Association of Programmed Death-Ligand 1 Expression with Fusion Variants and Clinical Outcomes in Patients with Anaplastic Lymphoma Kinase-Positive Lung Adenocarcinoma Receiving Crizotinib

A Poor Prognostic ALK Phenotype: A Review of Molecular Markers of Poor Prognosis in ALK Rearranged Nonsmall Cell Lung Cancer

BACKGROUND

Patients with nonsmall cell lung cancer with anaplastic lymphoma kinase (ALK) rearrangements derive a significant and durable clinical benefit from tyrosine kinase inhibitors (TKIs). However, early progression/death on treatment occurs in a subset of patients, which we term the poor prognostic ALK phenotype. This review aims to summarize the known molecular mechanisms that underlie this phenotype with a focus on variant 3 and TP53 mutations.

METHODS

A scoping review was performed using scientific databases such as Ovid Medline, Ovid Embase, and Cochrane Central Register of Controlled Trials. Studies included molecular markers of poor prognosis, with a focus on TP53 mutations, variant 3 re-arrangements, and poor clinical response to TKIs.

RESULTS

Of 4371 studies screened, 108 were included. Numerous studies implicated a negative prognostic role of variant 3, likely mediated through the acquisition of on-target resistance mutations and TP53 mutations which are associated with greater chromosomal instability and mutational burden. Co-occurring variant 3 and TP53 mutations were associated with even worse survival. Other mediators of early resistance development include aberrations in cell cycle regulators and mutations in cell signaling pathways. Comprehensive genomic analysis from first-line TKI clinical trial data was unable to identify a singular genomic signature that underlies the poor prognostic phenotype but implicated a combination of pathways.

CONCLUSIONS

This scoping review highlights that the poor prognostic ALK phenotype is likely composed of a heterogeneous variety of genomic factors. There remains an unmet need for a genomic assay to integrate these various molecular markers to predict this ALK phenotype.

Treatment of metastatic ALK-positive non-small cell lung cancer: real-world outcomes in a single center study

Background

Rearrangement in anaplastic lymphoma kinase (ALK) occurs in 4-7% of non-small cell lung cancer (NSCLC) cases. Despite improved survival with tyrosine kinase inhibitors (TKIs), treatment resistance remains challenging. This retrospective study analyzed advanced ALK-positive NSCLC patients, focusing on clinical aspects, treatments, resistance, and outcomes.

Methods

Patients diagnosed between January 2009 and December 2021 who received at least one ALK-TKI line at the Karolinska University Hospital, were included. We evaluated crizotinib or 2nd generation ALK-TKI effectiveness in first-line treatment and lorlatinib in subsequent lines. Overall survival (OS) was defined as from the date of advanced lung cancer diagnosis until the date of last follow-up (April 22, 2022) or the date of death from any cause. Progression-free survival (PFS), from the date of starting ALK-TKI until the date of progression, death, or last follow-up. Resistance mechanisms were assessed through re-biopsies utilizing next-generation sequencing (NGS).

Results

Out of 160 eligible patients, 10 were excluded. Median follow-up was 54.0 months from diagnosis and 45.0 months from initial ALK-TKI treatment. Crizotinib showed a median PFS of 8.0 months and a median OS of 35.0 months. Second generation ALK-TKIs demonstrated a median PFS of 52.0 months [OS was not reached (NR)]. Overall, the median OS was 65.0 months. Poor prognostic factors included male sex, thromboembolism, crizotinib treatment, and chronic obstructive pulmonary disease (COPD)/asthma. Rebiopsies in 18 cases revealed secondary ALK mutations in 8 patients, correlating with a shorter median PFS in subsequent ALK-TKI treatment (1.0 vs. 7.0 months).

Conclusions

This comprehensive study, spanning over a decade, provides crucial insights into the clinical characteristics, treatment patterns, and resistance mechanisms of advanced ALK-positive NSCLC, where median OS exceeds 5 years. Re-biopsies during treatment are essential for advancing our understanding of resistance mechanisms and the tumor dynamics evolving during ALK-TKI therapy.

