ALK Protein Expression Research Articles

PD-L1/PD-1 Check Point in Anaplastic Large Cell Lymphoma, ALK+: A Case Report with Immunohistochemical and Molecular Study

Anaplastic large cell lymphoma, ALK+ (ALK+ ALCL) is a T-cell lymphoma consisting of large and pleomorphic lymphoid cells, often with horseshoe-shaped nuclei, with a chromosomal translocation involving the ALK gene and expression of ALK protein and CD30. ALK+ ALCL must be distinguished from primary cutaneous ALCL and from other subtype of T-cell or B-cell lymphoma with anaplastic features and/or CD30 expression. PD-L1/PD-1 check point physiologically plays a key role in induction and maintenance of immune tolerance to self-antigens and limits normal immune response against microorganisms. PD-L1 has been demonstrated in the whole spectrum of normal hematopoietic and non-hematopoietic cells, as well as in a large variety of epithelial cells. Moreover, it is also very commonly expressed by a large number of malignant cell types of epithelial and hematopoietic cell origin, and its activation is one of the major mechanisms exerted by neoplastic cells to evade elimination by the host immune system. Here we report a case of an ALK+ ALCL, with confirmed FISH rearrangement of ALK gene, PD-L1-positive and discuss the molecular mechanism involved in its immunohistochemical profile.

A study of EGFR wild-type non-small cell lung cancer ALK genetic mutation

Background: the positive rate and clinicopathological features of EML4-ALK, the relationship between EGFR mutations in non-small cell lung cancer (NSCLC) patients are the state of confusion, automatic immunohistochemistry to detect the expression of ALK protein, to provide reference for clinical diagnosis and treatment.

Effect and mechanism of silibinin on the inhibition of ALK positive NSCLC cells by sensitizing crizotinib

Objective: To explore the synergistic effect of silibinin combined with crizotinib on anaplastic lymphoma kinase positive (ALK+ ) non-small cell lung cancer (NSCLC) cells and its mechanism. Methods: H2228 and H3122 cells were treated with silibinin, crizotinib alone or in combination. Cell proliferation was measured by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and colony formation assay. Migration or invasion ability was tested by wound healing assay or transwell assay, respectively. Expressions of E-Cadherin and vimentin protein were examined by immunofluorescence staining. The protein expressions of ALK, p-ALK, E-Cadherin and Vimentin were detected by western blotting.The anti-cancer effect of silibinin combined with crizotinib in vivo was determined by subcutaneously injecting 2×10(6) H2228 cells into immunodeficient nude mice. Results: The result of MTT assay showed that the cell viability of H2228 or H3122 treated with 100 μmol/L silibinin was (88.38±4.10)% or (72.27±3.62)%, respectively, marginally decreased compared with that of the control. The 50% inhibitory concentration (IC(50)) of H2228 cells treated with crizotinib alone or combined with 100 μmol/L silibinin was (917.10±7.75) nmol/L or (238.73±7.67) nmol/L, respectively. The IC(50) of H3122 cells treated with crizotinib alone or combined with 100 μmol/L silibinin was (472.50±15.70) nmol/L or (206.10±12.01) nmol/L, respectively. The IC(50s) of H2228 and H3122 cells were significantly decreased by combined treatment of crizotinib and silibinin compared to crizotinib treatment alone (P<0.01). When compared with the control group, colony forming ratios of H2228 cells were (83.34±2.72)% in 100 μmol/L silibinin treatment group, (69.42±3.06)% in 400 nmol/L crizotinib treatment group and (27.32±1.42)% in combined treatment group. When compared with the control group, colony forming ratios of H3122 cells were (84.45±5.67)% in 100 μmol/L silibinin treatment group, (45.02±5.83)% in 400 nmol/L crizotinib treatment group and (17.43±3.83)% in combined treatment group. Silibinin combined with crizotinib treatment significantly inhibited the colony formation ability of H2228 and H3122 cells (P<0.01). Migration and invasion results showed that combined treatment of crizotinib and silibinin markedly inhibited the migration and invasion ability of H2228 cells (P<0.01). Western blot results indicated that treated with silibinin alone or in combination of crozitinib for 48 hours, the protein level of E-cadherin in H2228 cells was upregulated, while the expressions of p-ALK and vimentin were downregulated, without obvious alteration of ALK protein expression. In the xenograft model, the mean tumor weight was (9.40±2.58)g in crizotinib treatment group and (4.58±1.07)g in the combined treatment group. The inhibitory effect of tumor growth in vivo of combined treatment was significantly superior to that of crizotinib treatment alone (P<0.05). Conclusion: Silibinin enhances the inhibitory effect of crizotinib on ALK positive NSCLC cells, which may be associated with suppression of ALK activity and mesenchymal-epithelial transition.

