting the PD-1/PD-L1 Pathway in Renal Cell Carcinoma.

Renal cell carcinoma encompass distinct diseases with different pathologic features and distinct molecular pathways. Immune checkpoint inhibitors targeting the programmed death receptor ligand 1 (PD-L1)/programmed death receptor 1 (PD-1) pathway alone or in combination have greatly changed clinical management of metastatic renal cell carcinoma, now competing with antiangiogenic drugs in monotherapy for first-line treatment. However, long-term response rates are low, and biomarkers are needed to predict treatment response. Quantification of PD-L1 expression by immunohistochemistry was developed as a promising biomarker in clinical trials, but with many limitations (different antibodies, tumour heterogeneity, specimens, and different thresholds of positivity). Other biomarkers, including tumour mutational burden and molecular signatures, are also developed and discussed in this review.

Whole genome duplication is an early event leading to aneuploidy in IDH-wild type glioblastoma.

Glioblastoma, the most frequent and lethal form of glioma, displays chromosome instability and recurrent somatic copy number alterations (SCNA). Chromothripsis and whole genome duplication (WGD) have been recently identified in cancer. In the present study, we analyzed SCNA and determine the ploidy pattern in 123 IDH-wild-type glioblastomas, using SNP array data. WGD and chromothripsis events were validated using, respectively, FISH and CTLPScanner. WGD was detected in 11.4% glioblastomas (14/123) and was associated with TP53 mutation (p = 0.0068). It was an early event occurring after the recurrent SCNA observed in diffuse high-grade gliomas. Glioblastomas with WGD were more aneuploid compared to glioblastomas without WGD (p < 0.0001). Chromothripsis occurred in 29.3% glioblastomas (36/123) and mostly affected chromosomes 7, 9 and 12, with amplification of oncogenes (EGFR, MDM2/CDK4), and homozygous deletion of tumor suppressor genes (CDKN2A). There was a significant association between chromothripsis and gene rearrangement at a given locus. WGD is an early genetic event significantly associated to TP53 mutation and leading to chromosome instability and aneuploidy in IDH-wild-type glioblastoma. Chromothripsis recurrently targets oncogenes and tumor suppressor genes that are key players in gliomagenesis and tumor progression. The occurrence of chromothripsis points to underlying gene rearrangements (including gene fusions), potential therapeutic targets in glioblastoma.

[Low-grade eosinophilic unclassified renal cell carcinoma, a recently proposed entity in the spectrum of eosinophilic renal cells tumors: Report of one case and discussion]. / Le carcinome rénal inclassé de bas grade à cellules éosinophiles, une entité récemment proposée dans le spectre des tumeurs rénales à cellules éosinophiles : étude d'un cas et discussion.

Low-grade eosinophilic unclassified renal cell carcinoma is a rare kidney tumor recently described, not included in the WHO classification, which is very close to oncocytoma. It is unknown to most pathologists and clinicians. From a histopathological point of view, this tumor is composed of oncocytic cells arranged in a diffuse and solid pattern, without cell nests, that makes it possible to differentiate it from oncocytoma, and expresses cytokeratin 7 (CK7) heterogeneously. We report a case with a cranial vault metastasis, and present the features to differentiate this entity from oncocytoma. Furthemore, we discuss about unclassified renal cell carcinomas with oncocytic cells.

Clinicopathological characteristics of ROS1- and RET-rearranged NSCLC in caucasian patients: Data from a cohort of 713 non-squamous NSCLC lacking KRAS/EGFR/HER2/BRAF/PIK3CA/ALK alterations.

