Histologic and cytomorphologic features of ALK-rearranged lung adenocarcinomas

Cytomorphological and histomorphological features of lung adenocarcinoma with epidermal growth factor receptor mutation and anaplastic lymphoma kinase gene rearrangement

Lung cancer is among the lethal and most prevalent oncological diseases globally. It is known that two types of mutations, namely anaplastic lymphoma kinase (ALK) gene rearrangement and epidermal growth factor receptor (EGFR) gene mutation, are responsible for the development of lung adenocarcinoma. The present study aimed to investigate the differences in the frequency of clinical, cytomorphological and histomorphological features of ALK and EGFR-positive lung adenocarcinomas. The present retrospective study comprised 101 patients diagnosed with lung adenocarcinoma. Based on the molecular findings, the patients were categorized into three groups as follows: The ALK-rearranged group (n=28), the EGFR group (n=42) and the negative group (n=31). The clinical features analyzed included sex, age, smoking status and disease stage. The cytomorphological and histomorphological features examined encompassed the following: Cell cluster size, the arrangement of tumor cells, the size of nuclei, nuclear atypia, the visibility of nucleoli, the presence of necrosis, intracytoplasmic vacuoles, signet ring cells, stromal characteristics and the presence of inflammatory infiltrate presence. The results indicated that the female sex was more prevalent in the EGFR group, but statistically significant differences (P<0.05) were observed between the EGFR and negative group. A significantly greater percentage of non-smokers was identified in the EGFR group compared with the ALK group (P<0.01). The majority of patients with confirmed ALK or EGFR mutations received onco-specific treatment. Focal and abundant necrosis was significantly less common in cytological samples in the EGFR group than in the other groups (21.43 vs. 57.14 and 51.61%, combined, P<0.01). No significant differences were observed in other cytomorphological features between the groups. Intracytoplasmic vacuoles, signet ring cells and cells with visible nucleoli were significantly more frequent in histological specimens of the ALK group (P<0.01). The predictive model composed of these features or combined with sex and smoking habits exhibited statistically significant differences for mutation status as a criterion (P<0.01). Collectively, the findings of the present study confirmed that, in addition to clinical characteristics, certain cytological and histological features of lung adenocarcinoma are associated with the mutational status of the tumor.

Using ex vivo bioengineered lungs to model pathologies and screening therapeutics: A proof-of-concept study

Respiratory diseases, claim over eight million lives annually. However, the transition from preclinical to clinical phases in research studies is often hindered, partly due to inadequate representation of preclinical models in clinical trials. To address this, we conducted a proof-of-concept study using an ex vivo model to identify lung pathologies and to screen therapeutics in a humanized rodent model. We extracted and decellularized mouse heart-lung tissues using a detergent-based technique. The lungs were then seeded and cultured with human cell lines (BEAS-2B, A549, and Calu3) for 6-10 days, representing healthy lungs, cancerous states, and congenital pathologies, respectively. By manipulating cultural conditions and leveraging the unique characteristics of the cell lines, we successfully modeled various pathologies, including advanced-stage solid tumors and the primary phase of SARS-CoV-2 infection. Validation was conducted through histology, immunofluorescence staining, and pathology analysis. Additionally, our study involved pathological screening of the efficacy and impact of key anti-neoplastic therapeutics (Cisplatin and Wogonin) in cancer models. The results highlight the versatility and strength of the ex vivo model in representing crucial lung pathologies and screening therapeutics during the preclinical phase. This approach holds promise for bridging the gap between preclinical and clinical research, aiding in the development of effective treatments for respiratory diseases, including lung cancer.

Establishment of artificial intelligence model for precise histological subtyping of lung adenocarcinoma and its application to quantitative and spatial analysis

BACKGROUND

The histological subtype of lung adenocarcinoma is a major prognostic factor. We developed a new artificial intelligence model to classify lung adenocarcinoma images into seven histological subtypes and adopted the model for whole-slide images to investigate the relationship between the distribution of histological subtypes and clinicopathological factors.

METHODS

Using histological subtype images, which are typical for pathologists, we trained and validated an artificial intelligence model. Then, the model was applied to whole-slide images of resected lung adenocarcinoma specimens from 147 cases.

RESULT

The model achieved an accuracy of 99.7% in training sets and 90.4% in validation sets consisting of typical tiles of histological subtyping for pathologists. When the model was applied to whole-slide images, the predominant subtype according to the artificial intelligence model classification matched that determined by pathologists in 75.5% of cases. The predominant subtype and tumor grade (using the WHO fourth and fifth classifications) determined by the artificial intelligence model resulted in similar recurrence-free survival curves to those determined by pathologists. Furthermore, we stratified the recurrence-free survival curves for patients with different proportions of high-grade components (solid, micropapillary and cribriform) according to the physical distribution of the high-grade component. The results suggested that tumors with centrally located high-grade components had a higher malignant potential (P < 0.001 for 5-20% high-grade component).

CONCLUSION

The new artificial intelligence model for histological subtyping of lung adenocarcinoma achieved high accuracy, and subtype quantification and subtype distribution analyses could be achieved. Artificial intelligence model therefore has potential for clinical application for both quantification and spatial analysis.

Clinicopathological and molecular characterization of resected lung adenocarcinoma: Correlations with histopathological grading systems in Chinese patients

PURPOSE

Driver mutations inform lung adenocarcinoma (LUAD) targeted therapy. Association of histopathological attributes and molecular profiles facilitates clinically viable testing platforms. We assessed correlations between LUAD clinicopathological features, mutational landscapes, and two grading systems among Chinese cases.

METHODS

79 Chinese LUAD patients undergoing resection were subjected to targeted sequencing. 68 were invasive nonmucinous adenocarcinoma (INMA), graded via: predominant histologic pattern-based grading system (P-GS) or novel IASLC grading system (I-GS). Driver mutation distributions were appraised and correlated with clinical and pathological data.

RESULTS

Compared to INMA, non-INMA exhibited smaller, well-differentiated tumors with higher mucin content. INMA grade correlated with size, lymph invasion (P-GS), and driver/EGFR mutations. Mutational spectra varied markedly between grades, with EGFR p.L858R and exon 19 deletion mutations predominating in lower grades; while high-grade P-GS tumors often harbored EGFR copy number variants and complex alterations alongside wild-type cases. I-GS upgrade of P-GS grade 2 to grade 3 was underpinned by ≥20 % high-grade regions bearing p.L858R or ALK fusions. Both systems defined tumors of distinctive phenotypic attributes and molecular genotypes.

CONCLUSIONS

INMA represent larger, mucin-poor, molecularly heterogeneous LUAD with divergent grade-specific mutation profiles. Stronger predictor of clinicopathological attributes and driver mutations, P-GS stratification offers greater accuracy for molecular testing. A small panel encompassing EGFR and ALK captures the majority of P-GS grade 1/2 mutations whereas expanded panels are optimal for grade 3.

Patho-transcriptomic analysis of invasive mucinous adenocarcinoma of the lung (IMA): comparison with lung adenocarcinoma with signet ring cell features (SRCC)

Background

Invasive mucinous adenocarcinoma (IMA) comprises ∼5% of lung adenocarcinoma. There is no effective therapy for IMA when surgical resection is not possible. IMA is sometimes confused with adenocarcinoma with signet ring cell features (SRCC) pathologically since both adenocarcinomas feature tumor cells with abundant intracellular mucin. The molecular mechanisms by which such mucin-producing lung adenocarcinomas develop remain unknown.

Methods

Using a Visium spatial transcriptomics approach, we analyzed IMA and compared it with SRCC patho-transcriptomically. Combining spatial transcriptomics data with in vitro studies using RNA-seq and ChIP-seq, we assessed downstream targets of transcription factors HNF4A and SPDEF that are highly expressed in IMA and/or SRCC.