Comparing Genomic Profiles of ALK Fusion-Positive and ALK Fusion-Negative Nonsmall Cell Lung Cancer Patients

Background  Anaplastic lymphoma kinase ( ALK ) fusion events account for 3 to 7% of genetic alterations in patients with nonsmall cell lung cancer (NSCLC). This study aimed to explore the landscape of ALK fusion-positive and ALK fusion-negative in a large cohort of NSCLC patients. Methods  The formalin-fixed paraffin-embedded specimens of NSCLC patients who underwent next-generation sequencing from 2020 to 2023 in Yinfeng Gene Technology Co., Ltd. Clinical laboratory were included in this study. Results  In the current study, a total of 180 (3.20%) patients tested positive for ALK fusions in 5,622 NSCLC samples. Within the ALK -positive cohort, a total of 228 ALK fusions were identified. Furthermore, five novel ALK fusion partners, including DAB1-ALK , KCMF1-ALK , KIF13A-ALK , LOC643770-ALK , and XDH-ALK were identified. In cases with ALK fusion-positive, TP53 alterations were the most prevalent (26.3%), followed by CDKN2A (8.4%), epidermal growth factor receptor ( EGFR , 5.6%), and ALK (5.6%). By contrast, EGFR alterations were most prevalent (51%) in patients with ALK fusion-negative NSCLC, followed by TP53 (42.7%), KRAS (11.6%), and CDKN2A (11.3%). A total of 10 cases where ALK fusion co-occurred with EGFR mutations were also identified. Notably, the ALK fusion positivity rate was higher in younger patients ( p  < 0.0001) and in female patients ( p  = 0.0429). Additionally, positive ALK test results were more prevalent in patients with high programmed death-ligand 1 expression, especially when applying a 50% cutoff. Conclusions  Collectively, these findings offer valuable genomic insights that could inform the personalized clinical care of patients with NSCLC harboring ALK fusions within the context of precision medicine.

Impact of Tumor-intrinsic Molecular Features on Survival and Acquired Tyrosine Kinase Inhibitor Resistance in ALK-positive NSCLC

While tyrosine kinase inhibitors (TKI) have shown remarkable efficacy in anaplastic lymphoma kinase (ALK) fusion-positive advanced non-small cell lung cancer (NSCLC), clinical outcomes vary and acquired resistance remains a significant challenge. We conducted a retrospective study of patients with ALK-positive NSCLC who had clinico-genomic data independently collected from two academic institutions (n = 309). This was paired with a large-scale genomic cohort of patients with ALK-positive NSCLC who underwent liquid biopsies (n = 1,118). Somatic co-mutations in TP53 and loss-of-function alterations in CDKN2A/B were most commonly identified (24.1% and 22.5%, respectively in the clinical cohort), each of which was independently associated with inferior overall survival (HR: 2.58; 95% confidence interval, CI: 1.62-4.09 and HR: 1.93; 95% CI: 1.17-3.17, respectively). Tumors harboring EML4-ALK variant 3 (v3) were not associated with specific co-alterations but were more likely to develop ALK resistance mutations, particularly G1202R and I1171N (OR: 4.11; P < 0.001 and OR: 2.94; P = 0.026, respectively), and had inferior progression-free survival on first-line TKI (HR: 1.52; 95% CI: 1.03-2.25). Non-v3 tumors were associated with L1196M resistance mutation (OR: 4.63; P < 0.001). EML4-ALK v3 and somatic co-alterations in TP53 and CDKN2A/B are associated with inferior clinical outcomes. v3 status is also associated with specific patterns of clinically important ALK resistance mutations. These tumor-intrinsic features may inform rational selection and optimization of first-line and consolidative therapy.

SIGNIFICANCE

In a large-scale, contemporary cohort of patients with advanced ALK-positive NSCLC, we evaluated molecular characteristics and their impact on acquired resistance mutations and clinical outcomes. Our findings that certain ALK variants and co-mutations are associated with differential survival and specific TKI-relevant resistance patterns highlight potential molecular underpinnings of the heterogenous response to ALK TKIs and nominate biomarkers that may inform patient selection for first-line and consolidative therapies.

