Clinical features of squamous cell lung cancer with anaplastic lymphoma kinase (ALK)-rearrangement: a retrospective analysis and review

Rediscovering immunohistochemistry in lung cancer

Several observations indicate that protein expression analysis by immunohistochemistry (IHC) remains relevant in individuals with non-small-cell lung cancer (NSCLC) when considering targeted therapy, as an early step in diagnosis and for therapy selection. Since the advent of next-generation sequencing (NGS), the role of IHC in testing for NSCLC biomarkers has been forgotten or ignored. We discuss how protein-level investigations maintain a critical role in defining sensitivity to lung cancer therapies in oncogene- and non-oncogene-addicted cases and in patients eligible for immunotherapy, suggesting that IHC testing should be reconsidered in clinical practice. We also argue how a panel of IHC tests should be considered complementary to NGS and other genomic assays. This is relevant to current clinical diagnostic practice but with potential future roles to optimize the selection of patients for innovative therapies. At the same time, strict validation of antibodies, assays, scoring systems, and intra- and interobserver reproducibility is needed.

Distinction of ALK fusion gene- and EGFR mutation-positive lung cancer with tumor markers

BACKGROUND

It is difficult to predict gene mutations individually based on clinical background alone. Tumor markers may help to predict each gene mutation. Identifying tumor markers that can predict gene mutation will facilitate timely genetic testing and intervention.

METHODS

We selected 134 cases of advanced or recurrent ALK-positive and 172 cases of advanced or recurrent EGFR-positive lung cancer from our clinical database. The cutoff values for the tumor markers were defined as 5.0 ng/mL or higher for carcinoembryonic antigen (CEA) and 3.5 ng/mL or higher for soluble fragment of cytokeratin 19 (CYFRA21-1) in accordance with the institutional standards. A positive CYFRA21-1:CEA ratio was defined as 0.7 or higher.

RESULTS

The CEA-positivity rate was 49% for ALK-positive lung cancers and 73% for EGFR-positive lung cancers, which was significantly different (p < 0.001). The CYFRA21-1 positivity rate was significantly higher in ALK-positive lung cancer (36%) compared with EGFR-positive lung cancer (23%) (p = 0.034). The median CYFRA21-1:CEA ratio was 0.395 for the ALK group, which was significantly higher compared with 0.098 for the EGFR group (p < 0.001). These trends were similar when excluding histology other than adenocarcinoma. The median time-to-treatment failure (TTF) for initial tyrosine kinase inhibitor (TKI) therapy was 308 days for the high CYFRA21-1:CEA ratio group and 617 days for the low CYFRA21-1:CEA ratio group for ALK-positive lung cancer (p = 0.100).

CONCLUSIONS

A higher proportion of patients with ALK-positive lung cancer were CYFRA21-1 positive and had higher CYFRA21-1:CEA ratios compared with EGFR-positive lung cancer patients.

Clinical characteristics and progression of pre-/minimally invasive lung adenocarcinoma harboring ALK or RET rearrangements: a retrospective cohort study

Background

Patients harboring anaplastic lymphoma kinase (ALK) or rearranged during transfection (RET) rearrangements are usually diagnosed at a relatively late stage with nodal and distant metastasis, and rapid progression course of ALK/RET fusion-positive lung cancer were well-known. However, clinical characteristics and course of pre-/minimally invasive lung adenocarcinoma harboring ALK or RET fusions are poorly described. Identifying patients with gene fusions at early stage may offer surgical options that could cure those patients.

Methods

We retrospectively included patients with surgically resected pre-/minimally invasive lung adenocarcinomas harboring epidermal growth factor receptor (EGFR) mutations or ALK/RET rearrangements, and further compared the patient clinical characteristics, nodule natural course, and survival outcomes. Radiological characteristics including ground-glass component, cystic airspace, pleural attachment, etc. were specially assessed for this study. EGFR (exons 18-22) was detected by Sanger sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the ALK/RET rearrangements. Lung cancer-specific survival (LCSS), relapse-free survival (RFS), and overall survival (OS) were all evaluated.