Results

Spatial transcriptomics analysis indicated that there are 6 distinct cell clusters in IMA and SRCC. Notably, two clusters (C1 and C3) of mucinous tumor cells exist in both adenocarcinomas albeit at a different ratio. Importantly, a portion of genes (e.g., NKX2-1 , GKN1 , HNF4A and FOXA3 ) are distinctly expressed while some mucous-related genes (e.g., SPDEF and FOXA2 ) are expressed in both adenocarcinomas. We determined that HNF4A induces MUC3A/B and TM4SF4 and that BI 6015, an HNF4A antagonist, suppressed the growth of IMA cells. Using mutant SPDEF that is associated with COVID-19, we also determined that an intact DNA-binding domain of SPDEF is required for SPDEF-mediated induction of mucin genes ( MUC5AC , MUC5B and AGR2 ). Additionally, we found that XMU-MP-1, a SPDEF inhibitor, suppressed the growth of IMA cells.

Conclusion

These results revealed that IMA and SRCC contain heterogenous tumor cell types, some of which are targetable.

Lung cancer in patients who have never smoked - an emerging disease

Lung cancer is the most common cause of cancer-related deaths globally. Although smoking-related lung cancers continue to account for the majority of diagnoses, smoking rates have been decreasing for several decades. Lung cancer in individuals who have never smoked (LCINS) is estimated to be the fifth most common cause of cancer-related deaths worldwide in 2023, preferentially occurring in women and Asian populations. As smoking rates continue to decline, understanding the aetiology and features of this disease, which necessitate unique diagnostic and treatment paradigms, will be imperative. New data have provided important insights into the molecular and genomic characteristics of LCINS, which are distinct from those of smoking-associated lung cancers and directly affect treatment decisions and outcomes. Herein, we review the emerging data regarding the aetiology and features of LCINS, particularly the genetic and environmental underpinnings of this disease as well as their implications for treatment. In addition, we outline the unique diagnostic and therapeutic paradigms of LCINS and discuss future directions in identifying individuals at high risk of this disease for potential screening efforts.

Molecular pathology of non-small cell carcinoma

Currently, lung cancer is treated by the highest number of therapeutic options and the benefits are based on multiple large-scale sequencing studies, translational research and new drug development, which has promoted our understanding of the molecular pathology of lung cancer. According to the driver alterations, different characteristics have been revealed, such as differences in ethnic prevalence, median age and alteration patterns. Consequently, beyond traditional chemoradiotherapy, molecular-targeted therapy and treatment with immune check-point inhibitors (ICI) also became available major therapeutic options. Interestingly, clinical results suggest that the recently established therapies target distinct lung cancer proportions, particularly between the EGFR/ALK and PD-1/PD-L1-positive subsets, e.g. the kinase inhibitors target driver mutation-positive tumours, whereas driver mutation-negative tumours respond to ICI treatment. These therapeutic efficacy-related differences might be explained by the molecular pathogenesis of lung cancer. Addictive driver mutations promote tumour formation with powerful transformation performance, resulting in a low tumour mutation burden, reduced immune surveillance, and subsequent poor response to ICIs. In contrast, regular tobacco smoke exposure repeatedly injures the proximal airway epithelium, leading to accumulated genetic alterations. In the latter pathway, overgrowth due to alteration and immunological exclusion against neoantigens is initially balanced. However, tumours could be generated from certain clones that outcompete immunological exclusion and outgrow the others. Consequently, this cancer type responds to immune check-point treatment. These pathogenic differences are explained well by the two-compartment model, focusing upon the anatomical and functional composition of distinct cellular components between the terminal respiratory unit and the air-conducting system.

Clinicopathological features and prognostic significance of pulmonary adenocarcinoma with signet ring cell components: meta-analysis and SEER analysis

Pulmonary adenocarcinoma is a common type of lung cancer that has been on the rise in recent years. Signet ring cell components (SRCC) can be present in various patterns of pulmonary adenocarcinoma, including papillary, acinar, and solid patterns. "Signet ring cell carcinoma" is a distinct subtype in the 2014 WHO classification of lung neoplasms, subsequent WHO classifications in 2015 and 2021 have deemed signet ring cells as accompanying morphological features with no clinical significance. The prognostic and clinical implications of SRCC in pulmonary adenocarcinoma remain controversial. Therefore, we conducted a meta-analysis to investigate the clinicopathological features and prognostic factors of SRCC in pulmonary adenocarcinoma. We conducted a comprehensive search in PubMed, EMBASE, and Web of Science to identify studies that examined the clinicopathological features and prognostic implications of pulmonary adenocarcinoma with SRCC. We used both fixed- and random-effects models to analyze the data and calculate the pooled hazard ratio (HR) and odds ratio (OR) with 95% confidence intervals (CIs). Additionally, we explored the prognostic significance of SRCC in pulmonary adenocarcinoma using the Surveillance, Epidemiology, and End Results (SEER) database. Our meta-analysis included 29 studies with pulmonary adenocarcinoma and SRCC components. The results showed that pulmonary adenocarcinoma with SRCC was associated with larger tumor size (OR = 1.99; 95% CI, 1.62-2.44, p < 0.001), advanced overall stage (OR = 5.18, 95% CI, 3.28-8.17, p < 0.00001) and lymph node stage (OR = 5.79, 95% CI, 1.96-17.09, p = 0.001), and worse overall survival (OS) compared to those without SRCC (HR = 1.80, 95% CI, 1.50-2.16, p < 0.00001). Analysis using the SEER dataset confirmed these findings. Our meta-analysis provides evidence that pulmonary adenocarcinoma with SRCC is associated with distinct clinicopathological features and a poorer prognosis. These findings have important implications for the management and treatment of patients. However, further studies are needed to validate these findings and explore the significance of SRCC in various subtypes of pulmonary adenocarcinoma.

Primary Lung Adenocarcinoma With ALK Gene Rearrangement Mostly Occupied by the Signet-Ring Cell Carcinoma Component: A Case Report

Primary lung carcinoma tumors possessing a signet-ring cell carcinoma (SRCC) component at varying proportions are rare, while those primarily composed of an SRCC component are much rarer. Reported here is a case of primary lung adenocarcinoma primarily composed of an SRCC component with a scant acinar component that developed in an 81-year-old male. Approximately 95% of the adenocarcinoma was occupied by an SRCC component that was shown to be diastase-resistant based on positive periodic acid-Schiff staining. Immunostaining for ALK and fluorescence in situ hybridization analysis (break-apart assay) showed the presence of an ALK gene rearrangement. Findings in this case indicated a primary lung adenocarcinoma with ALK gene rearrangement, in which an SRCC component accounted for approximately 95% of the tumor.

Rare molecular subtypes of lung cancer

Oncogenes that occur in ≤5% of non-small-cell lung cancers have been defined as 'rare'; nonetheless, this frequency can correspond to a substantial number of patients diagnosed annually. Within rare oncogenes, less commonly identified alterations (such as HRAS, NRAS, RIT1, ARAF, RAF1 and MAP2K1 mutations, or ERBB family, LTK and RASGRF1 fusions) can share certain structural or oncogenic features with more commonly recognized alterations (such as KRAS, BRAF, MET and ERBB family mutations, or ALK, RET and ROS1 fusions). Over the past 5 years, a surge in the identification of rare-oncogene-driven lung cancers has challenged the boundaries of traditional clinical grade diagnostic assays and profiling algorithms. In tandem, the number of approved targeted therapies for patients with rare molecular subtypes of lung cancer has risen dramatically. Rational drug design has iteratively improved the quality of small-molecule therapeutic agents and introduced a wave of antibody-based therapeutics, expanding the list of actionable de novo and resistance alterations in lung cancer. Getting additional molecularly tailored therapeutics approved for rare-oncogene-driven lung cancers in a larger range of countries will require ongoing stakeholder cooperation. Patient advocates, health-care agencies, investigators and companies with an interest in diagnostics, therapeutics and real-world evidence have already taken steps to surmount the challenges associated with research into low-frequency drivers.

Discordant results for ALK based on immunohistochemistry versus fluorescence in situ hybridization in a cohort of patients diagnosed with lung adenocarcinoma

INTRODUCTION

Anaplastic lymphoma kinase (ALK) rearrangement located on the short arm of chromosome 2, region 2 and band 3 is frequent in lung cancer patients who respond to targeted therapies with ALK inhibitors Therefore, their identification has become a standard diagnostic test in patients with advanced NSCLS, as such chromosomal alterations may lead to the activation of important signalling pathways involved in cell survival and proliferation.