INTERRELATION OF THE EXPRESSION OF PROTEINS ALK, HER2 AND AMPLIFICATION OF THE GENE OF HER2 WITH THE PROLIFERATIVE ACTIVITY AND SURVIVAL IN PATIENTS WITH STAGE I-II LUNG ADENOCARCINOMA

To investigate protein content of ALK, Her2 and gene of Her2, CEP17 in interrelation with proliferative activity and survival in I-II stages lung adenocarcinoma cases. There were investigated 82 surgery samples taken from I-II stage lung adenocarcinoma patients. With the use of immunohistochemical method ALK protein (clone D5F3, Ventana), Her2 protein (clone 4B5, Ventana), topoizomerase IIα (clone JS5B4, Ventana), Ki-67 (clone MIB-1, Dako) were determined, Her2 gene was investigated with the use of the SISH method (Ventana) also. The positive expression of ALK is detected in 4(5%) cases, Her2 - in 16(20%) cases and amplification of Her2 gene - in 7(9%) cases. In lung adenocarcinoma with positive expression of ALK protein and amplification of Her2 gene low proliferative activity was noted (on labeling index Ki-67 and topoizomerase IIα). The survival of lung adenocarcinoma patients was less in cases of a positive expression of ALK protein in comparison with patients with the negative expression (difference is not reliable). Statistically significant low survival rates of patients is found in cases with amplification of Her2 gene. According to data mono- and multifactor regression analysis the amplification of Her2 gene has been interrelated with the poor forecast. Mutation of ALK gene and amplification of Her2 gene are interrelated with the proliferative activity and survival rate of lung adenocarcinoma patients.

Dichotomous ALK-IHC Is a Better Predictor for ALK Inhibition Outcome than Traditional ALK-FISH in Advanced Non-Small Cell Lung Cancer.

Purpose: ALK rearrangement detection using FISH is the standard test to identify patients with non-small cell lung carcinoma (NSCLC) eligible for treatment with ALK inhibitors. Recently, ALK protein expression in resectable NSCLC showed predictive value. We evaluated tumor response rate and survival after crizotinib treatment of patients with advanced NSCLC with ALK activation using both dichotomous immunohistochemical (IHC) staining and FISH.Experimental Design: Patients with stage IV NSCLC treated with crizotinib were selected. Tumor response was assessed. ALK rearrangements were detected by FISH (Vysis ALK-break-apart FISH-Probe KIT) and IHC [Ventana ALK (D5F3) CDx assay]. Cohorts of patients with ALK-FISH-positive advanced NSCLC from four other hospitals were used for validation.Results: Twenty-nine consecutive patients with ALK-positive advanced NSCLC diagnosed by FISH and/or IHC on small biopsies or fine-needle aspirations (FNA) were treated with ALK inhibitors. All ALK-IHC-positive patients responded to crizotinib except three with primary resistance. No tumor response was observed in 13 ALK-FISH-positive but ALK-IHC-negative patients. This was confirmed in an external cohort of 16 patients. Receiver operator characteristic (ROC) curves for ALK-IHC and ALK-FISH compared with treatment outcome showed that dichotomous ALK-IHC outperforms ALK-FISH [tumor response area under the curve: (AUC), 0.86 vs. 0.64, P = 0.03; progression-free survival (PFS): AUC 0.86 vs. 0.36, P = 0.005; overall survival (OS): AUC, 0.78 vs. 0.41, P = 0.01, respectively].Conclusions: Dichotomous ALK-IHC is superior to ALK-FISH on small biopsies and FNA to predict tumor response and survival to crizotinib for patients with advanced NSCLC. Our data strongly suggest adapting the guidelines and using dichotomous ALK-IHC as standard companion diagnostic test to select patients with NSCLC who benefit from ALK-targeting therapy. Clin Cancer Res; 23(15); 4251-8. ©2017 AACR.

ALK Expression Is a Novel Marker for the WNT-activated Type of Pediatric Medulloblastoma and an Indicator of Good Prognosis for Patients.

