Antibody 1A4 with routine immunohistochemistry demonstrates high sensitivity for ALK rearrangement screening of Chinese lung adenocarcinoma patients: A single-center large-scale study

Anaplastic lymphoma kinase rearrangements in patients with non-small cell lung cancer in Jordan

Objective

Anaplastic lymphoma kinase (ALK) rearrangement is an important oncogenic driver in some non-small cell lung cancers (NSCLC). Treatment with ALK tyrosine kinase inhibitors improves survival. The availability of diagnostic immunohistochemistry (IHC) has led to a paradigm shift in ALK testing. This study examined the prevalence of ALK rearrangement in Jordanian patients with NSCLC and compared the results of IHC and fluorescence in situ hybridization (FISH) for detecting ALK rearrangement.

Methods

This retrospective study on 449 patients with NSCLC treated at the King Hussein Cancer Center in Jordan tested biopsy samples for ALK rearrangement using FISH and/or IHC (D5F3) between 2018 and 2020.

Results

Eighteen patients (4%) had ALK-positive NSCLC. The calculated sensitivity and specificity of ALK immunostaining compared with FISH were 87.5% and 96%, respectively. ALK-positive patients were significantly younger than their ALK-negative counterparts, and women were three times more likely to carry ALK rearrangement than men. ALK rearrangement was significantly associated with smoking history, with most ALK-positive patients being non-smokers, former smokers, or light smokers.

Conclusions

IHC is a reasonable alternative to FISH for ALK testing with advantages in terms of robustness, turnaround times, and cost-effectiveness.

Molecular diagnosis in non-small-cell lung cancer: expert opinion on ALK and ROS1 testing

The effectiveness of targeted therapies with tyrosine kinase inhibitors in non-small-cell lung cancer (NSCLC) depends on the accurate determination of the genomic status of the tumour. For this reason, molecular analyses to detect genetic rearrangements in some genes (ie, ALK, ROS1, RET and NTRK) have become standard in patients with advanced disease. Since immunohistochemistry is easier to implement and interpret, it is normally used as the screening procedure, while fluorescence in situ hybridisation (FISH) is used to confirm the rearrangement and decide on ambiguous immunostainings. Although FISH is considered the most sensitive method for the detection of ALK and ROS1 rearrangements, the interpretation of results requires detailed guidelines. In this review, we discuss the various technologies available to evaluate ALK and ROS1 genomic rearrangements using these techniques. Other techniques such as real-time PCR and next-generation sequencing have been developed recently to evaluate ALK and ROS1 gene rearrangements, but some limitations prevent their full implementation in the clinical setting. Similarly, liquid biopsies have the potential to change the treatment of patients with advanced lung cancer, but further research is required before this technology can be applied in routine clinical practice. We discuss the technical requirements of laboratories in the light of quality assurance programmes. Finally, we review the recent updates made to the guidelines for the determination of molecular biomarkers in patients with NSCLC.

The extent of expression of thyroid transcription factor 1, cytokeratin 7, and anaplastic lymphoma kinase in lung adenocarcinoma

Background:

New forms of genetic alteration were developed giving a new era of lung adenocarcinoma (AdC) with diverse clinical and pathological features.

Aim and Objectives:

The aim is to investigate the ALK-rearranged gene as one of these genetic alterations in AdC. The role of TTF-1 and CK7 is to exclude the metastases.

Material and Methods:

Paraffin-embedded 50 AdC specimens were cut into 4-mm thick sections and stained with the primary antibody, using an anti-TTF-1 antibody, (all at a 1:200 dilution, mouse monoclonal antibody; Dako, Denmark), anti-CK 7 antibody (DAKO, Carpentaria, CA), and the rabbit monoclonal anti- ALK antibody (D5F3) (Ventana, USA). Positive reactivity was considered as brown nuclear immunostaining for TTF-1 and cytoplasmic for CK 7and both cytoplasmic and nuclear for ALK.

Results:

The median age was 56±2, with male to female ratio 7:3. Forty-four cases revealed a mixed pattern (88%), with focal intraluminal mucin. Forty-one cases (82%) were positive for TTF-1, of these; weak (13; %), moderate (16; %) and strong (12; %). Regarding CK7; 48 cases (96%) were positive; weak (7 cases; 14.5; %), moderate (18 cases; 37.5%) and strong (23 case; 47.9 %) of the positive cases. Regarding D5F3; five cases (10%) were positive; weak (1 case; 20 %), moderate (2 cases; 40 %) and strong (2 cases; 40%) out of the positive cases. Four ALK-positive cases were male and ALK-positive patients ranged from 42-55 years with median 48.

Conclusion:

Despite the incidence of ALk-AdC is uncommon, it might be suspected in lesions of lower age group especially with mucinous foci.