METHODS

To investigate the ALK gene status, we performed FISH and IHC assays in 18 lung adenocarcinoma patients, 12 women and 6 men, aged between 29 and 85 years. Paraffin-embedded samples were analyzed in the Pathology Department of the Hospital Universitario San Ignacio.

RESULTS

Results between the two techniques in 5 patients showed discordant patterns, being positive for FISH and negative for IHC. The borderline to define ALK positivity was set at 15%, These results present experimental evidence that the techniques differ in specific situations.

CONCLUSIONS

Our findings show that it is advisable to investigate the ALK gene status in patients with suspected lung cancer using both FISH and IHC in combination.

Deep learning-based tumor microenvironment segmentation is predictive of tumor mutations and patient survival in non-small-cell lung cancer

BACKGROUND

Despite the fact that tumor microenvironment (TME) and gene mutations are the main determinants of progression of the deadliest cancer in the world - lung cancer, their interrelations are not well understood. Digital pathology data provides a unique insight into the spatial composition of the TME. Various spatial metrics and machine learning approaches were proposed for prediction of either patient survival or gene mutations from this data. Still, these approaches are limited in the scope of analyzed features and in their explainability, and as such fail to transfer to clinical practice.

METHODS

Here, we generated 23,199 image patches from 26 hematoxylin-and-eosin (H&E)-stained lung cancer tissue sections and annotated them into 9 different tissue classes. Using this dataset, we trained a deep neural network ARA-CNN. Next, we applied the trained network to segment 467 lung cancer H&E images from The Cancer Genome Atlas (TCGA) database. We used the segmented images to compute human-interpretable features reflecting the heterogeneous composition of the TME, and successfully utilized them to predict patient survival and cancer gene mutations.

RESULTS

We achieved per-class AUC ranging from 0.72 to 0.99 for classifying tissue types in lung cancer with ARA-CNN. Machine learning models trained on the proposed human-interpretable features achieved a c-index of 0.723 in the task of survival prediction and AUC up to 73.5% for PDGFRB in the task of mutation classification.

CONCLUSIONS

We presented a framework that accurately predicted survival and gene mutations in lung adenocarcinoma patients based on human-interpretable features extracted from H&E slides. Our approach can provide important insights for designing novel cancer treatments, by linking the spatial structure of the TME in lung adenocarcinoma to gene mutations and patient survival. It can also expand our understanding of the effects that the TME has on tumor evolutionary processes. Our approach can be generalized to different cancer types to inform precision medicine strategies.

Artificial Intelligence-Powered Prediction of ALK Gene Rearrangement in Patients With Non-Small-Cell Lung Cancer

PURPOSE

Several studies reported the possibility of predicting genetic abnormalities in non-small-cell lung cancer by deep learning (DL). However, there are no data of predicting ALK gene rearrangement (ALKr) using DL. We evaluated the ALKr predictability using the DL platform.

MATERIALS AND METHODS

We selected 66 ALKr-positive cases and 142 ALKr-negative cases, which were diagnosed by ALKr immunohistochemical staining in our institution from January 2009 to March 2019. We generated virtual slide of 300 slides (150 ALKr-positive slides and 150 ALKr-negative slides) using NanoZoomer. HALO-AI was used to analyze the whole-slide imaging data, and the DenseNet network was used to build the learning model. Of the 300 slides, we randomly assigned 172 slides to the training cohort and 128 slides to the test cohort to ensure no duplication of cases. In four resolutions (16.0/4.0/1.0/0.25 μm/pix), ALKr prediction models were built in the training cohort and ALKr prediction performance was evaluated in the test cohort. We evaluated the diagnostic probability of ALKr by receiver operating characteristic analysis in each ALKr probability threshold (50%, 60%, 70%, 80%, 90%, and 95%). We expected the area under the curve to be 0.64-0.85 in the model of a previous study. Furthermore, in the test cohort data, an expert pathologist also evaluated the presence of ALKr by hematoxylin and eosin staining on whole-slide imaging.

RESULTS

The maximum area under the curve was 0.73 (50% threshold: 95% CI, 0.65 to 0.82) in the resolution of 1.0 μm/pix. In this resolution, with an ALKr probability of 50% threshold, the sensitivity and specificity were 73% and 73%, respectively. The expert pathologist's sensitivity and specificity in the same test cohort were 13% and 94%.

CONCLUSION

The ALKr prediction by DL was feasible. Further study should be addressed to improve accuracy of ALKr prediction.

Primary pulmonary epithelioid inflammatory myofibroblastic sarcoma: a rare entity and a literature review

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is an aggressive subtype of inflammatory myofibroblastic tumor (IMT) harboring anaplastic lymphoma kinase (ALK) gene fusions and is associated with high risk of local recurrence and poor prognosis. Herein, we present a young, non-smoking male who presented with complaints of cough and dyspnoea and was found to harbor a large right lower lobe lung mass. Biopsy showed a high-grade epithelioid to rhabdoid tumor with ALK and desmin protein expression. The patient initially received 5 cycles of crizotinib and remained stable for 1 year; however, he then developed multiple bony metastases, for which complete surgical resection was performed. Histopathology confirmed the diagnosis of EIMS, with ALK gene rearrangement demonstrated by fluorescence in situ hybridization. Postoperatively, the patient is asymptomatic with stable metastatic disease on crizotinib and has been started on palliative radiotherapy. EIMS is a very rare subtype of IMT that needs to be included in the differential diagnosis of ALKexpressing lung malignancies in young adults.

Nuclear Morphological Characteristics in Breast Cancer: Correlation with Hormone Receptor and Human Epidermal Growth Factor Receptor 2

Background

Hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) are the common diagnostic/prognostic markers in breast cancer. Few articles have recently reported the correlation between cytology and molecular subtypes. We combined nuclear morphological characteristics with HR and HER2 status to observe the relationship and provide ideas for machine learning.

Methods

We reanalyzed fine-needle aspiration cytology samples and core-needle puncture histological specimens from 142 patients with invasive breast cancer between March 2019 and December 2019, and the findings were compared with the two groups (HR+/HER2- and HR-/HER2+) following nuclear cytomorphological features: nuclear/cytoplasmic ratio, difference of nuclear size, nuclear pleomorphism, chromatin feature, nuclear membrane and nucleoli, and Nottingham grading.

Results

Two groups were significantly associated with the difference of nuclear size, nuclear pleomorphism, and nucleoli (P < 0.001) and consistent with histological grading (P < 0.001). Moreover, nucleolar characteristics of size and number had obviously statistical significance (P < 0.001). Multiple micro-nucleoli were frequently seen in the HR+/HER2- group compared with the HR-/HER2+ group which mostly were observed centered medium-large nucleoli. We described four interesting nuclear morphologies in the experiment.

Conclusions

There were significant differences in nuclear characteristics between two groups. HR and HER2 status not only might be predicted in cytological samples, but some specific nuclear morphological features might have potential value to help us understand molecular function and predict more information.

Pathological cytomorphologic features and the percentage of ALK FISH-positive cells predict pulmonary adenocarcinoma prognosis: a prospective cohort study

Background

We conducted a study to explore the relationship between pathological cytomorphologic features and the percentage of anaplastic lymphoma kinase (ALK)-positive cells to better predict pulmonary adenocarcinoma prognosis with crizotinib treatment.

Patients and methods

We investigated 60 cases of patients with ALK-positive advanced or metastatic non-small cell lung cancer (NSCLC). Immunohistochemistry was performed to screen for ALK rearrangement. Fluorescence in situ hybridization (FISH) was used to detect the percentage of ALK-positive cells. The primary objectives of the study were the progression-free survival (PFS), the 3-year overall survival, and the 3-year overall survival (OS) rates. The secondary objectives of the study were the disease control rate (DCR) and the overall response rate (ORR).

Results

We compared the pathological cytomorphologic features of 60 cases of ALK-positive pulmonary adenocarcinoma, of which 21 cases were ALK-positive with signet ring cell cytomorphologic characteristics. There were statistical differences in the ORR (p = 0.019), DCR (p = 0.032), and PFS (p = 0.047) between the signet ring cell group and group without signet ring cells. Of these, 37 cases were ALK-positive with EML4 (echinoderm microtubule associated protein like 4)-ALK high percentage of positivity group. These cases benefited more from crizotinib treatment in the ORR (p = 0.046) and achieved a longer PFS (p = 0.036) compared to those with EML4-ALK low percentage of positivity group.