High PD-L1 Expression Correlates with an Immunosuppressive Tumour Immune Microenvironment and Worse Prognosis in ALK-Rearranged Non-Small Cell Lung Cancer

High tumour programmed cell death-ligand 1 (PD-L1) expression is associated with poor progression-free survival (PFS) after tyrosine kinase inhibitor (TKI) therapy in ALK-rearranged non-small cell lung cancer (NSCLC). However, the characteristics of the tumour microenvironment (TME) and their prognostic values in ALK-rearranged NSCLC are unknown. Here, we collected tumour tissues from pretreated ALK-rearranged NSCLC patients, immunohistochemical staining was used to assess PD-L1 expression, and tumour-infiltrating immune cells were determined via multiplex immunofluorescence staining (mIF). Our data showed that the median values of PFS for the high PD-L1 group and low PD-L1 group who received ALK-TKI treatment were 4.4 and 16.4 months, respectively (p = 0.008). The median overall survival (OS) of the two groups was 24.0 months and not reached, respectively (p = 0.021). Via univariate and multivariate analyses, a high PD-L1 expression and a worse ECOG PS were determined to be independent prognostic factors of OS (HR = 3.35, 95% CI: 1.23-9.11, p = 0.018; HR = 6.42, 95% CI: 1.45-28.44, p = 0.014, respectively). In addition, the high PD-L1 group had increased Tregs and exhausted CD8+ T cells in both the tumour and stroma (all p < 0.05). High PD-L1 expression was an adverse predictive and prognostic biomarker for ALK-rearranged NSCLC. The characteristics of the TME in patients with high PD-L1 expression were shown to have an immunosuppressive status.

Association of PD-L1 expression with efficacy of alectinib in advanced NSCLC patients with ALK fusion

BACKGROUND

Programmed cell death-ligand 1 (PD-L1) expression was found to be a biomarker of inferior efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutated non-small cell lung cancer (NSCLC). However, whether PD-L1 expression could also serve as a similar biomarker in anaplastic lymphoma kinase (ALK)-positive patients, especially for those treated with front-line alectinib, remains unclear. The aim of the study is to investigate the association of PD-L1 expression and efficacy of alectinib in this setting.

METHODS

From January 2018 to March 2020, 225 patients with ALK-rearranged lung cancer were consecutively collected at Shanghai Pulmonary Hospital, Tongji University. Baseline PD-L1 expression was detected using immunohistochemistry (IHC) in 56 patients of advanced ALK-rearranged lung cancer who received front-line alectinib.

RESULTS

Among the 56 eligible patients, 30 (53.6%) were PD-L1 expression negative, 19 (33.9%) patients had TPS 1%-49% and 7 (12.5%) had TPS ≥ 50%.We found no statistically significant associations between PD-L1 positivity and objective response rate (ORR, 90.0% vs. 80.8%, p = 0.274) or progression-free survival (PFS, not reached vs. not reached, HR: 0.98, 95 %CI: 0.37-2.61, p = 0.97) in patients treated with alectinib. Meanwhile, patients with PD-L1 high expression (TPS ≥ 50%) had a trend of longer PFS (not reached vs. not reached, p = 0.61).

CONCLUSIONS

PD-L1 expression might not serve as a predict biomarker for the efficacy of front-line alectinib in ALK-positive NSCLC patients.

Case report: Novel junctional sarcoplasmic reticulum protein 1 intergenic region–anaplastic lymphoma kinase fusion in a patient with lung adenocarcinoma responds to alectinib

Novel anaplastic lymphoma kinase (ALK) fusions are still being discovered in non-small cell lung cancer (NSCLC). Most patients with ALK+ NSCLC respond favorably to ALK tyrosine kinase inhibitors. In this case report, we identified a novel nonreciprocal ALK fusion, namely, junctional sarcoplasmic reticulum protein 1 (JSRP1) intergenic region–ALK fusion (Jintergenic: A20) via next-generation sequencing in a female patient initially diagnosed with stage IV B lung adenocarcinoma. Further examination of biopsy specimen and analysis of clinical samples by a multidisciplinary team confirmed the diagnosis of ALK+ NSCLC. At the 2- and 4-months follow-up after receiving alectinib, the patient responded rapidly, implying that alectinib had a remarkable therapeutic effect. We identified a novel JSRP1 intergenic region–ALK fusion as a carcinogenic mutation that responds to alectinib, thereby expanding the spectrum of ALK fusion partners in ALK + NSCLC. This study may help clinicians detect oncogenic mutations and provide timely treatment to patients with ALK+ NSCLC.