ALK gene rearrangements were identified in a variety of cancers, including neuroblastoma, where the presence of ALK expression is associated with adverse prognosis. ALK mutations have recently been found in the pediatric brain tumor medulloblastoma, and microarray data indicate that ALK is highly expressed in a subset of these tumors. Therefore, we investigated whether ALK expression correlates with transcriptional profiles and clinical features of medulloblastoma. Tumors from 116 medulloblastoma patients were studied at diagnosis for the detection of ALK expression at the RNA level by an application of NanoString technology and at the protein level by immunohistochemistry using antibody ALK clone D5F3. The results indicate that ALK expression, at both the RNA and the protein levels, is strongly associated with the WNT-activated type of tumors and therefore may serve as a useful marker for the detection of this type of medulloblastoma. Importantly, ALK protein expression alone is also an indicator of good prognosis for medulloblastoma patients.

ALK protein expression in pulmonary adenocarcinoma of Tunisian patients

ABSTRACTBackground. It is now necessary to determine ALK status in order to use targeted therapy. Aim: herein, we assess immunohistochemical profile of ALK protein in a series of Tunisian patients with pulmonary adenocarcinoma.Materials and Methods. ALK protein expression was studied applying the D5F3 antibody with a fully automated Ventana CDx technique on a series of 19 patients.Results. Positive ALK expression was found in one case (5.2%) corresponding to a papillary adenocarcinoma which showed a strong granular and homogenous cytoplasmic staining. The patient was a 30-years-old woman.Conclusion. The frequency of positive ALK expression based on immunohistochemistry in our series was similar to that reported in the world literature.

P1.02-042 Detection of ALK Protein Expression in Lung Adenocarcinomas, a Consecutive Series of Cases from Northeastern Brazil

There have been very few studies on ALK status in lung adenocarcinomas in Latin American population. No prior reports in Northeastern Brazil have been published. We analyzed ALK protein expression with a specific antibody (D5F3 clone) with the Ventana system in a series of consecutive cases from Northeastern Brazil, a previously untested population, and correlated with histologic subtypes according to the 2015 WHO Classification. A total of 94 patients (55% female, mean age 62 years) were tested, including 51 solid, 29 acinar, 6 lepidic, 6 papillary predominant and 2 sarcomatoid carcinomas with adenocarcinoma components. There were 9 positive cases (9.5%), 5 solid predominant, 3 acinar predominant and 1 lepidic. One of the 3 acinar cases had a mucinous component. The positive cases were more often male (p<0.05) with no significant differences in relation to age, smoking history or histologic subtype. The negative cases showed a 32% EGFR mutation rate. Follow-up will be presented. We will describe a series of consecutive adenocarciomas from a population with unknown ALK status with a higher than expected rates, and correlate with the 2015 WHO Classification of Tumors.

P1.02-046 ALK IHC is Highly Sensitive to Fixation Parameters

An ALK genetic translocation event occurs in ∼2-7% of non-small cell lung carcinoma patients (NSCLC), resulting in the constitutive expression of an active chimeric ALK protein, which leads to tumor proliferation. Ventana has developed a fully automated immunohistochemistry (IHC) assay using the VENTANA anti-ALK (D5F3) Rabbit Monoclonal Primary Antibody (ALK (D5F3)) to detect the ALK protein in formalin fixed paraffin embedded tissue. ALK IHC testing is becoming more widespread in NSCLC; however, information concerning the impact of pre-analytical conditions on the ALK antigen is limited. We used human cell lines expressing ALK, generated as xenografts to evaluate the effect of Fixation Type, Time, and Delay to Fixation (Ischemia) on the ALK antigen as measured by the ALK (D5F3) antibody staining intensity. NCI-H2228 human NSCLC cell lines were used to generate xenograft tumors in SCID mice. In order to assess ischemia (delay to fixation) H2228 xenografts were used to model ischemia in 10% NBF. The impact of fixation on staining performance of the ALK (D5F3) primary antibody was assessed using the H2228 xenografts to model fixation type and fixation time for 10% NBF, Zinc Formalin, 95% Alcohol, Alcoholic Formalin Acid, B5, and Prefer for 1, 6, 12, 24 and 72 hours. Each of the stained slides were evaluated by a pathologist using a qualitative assessment and scored on a 0-3+ intensity scale (0 = no staining detected, 1+= weak staining detected, 2+= moderate staining detected, 3+ = strong staining detected). Fixation in all time points in B5, Prefer, and AFA, as well as ethanol, severely compromised staining intensity of ALK (by decreasing staining intensity greater than 0.5 points). Ischemia greater than 6 hours also decreased staining intensity. In contrast, EGFR (5B7) and TTF1 (SP141) antigens were robust across a wide range of fixation times and types, as well as ischemia times. The ALK antigen is highly sensitive to fixative time, type and ischemia. The data indicate that the detection of ALK by IHC is impacted by fixation conditions. Strikingly, antigens detected by other lung antibodies (EGFR, TTF1) are more robust in comparison across a range of conditions. Standardized pre-analytical conditions are critical to achieve appropriate staining for ALK IHC and to mitigate the risk of false negative results. The recommendations for pre-analytical conditions for ALK are to fix at least 6 hours in 10% neutral buffered formalin.