Targeted therapies have substantially changed the management of non-small cell lung cancer (NSCLC) patients with driver oncogenes. Given the high frequency, EGFR and ALK aberrations were the first to be detected and paved the way for tyrosine kinase inhibitor (TKI) treatments. Other kinases such as ROS1 and more recently RET have emerged as promising targets, and ROS1 and RET TKIs are already available for precision medicine. We screened a large cohort of 713 Caucasian non-squamous NSCLC patients lacking EGFR/KRAS/BRAF/HER2/PI3KCA/ALK aberrations for ROS1 and RET rearrangements using fluorescence in situ hybridization to determine the frequency and clinicopathological characteristics of ROS1- and RET-positive patients. Frequencies of ROS1 and RET rearrangements were 2.1% and 2.52%, respectively. Contrary to common belief, both ROS1 and RET rearrangements were detected in patients with a history of smoking, and the RET-positive patients were not younger than the negative patients. Moreover, RET but not ROS1 rearrangement was associated with the female gender. Nearly half of the ROS1-rearranged patients were successfully treated with ROS1 TKIs. In contrast, only 5/18 RET-positive patients received off-label RET TKIs. Two patients had stable disease, and three experienced disease progression. In addition to the 18 RET-positive cases, 10 showed isolated 5' signals. The clinical relevance is unknown but if the frequency is confirmed by other groups, the question whether these patients are eligible to TKIs will arise. More potent RET TKIs are under development and may improve the response rate in RET-positive patients. Therefore, we recommend the routine implementation of RET testing in non-squamous NSCLC patients, including those with a history of smoking.

Clear cell renal cell carcinoma: a comparative study of histological and chromosomal characteristics between primary tumors and their corresponding metastases.

Clear cell renal cell carcinoma (ccRCC) has a poor prognosis with a 50% risk of metastases. Little is known about the phenotypic and molecular profiles of metastases regarding their corresponding primary tumors. This study aimed to screen phenotypic and genotypic differences between metastases and their corresponding primary tumors. We selected four cases with available frozen material. The histological, immunohistochemical (VEGFA, CD31, SMA, Ki67, p53, PAR-3), FISH (VHL gene), next-generation sequencing (VHL and c-MET genes), multiplex ligation-dependent probe amplification, and array-(comparative genomic hybridization) CGH analyses were realized. Metastases were nodal, hepatic (synchronous), adrenal, and pulmonary (metachronous). High-grade tumor cells were significantly more frequent in metastases (p = 0.019). Metastases and high-grade zones of primary tumors shared similar characteristics compared to low-grade zones: a lower microscopic vascular density (43.5 vs 382.5 vessels/mm2; p = 0.0027), a higher expression of VEGF (73 vs 10%, p = 0.045), Ki67 (37.6 vs 8.3%; p = 0.011), and p53 (54 vs 10.6%; p = 0.081), and a cytoplasmic and membranous PAR-3 staining. Metastases exhibited more chromosomal imbalances than primary tumors in total (18.75 ± 6.8; p = 0.044) with more genomic gains (13.5 ± 7; p = 0.013). The loss of chromosome 9 and gain of Xq were found in both primary tumors and metastases but gains of loci or chromosomes 2p, 3q, 5, 8q, 12, and 20 were only found in metastases. The VHL gene status was similar in each tumor couple. Although metastases and primary tumors share common histological features, this study highlights chromosomal differences specific to metastases which could be involved in ccRCC metastatic evolution.

Correlation of c-MET Expression with PD-L1 Expression in Metastatic Clear Cell Renal Cell Carcinoma Treated by Sunitinib First-Line Therapy.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is highly metastatic. Cabozantinib, an anti-angiogenic tyrosine kinase inhibitor that targets c-MET, provided interesting results in metastatic ccRCC treatment. OBJECTIVE: To understand better the role of c-MET in ccRCC, we assessed its status in a population of patients with metastatic ccRCC. PATIENTS AND METHODS: For this purpose, tumor samples were analyzed for c-MET expression by immunohistochemistry (IHC), for c-MET copy number alterations by fluorescence in situ hybridization (FISH), and for c-MET mutations by next generation sequencing (NGS) in a retrospective cohort of 90 primary ccRCC of patients with metastases treated by first-line sunitinib. The expression of c-MET was correlated with pathological, immunohistochemical (VEGFA, CAIX, PD-L1), clinical, and molecular criteria (VHL status) by univariate and multivariate analyses and to clinical outcome using Kaplan-Meier curves compared by log-rank test. RESULTS: Of ccRCC, 31.1% had low c-MET expression (absent to weak intensity by IHC) versus 68.9% with high expression (moderate to strong intensity). High expression of c-MET was associated with a gain in FISH analysis (p=0.0284) without amplification. No mutations were detected in NGS. Moreover, high c-MET expression was associated with lymph node metastases (p=0.004), sarcomatoid component (p=0.029), VEGFA (p=0.037), and PD-L1 (p=0.001) overexpression, the only factor that remained independently associated (p<0.001) after logistic regression. No difference was observed in clinical outcomes. CONCLUSION: This study is the first to analyse c-MET status in metastatic ccRCC. The high expression of c-MET in the majority of ccRCC and its independent association with PD-L1 expression, may suggest a potential benefit from combining c-MET inhibitors and targeted immunotherapy.