Various impacts of driver mutations on the PD-L1 expression of NSCLC

We aimed to evaluate whether different driver mutations have varying impacts on the programmed cell death-ligand 1 (PD-L1) expression of non-small cell lung cancer (NSCLC), and whether the prognostic roles of PD-L1 amongst our patients were divergent. This was a single-institute study that included patients with NSCLC. Six driver mutations, PD-L1 status, and the outcomes of treatment were assessed. A total of 1,001 NSCLC patients were included for analysis. Overall, the PD-L1 positive (TPS ≥ 1%) and strong positive (TPS ≥ 50%) rates were 52.2% and 17.3%, respectively. As compared with wild type lung adenocarcinoma, EGFR-mutant and HER2-mutant patients had similarly low PD-L1 and strong PD-L1 positive rates. BRAF-mutant patients had numerically higher PD-L1 and strong PD-L1 positive rates. Patients with fusion mutation (ALK and ROS1) (aOR 2.32 [95% CI 1.10-4.88], P = 0.027 and 2.33 [95% CI 1.11-4.89], P = 0.026), KRAS mutation (aOR 2.58 [95% CI 1.16-5.75], P = 0.020 and 2.44 [95% CI 1.11-5.35], P = 0.026), and non-adenocarcinoma histology (aOR 2.73 [95% CI 1.72-4.34], P < 0.001 and 1.93 [95% CI 1.13-3.30], P = 0.016) all had significantly higher PD-L1 and strong PD-L1 positive rates. A trend towards longer survival was noted in ROS-1 rearranged and KRAS-mutant patients with strong PD-L1 expression who had received crizotinib and chemotherapy, respectively. In conclusion, individual driver mutations had various impacts on the PD-L1 expression of NSCLC patients. The prognostic role of PD-L1 may also be divergent amongst patients harboring different driver mutations.

State-of-the-Art Molecular Oncology of Lung Cancer in Taiwan

Lung cancers are life-threatening malignancies that cause great healthcare burdens in Taiwan and worldwide. The 5-year survival rate for Taiwanese patients with lung cancer is approximately 29%, an unsatisfactorily low number that remains to be improved. We first reviewed the molecular epidemiology derived from a deep proteogenomic resource in Taiwan. The nuclear factor erythroid 2-related factor 2 (NRF2)antioxidant mechanism was discovered to mediate the oncogenesis and tumor progression of lung adenocarcinoma. Additionally, DNA replication, glycolysis and stress response are positively associated with tumor stages, while cell-to-cell communication, signaling, integrin, G protein coupled receptors, ion channels and adaptive immunity are negatively associated with tumor stages. Three patient subgroups were discovered based on the clustering analysis of protein abundance in tumors. The first subgroup is associated with more advanced cancer stages and visceral pleural invasion, as well as higher mutation burdens. The second subgroup is associated with EGFR L858R mutations. The third subgroup is associated with PI3K/AKT pathways and cell cycles. Both EGFR and PI3K/AKT signaling pathways have been shown to induce NRF2 activation and tumor cell proliferation. We also reviewed the clinical evidence of patient outcomes in Taiwan given various approved targeted therapies, such as EGFR-tyrosine kinase inhibitors and anaplastic lymphoma kinase (ALK)inhibitors, in accordance with the patients’ characteristics. Somatic mutations occurred in EGFR, KRAS, HER2 and BRAF genes, and these mutations have been detected in 55.7%, 5.2%, 2.0% and 0.7% patients, respectively. The EGFR mutation is the most prevalent targetable mutation in Taiwan. EML4-ALK translocations have been found in 9.8% of patients with wild-type EGFR. The molecular profiling of advanced NSCLC is critical to optimal therapeutic decision-making. The patient characteristics, such as mutation profiles, protein expression profiles, drug-resistance profiles, molecular oncogenic mechanisms and patient subgroup systems together offer new strategies for personalized treatments and patient care.

Investigation on the survival implications of PD-L1 expression status in ALK- rearranged advanced non-small cell lung cancer treated with first-line crizotinib

BACKGROUND

Programmed cell death-ligand 1 (PD-L1) expression has been associated with shorter progression-free survival (PFS) of crizotinib-treated patients with anaplastic lymphoma kinase (ALK) rearranged non-small cell lung cancer (NSCLC). However, the association between PD-L1 expression and overall survival (OS) in ALK-rearranged NSCLC remains unclear. In this study, we investigated the survival implication of baseline PD-L1 expression status in crizotinib-treated patients with ALK-rearranged advanced NSCLC.