Correlation among Genetic Variations of c-MET in Chinese Patient with Non-Small Cell Lung Cancer

Aims: The aim of this study was to determine the relationship between amplification, protein expression and somatic mutation of c-MET in advanced Non-small cell lung cancer. The influence of c-MET abnormalities on clinical outcomes of patients undergoing Crizotinib therapy for treatment of Non-Small Cell Lung Cancer was also evaluated. Methods: c-MET protein expression, gene copy number (GCN) and somatic mutation for exon 14 were detected by Immunohistochemistry, fluorescent In Situ Hybridization and Denaturing High Performance Liquid Chromatography, respectively, in a large series of 196 NSCLC patients. The correlation of c-MET abnormalities and clinical outcome of targeted therapy was analyzed by McNemar’s test. Results: c-MET expression was observed in 28.6% (56/196) cases, and among those 13.8% (27/196) was shown to be FISH positive. Only 2.67% patients in this study carried the c-MET mutation. All cases that were c-MET FISH positive were also shown to express c-MET by IHC. However, only half of the cases that were positive for c- MET expression were found to be FISH positive. Among 31 patients with moderate c-MET IHC staining, 11 cases (35.5%) were FISH positive, while 16/25 cases with high IHC staining were also FISH positive. Six patients received Crizotinib as a first-line or second/third-line therapy. Among them, three cases showed ALK protein expression, two patients showed expression of the ROS1 fusion gene, and one was positive for c-MET expression by IHC. The response to Crizotinib in the three patients positive for ALK were all PR, while the c-MET positive patient showed SD and both cases with expression of the ROS1 gene showed PD. Conclusions: IHC could be a preliminary screening test to facilitate selection of patients with c-MET amplification for ALK inhibitor therapy.

P3.02a-010 Evaluation of Aberrant ALK Expression in Lung Cancer by RT-PCR and Comparison with FISH and Immunohistochemistry: Topic: ALK Biomarkers

In advanced lung cancer patients the gold standard for detecting ALK gene rearrangements is fluorescence in situ hybridization (FISH), and ALK protein expression can be also evaluated by immunohistochemistry (IHC). A single analysis performed alone may not detect all the ALK-positive cases and some patients with discordant FISH and IHC respond to tyrosine kinase inhibitors (TKIs). In this study we evaluated ALK aberrant expression in lung cancer patients by a reverse-transcription (RT)-PCR, to investigate its clinical utility and its concordance with FISH and IHC. ALK aberrant expression was retrospectively investigated on RNA from formalin-fixed paraffin-embedded tissue (FFPEt) of 24 advanced lung adenocarcinoma patients, previously evaluated by FISH and IHC. We used a one-step Scorpion RT-PCR that allowed in a single reaction either the mRNA reverse transcription and the cDNA amplification for ALK kinase-domain, normally not expressed, and a control gene, to assess RNA quality. Results are reported in Table 1. Despite the instability of mRNA from FFPEt, only 2 samples resulted inadequate for RT-PCR. RT-PCR was in disagreement with both FISH and IHC in one case, which is likely to be a RT-PCR false positive. RT-PCR did not detect ALK aberrant expression in a FISH positive case, which was negative also by IHC; unfortunately, this patient died after a cycle of pemetrexed therapy, before undergoing a second line TKI treatment. The presence of ALK rearrangements does not necessarily imply increased protein levels, because of the complex transcriptional and post-transcriptional regulations, so further analysis at RNA levels may clarify discrepancy between FISH and IHC allowing a better stratification of patients who could benefit from TKIs. Therefore, according to our results the RT-PCR evaluating ALK aberrant expression regardless of the fusion partners should be considered for introduction into routine ALK testing in lung cancer.