Results

Of 238 patients with pre-/minimally invasive lung adenocarcinomas, 226 patients had EGFR mutations, 7 patients had ALK fusions, and 5 patients had RET fusions. Average age at surgery was 45.3 years for ALK/RET-positive group and 52.6 years for EGFR-positive group (P=0.049). Radiologically, among the 12 patients with ALK/RET fusions, the majority of lesions (10/12) manifested as mixed ground-glass opacities (mGGOs), which was significantly more prevalent when compared with patients with EGFR mutations (83.4% vs. 24.3%, P<0.001). Moreover, a substantial proportion of cystic airspace was found in ALK/RET-positive group but not in EGFR-positive group (66.7% vs. 14.2%, P<0.001). Among four patients with ALK/RET fusions undergoing surveillance over 1 year before surgery, two of them developed rapid radiologic progression. The 5-year LCSS and RFS were 100%, 100% for ALK/RET-positive group, and 100%, 100% for EGFR-positive group, respectively.

Conclusions

ALK/RET-positive pre-/minimally invasive lung adenocarcinomas were mostly characterized as mGGOs with cystic airspace developing rapid nodule progression, and no recurrence occurred during long-term follow-up after resection. This provides insights into proper curative surgery timing in the management of patients with gene fusions. However, these findings must be treated with caution and validated in future multi-center studies with larger sample size.

From Development to Place in Therapy of Lorlatinib for the Treatment of ALK and ROS1 Rearranged Non-Small Cell Lung Cancer (NSCLC)

Following the results of the CROWN phase III trial, the third-generation macrocyclic ALK inhibitor lorlatinib has been introduced as a salvage option after the failure of a first-line TKI in ALK-rearranged NSCLC, while its precise role in the therapeutic algorithm of ROS1 positive disease is still to be completely defined. The ability to overcome acquired resistance to prior generation TKIs (alectinib, brigatinib, ceritinib, and crizotinib) and the high intracranial activity in brain metastatic disease thanks to increased blood-brain barrier penetration are the reasons for the growing popularity and interest in this molecule. Nevertheless, the major vulnerability of this drug resides in a peculiar profile of related collateral events, with neurological impairment being the most conflicting and debated clinical issue. The cognitive safety concern, the susceptibility to heterogeneous resistance pathways, and the absence of a valid alternative in the second line are strongly jeopardizing a potential paradigm shift in this oncogene-addicted disease. So, when prescribing lorlatinib, clinicians must face two diametrically opposed characteristics: a great therapeutic potential without the intrinsic limitations of its precursor TKIs, a cytotoxic activity threatened by suboptimal tolerability, and the unavoidable onset of resistance mechanisms we cannot properly manage yet. In this paper, we give a critical point of view on the stepwise introduction of this promising drug into clinical practice, starting from its innovative molecular and biochemical properties to intriguing future developments, without forgetting its weaknesses.

Current status and challenges of immunotherapy in ALK rearranged NSCLC

Rearrangements of the anaplastic lymphoma kinase (ALK) gene account for 5-6% in non-small cell lung cancer (NSCLC). ALK rearranged NSCLC is sensitive to ALK tyrosine kinase inhibitors (TKIs) but prone to drug resistance. Meanwhile, ALK rearranged NSCLC has poor response to single immunotherapy. Here we mainly describe the immune escape mechanisms of ALK mutated NSCLC and the role of related biomarkers. Additionally, we collate and evaluate preclinical and clinical studies of novel immune combination regimens, and describe the prospects and perspectives for the in vivo application of novel immune technologies in patients with ALK rearranged NSCLC.

Breast cancer circulating tumor cells with mesenchymal features-an unreachable target?