Conclusions

Signet ring cell cytomorphologic characteristics of pulmonary adenocarcinoma are associated with the percentage of ALK-positive cells. Signet ring cell cytomorphologic characteristics and the percentage of ALK-positive cells might predict the prognosis of pulmonary adenocarcinoma with crizotinib treatment.

Trial registration

The study was approved by the Institutional Review Board (Medical Ethics Committee of Yantai Yuhuangding Hospital). The registration number is NO.2016[193].

Individualized nomogram for predicting ALK rearrangement status in lung adenocarcinoma patients

OBJECTIVES

To develop a nomogram to identify anaplastic lymphoma kinase (ALK) mutations in lung adenocarcinoma patients using clinical, CT, PET/CT, and histopathological features.

METHODS

This retrospective study included 399 lung adenocarcinoma patients (129 ALK-rearranged patients and 270 ALK-negative patients) that were randomly divided into a training cohort and an internal validation cohort (4:1 ratio). Clinical factors, radiologist-defined CT features, maximum standard uptake values (SUVmax), and histopathological features were used to construct predictive models with stepwise backward-selection multivariate logistic regression (MLR). The models were then evaluated using the AUC. The integrated model was compared to the clinico-radiological model using the DeLong test to evaluate the role of histopathological features. An associated individualized nomogram was established.

RESULTS

The integrated model reached an AUC of 0.918 (95% CI, 0.886-0.950), sensitivity of 0.774, and specificity of 0.934 in the training cohort and an AUC of 0.857 (95% CI, 0.777-0.937), sensitivity of 0.739, and specificity of 0.810 in the validation cohort. The MLR analysis showed that younger age, never smoker, lymph node enlargement, the presence of cavity, high SUVmax, solid or micropapillary predominant histology subtype, and local invasiveness were strong and independent predictors of ALK rearrangements. The nomogram calculated the risk of harboring ALK mutation for lung adenocarcinoma patients and exhibited a good generalization ability.

CONCLUSION

Our study demonstrates that histopathological features added value to the imaging characteristics-based model. The nomogram with clinical, imaging, and histopathological features can serve as a supplementary non-invasive tool to evaluate the probability of ALK rearrangement in lung adenocarcinoma.

KEY POINTS

• The developed nomogram can accurately predict the probability of lung adenocarcinoma harboring ALK-fused gene. • Pathological analysis is important to predict ALK rearrangement in lung adenocarcinoma. • Lung adenocarcinoma with lepidic predominant growth pattern and TTF-1 negativity is unlikely to have ALK rearrangement.

Anti-PD-1 Therapy Achieved Disease Control After Multiline Chemotherapy in Unresectable KRAS-Positive Hepatoid Lung Adenocarcinoma: A Case Report and Literature Review

Hepatoid adenocarcinoma of the lung (HAL) is extremely rare and standardized treatment strategy for HAL has not been established. Patients with unresectable HAL have a shorter survival time ranges from 1 to 36 months. Here, we reported a 65-year-old female patient with unresectable alpha-fetoprotein-producing HAL harboring KRAS-G12V and no other targetable driver mutations. The patient was treated with multiple lines of chemotherapies followed by PD-1 inhibitor, sintilimab, due to positive staining of PD-L1, and achieved an overall survival of 52 months. Although the disease was under control, the patient experienced fifth-grade pneumonia and died after 6 months of anti-PD-1 treatment. This is the first case of KRAS-positive HAL patient achieved stable disease by PD-1 inhibitor, which may provide valuable information for the treatment strategy development of advanced HAL patients, and highlights the importance of molecular diagnosis in treatment decision-making.

Frequent appearance of club cell (Clara cell)-like cells as a histological marker for ALK-positive lung adenocarcinoma

Anaplastic lymphoma kinase-rearranged (ALK⁺ ) lung cancers show characteristic histological features, such as solid signet ring cell patterns and mucinous cribriform patterns; however, these features are not always observed in ALK⁺ lung cancers. We noticed that club cell (Clara cell)-like cells (CLCs) were frequently present in the papillary portion of ALK⁺ lung adenocarcinomas. In this study, we investigated the importance of CLCs in papillary patterns of ALK⁺ lung cancers. We compared the histological features of 18 ALK⁺ cases with 62 control cases (22 epidermal growth factor receptor-positive (EGFR⁺ ) and 40 ALK- and EGFR-negative (ALK^- /EGFR^- ) cases). The present study analyzed presence of papillary pattern, proportion of papillary pattern area, presence of micropapillary pattern, frequency of CLCs and lengths of snout. The frequency of CLCs in ALK⁺ cases was significantly higher than that in EGFR⁺ cases and ALK^- /EGFR^- cases. Micropapillary pattern was more frequently observed in ALK⁺ cases than that in ALK^- /EGFR^- cases (P < 0.001). The present study indicated that the high frequency of CLCs in papillary patterns was significantly associated with ALK⁺ cases. When solid signet ring cell patterns and mucinous cribriform patterns are absent, the high frequency of CLCs in papillary adenocarcinoma could be a useful histological marker for ALK⁺ lung cancers.

Histomorphologic features of lung adenocarcinomas exhibiting ALK gene rearrangement

With the advent of tyrosine kinase inhibitors, the identification of tumors with alterations in tyrosine kinase genes has become important to guide treatment. Lung adenocarcinomas harboring ALK translocations may be targeted with drugs such as crizotinib. We undertook a retrospective review of our institution's pathology records from January 2015 through September 2017 and identified 10 lung adenocarcinomas with ALK rearrangements. We reviewed the histomorphologic features and immunohistochemical results from these 10 cases. Morphologic features included patterns such as acinar, papillary, micropapillary, and solid, as well as features such as cribriform, signet ring, and extracellular mucin. Acinar (including simple and cribriform) was the most common pattern, followed by papillary. Solid and signet ring features were the least common. These findings were consistent with prior histomorphologic studies of ALK-positive lung adenocarcinomas. Certain histomorphologic patterns are associated with ALK positivity. However, histomorphologic features are neither absolutely sensitive nor absolutely specific in suggesting ALK rearrangement. Thus, identification of lung adenocarcinomas that may benefit from treatment with tyrosine kinase inhibitors requires comprehensive molecular testing.

Concomitant EGFR Mutation and EML4-ALK Rearrangement in Lung Adenocarcinoma Is More Frequent in Multifocal Lesions

BACKGROUND

The coexistence of epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement in patients with multifocal lung adenocarcinomas (LUAC) constitutes a rare molecular subtype of lung cancer. We aimed to investigate the intertumoral heterogeneity of pathologic and genetic characteristics of multifocal LUAC with EGFR/ALK co-alterations.

PATIENTS AND METHODS

A total of 1059 LUAC patients who underwent resection were investigated to screen for EGFR or ALK alterations using amplification refractory mutation system polymerase chain reaction and immunohistochemistry/fluorescence in situ hybridization. Molecular testing was extensively performed in patients with synchronous multifocal LUAC. Clonal evolution analysis was implemented using next-generation sequencing.

RESULTS

A total of 97 multiple synchronous lesions were observed among 1059 LUAC patients. Patients with at least 1 sample harboring EGFR mutation or ALK rearrangement were 62.89% (61/97) and 14.43% (14/97), respectively. Patients with concomitant EGFR and ALK alterations were 4.71% (4/97). Comparatively, patients with unifocal LUAC harboring EGFR mutation, ALK rearrangement, and EGFR/ALK co-alterations were 58.25% (570/962), 6.44% (62/962), and 0.83% (8/962), respectively. The prevalence of EGFR/ALK co-alterations in the multifocal LUAC was significantly higher than that in the unifocal LUAC (4.71% (4/97) vs. 0.83% (8/962)). Furthermore, we present 4 cases of EGFR/ALK co-altered multifocal LUAC with different morphological and molecular patterns. In addition to radiographic, pathological, and molecular testing results, clonal evolutional analysis could also be used to distinguish intertumoral heterogeneity.

CONCLUSION

The results highlight the importance of distinguishing synchronous primary tumors from intrapulmonary metastases, and of assessing the relative abundance of EGFR mutation and ALK rearrangement in patients with multifocal adenocarcinomas with EGFR/ALK co-alterations.