Synchronous Metastatic Clear-Cell Renal Cell Carcinoma: A Distinct Morphologic, Immunohistochemical, and Molecular Phenotype.

INTRODUCTION: Clear cell renal cell carcinomas (ccRCCs) are highly metastatic tumors with metastases detected at diagnosis (synchronous) or during follow-up (metachronous). To date, there have been no reports comparing primary ccRCC of patients with synchronous and metachronous metastases, who are different in terms of prognosis. Determining whether there is a phenotypic difference between these 2 groups could have important clinical implications. PATIENTS AND METHODS: In a retrospective consecutive cohort of 98 patients with ccRCC, 48 patients had metastases, including 28 synchronous and 20 metachronous presentations, with a follow-up of 10 years. For each primary tumor in these metastatic patients, pathologic criteria, expression of vascular endothelial growth factor, partitioning-defective 3, CAIX, and programmed death ligand 1 as detected by immunohistochemistry, and complete VHL status were analyzed. Univariate analysis was performed, and survival was assessed using Kaplan-Meier curves compared by log-rank test. RESULTS: Compared with primary ccRCC in patients with metachronous metastases, primary ccRCC in patients with synchronous metastases were significantly associated with a poorer Eastern Cooperative Oncology Group performance (P = .045), higher pT status (P = .038), non-inactivated VHL gene (P = .01), sarcomatoid component (P = .007), expression of partitioning-defective 3 (P = .007), and overexpressions of vascular endothelial growth factor (> 50%) (P = .017) and programmed death ligand 1 (P = .019). Patients with synchronous metastases had a worse cancer-specific survival than patients with metachronous metastases even from metastatic diagnosis (median survival, 16 months vs. 46 months, respectively; P = .01). CONCLUSION: This long-term study is the first to support the notion that synchronous m-ccRCC has a distinct phenotype. This is probably linked to the occurrence of oncogenic events that could explain the worse prognosis. These particular patients with metastases could benefit from specific therapy.

Differential diagnosis of atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma: utility of p16 in combination with MDM2 and CDK4 immunohistochemistry.

The differential diagnosis between atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS) and dedifferentiated liposarcoma (DDLPS) from their morphologic counterparts is challenging. Currently, the diagnosis is guided by MDM2 and CDK4 immunohistochemistry (IHC) and is confirmed by the amplification of the corresponding genes. Recently, p16 IHC has been proposed as a useful diagnostic biomarker. The objective was to assess the utility of p16 IHC in the differential diagnosis of ALT/WDLPS and DDLPS. Our series included 101 tumors that were previously analyzed using fluorescence in situ hybridization for MDM2 and CDK4 amplification. We compared sensitivity and specificity of p16 IHC to MDM2 and CDK4 IHC in the differential diagnosis of ALT-WDLPS (n=19) versus benign adipocytic tumors (n=44) and DDLPS (n=18) versus mimicking sarcomas (n=20). In the differential diagnosis of ALT-WDLPS, p16 had a sensitivity of 89.5% but a specificity of 68.2%, which was impaired by false-positive lipomas with secondary changes, especially in biopsies. Likewise, in the differential diagnosis of DDLPS, p16 had a sensitivity of 94.4% and a specificity of 70%, which hampered its use as a single marker. However, adding p16 to MDM2 and/or CDK4 increased diagnostic specificity. Indeed, MDM2+/p16+ tumors were all ALT-WDLPS, and MDM2-/p16- tumors were all benign adipocytic tumors. Moreover, all MDM2+/CDK4+/p16+ tumors were DDLPS, and the MDM2-/CDK4-/p16- tumor was an undifferentiated sarcoma. Although the use of p16 as a single immunohistochemical marker is limited by its specificity, its combination with MDM2 and CDK4 IHC may help discriminate ALT-WDLPS/DDLPS.

