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

Ensartinib in the treatment of anaplastic lymphoma kinase-positive locally advanced or metastatic patients with lung squamous or adenosquamous carcinoma: A real-world, retrospective study

AIM

To report the efficacy and safety of ensartinib, an anaplastic lymphoma kinase (ALK) inhibitor, in treating patients with ALK-positive advanced lung squamous cell carcinoma (LUSC) or lung adenosquamous carcinoma (LASC) in China.

METHODS

This retrospective study analyzed data for 36 advanced-stage patients with ALK-positive LUSC (cohort A) and 13 patients with ALK-positive LASC (cohort B) between December 16, 2020 and December 16, 2021. All patients received once-daily ensartinib 225 mg. Outcome analysis included the demographic characteristics, tumor response, progression-free survival (PFS), and treatment-related adverse events (TRAE).

RESULTS

Among the 49 patients, the majority were under 65 years old (73.5%), non-smokers (85.7%), had an Eastern Cooperative Oncology Group Performance Status of 0-1 (77.6%), and were at stage IV (71.4%). All patients were included in the efficacy and safety analysis. Seven PFS events were reported in cohort A while no patients experienced PFS events in cohort B. The median PFS was not estimable for both cohorts. In cohort A, the objective response rate (ORR) was 63.9%, and the disease control rate (DCR) was 83.3%. In the cohort B, the ORR was 76.9% and the DCR was 100.0%. Rash was the only TRAE reported in the cohort A (8.3%) and cohort B (23.1%). No patients had grade 3 or higher TRAE.

CONCLUSION

Ensartinib has been tentatively proven favorable efficacy and tolerability in the treatment of patients with ALK-positive advanced LUSC or LASC in the real-world. However, confirmatory studies are still needed in larger sample sizes.

Potential unreliability of ALK variant allele frequency in the efficacy prediction of targeted therapy in NSCLC

Anaplastic lymphoma kinase (ALK) is the most common fusion gene involved in non-small cell lung cancer (NSCLC), and remarkable response has been achieved with the use of ALK tyrosine kinase inhibitors (ALK-TKIs). However, the clinical efficacy is highly variable. Pre-existing intratumoral heterogeneity (ITH) has been proven to contribute to the poor treatment response and the resistance to targeted therapies. In this work, we investigated whether the variant allele frequencies (VAFs) of ALK fusions can help assess ITH and predict targeted therapy efficacy. Through the application of next-generation sequencing (NGS), 7.2% (326/4548) of patients were detected to be ALK positive. On the basis of the adjusted VAF (adjVAF, VAF normalization for tumor purity) of four different threshold values (adjVAF < 50%, 40%, 30%, or 20%), the association of ALK subclonality with crizotinib efficacy was assessed. Nonetheless, no statistical association was observed between median progression-free survival (PFS) and ALK subclonality assessed by adjVAF, and a poor correlation of adjVAF with PFS was found among the 85 patients who received first-line crizotinib. Results suggest that the ALK VAF determined by hybrid capture-based NGS is probably unreliable for ITH assessment and targeted therapy efficacy prediction in NSCLC.

Frequent EGFR exon 20 insertion in the so-called peripheral-type squamous cell neoplasm of uncertain malignant potential: a variant of bronchiolar adenoma or under-recognised entity?

INTRODUCTION

Herein we describe a series of rare peripheral pulmonary neoplasms temporarily termed "peripheral type squamous cell neoplasm of uncertain malignant potential (PSCN-UMP)" and investigate their relationship to bronchiolar adenoma (BA) and squamous cell carcinoma (SCC).

MATERIALS AND METHODS

The histologic and immunohistochemical features of 10 PSCN-UMPs and six BAs were compared. Whole exome sequencing (WES) and bioinformatics analysis were performed to further compare the genetic features of PSCN-UMPs, BAs, and NSCLCs.

RESULTS

All PSCN-UMPs were peripherally located and histologically characterised by the lepidic, nested, and papillary proliferation of relatively bland squamous cells, accompanied by entrapped hyperplastic reactive pneumocytes. The basal squamous cells coexpressed TTF1 and squamous markers. Both cellular components exhibited bland morphology and a low proliferative activity. The six BAs met the morphologic and immunophenotypic features of proximal-type BA. Genetically, driver mutations, including frequent EGFR exon 20 insertions, were found in PSCN-UMPs, while the KRAS mutation, BRAF mutation, and ERC1::RET fusion were detected in BAs. PSCN-UMPs also shared some alterations with BAs in mutational signatures, while copy number variants (CNV) were enriched in MET and NKX2-1 in PSCN-UMP and MCL1, MECOM, SGK1, and PRKAR1A in BA.

CONCLUSION

PSCN-UMPs exhibited the proliferation of bland squamous cells accompanied by entrapped pneumocytes and frequent EGFR exon 20 insertions, which showed distinct features from BAs and SCCs. Recognition of this specific entity will help to expand the morphologic and molecular spectrum of peripheral lung squamous neoplasms.

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.