Cytomorphological Features of Lung Adenocarcinoma with Anaplastic Lymphoma Kinase Gene Rearrangement

Background:

The anaplastic lymphoma kinase (ALK) gene rearrangement is a predictive and prognostic marker in pulmonary adenocarcinoma. A series of clinical and pathological features have been documented in patients who harbor this translocation.

Aims:

The objectives of this study were to analyze the specific cytomorphological features of lung adenocarcinoma that harbored the ALK gene rearrangement and to compare the morphological features with the mutation-negative cases.

Materials and Methods:

The study sample of 40 cases included 15 ALK-positive cases and 25 ALK-negative cases. After the diagnosis was established, testing for ALK rearrangement was on the histopathology sample. The corresponding fine-needle aspiration cytology slides were retrieved from the records and cytomorphological features were analyzed.

Results:

A comparison of pattern between the ALK-positive and ALK-negative group revealed that the sheet-like pattern and singly scattered cells were more common in the ALK-positive group. Moderate-to-severe nuclear pleomorphism was identified in 80% of ALK-positive cases and 72% of ALK-negative cases. The presence of mucinous features and/or signet ring morphology was the most striking feature of ALK-positive cases with P value of 0.002. The presence of necrosis in the background was identified in 80% of ALK-positive cases and was statistically significant (P = 0.001).

Conclusion:

This is among the few studies from India, where a detailed analysis of the cytomorphological features of cases with ALK phenotype versus the mutation negative cases has been performed.

Solid predominant subtype in lung adenocarcinoma is related to poor prognosis after surgical resection: A systematic review and meta-analysis

BACKGROUND

Recent studies have indicated that solid predominant (SP) subtype of lung adenocarcinoma (LADC) may be associated with early recurrence and worse prognosis. Hence, a systematic review and meta-analysis were performed to evaluate the association between LADC subtype and survival.

METHODS

The MEDLINE, SCOPUS, Web of Science and Cochrane Libraries were reviewed for eligible studies in December 2017. Studies were included if they compared outcomes of patients with and without SP subtype in resection specimens of LADC patients after surgical treatment by using multivariate Cox regression analysis. A meta-analysis for overall survival (OS) and disease-free survival (DFS) was performed. The hazard ratios (HR) or odds ratios with 95% confidence intervals (CIs) from each study were used to calculate pooled HRs. Statistical analyses were performed using Review Manager 5.3.

RESULTS

In total, 14 eligible studies including 12,137 LADC patients were identified, which assessed the impact of SP subtype on OS and DFS in patients treated with pulmonary resection. SP subtype was reported in 1246 (10.2%) patients and was associated with significantly worse OS (pooled HR, 1.51; 1.29-1.75) and DFS (pooled HR, 1.26; 1.14-1.40).

CONCLUSIONS

SP subtype is associated with significantly worse OS and DFS in patients with LADC after pulmonary resection. These data provide evidence for the integration of the distinct histological LADC subtyping into prognostic tools and guidelines for adjuvant treatment after complete surgical resection.

Anaplastic lymphoma kinase fusions: Roles in cancer and therapeutic perspectives

Receptor tyrosine kinase (RTK) anaplastic lymphoma kinase (ALK) serves a crucial role in brain development. ALK is located on the short arm of chromosome 2 (2p23) and exchange of chromosomal segments with other genes, including nucleophosmin (NPM), echinoderm microtubule-associated protein-like 4 (EML4) and Trk-fused gene (TFG), readily occurs. Such chromosomal translocation results in the formation of chimeric X-ALK fusion oncoproteins, which possess potential oncogenic functions due to constitutive activation of ALK kinase. These proteins contribute to the pathogenesis of various hematological malignancies and solid tumors, including lymphoma, lung cancer, inflammatory myofibroblastic tumors (IMTs), Spitz tumors, renal carcinoma, thyroid cancer, digestive tract cancer, breast cancer, leukemia and ovarian carcinoma. Targeting of ALK fusion oncoproteins exclusively, or in combination with ALK kinase inhibitors including crizotinib, is the most common therapeutic strategy. As is often the case for small-molecule tyrosine kinase inhibitors (TKIs), drug resistance eventually develops via an adaptive secondary mutation in the ALK fusion oncogene, or through engagement of alternative signaling mechanisms. The updated mechanisms of a variety of ALK fusions in tumorigenesis, proliferation and metastasis, in addition to targeted therapies are discussed below.

Qualitative and quantitative cytomorphological features of primary anaplastic lymphoma kinase-positive lung cancer

OBJECTIVE

Anaplastic lymphoma kinase (ALK) positive (+) lung cancers are predictive for response to crizotinib and alectinib. There are many cases of lung cancer in which surgery cannot be performed, and such cases require diagnosis by cytological specimen or biopsy. Estimating ALK (+) lung cancer from cytomorphology would allow molecular testing to proceed without the waste of a small amount of specimen. The purpose of this study was to assess whether qualitative and quantitative cytomorphological features are sufficient for distinguishing primary ALK (+) from ALK (-) lung cancer.

METHODS

We examined eight qualitative cytomorphological parameters and three quantitative nuclear morphometric parameters in 17 cases of primary ALK (+) lung cancer, diagnosed by fluorescence in situ hybridisation (FISH) using histological specimens, and in 41 cases of ALK (-) lung cancer. Quantitative nuclear morphometric parameters were analysed by a computer-assisted image analysis system.

RESULTS

In ALK (+) lung cancer, three qualitative parameters (signet ring cells, nuclear grooves and single type nucleoli) and two quantitative parameters (large nuclear area and irregular nuclear shape) were observed in significantly higher proportions. However, in ALK (-) lung cancer, one qualitative parameter (unclear and multiple type nucleoli) was seen significantly more often.

CONCLUSIONS

These results show that the cytomorphological features of signet ring cells, nuclear grooves and nucleoli shape can help to triage a small amount of cytological and biopsy specimens for appropriate molecular testing of primary ALK (+) lung cancer.

Challenges in ALK inhibition of ALK-positive non-small-cell lung cancer: from ALK positivity detection to treatment strategies after relapse

ALK positivity, despite representing only in a small proportion of patients with non-small-cell lung cancer, is worth researching at diagnosis given the possibility to treat these patients with some targeted ALK inhibitors, which are more potent than chemotherapy. Thanks to understanding the resistance mechanisms, newer and more selective inhibitors are now available in clinical practice. Hence, this disease represents, after EGFR inhibition, a largely effective precision medicine approach. However, there are still some clinical situations in which the targeted drug seems to be ineffective. This review discusses some uncertainty about such a 'precision medicine application', focusing on some weaknesses and giving perspectives and suggestions to improve the management of this specific population.

Clonally-related primary ALK rearranged adenocarcinoma and associated metastatic lesions

ALK rearrangement is a driver gene in non‐small cell lung cancer (NSCLC). ALK‐positive tumors are sensitive to ALK‐tyrosine kinase inhibitors (TKIs). The detection of key driver genes is crucial to enable personalized treatment. Different histomorphological patterns have different driver genes. Herein, we report the case of a 42‐year‐old male patient diagnosed with adenocarcinoma with different histomorphologies in the primary lung site (mucinous type) and lymph node metastasis (solid type), of the same genotype, both presenting with ALK rearrangement but negative for EGFR mutation. This histological heterogeneity did not necessarily indicate a genomic difference. Genomic analysis may be a supplement to the histological features of ALK‐rearranged tumors. These gene alterations could aid the choice of an appropriate TKI and predict therapeutic response.