ALK immunohistochemistry positive, FISH negative NSCLC is infrequent, but associated with impaired survival following treatment with crizotinib

OBJECTIVE

Metastasized non-small cell lung cancer (NSCLC) with an anaplastic lymphoma kinase (ALK) rearrangement is usually sensitive to a range of ALK-tyrosine kinase inhibitors. ALK-positive NSCLC have been identified in pivotal phase III trials with fluorescence in situ hybridization (ALK FISH+). These tumors are also expressing the fusion product (ALK immunohistochemistry (IHC)+). However, discrepant cases occur, including ALK IHC + FISH-. The aim of this study was to collect ALK IHC + cases and compare within this group response to crizotinib treatment of ALK FISH + cases with ALK FISH- cases.

MATERIALS AND METHODS

In this European prospective multicenter research study patients with Stage IV ALK IHC + NSCLC treated with crizotinib were enrolled. Tumor slides were validated centrally for ALK IHC and ALK FISH.

RESULTS

Registration of 3523 ALK IHC tests revealed a prevalence of 2.7% (n = 94) ALK IHC + cases. Local ALK FISH analysis resulted in 48 concordant (ALK IHC+/FISH+) and 16 discordant (ALK IHC+/FISH-) cases. Central validation revealed 37 concordant and 7 discordant cases, 5 of which had follow-up. Validation was hampered by limited amount of tissue in biopsy samples. The PFS at 1 year for ALK concordant and discordant was 58% and 20%, respectively (HR = 2.4; 95% CI: 0.78-7.3; p = 0.11). Overall survival was significantly better for concordant cases than discordant cases after central validation (HR=4.5; 95% CI= 1.2-15.9; p=0.010.

CONCLUSION

ALK IHC + FISH- NSCLC is infrequent and associated with a worse outcome on personalized treatment. A suitable predictive testing strategy may be to screen first with IHC and then confirm with FISH instead of considering ALK IHC equivalent to ALK FISH according to the current guidelines.

Value of SATB2, ISL1, and TTF1 to differentiate rectal from other gastrointestinal and lung well-differentiated neuroendocrine tumors

BACKGROUND

Management of neuroendocrine tumors (NETs) depends on the primary site, but the location of many well-differentiated (WD) NETs is elusive. Organ-specific markers are required for pathological diagnosis from biopsy. Transcription factors with good organ specificity include TTF1 (thyroid transcription factor 1; lung), CDX2 (caudal type homeobox transcription factor 2; midgut), and ISL1 (ISL LIM homeobox 1) and PAX8 (paired box 8) for the pancreas and rectum. SATB2 (SATB homeobox 2) has shown high sensitivity and specificity in colorectal adenocarcinoma. This study determined the viability of SATB2 and other transcription factors as markers, single or in combination, for WD-NETs of various sites.

METHODS

Immunohistochemical staining of 81 WD-NETs from 8 organ sites was performed to identify SATB2, TTF1, CDX2, ISL1, and PAX8. Receiver operating characteristic (ROC) curves were constructed for different combinations of the 5 markers to determine sensitivity and specificity.

RESULTS

Among the WD-NETs, SATB2 was predominantly found in those of the rectum; TTF1 in the lung, larynx, and esophagus; and ISL1 in the duodenum and rectum. PAX8 and CDX2 showed poor organ specificity. ROC profiles showed 50% sensitivity and 96% specificity to lung for TTF1⁺ ISL1-; and 65% sensitivity and 100% specificity to rectum for SATB2⁺ ISL1- TTF1-. ISL1⁺ SATB2- TTF1- showed 83% sensitivity and 85% specificity to the duodenum, and 44% sensitivity and 87% specificity to the pancreas. A literature search showed that there was no significant difference in the expression rates of the five transcription factors (TTF1, CDX2, SATB2, PAX8 and ISL1) between primary and metastatic WD-NETs at the same organ when there was a large sample size.

CONCLUSION

Among the 5 transcription factors tested, SATB2 may be a viable marker of WE-NETs of the rectum. The combination of SATB2, ISL1, and TTF1 may help estimate the locations of WD-NETs of unknown origin.

ALK (D5F3) CDx: an immunohistochemistry assay to identify ALK-positive NSCLC patients

Screening for anaplastic lymphoma kinase (ALK) rearrangements is a very important process in treatment decision making for advanced non-small-cell lung cancer (NSCLC). Although fluorescent in situ hybridization (FISH) is considered the universally accepted reference standard, it is associated with technical difficulties and high costs that have made global implementation of this assay challenging. Conversely, ALK immunohistochemistry has shown high sensitivity and specificity compared to FISH and other molecular assays and is more cost-effective. In fact, the ALK (D5F3) CDx immunohistochemistry assay was approved by the US Food and Drug Administration as a standalone test for ALK rearrangements in lung cancer in 2015. In this review, we will discuss the overview of ALK rearrangements in NSCLC, various testing methods for ALK rearrangements, and the details of immunohistochemistry for ALK, in particular one with the ALK antibody clone D5F3.