Circulating tumor cells (CTCs) mediate dissemination of solid tumors and can be an early sign of disease progression. Moreover, they show a great potential in terms of non-invasive, longitudinal monitoring of cancer patients. CTCs have been extensively studied in breast cancer (BC) and were shown to present a significant phenotypic plasticity connected with initiation of epithelial-mesenchymal transition (EMT). Apart from conferring malignant properties, EMT affects CTCs recovery rate, making a significant portion of CTCs from patients’ samples undetected. Wider application of methods and markers designed to isolate and identify mesenchymal CTCs is required to expand our knowledge about the clinical impact of mesenchymal CTCs. Therefore, here we provide a comprehensive review of clinical significance of mesenchymal CTCs in BC together with statistical analysis of previously published data, in which we assessed the suitability of a number of methods/markers used for isolation of CTCs with different EMT phenotypes, both in in vitro spike-in tests with BC cell lines, as well as clinical samples. Results of spiked-in cell lines indicate that, in general, methods not based on epithelial enrichment only, capture mesenchymal CTCs much more efficiently that CellSearch^® (golden standard in CTCs detection), but at the same time are not much inferior to Cell Search^®, though large variation in recovery rates of added cells among the methods is observed. In clinical samples, where additional CTCs detection markers are needed, positive epithelial-based CTCs enrichment was the most efficient in isolating CTCs with mesenchymal features from non-metastatic BC patients. From the marker side, PI3K and VIM were contributing the most to detection of CTCs with mesenchymal features (in comparison to SNAIL) in non-metastatic and metastatic BC patients, respectively. However, additional data are needed for more robust identification of markers for efficient detection of CTCs with mesenchymal features.

Case Report: Significant Clinical Benefit From Pemetrexed-Based Therapy in ROS1- and ALK-rearranged Lung Cancer With Adenosquamous Histology

Pemetrexed (used as a platinum doublet or as a maintenance regimen) is an established therapy for patients with advanced non-squamous non-small-cell lung cancer (NSCLC). In addition, certain gene rearrangements (e.g., ALK, ROS1, RET) appear to especially benefit from the use of pemetrexed. Inferior outcomes with pemetrexed compared to other chemotherapies in patients with NSCLC demonstrating squamous histology removed these patients from the labeled indication for the drug. While most squamous cases do not harbor driver oncogenes, rare exceptions exist. Whether the poor outcomes with pemetrexed extend to NSCLC with squamous component harboring driver oncogenes remains unexplored. In this case series, we describe two patients with adenosquamous histology harboring an ROS1 and ALK gene arrangement, respectively, who derived significant benefit from pemetrexed-based therapy. These cases suggest that the value of pemetrexed may need to be re-explored in adenosquamous NSCLC harboring such alterations.

Efficacy of Targeted Inhibitors in Metastatic Lung Squamous Cell Carcinoma With EGFR or ALK Alterations

Introduction

The efficacy of targeted therapies in oncogene-driven lung adenocarcinomas (LUADs) has been well established; however, the benefit for EGFR-mutant or ALK-rearranged lung squamous cell carcinomas (LUSCs) is less known, partially owing to the rarity of the incidence.

Methods

We reviewed the database of the MD Anderson Cancer Center and identified metastatic LUSC with classic EGFR or ALK alterations.

Results

There were eight patients with EGFR-mutant LUSC (median age = 58 y) and six patients with EML4-ALK LUSC (median age = 50 y) who received tyrosine kinase inhibitors (TKIs) that were identified. Of the 14 patients, 11 (79%) were females and 12 (86%) were never smokers, similar to the demographics of EGFR or ALK LUAD. With TKI treatment, seven of eight cases of EGFR LUSC and four of six cases of ALK LUSC achieved partial response or stable disease, but the progression-free survival was 4.9 months and 2.9 months for EGFR-mutant and ALK-rearranged LUSC, respectively. In addition, we compared comutation profile of EGFR-mutant LUAD (The Cancer Genome Atlas, n = 46) versus LUSC (n = 19) and found that the comutation patterns are more consistent with squamous disease with a higher incidence of PIK3CA (p = 0.02) and KRAS or BRAF (p = 0.04) alterations.

Conclusions

EGFR or ALK alterations occur in patients with LUSC, especially never-smoker females. TKI treatments render clinical benefit in disease control, but the duration was considerably truncated compared with those historically observed in LUAD.