Expression of ALK protein in 7 371 pulmonary adenocarcinoma samples, with analysis of clinicopathologic features

To study the expression of ALK protein in pulmonary adenocarcinoma as detected by Ventana immunohistochemistry, with correlation of clinicopathologic features. Immunohistochemical study for ALK protein using Ventana ALK (D5F3) kit was carried in 7 371 pulmonary adenocarcinoma samples. The clinicopathologic features were subsequently analyzed. ALK fusion protein was detected in 446 of the 7 371 lung adenocarcinoma samples studied (6.05%). The ALK positivity rate in small biopsy samples was higher than that in surgical specimens [9.02% (153/1 696) versus 5.16% (293/5 675); P<0.01]. ALK fusion protein expression correlated with patient age, sample type and smoking history. ALK positivity rate in each age group increased with younger patient age. ALK positivity rate was 45.45% (10/22) in patients younger than 30 years old. The positivity rate of ALK fusion protein in adenocarcinoma in-situ, minimally invasive adenocarcinoma and invasive adenocarcinoma was 0, 0.48% (2/418) and 5.63% (291/5 165), respectively. The differences of ALK positivity rate amongst different subtypes had statistical significance (P<0.01). Invasive mucinous adenocarcinoma had highest ALK positivity rate, followed by invasive adenocarcinoma with predominantly solid pattern. ALK fusion protein is more often found in young patients with pulmonary adenocarcinoma, especially in those younger than 30 years old. ALK fusion protein is rarely expressed in early-stage pulmonary adenocarcinoma. Invasive mucinous adenocarcinoma and invasive adenocarcinoma with solid pattern have higher ALK positivity rate than other adenocarcinoma subtypes.

ALK+ lung adenocarcinoma in never smokers and long-term ex-smokers: prevalence and detection by immunohistochemistry and fluorescence in situ hybridization.

ALK gene rearrangements are identified in 2-5% of all non-small cell lung cancer and are more common in lifetime non-smokers with adenocarcinoma, but the prevalence of ALK rearrangements is not as well characterized in long-term ex-smokers (quit >10years prior to diagnosis). Accurate and timely diagnosis of ALK-rearranged tumors is of clinical importance given the remarkable response to targeted inhibitors. ALK gene rearrangement may be detected by fluorescence in situ hybridization (FISH), and abnormal expression of ALK protein may be detected by immunohistochemistry (IHC), the latter of which is faster and less expensive. The aim of this study is to evaluate the prevalence of ALK rearrangement in non-smokers and long-term ex-smokers with lung adenocarcinoma and to assess the performance of IHC for the detection of ALK+ tumors when compared to FISH. Two hundred fifty-one cases of resected lung adenocarcinoma were retrospectively reviewed, including non-smokers (n=79) or long-term ex-smokers (n=172). ALK IHC and ALK FISH were performed on each case. Four cases demonstrated ALK rearrangement by FISH (4/251; 1.6%). All cases were non-smokers (4/79; 5.1%), and all were positive for ALK by IHC. No additional cases were considered positive by IHC, and only 26 (10.4%) cases were considered equivocal using a conservative approach to interpretation, resulting in a sensitivity of 100% and specificity of 89.5%. ALK rearrangement was not observed in lung adenocarcinoma arising in long-term ex-smokers, whereas it is seen in up to 5.1% of lifetime non-smokers. ALK IHC using the 5A4 antibody demonstrates high sensitivity, supporting its use as a screening test.

Inconsistent results in the analysis of ALK rearrangements in non-small cell lung cancer.

BackgroundIdentification of targetable EML4-ALK fusion proteins has revolutionized the treatment of a minor subgroup of non-small cell lung cancer (NSCLC) patients. Although fluorescence in situ hybridization (FISH) is regarded as the gold standard for detection of ALK rearrangements, ALK immunohistochemistry (IHC) is often used as screening tool in clinical practice. In order to unbiasedly analyze the diagnostic impact of such a screening strategy, we compared ALK IHC with ALK FISH in three large representative Swedish NSCLC cohorts incorporating clinical parameters and gene expression data.MethodsALK rearrangements were detected using FISH on tissue microarrays (TMAs), including tissue from 851 NSCLC patients. In parallel, ALK protein expression was detected using IHC, applying the antibody clone D5F3 with two different protocols (the FDA approved Ventana CDx assay and our in house Dako IHC protocol). Gene expression microarray data (Affymetrix) was available for 194 patients.ResultsALK rearrangements were detected in 1.7 % in the complete cohort and 2.0 % in the non-squamous cell carcinoma subgroup. ALK protein expression was observed in 1.8 and 1.4 % when applying the Ventana assay or the in house Dako protocol, respectively. The specificity and accuracy of IHC was high (> 98 %), while the sensitivity was between 69 % (Ventana) and 62 % (in house Dako protocol). Furthermore, only 67 % of the ALK IHC positive cases were positive with both IHC assays. Gene expression analysis revealed that 6/194 (3 %) tumors showed high ALK gene expression (≥ 6 AU) and of them only three were positive by either FISH or IHC.ConclusionThe overall frequency of ALK rearrangements based on FISH was lower than previously reported. The sensitivity of both IHC assays was low, and the concordance between the FISH and the IHC assays poor, questioning current strategies to screen with IHC prior to FISH or completely replace FISH by IHC.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2646-x) contains supplementary material, which is available to authorized users.