A stitch in time saves nine: external quality assessment rounds demonstrate improved quality of biomarker analysis in lung cancer

Biomarker analysis has become routine practice in the treatment of non-small cell lung cancer (NSCLC). To ensure high quality testing, participation to external quality assessment (EQA) schemes is essential. This article provides a longitudinal overview of the EQA performance for EGFR, ALK, and ROS1 analyses in NSCLC between 2012 and 2015.

The four scheme years were organized by the European Society of Pathology according to the ISO 17043 standard. Participants were asked to analyze the provided tissue using their routine procedures.

Analysis scores improved for individual laboratories upon participation to more EQA schemes, except for ROS1 immunohistochemistry (IHC). For EGFR analysis, scheme error rates were 18.8%, 14.1% and 7.5% in 2013, 2014 and 2015 respectively. For ALK testing, error rates decreased between 2012 and 2015 by 5.2%, 3.2% and 11.8% for the fluorescence in situ hybridization (FISH), FISH digital, and IHC subschemes, respectively. In contrast, for ROS1 error rates increased between 2014 and 2015 for FISH and IHC by 3.2% and 9.3%. Technical failures decreased over the years for all three markers.

Results show that EQA contributes to an ameliorated performance for most predictive biomarkers in NSCLC. Room for improvement is still present, especially for ROS1 analysis.

Immunohistochemistry for predictive biomarkers in non-small cell lung cancer

In the era of targeted therapy, predictive biomarker testing has become increasingly important for non-small cell lung cancer. Of multiple predictive biomarker testing methods, immunohistochemistry (IHC) is widely available and technically less challenging, can provide clinically meaningful results with a rapid turn-around-time and is more cost efficient than molecular platforms. In fact, several IHC assays for predictive biomarkers have already been implemented in routine pathology practice. In this review, we will discuss: (I) the details of anaplastic lymphoma kinase (ALK) and proto-oncogene tyrosine-protein kinase ROS (ROS1) IHC assays including the performance of multiple antibody clones, pros and cons of IHC platforms and various scoring systems to design an optimal algorithm for predictive biomarker testing; (II) issues associated with programmed death-ligand 1 (PD-L1) IHC assays; (III) appropriate pre-analytical tissue handling and selection of optimal tissue samples for predictive biomarker IHC.

ALK in Non-Small Cell Lung Cancer (NSCLC) Pathobiology, Epidemiology, Detection from Tumor Tissue and Algorithm Diagnosis in a Daily Practice

Patients with advanced-stage non-small cell lung carcinoma (NSCLC) harboring an ALK rearrangement, detected from a tissue sample, can benefit from targeted ALK inhibitor treatment. Several increasingly effective ALK inhibitors are now available for treatment of patients. However, despite an initial favorable response to treatment, in most cases relapse or progression occurs due to resistance mechanisms mainly caused by mutations in the tyrosine kinase domain of ALK. The detection of an ALK rearrangement is pivotal and can be done using different methods, which have variable sensitivity and specificity depending, in particular, on the quality and quantity of the patient’s sample. This review will first highlight briefly some information regarding the pathobiology of an ALK rearrangement and the epidemiology of patients harboring this genomic alteration. The different methods used to detect an ALK rearrangement as well as their advantages and disadvantages will then be examined and algorithms proposed for detection in daily routine practice.

Immunohistochemistry of Pulmonary Biomarkers: A Perspective From Members of the Pulmonary Pathology Society

The use of immunohistochemistry for the determination of pulmonary carcinoma biomarkers is a well-established and powerful technique. Immunohistochemisty is readily available in pathology laboratories, is relatively easy to perform and assess, can provide clinically meaningful results very quickly, and is relatively inexpensive. Pulmonary predictive biomarkers provide results essential for timely and accurate therapeutic decision making; for patients with metastatic non-small cell lung cancer, predictive immunohistochemistry includes ALK and programmed death ligand-1 (PD-L1) (ROS1, EGFR in Europe) testing. Handling along proper methodologic lines is needed to ensure patients receive the most accurate and representative test outcomes.

The impact of immunohistochemistry on the classification of lung tumors

INTRODUCTION

To highlight the role of immunohistochemistry to lung cancer classification on the basis of existing guidelines and future perspectives.

AREAS COVERED

Four orienting key-issues were structured according to an extensive review on the English literature: a) cancer subtyping; b) best biomarkers and rules to follow; c) negative and positive profiling; d) suggestions towards an evidence-based proposal for lung cancer subtyping. A sparing material approach based on a limited number of specific markers is highly desirable. It includes p40 for squamous cell carcinoma ('no p40, no squamous'), TTF1 for adenocarcinoma, synaptophysin for neuroendocrine tumors and vimentin for sarcomatoid carcinoma. A close relationship between genotype and phenotype also supports a diagnostic role for negative profiles. Expert commentary: Highly specific and sensitive IHC markers according to positive and negative diagnostic algorithms seem appropriate for individual patients' lung cancer subtyping.