RET Fusion Testing in Patients With NSCLC: The RETING Study.

Introduction: RET inhibitors with impressive overall response rates are now available for patients with NSCLC, yet the identification of RET fusions remains a difficult challenge. Most guidelines encourage the upfront use of next-generation sequencing (NGS), or alternatively, fluorescence in situ hybridization (FISH) or reverse transcriptase-polymerase chain reaction (RT-PCR) when NGS is not possible or available. Taken together, the suboptimal performance of single-analyte assays to detect RET fusions, although consistent with the notion of encouraging universal NGS, is currently widening some of the clinical practice gaps in the implementation of predictive biomarkers in patients with advanced NSCLC. Methods: This situation prompted us to evaluate several RET assays in a large multicenter cohort of RET fusion-positive NSCLC (n = 38) to obtain real-world data. In addition to RNA-based NGS (the criterion standard method), all positive specimens underwent break-apart RET FISH with two different assays and were also tested by an RT-PCR assay. Results: The most common RET partners were KIF5B (78.9%), followed by CCDC6 (15.8%). The two RET NGS-positive but FISH-negative samples contained a KIF5B(15)-RET(12) fusion. The three RET fusions not identified with RT-PCR were AKAP13(35)-RET(12), KIF5B(24)-RET(9) and KIF5B(24)-RET(11). All three false-negative RT-PCR cases were FISH-positive, exhibited a typical break-apart pattern, and contained a very high number of positive tumor cells with both FISH assays. Signet ring cells, psammoma bodies, and pleomorphic features were frequently observed (in 34.2%, 39.5%, and 39.5% of tumors, respectively). Conclusions: In-depth knowledge of the advantages and disadvantages of the different RET testing methodologies could help clinical and molecular tumor boards implement and maintain sensible algorithms for the rapid and effective detection of RET fusions in patients with NSCLC. The likelihood of RET false-negative results with both FISH and RT-PCR reinforces the need for upfront NGS in patients with NSCLC.

Validation of a Pathological Score for the Assessment of Bronchial Biopsies in Severe Uncontrolled Asthma: Beyond Blood Eosinophils.

BACKGROUND: Blood eosinophil count (BEC) is currently used as a surrogate marker of T2 inflammation in severe asthma but its relationship with tissue T2-related changes is elusive. Bronchial biopsy could add reliable information but lacks standardization. OBJECTIVES: To validate a systematic assessment of the bronchial biopsy for the evaluation of severe uncontrolled asthma (SUA) by standardizing a pathological score. METHODS: A systematic assessment of submucosal inflammation, tissue eosinophilic count/field (TEC), goblet cells hyperplasia, epithelial changes, basement membrane thickening, prominent airway smooth muscle and submucosal mucous glands was initially agreed and validated in representative bronchial biopsies of 12 patients with SUA by 8 independent pathologists. In a second phase, 62 patients with SUA who were divided according to BEC≥300cells/mm3 or less underwent bronchoscopy with bronchial biopsies and the correlations between the pathological findings and the clinical characteristics were investigated. RESULTS: The score yielded good agreement among pathologists regarding submucosal eosinophilia, TEC, goblet cells hyperplasia and mucosal glands (ICC=0.85, 0.81, 0.85 and 0.87 respectively). There was a statistically significant correlation between BEC and TEC (r=0.393, p=0.005) that disappeared after correction by oral corticosteroids (OCS) use (r=0.170, p=0.307). However, there was statistically significant correlation between FeNO and TEC (r=0.481, p=0.006) that was maintained after correction to OCS use (r=0.419, p=0.021). 82.4% of low-BEC had submucosal eosinophilia, 50% of them moderate to severe. CONCLUSION: A standardized assessment of endobronchial biopsy is feasible and could be useful for a better phenotyping of SUA especially in those receiving OCS.

Microbiome-derived cobalamin and succinyl-CoA as biomarkers for improved screening of anal cancer.