Advanced lung adenocarcinomas with ROS1-rearrangement frequently show hepatoid cell

Defining distinctive histologic characteristics of ROS1-rearranged non-small-cell lung carcinomas (NSCLCs) may help identify cases that merit molecular testing. However, the majority of previous reports have focused on surgical specimens but only limited studies assessed histomorphology of advanced NSCLCs. In order to identify the clinical and histological characteristics of ROS1-rearranged advanced NSCLCs, we examined five hundred sixteen Chinese patients with advanced NSCLCs using ROS1 fluorescence in situ hybridization and real-time polymerase chain reaction and then analyzed for clinical and pathological features. We performed univariate and multivariate analyses to identify predictive factors associated with ROS1 rearrangement. 19 tumors were identified with ROS1 rearrangement (3.7% of adenocarcinomas). 16 ROS1+ and 122 ROS1- samples with available medical records and enough tumor cells were included for histological analysis. Compared with ROS1-negative advanced NSCLCs, ROS1-rearranged advanced NSCLCs were associated with a younger age at presentation. ROS1 rearrangements were not significantly associated with sex, smoking history, drinking history and metastatic sites. The most common histological pattern was solid growth (12/16), followed by acinar (4/16) growth. 66.7% cases with solid growth pattern showed hepatoid cytology (8/12) and 75% cases with acinar growth pattern showed a cribriform structure (3/4). 18.8% cases were found to have abundant extracellular mucus or signet-ring cells (3/16). Only one case with solid growth pattern showed psammomatous calcifications. In conclusion, age, hepatoid cytology and cribriform structure are the independent predictors for ROS1-rearranged advanced NSCLCs, recognizing these may be helpful in finding candidates for genomic alterations, especially when available tissue samples are limited.

Clinicopathologic characteristics of EGFR, KRAS, and ALK alterations in 6,595 lung cancers

BACKGROUND

EGFR, KRAS, and ALK alterations are major genetic changes found in non-small cell lung cancers (NSCLCs). Testing advanced lung adenocarcinoma tumors for these three genes is now standard care. The purpose of this study was to investigate the clinicopathologic expression pattern of these three genes in East Asian NSCLC patients.

PATIENTS AND METHODS

We conducted a retrospective study of all patients tested for mutations of these three genes at a single institute in Korea between 2006 and 2014. Study data were extracted from electronic medical records. Univariate and multivariate logistic regression analyses were used to measure associations between clinicopathologic features and alterations of EGFR, KRAS, and ALK.

RESULTS

We detected 12 EGFR-mutated tumors with additional mutations in KRAS (N=6, 0.1%) or ALK (N=6, 0.1%). General clinicopathologic characteristics of tumors with EGFR, KRAS, or ALK mutations were similar to previous reports. Patients having EGFR L858R point mutations were older than patients having EGFR exon 19 deletions. EGFR G719X point mutations were more common in men and smokers than exon 19 deletions or L858R point mutations. Tumors having KRAS G12C mutations were less often of mucinous type than those with G12D or G12V, mutations.

CONCLUSIONS

This is the largest three gene molecular epidemiology study in East Asian NSCLC patients. Each genetic alteration was associated with distinct clinicopathologic characteristics. Furthermore, different age and sex are associated with different subtypes of EGFR and KRAS mutations.

Concordance of anaplastic lymphoma kinase (ALK) gene rearrangements between circulating tumor cells and tumor in non-small cell lung cancer

Anaplastic lymphoma kinase (ALK) gene rearrangement in non-small cell lung cancer (NSCLC) is routinely evaluated by fluorescent in-situ hybridization (FISH) testing on biopsy tissues. Testing can be challenging however, when suitable tissue samples are unavailable. We examined the relevance of circulating tumor cells (CTC) as a surrogate for biopsy-based FISH testing. We assessed paired tumor and CTC samples from patients with ALK rearranged lung cancer (n = 14), ALK-negative lung cancer (n = 12), and healthy controls (n = 5) to derive discriminant CTC counts, and to compare ALK rearrangement patterns. Blood samples were enriched for CTCs to be used for ALK FISH testing. ALK-positive CTCs counts were higher in ALK-positive NSCLC patients (3–15 cells/1.88 mL of blood) compared with ALK-negative NSCLC patients and healthy donors (0–2 cells/1.88 mL of blood). The latter range was validated as the ‘false positive’ cutoff for ALK FISH testing of CTCs. ALK FISH signal patterns observed on tumor biopsies were recapitulated in CTCs in all cases. Sequential CTC counts in an index case of lung cancer with no evaluable tumor tissue treated with crizotinib showed six, three and eleven ALK-positive CTCs per 1.88 mL blood at baseline, partial response and post-progression time points, respectively. Furthermore, ALK FISH rearrangement suggestive of gene copy number increase was observed in CTCs following progression. Recapitulation of ALK rearrangement patterns in the tumor on CTCs, suggested that CTCs might be used to complement tissue-based ALK testing in NSCLC to guide ALK-targeted therapy when suitable tissue biopsy samples are unavailable for testing.

Cytological markers for predicting ALK-positive pulmonary adenocarcinoma

BACKGROUND

ALK gene rearrangement is an important class of gene mutations in pulmonary adenocarcinoma. ALK-positive pulmonary adenocarcinoma exhibits characteristic histological features, such as signet ring cell carcinoma (SRCC) and a mucinous cribriform structure. However, when insufficient histological specimens are obtained, ALK-positivity must be predicted based on cytological features. The purpose of this study was to clarify the cytological characteristics of ALK-positive pulmonary adenocarcinoma.

METHODS

We compared the cytological findings of 16 ALK-positive cases with 40 ALK-negative cases. We examined various cytoplasmic features of SRCC, including the presence of pink, yellow, or orange mucin; green, vacuolar, or vesicular cytoplasm; and green globular cytoplasmic secretions. We also examined whether the SRCC cells exhibited a pattern of individually scattered cells, the formation of cell clusters, and formation of a mucinous cribriform pattern.

RESULTS

A univariate analysis showed that significantly frequent cytological findings included pink mucin, green cytoplasm, vacuolar cytoplasm, vesicular cytoplasm, green globular cytoplasmic secretions, an individually scattered pattern, cluster formation, and a mucinous cribriform structure (all, P < .05). A stepwise multivariate logistic regression analysis identified three significant contributing factors: pink mucin (P = .03), vesicular cytoplasm (P = .06), and an individually scattered pattern (P = .01) of SRCC. If the specimens showed two or three of these features, the sensitivity and specificity were both 88% for the prediction of ALK-positive cancers.

CONCLUSION

Three cytological features of SRCC (pink mucin, vesicular cytoplasm, and an individually scattered pattern) could be useful cytological markers for the prediction of ALK-positive pulmonary adenocarcinoma.

The Molecular Pathology of Lung Cancer

Advances in lung cancer genomics have revolutionized the diagnosis and treatment of this heterogeneous and clinically significant group of tumors. This article provides a broad overview of the most clinically relevant oncogenic alterations in common and rare lung tumors, with an emphasis on the pathologic correlates of the major oncogenic drivers, including EGFR, KRAS, ALK, and MET. Illustrations emphasize the morphologic diversity of lung adenocarcinoma, including genotype-phenotype correlations of genomic evolution in tumorigenesis. Molecular diagnostic approaches, including PCR-based testing, massively parallel sequencing, fluorescence in situ hybridization, and immunohistochemistry are reviewed.

Informing materials: drugs as tools for exploring cancer mechanisms and pathways

This paper builds on previous work that investigated anticancer drugs as 'informed materials', i.e., substances that undergo an informational enrichment that situates them in a dense relational web of qualifications and measurements generated by clinical experiments and clinical trials. The paper analyzes the recent transformation of anticancer drugs from 'informed' to 'informing material'. Briefly put: in the post-genomic era, anti-cancer drugs have become instruments for the production of new biological, pathological, and therapeutic insights into the underlying etiology and evolution of cancer. Genomic platforms characterize individual patients' tumors based on their mutational landscapes. As part of this new approach, drugs targeting specific mutations transcend informational enrichment to become tools for informing (and destabilizing) their targets, while also problematizing the very notion of a 'target'. In other words, they have become tools for the exploration of cancer pathways and mechanisms. While several studies in the philosophy and history of biomedicine have called attention to the heuristic relevance and experimental use of drugs, few have investigated concrete instances of this role of drugs in clinical research.