Identification and therapeutic evaluation of ALK rearrangements in non-small-cell lung cancer

This study aimed to present a comprehensive assessment of anaplastic lymphoma kinase (ALK) rearrangements evaluated by DNA/RNA-based next-generation sequencing (NGS) and Ventana immunohistochemistry (IHC) in patients with non-small-cell lung cancer (NSCLC) and to evaluate the therapeutic outcomes of ALK tyrosine kinase inhibitor (TKI) treatment. We investigated ALK gene fusions in 14,894 patients with NSCLC using Ventana IHC and NGS, including 12,533 cases detected via DNA-based NGS and 2,361 cases using RNA-based NGS. The overall percentage agreement (OPA), positive percentage agreement (PPA), and negative percentage agreement (NPA) were calculated when comparing the results between NGS and IHC. The therapeutic responses to ALK-TKIs were also evaluated. In total, 3.50% (439/12,533) of specimens were NGS ALK-positive (NGS-p) in the DNA-based NGS cohort and 3.63% (455/12,533) were IHC ALK-positive (IHC-p). The OPA of NGS was 99.60%, whereas its PPA and NPA were 92.75 and 99.86%, respectively. In the adenocarcinoma (ADC) subcohort, the PPA was 95.69%. In the RNA-based NGS cohort, 2.20% (52/2,361) of specimens were NGS-p and 2.63% (62/2,361) were IHC-p. The OPA of NGS was 99.49%; its PPA and NPA were 82.26 and 99.96%, respectively. Thirteen patients with discordant results received ALK-TKI treatment. In the seven NGS-p/IHC-negative (IHC-n) patients, the overall response rate (ORR) was 85.4% (6/7) and the disease control rate (DCR) was 100%. In the six NGS-negative/IHC-p patients, the ORR was 66.7% (4/6) and the DCR was 100%. In summary, a high concordance of ALK gene fusion detected via NGS and IHC was observed in this study. DNA-based NGS had a higher OPA, PPA, and PPA in the ADC subcohort, whereas RNA-based NGS had a higher NPA. Overall, the results suggest that the combination of NGS and IHC can improve the accuracy of ALK fusion detection; hence, a result determination algorithm for clinical detection of ALK gene fusion was also proposed.

Fusion-positive non-small cell lung carcinoma: Biological principles, clinical practice, and diagnostic implications

Based on superior efficacy and tolerability, targeted therapy is currently preferred over chemotherapy and/or immunotherapy for actionable gene fusions that occur in late-stage non-small cell lung carcinoma (NSCLC). Consequently, current clinical practice guidelines mandate testing for ALK, ROS1, NTRK, and RET gene fusions in all patients with newly diagnosed advanced non-squamous NSCLC (NS-NSCLC). Gene fusions can be detected using different approaches, but today RNA next-generation sequencing (NGS) or combined DNA/RNA NGS is the method of choice. The discovery of other gene fusions (involving, eg, NRG1, NUT, FGFR1, FGFR2, MET, BRAF, EGFR, SMARC fusions) and their partners has increased progressively in recent years, leading to the development of new and promising therapies and mandating the development and implementation of comprehensive detection methods. The purpose of this review is to focus on recent data concerning the main gene fusions identified in NSCLC, followed by the discussion of major challenges in this domain.

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.

Molecular biomarker testing for non-small cell lung cancer: consensus statement of the Korean Cardiopulmonary Pathology Study Group

Molecular biomarker testing is the standard of care for non–small cell lung cancer (NSCLC) patients. In 2017, the Korean Cardiopulmonary Pathology Study Group and the Korean Molecular Pathology Study Group co-published a molecular testing guideline which contained almost all known genetic changes that aid in treatment decisions or predict prognosis in patients with NSCLC. Since then there have been significant changes in targeted therapies as well as molecular testing including newly approved targeted drugs and liquid biopsy. In order to reflect these changes, the Korean Cardiopulmonary Pathology Study Group developed a consensus statement on molecular biomarker testing. This consensus statement was crafted to provide guidance on what genes should be tested, as well as methodology, samples, patient selection, reporting and quality control.

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+.

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.

Clinical evaluation of the effectiveness of fusion-induced asymmetric transcription assay-based reverse transcription droplet digital PCR for ALK detection in formalin-fixed paraffin-embedded samples from lung cancer

BACKGROUND

Accurate detection of anaplastic lymphoma kinase (ALK) rearrangement is the prerequisite for anti-ALK therapy for the patient with non-small cell lung cancer (NSCLC). Fusion-induced asymmetric transcription assay (FIATA)-based reverse transcription droplet digital PCR (RT-ddPCR) was developed and performed for ALK status survey in NSCLC samples.

METHODS

A total of 269 cases of formalin-fixed paraffin-embedded (FFPE) specimens from NSCLC, in which ALK status was confirmed by both fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC), were analyzed by FIATA-based RT-ddPCR.

RESULTS

In the ALK-positive group, the 3' ALK transcript copies range was 336.6-107 955.4, and the R3 [(the ratio of the 3' ALK transcript copy numbers to the internal reference gene transcript copy numbers) × 100] was 17.23-672.77. In the ALK-negative group, the 3' ALK transcript copies range was 3.7-1370.6, and the R3 range was 0.10-15.57. The lowest R3 level in the ALK-positive group was significantly higher than the highest R3 level in the ALK-negative group. A positive correlation between the proportion of cancer cells in the tissue section and ALK RNA expression level (R3) was found (P < 0.05). There was no relationship between the percentage of FISH positive cells or FISH positive signal patterns and R3 level of the ALK gene. Compared with FISH and IHC, the clinical sensitivity and specificity of FIATA-based RT-ddPCR for ALK detection were 100%, respectively.

CONCLUSIONS

An absolute quantitative FIATA-based RT-ddPCR was developed and validated for ALK fusion detection in NSCLC. This method can rapidly, accurately, and objectively classify ALK types and help with individual therapy.