Human papillomavirus can cause preinvasive, high-grade squamous intraepithelial lesions (HSILs) as precursors to cancer in the anogenital area, and the microbiome is suggested to be a contributing factor. Men who have sex with men (MSM) living with human immunodeficiency virus (HIV) have a high risk of anal cancer, but current screening strategies for HSIL detection lack specificity. Here, we investigated the anal microbiome to improve HSIL screening. We enrolled participants living with HIV, divided into a discovery (n = 167) and validation cohort (n = 46), and who were predominantly (93.9%) cisgender MSM undergoing HSIL screening with high-resolution anoscopy and anal biopsies. We identified no microbiome composition signatures associated with HSILs, but elevated levels of microbiome-encoded proteins producing succinyl coenzyme A and cobalamin were significantly associated with HSILs in both cohorts. Measurement of these candidate biomarkers alone in anal cytobrushes outperformed anal cytology as a diagnostic indicator for HSILs, increasing the sensitivity from 91.2% to 96.6%, the specificity from 34.1% to 81.8%, and reclassifying 82% of false-positive results as true negatives. We propose that these two microbiome-derived biomarkers may improve the current strategy of anal cancer screening.

Recommendations for optimizing the use of cytology in the diagnosis and management of patients with lung cancer.

Non-small cell lung cancer (NSCLC) is one of the oncological entities with the greatest evolution in molecular diagnosis due to the large number of diagnostic biomarkers and new treatments approved by international regulatory agencies. An accurate, early diagnosis using the least amount of tissue is the goal for the establishing and developing precision medicine for these patients. Rapid on-site evaluation (ROSE) provides cytological samples of optimal quantity and quality for a complete diagnosis of NSCLC. The usefulness of cytological samples has been demonstrated, not only for massive parallel sequencing but also for the quantification of the expression of programmed death-ligand 1 (PD-L1) and tumour mutational burden (TMB). Pre-analytical, analytical, and post-analytical recommendations are made for the management and appropriate use of cytological samples in order to obtain all the information necessary for the diagnosis and treatment of patients with NSCLC according to current quality parameters.

Cytological and molecular characterization of secretory breast carcinoma.

Secretory breast carcinoma is a rare neoplasm, histologically well-characterized, and secondary to ETV6-NTRK3 gene fusion, whose cytological features are scarcely described in the literature. We report the case of a woman with a history of secretory breast carcinoma 8 years before, who presented a periareolar nodule. A recurrence was diagnosed by fine-needle aspiration based on the cytomorphological features and pan-TRK immunocytochemistry on the cell block, and the patient underwent a mastectomy. The histology and molecular studies performed on the surgical specimen (immunohistochemistry, FISH and NGS) confirmed the diagnosis. Cytological smears showed abundant epithelial cellularity, in groups and single cells. These cells showed moderate atypia, with abundant cytoplasm. We observed intracytoplasmic inclusions and extracellular metachromatic globules. Immunocytochemical and immunohistochemical studies showed a triple negative breast tumour. NTRK overexpression was demonstrated with immunocytochemistry against pan-TRK on the cell block, as well as with immunohistochemistry in the surgical specimen. NTRK3 rearrangement was proved by FISH. In the primary tumour and in the recurrence, we demonstrated ETV6-NTRK3 fusion by NGS. After conducting a literature review, we have found 26 articles describing the cytological features of secretory breast carcinoma in 33 patients. The smears were described as groups of epithelial cells with vacuolated cytoplasm, single signet ring cells and a globular extracellular secretion. In only two cases molecular confirmation of the diagnosis with ETV6-NTRK3 fusion was proven, although not in the cytological specimen, but in the subsequent biopsy. The distinct cytological features of secretory breast carcinoma can help in its diagnosis, thus guiding the molecular studies. This is the first reported case that proves TRK overexpression, as a fusion surrogate, in the cytological sample.

Acute Dyspnea and Hemoptysis in an 84-Year-Old Man With Multiple Comorbidities.

CASE PRESENTATION: An 84-year-old man with an active smoking habit presented to the ED with dyspnea, hemoptysis, and thick phlegm that was difficult to clear. He reported no weight loss, no fever, and no chest pain or dysphonia. He denied both international travel and previous contact with confirmed cases of TB or SARS-CoV-2. He had no known occupational exposures. The patient's personal history included a resolved complete atrioventricular block that required a permanent pacemaker, moderate-to-severe COPD, rheumatoid arthritis (treated with oral prednisone, 2.5 mg/d) and B-chronic lymphocytic leukemia (treated with methotrexate and prophylactic oral supplements of ferrous sulfate). Moreover, he was in medical follow up because of a peptic ulcer, atrophic gastritis, and colonic diverticulosis. The patient also had a history of thoracic surgery after an episode of acute mediastinitis from an odontogenic infection, which required ICU management and temporal tracheostomy.

Screening for ROS1 fusions in patients with advanced non-small cell lung carcinomas using the VENTANA ROS1 (SP384) Rabbit Monoclonal Primary Antibody.