ALK rearrangement in specific subtypes of lung adenocarcinoma: immunophenotypic and morphological features

Lung adenocarcinomas are characterized by a variety of genetic and epigenetic changes that lead to activation of specific signaling pathways. This allowed the classification of lung adenocarcinomas according to genetic alterations and the clinical development of novel anticancer agents that affect the activity of specific oncoproteins. In such a context, chromosomal rearrangements that cause constitutive activation of ALK gene define a category of lung adenocarcinomas that is amenable to targeted therapy with ALK inhibitors. Thus, a major issue of current research is to define the morphological and immunophenotypic features of lung ALK-rearranged adenocarcinomas to improve the selection of tumors suitable for molecular genotyping. ALK status was determined, by immunohistochemistry and fluorescence in situ hybridization, in 94 surgically resected lung adenocarcinomas and correlated with histomorphological parameters. Indeed, ALK rearrangement was observed in 10/94 (11%) lung adenocarcinomas and enriched in tumors with a predominant mucinous (46%; p < 0.05) and solid (29%; p < 0.05) pattern. By contrast, it was lacking or sporadically observed in lung adenocarcinomas with predominant acinar, papillary or lepidic pattern. Moreover, the presence of signet-ring cells was predominantly observed in ALK-rearranged tumors (47%; p < 0.05). These data suggest that ALK rearrangement is associated with specific and distinct clinical-pathological characters compared to other genotypes. Thus, the knowledge of these characteristics can improve the diagnostic accuracy and lead to a better understanding of the behavior of ALK-rearranged NSCLC.

Diagnosis of anaplastic lymphoma kinase rearrangement in cytological samples through a fluorescence in situ hybridization-based assay: Cytological smears versus cell blocks

Anaplastic lymphoma kinase (ALK) status analysis of lung cytological specimens should be successfully encouraged in routine practice because biopsy specimens are not always available. To date, the US Food and Drug Administration has approved both fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) as diagnostic tests for identifying ALK-positive patients eligible for treatment with crizotinib. Although ALK IHC is an optimal diagnostic tool, FISH becomes mandatory in equivocal cases. ALK FISH of paraffin-embedded tissue material is still the gold standard, whereas the cytological specimen assay has not yet been completely standardized. Many controversial data have been reported on the adequacy of cytology cell blocks (CBs) versus conventional smears for FISH testing. This review discusses some critical issues related to ALK FISH of cytological samples, including the triaging of collected specimens to optimize the material, the use of CBs versus conventional smears, and alternative methods for an ALK rearrangement diagnosis. Conventional smears have the advantages of an immediate evaluation, no probe tissue-related artifactual loss, no fixation-related alterations, and usually sufficient material for an analytic preparation. On the other hand, CBs have several advantages, including the appropriate conservation of the tissue architecture, an absence of problems related to cell overlapping, and the ability to evaluate neoplastic cells in a dark field. Cancer Cytopathol 2017;125:303-312. © 2017 American Cancer Society.

A comprehensive analysis of clinical outcomes in lung cancer patients harboring a MET exon 14 skipping mutation compared to other driver mutations in an East Asian population

INTRODUCTION

Recurrent somatic splice-site alterations at MET exon 14 (MET^Δ14), which result in exon skipping and MET proto-oncogene, receptor tyrosine kinase (MET) activation, have been characterised. However, their demographic features and clinical outcomes in East Asian lung cancer patients have yet to be determined.

METHODS

A one-step reverse transcription-polymerase chain reaction (RT-PCR), using RNA samples from 850 East Asian lung cancer patients, was performed in order to detect MET^Δ14 and five other major driver mutations, including those in the EGFR, KRAS, ALK, HER2, and ROS1 genes. Immunohistochemistry (IHC) was used to confirm the overexpression of MET in patients harbouring the MET^Δ14 mutation. We analysed the demographic data and clinical outcomes of MET^Δ14 mutation positive lung cancer patients and compared them to those of MET^Δ14 mutation negative lung cancer patients.

RESULTS

In total, 27 lung adenocarcinoma (ADC) patients and 1 squamous cell carcinoma patient with the MET^Δ14 mutation were identified. The overall incidence was 3.3% for lung cancer and 4.0% for lung ADC. IHC demonstrated that the majority of lung cancer patients harboring a MET^Δ14 mutation exhibited a strong cytoplasmic expression of MET. MET^Δ14 mutation positive patients were generally quite elderly individuals. Stage IV MET^Δ14 mutation positive lung cancer patients receiving no specific anti-MET therapy were observed to have a similar overall survival (OS) compared to patients in the all negative group (P>0.05). In the multivariate analysis, mutation status was found not to be a major risk factor for OS in lung cancer patients without appropriate tyrosine kinase inhibitors treatment.

CONCLUSIONS

The OS of MET^Δ14 mutation positive lung cancer patients is comparable to that of the major driver gene mutation negative lung cancer patients.

Size of Non-lepidic Invasive Pattern Predicts Recurrence in Pulmonary Mucinous Adenocarcinoma: Morphologic Analysis of 188 Resected Cases with Reappraisal of Invasion Criteria

Background

We reviewed a series of 188 resected pulmonary mucinous adenocarcinomas (MAs) to clarify the prognostic significance of lepidic and non-lepidic patterns.

Methods

Non-lepidic patterns were divided into bland, non-distorted acini with uncertain invasiveness (pattern 1), unequivocal invasion into stroma (pattern 2), or invasion into alveolar spaces (pattern 3).

Results

The mean proportion of invasive patterns (patterns 2 and 3) was lowest in small (≤ 3 cm) tumors, and gradually increased in intermediate (> 3 cm and ≤ 7 cm) and large (> 7 cm) tumors (8.4%, 34.3%, and 50.1%, respectively). Adjusted T (aT) stage, as determined by the size of invasive patterns, was positively correlated with adverse histologic and clinical features including older age, male sex, and ever smokers. aTis tumors, which were exclusively composed of lepidic pattern (n = 9), or a mixture of lepidic and pattern 1 (n = 40) without any invasive patterns, showed 100% disease- free survival (DFS). The aT1mi tumors, with minimal (≤ 5 mm) invasive patterns (n = 63), showed a 95.2% 5-year DFS, with recurrences (n = 2) limited to tumors greater than 3 cm in total size (n = 23). Both T and aT stage were significantly associated with DFS; however, survival within the separate T-stage subgroups was stratified according to the aT stage, most notably in the intermediatestage subgroups. In multivariate analysis, the size of invasive patterns (p = .020), pleural invasion (p < .001), and vascular invasion (p = .048) were independent predictors of recurrence, whereas total size failed to achieve statistical significance (p = .121).

Conclusions

This study provides a rationale for histologic risk stratification in pulmonary MA based on the extent of invasive growth patterns with refined criteria for invasion.

ALK gene rearranged lung adenocarcinomas: molecular genetics and morphology in cohort of patients from North India

ALK gene rearrangement in the lung adenocarcinomas is the second most common (1.6-11.7% of NSCLC) targetable genomic change after EGFR mutations. However, the prevalence and clinicopathological features of ALK-rearranged lung adenocarcinomas from North India are lacking. A total of 240 cases of lung adenocarcinoma were screened for EGFR mutations and for ALK expression. Smoking status, TNM stage, and treatment response were recorded in all cases. Out of 240 cases screened, 37 cases were positive for EGFR mutations and 17 cases (7.08%) showed ALK positivity with immunohistochemistry and break-apart FISH. On excluding 37 EGFR mutation-positive cases, the incidence of ALK-positive adenocarcinoma appears to be higher (17/203 cases, 8.03%). Eight were men and nine were women with mean age of 51.7 years. Majority (62.5%) were non-smokers and had unresectable disease (70.6% stage IV, 17.6% IIIB). The morphological patterns noted were solid (12 cases), papillary (four cases), and micropapillary (one case). Signet ring (two cases) and clear cell change (one cases) were noted. Out of five patients who received crizotinib, three had partial response and two had stable disease. ALK-rearranged lung adenocarcinomas account for a minor proportion of NSCLC with prevalence similar to that reported in literature. However, as contrast to published data in our series, patients were in older age group and had solid and papillary pattern on morphology with an aggressive course.

Detection of novel and potentially actionable anaplastic lymphoma kinase (ALK) rearrangement in colorectal adenocarcinoma by immunohistochemistry screening

Purpose

Anaplastic lymphoma kinase (ALK) rearrangement has been detected in colorectal carcinoma (CRC) using advanced molecular diagnostics tests including exon scanning, fluorescence in situ hybridization (FISH), and next generation sequencing (NGS). We investigated if immunohistochemistry (IHC) can be used to detect ALK rearrangement in gastrointestinal malignancies.