Brigatinib treated ALK positive lung squamous cell carcinoma after failed chemotherapy: A case report

The definitive efficacy of anaplastic lymphoma kinase (ALK) inhibitors in ALK positive lung squamous cell carcinoma (sqCC) patients remain unclear. Here, we report a case in which brigatinib had a therapeutic effect on ALK‐positive lung squamous cell carcinoma. The patient in this report was diagnosed with ALK‐positive lung squamous cell carcinoma with brain metastases, and received brigatinib after failure of first‐line chemotherapy. Response duration was approximately 11 months, with tolerable side effects. In conclusion, a good clinical effect was achieved in a patient with ALK positive lung squamous cell carcinoma who received treatment with an ALK inhibitor.

Acquired ALK Resistance Mutations Identified from Liquid Biopsy in an ALK-Rearranged Squamous Cell Lung Cancer Patient Treated with Sequential ALK TKI Therapy: A Case Report

Anaplastic lymphoma kinase (ALK) rearrangement is extremely rare in lung squamous cell carcinoma (LSCC), and it remains controversial as to whether LSCC patients with ALK rearrangement can benefit from ALK tyrosine kinase inhibitors (TKIs). Here, we report an LSCC patient with ALK rearrangement who was treated with sequential ALK TKI therapies and experienced a clinical benefit of 35 months. Although the use of ALK TKIs showed clinical benefits, targeted next-generation sequencing (NGS) for dynamic monitoring of circulating tumor DNA (ctDNA) from patient plasma revealed the accumulation of ALK resistance mutations, which could provide valuable information in designing the treatment strategy. Our study highlights the importance of dynamic monitoring of ctDNA using NGS to discover tumor evolution to guide treatment decision-making and provides meaningful insights into the potential treatment options for ALK-positive LSCC patients.

ALK-rearranged squamous cell carcinoma of the lung

BACKGROUND

ALK rearrangement is a very rare subset of squamous cell carcinoma (SCC) and one of the clinical features in patients is lack of data. Here, we report eight patients diagnosed with SCC of the lung harboring ALK rearrangement.

METHODS

We collected primary NSCLC samples at the Beijing Chest Hospital between January 2012 and December 2018 for Ventana (D5F3) immunohistochemical detection. Among the 148 patients was diagnosed ALK-rearranged non small cell lung cancer (NSCLC), only eight cases was SCC. We collected patients information from electronic patent records (EPRs).

RESULTS

The eight cases of SCC were diagnosed by immunohistochemistry (IHC). Two were given crizotinib as second-line therapy. One patient had stable disease (SD) and progression-free survival (PFS) of six months. The other patient had progressive disease (PD) but PFS was only one month. The side effects were tolerable. This report identified 31 cases of ALK rearrangement in SCC patients from a literature search (including the eight patients in this study). These fusion genes are often seen in a younger age group (mean age: 55.6 years) and non-smokers (18/31, 58.1%). A total of 20 cases received an ALK inhibitor as first- or second-line treatment which included 11 with a partial response (PR), four with SD, and five with PD. The DCR and ORR was 75.0% (15/20) and 55.0% (11/20), respectively. The median duration time of therapy was 6.4 ± 4.4 months.

CONCLUSIONS

Patients with ALK-rearranged SCC obtained clinical benefit from ALK-inhibitor therapy, especially those who were non-smokers and whose tumors had been identified by IHC+/FISH+.

Transformation from adenocarcinoma to squamous cell lung carcinoma with MET amplification after lorlatinib resistance: A case report

To date, several studies have described the mechanism of resistance to first‐ or second‐generation anaplastic lymphoma kinase (ALK) inhibitors. Secondary ALK mutations, ALK gene amplification, and other bypass signal activations (i.e., KRAS mutation, EGFR mutation, amplification of KIT, and increased autophosphorylation of EGFR) are known as resistance mechanisms. However, little has been previously reported on acquired resistance mechanisms to lorlatinib. Here, we report a case of a patient with ALK‐positive lung adenocarcinoma that acquired resistance to lorlatinib during treatment for brain metastasis and showed histological transformation to squamous cell carcinoma with MET amplification. We also review the previous literature on the resistance mechanism to ALK inhibitors.