Advances in the clinicopathological and molecular classification of cutaneous mesenchymal neoplasms.

In recent years, there have been several important refinements in the classification of cutaneous mesenchymal neoplasms, including the description of new tumour types, along with the identification of novel and recurrent molecular genetic findings. In addition to providing new insights into tumour biology, many of these advances have had significant clinical consequences with regard to diagnostics, management, and prognostication. Newly described entities include pseudomyogenic haemangioendothelioma, haemosiderotic fibrolipomatous tumour, and fibroblastic connective tissue naevus, which are reviewed in the context of the principal differential diagnoses and significant clinical implications. Genetic characterization of several soft tissue tumour types that occur in the skin has resulted in the identification of diagnostically useful markers: ALK gene rearrangement with corresponding ALK protein expression by immunohistochemistry in epithelioid fibrous histiocytoma; the WWTR1-CAMTA1 fusion gene with CAMTA1 protein expression in epithelioid haemangioendothelioma; MYC amplification and overexpression in radiation-associated angiosarcoma; and EWSR1 gene rearrangement in cutaneous myoepithelial tumours. Finally, the classification of intradermal smooth muscle tumours and unclassified/pleomorphic dermal sarcoma has been refined, resulting in both improved classification and improved prognostication. Many of the tumour types listed above are encountered not only by specialist dermatopathologists, but also by practising general surgical pathologists, and this review should therefore provide a widely applicable update on the histological and molecular classification of cutaneous mesenchymal neoplasms, along with the appropriate use of ancillary diagnostic tests, in particular immunohistochemistry, in the evaluation of such lesions and their histological mimics.

Synergistic Activation upon MET and ALK Coamplification Sustains Targeted Therapy in Sarcomatoid Carcinoma, a Deadly Subtype of Lung Cancer

IntroductionGenetic alterations suitable for targeted therapy are poorly known issues in pulmonary sarcomatoid carcinoma (PSC), an uncommon and life-threatening family of non–small cell lung cancers. MethodsNinety-eight PSCs were assessed for MNNG HOS Transforming gene (MET) and anaplastic lymphoma receptor tyrosine kinase gene (ALK) status by fluorescence in situ hybridization (FISH) and for relevant protein expression by immunohistochemical analysis, also taking advantage of phosphorylated (p-) antibodies. Moreover, levels of ALK and MET mRNA were also determined by real-time polymerase chain reaction and Western blot analysis for downstream activation pathways involving p-MET, p–protein kinase B, p–mitogen-activated protein kinase, p-SRC proto-oncogene tyrosine-protein kinase, and p–focal adhesion kinase (p-FAK). ResultsMET amplification was detected by FISH in 25 of 98 PSCs (25.6%) and ALK amplification (but not the relevant rearrangement) was found in 16 of 98 (16.3%), with all ALK-amplified tumors also showing MET amplification (p < 0.0001). Nine PSCs, however, showed MET amplification without any ALK gene alteration. ALK protein expression was always lacking, whereas MET and p-MET were confined to the relevant amplified tumors only. Increased levels of ALK and MET mRNA were detectable in tumors with no direct relationship between mRNA content, protein expression, or alterations detected by FISH. Western blot assays showed complete activation of downstream signal pathways up to p-SRC proto-oncogene tyrosine-protein kinase, and p–focal adhesion kinase recruitment in MET and ALK–coamplified tumors only, whereas isolated MET amplification, MET and ALK borderline amplification (5%–10% of tumor cells with ≥15 copies of the relevant gene), or negative tumors showing eusomy or chromosome polysomy were confined to p–mitogen-activated protein kinase, p–protein kinase B, and/or p-MET activation. Multivariate survival analysis pushed a higher percentage of MET altered cells or a higher value of MET copy gain per cell to marginally emerge for overall survival (p = 0.140) and disease-free survival (p = 0.060), respectively. ConclusionsALK and MET seemed to act as synergistic, nonrandom coactivators of downstream signal when coamplified in a subset of patients with PSC, thus likely suggesting a combined mechanism of oncogene addiction. These alterations could be a suitable target for therapy based on specific inhibitors.

Comprehensive profiling of renal medullary and collecting duct carcinomas.