Experimental designs

Tissue microarrays (TMAs) from consecutive gastric carcinoma (GC) and CRC patients who underwent surgical resection at Samsung Medical Center, Seoul, Korea were screened by IHC using ALK monoclonal antibody 5A4. IHC positive cases were confirmed by FISH, nCounter assays, and NGS-based comprehensive genomic profiling (CGP). ALK IHC was further applied to CRC patients enrolled in a pathway-directed therapeutic trial.

Results

Four hundred thirty-two GC and 172 CRC cases were screened by IHC. No GC sample was ALK IHC positive. One CRC (0.6%) was ALK IHC positive (3+) that was confirmed by ALK FISH and a novel CAD-ALK (C35; A20) fusion variant that resulted from a paracentric inversion event inv(2)(p22–21p23) was identified by CGP. One out of 50 CRC patients enrolled in a pathway-directed therapeutic trial was ALK IHC positive (3+) confirmed by ALK FISH and found to harbor the EML4-ALK (E21, A20) fusion variant by CGP. Growth of a tumor cell line derived from this EML4-ALK CRC patient was inhibited by ALK inhibitors crizotinib and entrectinib.

Conclusions

ALK IHC is a viable screening strategy for identifying ALK rearrangement in CRC. ALK rearrangement is a potential actionable driver mutation in CRC based on survival inhibition of patient tumor-derived cell line by potent ALK inhibitors.

Identification of crucial microRNAs and genes in hypoxia-induced human lung adenocarcinoma cells

BACKGROUND

Variations of microRNA (miRNA) expression profile in hypoxic lung cancer cells have not been studied so far. Therefore, using miRNA microarray technology, this study aimed to study the miRNA expression profile and investigate the potential crucial miRNAs and their target genes in hypoxia-induced human lung adenocarcinoma cells.

MATERIALS AND METHODS

Based on miRNA microarray, miRNA expression profiling of hypoxia-induced lung adenocarcinoma A549 cells was obtained. After identification of differentially expressed miRNAs (DE-miRNAs) in hypoxic cells, target genes of DE-miRNAs were predicted, and functional enrichment analysis of targets was conducted. Furthermore, the expression levels of DE-miRNAs and their target genes were validated by real-time quantitative polymerase chain reaction. In addition, using miRNA mimics, the effect of overexpressed DE-miRNAs on A549 cell behaviors (cell proliferation, cell cycle, and apoptosis) was evaluated.

RESULTS

In total, 14 DE-miRNAs (nine upregulated miRNAs and five downregulated miRNAs) were identified in hypoxic cells, compared with normoxic cells. Target genes of both upregulated and downregulated miRNAs were enriched in the functions such as chromatin modification, and pathways such as Wnt signaling pathway and transforming growth factor (TGF)-β signaling pathway. The expression levels of several miRNAs and their target genes were confirmed, including hsa-miR-301b/FOXF2, hsa-miR-148b-3p/WNT10B, hsa-miR-769-5p/(SMAD2, ARID1A), and hsa-miR-622. Among them, hsa-miR-301b was verified to regulate FOXF2, and hsa-miR-769-5p was verified to modulate ARID1A. In addition, the overexpression of hsa-miR-301b and hsa-miR-769-5p significantly affected the cell cycle of A549 cells, but not cell proliferation and apoptosis.

CONCLUSION

miRNA expression profile was changed in hypoxia-induced lung cancer cells. Those validated miRNAs and genes may play crucial roles in the response of lung cancer cells to hypoxia.

Frequencies of ALK rearrangements in lung adenocarcinoma subtypes: a study of 2299 Chinese cases

Purpose

This study aimed to determine the relationship between ALK status and lung adenocarcinoma subtypes, according to the IALSC/ATS/ERS classification in Chinese patients.

Methods

A reclassification of 2299 surgically resected lung adenocarcinomas was performed, and ALK status was detected by immunohistochemistry (Ventana Medical Systems) in Shanghai Chest Hospital.

Results

ALK rearrangements were identified in 93 of 2299 tumors (4.0 %). The ALK rearrangements frequencies were: 14.8 % (16/108), 10.3 % (20/195), 7.6 % (13/170), 2.8 % (29/1035), 2.5 % (3/119), 2.0 % (11/539), 0.9 % (1/114), and 0 % (0/19) for variants of invasive adenocarcinoma, solid predominant, micropapillary predominant, acinar predominant, minimally invasive adenocarcinoma, papillary predominant, lepidic predominant, and adenocarcinoma in situ, respectively.

Conclusions

We reported significant discrepancies of ALK status in lung adenocarcinoma subtypes in Chinese patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-2607-5) contains supplementary material, which is available to authorized users.

ALK-rearranged pulmonary adenocarcinoma in Thai Patients: From diagnosis to treatment efficacy

Background

Anaplastic lymphoma kinase (ALK) gene rearrangement is detected in 3 % to 13 % of non-small cell lung carcinoma patients, and these patients benefit from ALK inhibitors. The aim of this study was to determine the prevalence, the clinical and histological characteristics and the treatment outcomes of ALK-rearranged lung adenocarcinoma using immunohistochemistry (IHC) IHC, reverse transcription polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH) methodologies.

Methods

A total of 268 pulmonary adenocarcinoma patients were screened for ALK expression by ALK IHC, which was confirmed by FISH and/or RT-PCR for ALK gene rearrangement. The treatment outcomes of ALK-rearranged patients were retrospectively reviewed.

Results

ALK gene rearrangement was identified in 26 cases (9.7 %) with no EGFR co-mutation, and it showed significant associations with younger age, female sex and non-smoker status (p < 0.05). A cribriform growth pattern was identified as the dominant histologic feature, and a solid signet ring cell component was focally present in a minority of the cases. Among 12 ALK-rearranged patients with conventional treatment, seven cases in the early stage of disease were cured and alive, and five patients in the late stage of the disease progressed and died, with a median overall survival (OS) at 14 months. Of the 14 patients receiving crizotinib, all of them had clinical benefit from crizotinib treatment, with one patient having a complete response (CR), 12 patients having a partial response (PR) and one patient having stable disease (SD). On the cutoff date, six of 14 patients were continuing crizotinib treatment with a median time of response of 7.5 (3–13) months, while eight patients had disease progression, and five of them died with a median OS at 8 months.

Conclusion

ALK gene rearrangement tended to occur in younger, non-smoking, female patients. ALK IHC is a reliable screening method to detect ALK gene rearrangement. Crizotinib therapy provided treatment benefit in ALK-rearranged adenocarcinoma patients especially in advanced stages of the disease.

A causal link from ALK to hexokinase II overexpression and hyperactive glycolysis in EML4-ALK-positive lung cancer

A high rate of aerobic glycolysis is a hallmark of malignant transformation. Accumulating evidence suggests that diverse regulatory mechanisms mediate this cancer-associated metabolic change seen in a wide spectrum of cancer. The echinoderm microtubule associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion protein is found in approximately 3-7% of non-small cell lung carcinomas (NSCLC). Molecular evidence and therapeutic effectiveness of FDA-approved ALK inhibitors indicated that EML4-ALK is a driving factor of lung tumorigenesis. A recent clinical study showed that NSCLC harboring EML4-ALK rearrangements displayed higher glucose metabolism compared to EML4-ALK-negative NSCLC. In the current work, we presented evidence that EML4-ALK is coupled to overexpression of hexokinase II (HK2), one of the rate-limiting enzymes of the glycolytic pathway. The link from EML4-ALK to HK2 upregulation is essential for a high rate of glycolysis and proliferation of EML4-ALK-rearranged NSCLC cells. We identified hypoxia-inducible factor 1α (HIF1α) as a key transcription factor to drive HK2 gene expression in normoxia in these cells. EML4-ALK induced hypoxia-independent but glucose-dependent accumulation of HIF1α protein via both transcriptional activation of HIF1α mRNA and the PI3K-AKT pathway to enhance HIF1α protein synthesis. The EML4-ALK-mediated upregulation of HIF1α, HK2 and glycolytic metabolism was also highly active in vivo as demonstrated by FDG-PET imaging of xenografts grown from EML4-ALK-positive NSCLC cells. Our data reveal a novel EML4-ALK-HIF1α-HK2 cascade to enhance glucose metabolism in EML4-ALK-positive NSCLC.