Wild-type VHL Clear Cell Renal Cell Carcinomas Are a Distinct Clinical and Histologic Entity: A 10-Year Follow-up.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is an aggressive tumor with 50% risk of metastases at initial diagnosis or at follow-up. An inactivation of the tumor-suppressor gene von Hippel-Lindau (VHL) is present in >70% of sporadic cases by two of three different mechanisms: locus deletion, gene mutation, or promoter hypermethylation. OBJECTIVE: To correlate the complete status of the VHL gene with clinical and pathologic criteria. DESIGN, SETTING, AND PARTICIPANTS: We retrospectively included 98 patients with ccRCC who underwent surgery between 2002 and 2005. VHL gene deletions (71 of 98; 72.4%), mutations (68 of 98; 69.4%), and promoter hypermethylations (13 of 98; 13.3%) were screened by gene copy analysis, gene sequencing, and methylation-specific multiplex ligation-dependent probe amplification, respectively. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Relationships between VHL subgroups and the studied criteria were analyzed using chi-square and Student t tests. Survival was analyzed with the log-rank test and Kaplan-Meier curves. RESULTS AND LIMITATIONS: Compared with ccRCCs with two events (66.3%), tumors with no or one genetic event (33.6%) were associated with a higher nuclear grade IV (p=0.02), metastases (p=0.04), sarcomatoid component (p=0.01), dense lymphocyte infiltrate (p=0.013), and vascular endothelial growth factor overexpression (>30%) (p=0.003), which was also an independent factor after multivariate analysis. Furthermore, wild-type VHL tumors (no inactivating event, 11.2%) were associated with nodal involvement (p=0.019), and patients with this type of tumor had a specific survival of 33 mo compared with patients with ccRCCs having one or two VHL inactivating events (107 mo; p=0.016). The retrospective design with small number of wild-type tumors was a limitation of this work. CONCLUSIONS: This long-term study (10-yr clinical follow-up) confirms that ccRCCs with wild-type VHL are highly aggressive tumors that need to be formally identified. PATIENT SUMMARY: Among activated VHL tumors, the wild-type subgroup defines an aggressive phenotype with worse survival rates, suggesting that these tumors must be more thoroughly screened.

Cytoplasmic PAR-3 protein expression is associated with adverse prognostic factors in clear cell renal cell carcinoma and independently impacts survival.

Clear cell renal cell carcinomas (ccRCCs) represent 70% of renal cancers, and several clinical and histolopathological factors are implicated in their prognosis. We recently demonstrated that the overexpression of PAR-3 protein encoded by the PARD3 gene could be implicated in renal oncogenesis. The object of this work was to study the association of intratumoral PAR-3 expression with known prognostic parameters and clinical outcome. In this aim, PAR-3 expression was assessed by immunohistochemistry in ccRCC tumors of 101 patients from 2003 to 2005. The immunostaining of PAR-3 was scored either as membranous (mPAR-3) or as both membranous and cytoplasmic (cPAR-3). Cytoplasmic PAR-3 was significantly associated with worse histopathological and clinical prognostic factors: Fuhrman grades 3 and 4, tumor necrosis, sarcomatoid component, adrenal invasion, renal and hilar fat invasion, eosinophilic component, a noninactivated VHL gene, higher tumor grade, lymph node involvement, metastasis, and worse clinical Eastern Cooperative Oncology Group and S classification scores. After multivariate analysis, 2 parameters were independently associated with cPAR-3: necrosis and eosinophilic components. In addition, cPAR-3 patients had shorter overall and progression-free survivals independently from strong prognostic validated factors like metastases. A cytoplasmic expression of PAR-3 is therefore implicated in worse clinical and pathological cancer features in ccRCC and could be useful to identify patients with high-risk tumors.