Introduction: The development of several ROS1 inhibitors means that the importance of accurately identifying ROS1-positive lung cancer patients has never been greater. Therefore, it is crucial that ROS1 testing assays become more standardized.Areas covered: Based on primary literature, combined with personal diagnostic and research experience, this review provide a pragmatic update on the use of the recently released VENTANA ROS1 (SP384) Rabbit Monoclonal Primary Antibody.Expert opinion: This assay provides high sensitivity, so it is an excellent analytical option when screening for ROS1 fusions in patients with advanced non-small cell lung carcinomas.

Canakinumab with and without pembrolizumab in patients with resectable non-small-cell lung cancer: CANOPY-N study design.

Canakinumab is a human IgGκ monoclonal antibody, with high affinity and specificity for IL-1ß. The Canakinumab Anti-Inflammatory Thrombosis Outcome Study (CANTOS) trial, evaluating canakinumab for cardiovascular disease, provided the first signal of the potential of IL-1ß inhibition on lung cancer incidence reduction. Here, we describe the rationale and design for CANOPY-N, a randomized Phase II trial evaluating IL-1ß inhibition with or without immune checkpoint inhibition as neoadjuvant treatment in patients with non-small-cell lung cancer. Patients with stage IB to IIIA non-small-cell lung cancer eligible for complete resection will receive canakinumab or pembrolizumab as monotherapy, or in combination. The primary end point is major pathological response by central review; secondary end points include overall response rate, major pathological response (local review), surgical feasibility rate and pharmacokinetics. Clinical trial registration: NCT03968419 (ClinicalTrials.gov).

Lay abstract A previous study showed that canakinumab reduced the risk of lung cancer in patients with heart disease. Canakinumab blocks an inflammatory protein called IL-1ß that is involved in cancer. Anti-cancer drugs used before surgery ('neo-adjuvant') can improve the success rate of surgery and may help prevent the cancer from returning. Neo-adjuvant trials help us understand how the drugs work and how they affect cancer. CANOPY-N (NCT03968419) is an ongoing randomized, exploratory, Phase II clinical trial testing canakinumab and pembrolizumab (a different cancer immunotherapy), alone or combined, for patients with early non-small-cell lung cancer. The study will test whether treatment can kill most cancer cells in the surgery sample ('major pathological response'). It will also investigate other effects on cancer biology, levels of molecules that measure possible clinical benefit ('biomarkers') and side effects.

Clinical-pathological and molecular characterization of long-term survivors with advanced non-small cell lung cancer.

Objective: Long-term survivors (LS) of non-small cell lung cancer (NSCLC) without driver alterations, displaying an overall survival (OS) of more than 3 years, comprise around 10% of cases in several series treated with chemotherapy. There are classical prognosis factors for these cases [stage, Eastern Cooperative Oncology Group (ECOG), etc.], but more data are required in the literature. In this multi-center study, we focused on LS of advanced NSCLC with OS above 36 months to perform a clinical-pathological and molecular characterization. Methods: In the first step, we conducted a clinical-pathological characterization of the patients. Afterwards, we carried out a genetic analysis by comparing LS to a sample of short-term survivors (SS) (with an OS less than 9 months). We initially used whole-genome RNA-seq to identify differentiating profiles of LS and SS, and later confirmed these with reverse transcription-polymerase chain reaction (RT-PCR) for the rest of the samples. Results: A total of 94 patients were included, who were mainly men, former smokers, having adenocarcinoma (AC)-type NSCLC with an ECOG of 0-1. We obtained an initial differential transcriptome expression, displaying 5 over- and 33 under-expressed genes involved in different pathways: namely, the secretin receptor, surfactant protein, trefoil factor 1 (TFF1), serpin, Ca-channels, and Toll-like receptor (TLRs) families. Finally, RT-PCR analysis of 40 (20 LS/20 SS) samples confirmed that four genes (surfactant proteins and SFTP) were significantly down-regulated in SS compared to LS by using an analysis of covariance (ANCOVA) model: SFTPA1 (P = 0.023), SFTPA2 (P = 0.027), SFTPB (P = 0.02), and SFTPC (P = 0.047). Conclusions: We present a sequential genetic analysis of a sample of NSCLC LS with no driver alterations, obtaining a differential RNA-seq/RT-PCR profile showing an abnormal expression of SF genes.

Assessment of a New ROS1 Immunohistochemistry Clone (SP384) for the Identification of ROS1 Rearrangements in Patients with Non-Small Cell Lung Carcinoma: the ROSING Study.