METHODS

Between October 1, 2015, and October 31, 2021, we retrospectively analyzed the baseline PD-L1 expression levels using immunohistochemistry 22C3 assay of tissue samples from 128 patients with ALK-rearranged advanced lung adenocarcinoma who were treated with first-line crizotinib.

RESULTS

Of the 128 baseline tumor specimens analyzed, a majority (76.6%, n = 98) had low PD-L1 expression (tumor proportion score (TPS) < 50%), wherein 58.6% (n = 75) had < 1% and 18.0% (n = 23) had 1%-49%, and the remaining 23.4% (n = 30) had high PD-L1 expression level (TPS ≥ 50%). High baseline PD-L1 expression was not associated with any clinical characteristic examined. Patients with high baseline PD-L1 (n = 30) expression level had significantly shorter median PFS (6 vs 11 months, p = 0.011) and OS (17 vs 53 months, p = 0.023) on crizotinib treatment than those with low PD-L1 level (n = 98).

CONCLUSIONS

A subset of patients with ALK-rearranged NSCLC having high baseline PD-L1 expression level (TPS of ≥ 50%) had poorer survival outcomes despite crizotinib therapy. Our study raises the need to investigate alternative treatment strategies to improve survival outcomes of this patient subset.

ALK fusion variant 3a/b, concomitant mutations, and high PD-L1 expression were associated with unfavorable clinical response to second-generation ALK TKIs in patients with advanced ALK-rearranged non-small cell lung cancer (GASTO 1061)

OBJECTIVES

Second-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) have significantly improved clinical outcomes in patients with advanced ALK-positive non-small cell lung cancer (NSCLC), but clinical responses vary widely. In this study, the impacts of ALK fusion variants, concomitant mutations, and PD-L1 expression on the clinical response were evaluated in patients receiving second-generation ALK TKIs.

MATERIALS AND METHODS

We retrospectively enrolled 193 patients with ALK-rearranged advanced NSCLC who received second-generation ALK TKIs at Sun-yat Sen University Cancer Center from January 2015 to December 2020. The ALK fusion variants and concomitant mutations were identified with next-generation sequencing, while PD-L1 expression was assessed by immunohistochemistry.

RESULTS

The median progression-free survival (PFS) was significantly shorter for variant 3a/b than for other variants (9.93 months vs 16.97 months, HR 1.941, P = 0.0014). Baseline concomitant mutations were significantly associated with shorter PFS while on ALK TKIs (median PFS, 10.87 months vs 22.47 months, HR 1.984, P = 0.002). A subset of 68 patients was analyzed for PD-L1 expression: TPS 0% in 32.4% (22/68) of the patients, 1-49% in 30.9% (21/68) of the patients, and ≥ 50% in 36.7% (25/68) of the patients. Expression of PD-L1 was significantly associated with variant 3a/b and concomitant mutations. Median PFS was shorter in patients with high PD-L1 expression (median PFS in patients with PD-L1 TPS of 0% vs 1-49% vs ≥ 50% were 27.43 months vs 30.63 months vs 9.50 months, respectively, P = 0.001). In multivariate analysis, PD-L1 expression (TPS ≥ 50%), concomitant mutations, and variant 3a/b remained negative prognostic factors for the clinical efficacy of second-generation ALK TKIs in ALK-rearranged non-small cell lung cancer.

CONCLUSION

ALK fusion variant 3a/b, concomitant mutations, and high PD-L1 expression were associated with unfavorable clinical response to second-generation TKIs in ALK-rearranged NSCLC.

The Resistance Mechanisms and Treatment Strategies for ALK-Rearranged Non-Small Cell Lung Cancer

Anaplastic lymphoma kinase (ALK) is a validated molecular target for non-small-cell lung cancer (NSCLC). The use of tyrosine kinase inhibitors (TKIs) has led to significantly improved survival benefits. However, the clinical benefits of targeting ALK using TKIs are limited due to the emergence of drug resistance. The landscape of resistance mechanisms and treatment decisions has become increasingly complex. Therefore, continued research into new drugs and combinatorial therapies is required to improve outcomes in NSCLC. In this review, we explore the resistance mechanisms of ALK TKIs in advanced NSCLC in order to provide a theoretical basis and research ideas for solving the problem of ALK drug resistance.