Detecting Resistance to Therapeutic ALK Inhibitors in Tumor Tissue and Liquid Biopsy Markers: An Update to a Clinical Routine Practice

The survival of most patients with advanced stage non-small cell lung cancer is prolonged by several months when they are treated with first- and next-generation inhibitors targeting ALK rearrangements, but resistance inevitably emerges. Some of the mechanisms of resistance are sensitive to novel ALK inhibitors but after an initial tumor response, more or less long-term resistance sets in. Therefore, to adapt treatment it is necessary to repeat biological sampling over time to look for different mechanisms of resistance. To this aim it is essential to obtain liquid and/or tissue biopsies to detect therapeutic targets, in particular for the analysis of different genomic alterations. This review discusses the mechanisms of resistance to therapeutics targeting genomic alterations in ALK as well as the advantages and the limitations of liquid biopsies for their identification.

Narrative review of molecular pathways of kinase fusions and diagnostic approaches for their detection in non-small cell lung carcinomas

The discovery of actionable oncogenic driver alterations has significantly improved treatment options for patients with advanced non-small cell lung cancer (NSCLC). In lung adenocarcinoma (LUAD), approved drugs or drugs in clinical development can target more than half of these altered oncogenic driver genes. In particular, several gene fusions have been discovered in LUAD, including ALK, ROS1, NTRK, RET, NRG1 and FGFR. All these fusions involve tyrosine kinases (TK), which are activated due to structural rearrangements on the DNA level. Although the overall prevalence of these fusions in LUAD is rare, their detection is extremely important, as they are linked to an excellent response to TK inhibitors. Therefore, reliable screening methods applicable to small tumor samples (biopsies and cytology specimens) are required in the diagnostic workup of advanced NSCLC. Several methods are at disposal in a routine laboratory to demonstrate, directly or indirectly, the presence of a gene fusion. These methods include immunohistochemistry (IHC), fluorescence in-situ hybridization (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR), multiplex digital color-coded barcode technology or next-generation sequencing (NGS) either on DNA or RNA level. In our review, we will summarize the increasing number of relevant fusion genes in NSCLC, point out their underlining molecular mechanisms and discuss different methods for the detection of fusion genes.

Different driver gene mutations in patients with synchronous multiple primary lung cancers: a case report

Background

Routine clinical and pathological examinations usually cannot fully conclusively determine the relationship between different lesions of lung cancer. Detailed genetic analysis of tumor samples may supply important additional information and identify second primary lung cancers.

Case presentation

In the present study, we report a case of synchronous multiple primary lung cancer (MPLC) composed of two distinct pathological subtypes with epidermal growth factor receptor (EGFR) gene mutations L858R of the acinar adenocarcinoma subtype and EML4–ALK rearrangement of the squamous cell carcinoma.

Conclusion

The present report highlights the clinical importance of molecular cancer biomarkers detection to guide management decisions in MPLC cases.

Characteristics and Response to Crizotinib in ALK-Rearranged, Advanced Non-Adenocarcinoma, Non-Small Cell Lung Cancer (NA-NSCLC) Patients: a Retrospective Study and Literature Review

BACKGROUND

Oncogenic fusion genes consisting of echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) can be detected in 5-7% of lung adenocarcinoma cases. The prevalence of ALK rearrangement in non-adenocarcinoma, non-small cell lung cancers (NA-NSCLC) is currently unknown. In addition, the efficacy of crizotinib in these patients has not been well established.

OBJECTIVES

The aim of this study was to investigate the prevalence of ALK rearrangement in NA-NSCLC patients and the therapeutic efficacy of crizotinib in these patients.

METHODS

We included NA-NSCLC patients who were tested for the presence of ALK rearrangement in our institution from January 2013 to May 2018. The effectiveness of crizotinib in ALK-positive patients was retrospectively analyzed. A literature review was performed and eligible previously published cases were analyzed in combination with our data.