572 Background: Renal medullary carcinoma (RMC) is an aggressive malignancy affecting predominantly young African Americans with sickle cell trait (SCT) or disease (SCD), while a pathologically similar collecting duct carcinoma (CDC) affects patients without sickle cell trait. Clinical responses to chemotherapy and IL-2 in RMC/CDC are poor and novel therapies are needed. Methods: 9 patients with RMC (ages 13-58 y. o., all male) and 15 patients (ages 26-74 y. o., M:F = 13:2) with collecting duct carcinoma (CDC) were studied. Expression of PD-L1 was evaluated with 2 monoclonal antibodies (SP142 and SP263) and tumor infiltrating lymphocytes (TIL) were evaluated for PD1 expression (MRQ-22 antibody) using immunohistochemistry (IHC). Additional studies included ALK protein expression (D5F3 antibody), gene translocation (break apart FISH), next generation sequencing (NGS), and microsatellite instability (MSI). Results: Cancer cell PD-L1 expression above the threshold ( ≥ 2+, ≥ 5%) was seen in 7/9 RMC and 5/13 CDC cases. Concordance between 2 PD-L1 antibodies was 94.4%. PD-1+ TIL were absent in 6/18 cases and variably present in 12/18 cases (from 1 to &gt; 15 TIL/40x power field). No MSI was detected in any of the cases tested (0/6). No case expressed ALK protein, but one case of CDC showed ALK gene re-arrangement. Mutations were identified in SMARCB1, FH, TP53 (3x), ATM, BRCA2, CHEK2 (2x), NF2 (3x), SETD2, and CDKN2A. No mutations in VHL or KDR were detected. One patient with RMC (and SCT) achieved complete clinical remission after treatment with bevacizumab plus paclitaxel. Conclusions: RMC and CDC strongly express PD-L1 in the majority of cases (12/22), suggesting that these patients may benefit from targeting the PD-L1/PD1 interaction. The absence of MSI in these cancers indicates a different mechanism of PD-L1 upregulation from colorectal carcinomas. Consistent with our previous study that showed frequent activation of (pseudo)hypoxia-induced pathways in RMCs (Human Pathology 2011;42:1979), we describe a case of RMC successfully treated with anti-VEGF therapy.

A standardized protocol for detection of ALK protein expression and gene fusion in lung adenocarcinoma cytologic specimens

The aim of this study was to establish a standardized protocol for detection of ALK protein expression and gene fusion in cytologic specimens. Lung adenocarcinoma cytologic specimens were collected from seven hospitals in Beijing city. A detection protocol for ALK protein expression and gene fusion was designed according to the results of comparative experiment. Ventana immunohistochemical (IHC) ALK(D5F3) detecting ALK protein expression was performed in 203 prepared formalin-fixed paraffin-embedded (FFPE) cell blocks. ALK gene fusion in 98 EGFR gene wild type cytologic specimens and in 4 bronchoalveolar lavage fluid (BL) samples was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). ALK gene fusion in the Ventana IHC ALK (D5F3) positive samples was further tested by fluorescence in situ hybridization (FISH). Six patients with ALK IHC-positive result were followed up to analyze the responses of crizotinib therapy. Comparative experiments: (1) Comparison of the results of 4% neutral buffered formalin fixed for different time (24 h, 48 h, 72 h) on the Ventana IHC ALK (D5F3) staining was conducted in two cases of IHC ALK positive FFPE cell blocks; (2) Comparing qRT-PCR results for ALK fusion in samples from FFPE cell blocks and cytospin prepared slides in 10 cases of lung adenocarcinoma cytologic specimens. Among the specimens examined using the standardized protocol recommended by this study, 229 cases of cytologic specimens met the diagnostic criteria of lung adenocarcinoma. Among them, 207 cases obtained ALK gene test results (by at least one method), with an ALK test ratio of 90.4% (207/229). FFPE cell blocks were successfully prepared in 203 cases, Ventana IHC ALK (D5F3) were successfully performed in all the 203 FFPE cell blocks (100%), and the ALK protein positive detection rate was 10.3% (21/203). ALK fusion was tested in 98 FFPE cytologic samples of EGFR wild types by qRT-PCR, and 96 out of 98 (97.96%) cytologic samples were successfully performed.18 out of 19 IHC ALK-positive cases were verified to be of ALK fusion status by qRT-PCR. The concordance rate was 94.7% (Kappa=0.967, P<0.001) between Ventana IHC ALK (D5F3) and qRT-PCR, and the sensitivity of the Ventana IHC ALK (D5F3) assay compared with qRT-PCR was 100% and the specificity was 98.7%. FISH assay was used to verify the positive cases detected by Ventana IHC ALK (D5F3) staining. Two cases of low tumor cell content FFPE samples obtained indefinite results by FISH test. The six patients with positive ALK protein expression received crizotinib therapy, and 5 paitents got treated effectively. For two ALK IHC positive cases, which were 4% neutral buffered formalin fixed for 72 h, the result of Ventana IHC ALK (D5F3) staining became weakened obviously and uneven. In 10 cases of samples, total RNA was extracted from FFPE cytologic sections and cytospin prepared slides, and the results of qRT-PCR test and ALK gene fusion showed good concordance. The standardized protocol recommended in this study expands the detection types and quantity of cytologic specimens for ALK protein expression and gene fusion and increased the detection rate. Ventana IHC ALK (D5F3) is a reliable method for detecting ALK protein expression in FFPE cell blocks. The pathologic quality control procedure prior to Ventana IHC ALK (D5F3) is crucial for the accuracy of testing the ALK gene status. When FFPE cell blocks could not be prepared or prepared unsuccessfully from the cytologic specimens, qRT-PCR may be an alternative option for the detection of ALK gene fusion.