Parallel FISH and immunohistochemical studies of ALK status in 3244 non-small-cell lung cancers reveal major discordances.

INTRODUCTION: Anaplastic lymphoma kinase (ALK) rearrangements occur in 1% to 7% of non-small-cell lung cancers (NSCLCs). Crizotinib, an ALK inhibitor, has been demonstrated to provide dramatic clinical benefits in ALK-positive advanced-stage NSCLC. Fluorescent in situ hybridization (FISH) has been established in clinical trials as the standard procedure method for detecting ALK rearrangements. Although the detection of ALK by immunohistochemistry (IHC) has been proposed for the screening of patients, large-scale studies are warranted to validate such a hierarchical approach. METHODS: In this article, we report the largest series thus far of parallel FISH and IHC ALK testing in 3244 consecutive NSCLC cases analyzed at two independent French centers. RESULTS: FISH-positive and/or IHC-positive results were demonstrated in 150 of 3244 cases (4.6%). An imbalanced sex ratio was detected, with women exhibiting a 2.2-fold relative risk for an alteration. Strikingly, only 80 of 150 specimens were classified as ALK positive by both techniques. The specimens with discordant FISH/IHC analyses were FISH-positive/IHC-negative (36), FISH-negative/IHC-positive (19), or FISH-noncontributive/IHC-positive (15). Thus, a single FISH or IHC analysis performed alone would have failed to detect approximately one-fourth of the ALK-positive cases with similar findings in our two centers. CONCLUSIONS: This study highlights the feasibility of systematic NSCLC testing by both FISH and IHC in routine practice. Many preanalytical factors may account for the apparent discrepancies between both methods, suggesting that hierarchical screening may underscore ALK-positive cases. This significant level of discrepancy supports the need of combined testing to optimize the detection of ALK-inhibitor-eligible patients given that some patients with discordant testing were found to respond to crizotinib.

Postnatal diagnosis of 9q interstitial imbalances involving PTCH1, resulting from a familial intrachromosomal insertion.

Insertions are rare chromosomal rearrangements resulting from a three breaks mechanism. The risk of chromosomal imbalance in the offspring is estimated to be 15-50%. We have identified a familial history of direct, paracentric intrachromosomal 9q insertion, balanced in healthy members. For intrachromosomal insertions, unbalanced products in the offspring are always recombinants and in our case, reciprocal deletion and duplication of the inserted segment (9q22.31-9q31.1) were observed. These imbalances involved several genes, including PTCH1. PTCH1 haploinsufficiency causes Gorlin syndrome, an autosomal dominant disorder usually linked to the gene mutation but sometimes due to a 9q deletion. Clinical findings are different in 9q deletions and duplications including PTCH1, notably concerning the predisposition to benign and malignant tumors reported in the Gorlin syndrome. Furthermore, some features may be reciprocal. This history of intrachromosomal insertion highlights the importance of morphological cytogenetic analyses to provide an accurate genetic counseling.

MLL-SEPT5 fusion transcript in infant acute myeloid leukemia with t(11;22)(q23;q11).

Chromosomal rearrangements involving the MLL gene at band 11q23 are the most common genetic alteration encountered in infant acute myeloid leukemia. Reciprocal translocation represents the most frequent form of MLL rearrangement. Currently, more than 60 partner genes have been identified. We report here a case of de novo acute myeloid leukemia with a t(11;22)(q23;q11) in a 23-month-old child. Fluorescence in situ hybridization study revealed that the 3'MLL segment was translocated onto the derivative chromosome 22 and the breakpoint on chromosome 22 was located in or near the SEPT5 gene at 22q11.21. Long distance inverse-polymerase chain reaction was used to identify precisely the MLL partner gene and confirmed the MLL-SEPT5 fusion transcript. Involvement of the SEPT5 gene in MLL rearrangement occurs very rarely. Clinical, cytogenetic and molecular features of acute myeloid leukemia with a MLL-SEPT5 fusion gene are reviewed.