INTRODUCTION: The ROS1 gene rearrangement has become an important biomarker in NSCLC. The College of American Pathologists/International Association for the Study of Lung Cancer/Association for Molecular Pathology testing guidelines support the use of ROS1 immunohistochemistry (IHC) as a screening test, followed by confirmation with fluorescence in situ hybridization (FISH) or a molecular test in all positive results. We have evaluated a novel anti-ROS1 IHC antibody (SP384) in a large multicenter series to obtain real-world data. METHODS: A total of 43 ROS1 FISH-positive and 193 ROS1 FISH-negative NSCLC samples were studied. All specimens were screened by using two antibodies (clone D4D6 from Cell Signaling Technology and clone SP384 from Ventana Medical Systems), and the different interpretation criteria were compared with break-apart FISH (Vysis). FISH-positive samples were also analyzed with next-generation sequencing (Oncomine Dx Target Test Panel, Thermo Fisher Scientific). RESULTS: An H-score of 150 or higher or the presence of at least 70% of tumor cells with an intensity of staining of 2+ or higher by the SP384 clone was the optimal cutoff value (both with 93% sensitivity and 100% specificity). The D4D6 clone showed similar results, with an H-score of at least 100 (91% sensitivity and 100% specificity). ROS1 expression in normal lung was more frequent with use of the SP384 clone (p < 0.0001). The ezrin gene (EZR)-ROS1 variant was associated with membranous staining and an isolated green signal FISH pattern (p = 0.001 and p = 0.017, respectively). CONCLUSIONS: The new SP384 ROS1 IHC clone showed excellent sensitivity without compromising specificity, so it is another excellent analytical option for the proposed testing algorithm.

Indoor Radon in EGFR- and BRAF-Mutated and ALK-Rearranged Non-Small-Cell Lung Cancer Patients.

BACKGROUND: Radon gas is the leading cause of lung cancer in the nonsmoking population. The World Health Organization (WHO) recommends indoor concentrations of < 100 Bq/m³. Several molecular alterations have been described in non-small-cell lung cancer (NSCLC), mainly in nonsmokers, with no risk factors identified. We studied the role of indoor radon in NSCLC patients harboring specific driver alterations. PATIENTS AND METHODS: We assessed the radon concentration from EGFR-, BRAF-mutated (m), and ALK-rearranged (r) NSCLC patients measured by an alpha-track detector placed in their homes between September 2014 and August 2015. Clinical characteristics were collected prospectively, and pathologic samples were reviewed retrospectively. RESULTS: Forty-eight patients were included (36 EGFRm, 10 ALKr, 2 BRAFm). Median radon concentration was 104 Bq/m³ (IQR 69-160) overall, and was 96 Bq/m³ (42-915) for EGFRm, 116 (64-852) for ALKr, and 125 for BRAFm, with no significant differences. Twenty-seven patients (56%) had indoor radon above WHO recommendations, 8 (80%) of 10 ALKr, 2 (100%) of 2 BRAFm, and 17 (47%) of 36 EGFRm. CONCLUSION: The median indoor radon concentration was above the WHO recommendations, with no differences between EGFR, ALK, and BRAF patients. Concentrations above the WHO recommendations were most common with ALKr and BRAFm. These findings should be validated in larger studies.

Efficacy of immunotherapy in sarcomatoid lung cancer, a case report and literature review.

Sarcomatoid carcinoma is a subtype of non-small cell lung cancer (NSCLC) characterized by mesenchymal - epithelial transition component and awful prognosis. In this report, based on a case of stage IV lung sarcomatoid carcinoma with an extraordinary evolution and survival over 4 years, we address unresolved questions about the treatment of this cancer. We also make a literature review about the key factors that characterize this histology and that should be considered when treating those patients. Sarcomatoid carcinoma presents with mutations as KRAS, EGFR, ALK or MET in up to 70% of cases, and an important expression of PD-L1 (also called B7-H1), which can influence treatment of those patients with new drugs as immune checkpoint inhibitors. Immunotherapy has changed the horizon of patients with stage IV lung cancers without driver mutations, as their survival has improved extraordinary. Moreover, radical treatments are being considered in long survivors with oligometastatic disease. In this report, we review targeted and radical therapy, treatment duration and the mechanisms responsible of disease evolution of sarcomatoid tumors.

Epigenetic prediction of response to anti-PD-1 treatment in non-small-cell lung cancer: a multicentre, retrospective analysis.