ALK rearrangement and overexpression in epithelioid fibrous histiocytoma

Epithelioid benign fibrous histiocytoma, also known as 'epithelioid cell histiocytoma,' has traditionally been considered a morphologic variant of cutaneous fibrous histiocytoma (dermatofibroma). In addition to its characteristic epithelioid cytomorphology, several phenotypic differences suggest that epithelioid fibrous histiocytoma may differ biologically from other variants. Recently, ALK rearrangement was described in two cases of epithelioid fibrous histiocytoma and separately in two cases reported as 'atypical' fibrous histiocytoma (with epithelioid features), with corresponding ALK expression detectable by immunohistochemistry. The goals of this study were to determine the frequency of ALK expression by immunohistochemistry in epithelioid fibrous histiocytoma, to determine its value for the diagnosis of epithelioid fibrous histiocytoma among variants and other histologic mimics, and to evaluate ALK gene rearrangement in epithelioid fibrous histiocytoma. ALK protein expression was evaluated in whole tissue sections from 33 epithelioid fibrous histiocytomas, 41 other cases of fibrous histiocytoma (11 conventional and 10 each cellular, atypical, and aneurysmal types), 10 cutaneous syncytial myoepitheliomas, and 5 atypical fibroxanthomas, using a mouse anti-ALK monoclonal antibody. Fluorescence in situ hybridization (FISH) was performed using break-apart probes. In total, 29/33 (88%) cases of epithelioid fibrous histiocytoma showed diffuse cytoplasmic ALK expression. Staining was moderate to strong in intensity in all cases except one, which showed diffuse weak expression. All other tumor types were negative for ALK expression. FISH demonstrated ALK rearrangement in all ALK-immunoreactive cases evaluated (n=13), and not in one ALK expression-negative epithelioid fibrous histiocytoma successfully examined. In conclusion, the majority of epithelioid fibrous histiocytomas demonstrate ALK expression and ALK gene rearrangement. ALK expression is not seen in other variants of fibrous histiocytoma, providing a useful diagnostic tool to distinguish epithelioid fibrous histiocytoma from most histologic mimics. The expression of ALK suggests that epithelioid fibrous histiocytoma is a biologically distinct tumor type, unrelated to conventional fibrous histiocytoma and histologic variants.

Alterations of ALK gene and protein expression in prostatic cancer and its clinical significance

To investigate ALK genomic rearrangements and expression in prostate cancer, and their clinical implications. Two hundred and eighty-one cases of prostate cancer were included. ALK gene rearrangements were assessed by FISH in all cases, and ALK protein expression was assessed by immunohistochemistry in 191 cases. The ALK gene was truncated (mostly 5' deletion) in 18 of 281 (6.4%) cases. EML4-ALK fusion gene was not detected. Genomic rearrangement of ALK gene was not statistically associated with Gleason score, age, TNM or baseline PSA level (P > 0.05). In all 18 cases, there were nuclear expression of ALK protein; in 12 cases, the expression was seen in 5%-30% of the tumor cells, and in the remaining 6 cases, the expression was seen in < 5% of the tumor cells. ALK gene rearrangements occurred in 6.4%, of prostate cancer, and these may not be associated with disease progressions. The ALK protein expresses in the nucleus. The EML4-ALK fusion gene was not found in prostate cancer.