RESULTS

A total of 4662 patients were screened and 1696 NA-NSCLC patients were tested for the presence of ALK rearrangement during the study period. Thirty-two positive patients were identified (1.9%, 95% CI, 1.2-2.5%). A statistically higher percentage of younger (58.0 vs. 63.0, p = 0.01), female patients (53.1% vs. 10.8%, p < 0.01) who were non-smokers (71.9% vs. 40.6%, p < 0.01) and whose tumors contained adenocarcinoma components (34.4% vs. 6.1%, p < 0.01) were observed in the ALK-positive group. Eighteen patients were excluded from the study and 14 eligible patients were included for survival analysis. The median duration of crizotinib treatment (MDT) as a proxy for progression-free survival of the 14 eligible patients in our institution was 6.0 months (95% CI, 1.2-10.8 months). We combined our data with sporadic cases from 16 previous publications (total n = 37) and found that the MDT was 7.0 months (95% CI, 6.0-8.0 months).

CONCLUSIONS

Our study suggests the opportunity to test ALK rearrangement in NA-NSCLC patients, especially in younger, female, non-smoking patients containing adenocarcinoma components. Crizotinib provides an option for the treatment of NA-NSCLC patients who have an ALK rearrangement.

Alectinib in the treatment of ALK-positive metastatic non-small cell lung cancer: clinical trial evidence and experience with a focus on brain metastases

Molecular profiling of metastatic nonsquamous non-small cell lung cancer (NSCLC) is required to guide the treatment strategy. Anaplastic lymphoma kinase (ALK) gene rearrangements are found in approximately 5% of lung adenocarcinomas and are associated with specific clinical features including a high risk of brain metastases. Crizotinib was the first ALK inhibitor developed and it demonstrated improved outcomes in patients with ALK-positive advanced NSCLC in comparison with chemotherapy. However, despite an initial response, all ALK-positive NSCLC patients develop acquired resistance to crizotinib. Because the most frequent mechanism of resistance is the development of a secondary ALK mutation, second (ceritinib, alectinib, brigatinib) and third-generation (lorlatinib) ALK inhibitors were developed. Alectinib is a second-generation ALK inhibitor and was shown to be effective for a broad spectrum of ALK rearrangements and ALK mutations. It was also shown to have high intracranial efficacy. In this article, we review clinical trial evidence of alectinib efficacy as well as publications reporting the experience of alectinib in daily practice, with a focus on brain metastases.

A study of ALK-positive pulmonary squamous-cell carcinoma: From diagnostic methodologies to clinical efficacy

BACKGROUND

High concordance has been observed between Ventana D5F3 ALK immunohistochemistry (IHC) and fluorescence in-situ hybridization (FISH) in lung adenocarcinoma (LADC). However, whether a similar conclusion can be applied to lung squamous-cell carcinoma (LSCC) has remained unclear. We therefore evaluated the ALK (anaplastic lymphoma kinase) status and the therapeutic effect of an ALK tyrosine kinase inhibitor (TKI) in IHC- or FISH-positive LSCC.

MATERIALS AND METHODS

A total of 2403 LSCC patients from three institutions were screened for ALK aberration by IHC. All IHC-positive cases were subjected to FISH (with an approximately equal number of negative cases as a control group) and next-generation sequencing (NGS). Clinical efficacy was evaluated for the patients who received TKI therapy.

RESULTS

In 2403 cases of LSCC, 37 cases were identified as ALK-positive by IHC. After quality control, 28 cases were succeeded by FISH (six with insufficient tissue, three with lack of signals) and 13 by NGS (24 failed due to insufficient samples or poor DNA quality); the percentage of non-diagnostic tests was 24.3% (9/37) and 64.9% (24/37), respectively. Four cases (4/2394, 0.17%) analyzed by FISH were determined as ALK-positive. For the control group (40 ALK IHC), FISH demonstrated no samples with ALK gene fusion. The concordance between ALK IHC- and ALK FISH-positive results was 14.3% (4/28). In the 13 cases studied by NGS, two cases showed ALK-EML4 fusion (consistent with two FISH-positive results), and two cases were interpreted as harboring an ALK-association gene mutation. Among four patients (two FISH-positive and two IHC-positive only cases) receiving TKI therapy, two patients had stable disease and the other two had progressive disease.

CONCLUSIONS

The positive concordance rate of ALK IHC and FISH in LSCC is far less than that reported for LADC. Therefore, ALK IHC detection in LSCC cannot be used as a diagnostic method for ALK rearrangement.