BACKGROUND: Anti-programmed death-1 (PD-1) treatment for advanced non-small-cell lung cancer (NSCLC) has improved the survival of patients. However, a substantial percentage of patients do not respond to this treatment. We examined the use of DNA methylation profiles to determine the efficacy of anti-PD-1 treatment in patients recruited with current stage IV NSCLC. METHODS: In this multicentre study, we recruited adult patients from 15 hospitals in France, Spain, and Italy who had histologically proven stage IV NSCLC and had been exposed to PD-1 blockade during the course of the disease. The study structure comprised a discovery cohort to assess the correlation between epigenetic features and clinical benefit with PD-1 blockade and two validation cohorts to assess the validity of our assumptions. We first established an epigenomic profile based on a microarray DNA methylation signature (EPIMMUNE) in a discovery set of tumour samples from patients treated with nivolumab or pembrolizumab. The EPIMMUNE signature was validated in an independent set of patients. A derived DNA methylation marker was validated by a single-methylation assay in a validation cohort of patients. The main study outcomes were progression-free survival and overall survival. We used the Kaplan-Meier method to estimate progression-free and overall survival, and calculated the differences between the groups with the log-rank test. We constructed a multivariate Cox model to identify the variables independently associated with progression-free and overall survival. FINDINGS: Between June 23, 2014, and May 18, 2017, we obtained samples from 142 patients: 34 in the discovery cohort, 47 in the EPIMMUNE validation cohort, and 61 in the derived methylation marker cohort (the T-cell differentiation factor forkhead box P1 [FOXP1]). The EPIMMUNE signature in patients with stage IV NSCLC treated with anti-PD-1 agents was associated with improved progression-free survival (hazard ratio [HR] 0·010, 95% CI 3·29 × 10-4-0·0282; p=0·0067) and overall survival (0·080, 0·017-0·373; p=0·0012). The EPIMMUNE-positive signature was not associated with PD-L1 expression, the presence of CD8+ cells, or mutational load. EPIMMUNE-negative tumours were enriched in tumour-associated macrophages and neutrophils, cancer-associated fibroblasts, and senescent endothelial cells. The EPIMMUNE-positive signature was associated with improved progression-free survival in the EPIMMUNE validation cohort (0·330, 0·149-0·727; p=0·0064). The unmethylated status of FOXP1 was associated with improved progression-free survival (0·415, 0·209-0·802; p=0·0063) and overall survival (0·409, 0·220-0·780; p=0·0094) in the FOXP1 validation cohort. The EPIMMUNE signature and unmethylated FOXP1 were not associated with clinical benefit in lung tumours that did not receive immunotherapy. INTERPRETATION: Our study shows that the epigenetic milieu of NSCLC tumours indicates which patients are most likely to benefit from nivolumab or pembrolizumab treatments. The methylation status of FOXP1 could be associated with validated predictive biomarkers such as PD-L1 staining and mutational load to better select patients who will experience clinical benefit with PD-1 blockade, and its predictive value should be evaluated in prospective studies. FUNDING: "Obra Social" La Caixa, Cellex Foundation, and the Health and Science Departments of the Generalitat de Catalunya.

Case report of a primary effusion lymphoma successfully treated with oral valganciclovir after failing chemotherapy.

Primary effusion lymphoma is a rare non-Hodgkin lymphoma that presents with pleural effusions and lacking of tumour mass. It is universally associated with human herpesvirus 8 (HHV8) and is more frequent among immunosuppressed patients. There is no standard treatment, chemotherapy and anti-HIV therapy have been used with poor results, but there is still no strong evidence supporting the use of valganciclovir. We present the case of a HIV positive man that presented with pleural effusion compatible with primary effusion lymphoma and positivity for HHV8 DNA in blood. Bortezomib-containing treatment protocol was started, but the disease progressed within the chemotherapy. Therefore, treatment with oral valganciclovir was decided and the patient achieved a sustained radiological complete response. HHV8 DNA turned negative 6 months after starting the treatment with valganciclovir.

Screening for precancerous anal lesions with P16/Ki67 immunostaining in HIV-infected MSM.

BACKGROUND: Screening of anal cancer in HIV-infected MSM with anal cytology results in high rates of false positive results and elevated burden of high-resolution anoscopies. High-risk HPV up-regulates p16 and Ki67 expression in epithelial cells. We assessed the usefulness of P16/Ki-67 immunostaining cytology for the diagnosis of precancerous anal lesions. METHODOLOGY: Cross-sectional multicenter study. Concomitant anal liquid cytology with p16/Ki-67 immunostaining and HRA with biopsy of acetowhite lugol-negative lesions was performed in HIV-infected MSM. We compared the diagnostic performance of an abnormal anal cytology and p16/Ki-67 immunostaining relative to HRA-guided biopsy by logistic regression and comparison of ROC areas. RESULTS: We included 328 HIV-infected MSM. HSIL was histologically diagnosed in 72 subjects (25.1%), and 2 (0.6%) were diagnosed with anal cancer. An abnormal cytology showed a sensitivity of 95.6% and a specificity of 58.8% for the diagnosis of biopsy-proven HSIL. P16/Ki67 positivity was associated with the presence of biopsy-proven HSIL (P trend = 0.004) but with low sensitivity (41.2%) and specificity (71%). The combination of standard cytology with P16/Ki67 immunostaining did not increment the predictive value of standard cytology alone (AUC 0.685 vs. 0.673, respectively, P = 0.688). CONCLUSION: In HIV-infected MSM P16/Ki67 immunostaining does not improve the diagnostic accuracy of anal cytology, which shows a high sensitivity yet poor specificity. Other approaches aimed at improving the diagnostic accuracy of current techniques for the diagnostic of precancerous HSIL are warranted.

HIV, HPV, and microbiota: partners in crime?

Altered interplay between gut mucosa and dysbiotic bacteria during HIV infection seems to fuel chronic immune dysfunction and might explain the excess rates of human papillomavirus (HPV)-associated anal cancer in HIV-infected individuals. Here, we show in HIV-infected MSM undergoing screening for HPV-related cancer that specific fecal and mucosal bacteria are able to predict the existence of precancerous anal lesions. If confirmed, these bacterial biomarkers could be exploited either as diagnostic tools or therapeutic targets.

In-office cup biopsy and laryngeal cytology versus operating room biopsy for the diagnosis of pharyngolaryngeal tumors: Efficacy and cost-effectiveness.

BACKGROUND: In-office biopsy is an effective technique to diagnose the nature of pharyngolaryngeal lesions. METHODS: We selected patients with pharyngolaryngeal lesions suspicious for malignancy. For in-office biopsy procedures, laryngeal cytology and direct laryngoscopy biopsy were performed, and diagnostic parameters and costs were estimated. RESULTS: Eighty-eight patients were selected for this study. For laryngeal cytology, sensitivity was 70.3% (95% confidence interval [CI] = 59.9% to 80.7%), specificity 100% with a positive predictive value of 100% and a negative predictive value of 50% (95% CI = 35.2% to 64.8%). In-office biopsy sensitivity was 81% (95% CI = 72.6% to 89.3%), specificity 100% with a positive predictive value of 100% and a negative predictive value of 20% (95% CI = 2.5% to 37.5%). At our hospital, the use of in-office biopsies as a first approach for diagnosis saves $50,140.80 U.S. per annum. CONCLUSION: In-office biopsy is a more affordable technique that enables histologic diagnosis of pharyngolaryngeal lesions in a large percentage of patients.

Accurate identification of ALK positive lung carcinoma patients: novel FDA-cleared automated fluorescence in situ hybridization scanning system and ultrasensitive immunohistochemistry.

BACKGROUND: Based on the excellent results of the clinical trials with ALK-inhibitors, the importance of accurately identifying ALK positive lung cancer has never been greater. However, there are increasing number of recent publications addressing discordances between FISH and IHC. The controversy is further fuelled by the different regulatory approvals. This situation prompted us to investigate two ALK IHC antibodies (using a novel ultrasensitive detection-amplification kit) and an automated ALK FISH scanning system (FDA-cleared) in a series of non-small cell lung cancer tumor samples. METHODS: Forty-seven ALK FISH-positive and 56 ALK FISH-negative NSCLC samples were studied. All specimens were screened for ALK expression by two IHC antibodies (clone 5A4 from Novocastra and clone D5F3 from Ventana) and for ALK rearrangement by FISH (Vysis ALK FISH break-apart kit), which was automatically captured and scored by using Bioview's automated scanning system. RESULTS: All positive cases with the IHC antibodies were FISH-positive. There was only one IHC-negative case with both antibodies which showed a FISH-positive result. The overall sensitivity and specificity of the IHC in comparison with FISH were 98% and 100%, respectively. CONCLUSIONS: The specificity of these ultrasensitive IHC assays may obviate the need for FISH confirmation in positive IHC cases. However, the likelihood of false negative IHC results strengthens the case for FISH testing, at least in some situations.