Tumor Mutation Burden and Differentially Mutated Genes Among Immune Phenotypes in Patients with Lung Adenocarcinoma

Introduction

Nowadays, immune checkpoint blockades (ICBs) have been extensively applied in non-small cell lung cancer (NSCLC) treatment. However, the outcome of anti-program death-1/program death ligand-1 (anti-PD-1/PD-L1) therapy is not satisfying in EGFR-mutant lung adenocarcinoma (LUAD) patients and its exact mechanisms have not been fully understood. Since tumor mutation burden (TMB) and tumor immune phenotype had been thought as potential predictors for efficacy of ICBs, we further studied the TMB and immune phenotype in LUAD patients to explore potential mechanisms for poor efficacy of ICBs in EGFR positive mutated patients and to find possible factors that could impact the tumor immune phenotype which might uncover some new therapeutic strategies or combination therapies.

Methods

We enrolled 223 LUAD patients who underwent surgery in our hospital. We evaluated TMB through targeted panel sequencing. The tumor immune phenotype, which could be divided into non-inflamed, intermediate and inflamed, was determined through immunohistochemistry using formalin-fixed paraffin-embedded samples. Enumeration data were analyzed by Chi-square test or Fisher exact test and shown as number (proportion). Logistic regression model was employed for univariate and multivariate analysis of the association between TMB levels and clinical characteristics.

Results

The median TMB level was 4.0445 mutations/Mb. Multivariate analysis showed the TMB level was significantly associated with age (P=0.026), gender (P=0.041) and EGFR mutation status (P=0.015), and in EGFR-mutant patients we found a lower proportion of patients with mutated KRAS and BRCA2. Furthermore, we found patients with or without metastatic lesions would have different immune phenotype (P=0.007). And the mutational frequencies of ALK, CDKN2A, MAP2K1, IDH2 and PTEN were significantly different among three immune phenotypes.

Conclusion

Low TMB level could be the reason for the poor efficacy of ICBs in patients having EGFR mutation. And mutational frequencies of KRAS and BRCA2 were lower in EGFR-mutant patients. Furthermore, ALK, CDKN2A, MAP2K1, IDH2 and PTEN might involve in the formation of immune phenotypes.

Earlier extracranial progression and shorter survival in ALK-rearranged lung cancer with positive liquid rebiopsies

BACKGROUND

Liquid rebiopsies can detect resistance mutations to guide therapy of anaplastic lymphoma kinase-rearranged (ALK+) non-small-cell lung cancer (NSCLC) failing tyrosine kinase inhibitors (TKI). Here, we analyze how their results relate to the anatomical pattern of disease progression and patient outcome.

METHODS

Clinical, molecular, and radiologic characteristics of consecutive TKI-treated ALK+ NSCLC patients were analyzed using prospectively collected plasma samples and the 17-gene targeted AVENIO kit, which covers oncogenic drivers and all TP53 exons.

RESULTS

In 56 patients, 139 instances of radiologic changes were analyzed, of which 133 corresponded to disease progression. Circulating tumor DNA (ctDNA) alterations were identified in most instances of extracranial progression (58/94 or 62%), especially if concomitant intracranial progression was also present (89%, P<0.001), but rarely in case of isolated central nervous system (CNS) progression (8/39 or 21%, P<0.001). ctDNA detectability correlated with presence of "short" echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion variants (mainly V3, E6:A20) and/or TP53 mutations (P<0.05), and presented therapeutic opportunities in <50% of cases. Patients with extracranial progression and positive liquid biopsies had shorter survival from the start of palliative treatment (mean 52 vs. 69 months, P=0.002), regardless of previous and subsequent therapy and initial ECOG performance status. Furthermore, for patients with extracranial progression, ctDNA detectability was associated with shorter next-line progression-free survival (PFS) (3 vs. 13 months, P=0.003) if they were switched to another systemic therapy (49/86 samples), and with shorter time-to-next-treatment (TNT) (3 vs. 8 months, P=0.004) if they were continued on the same treatment due to oligoprogression (37/86). In contrast, ctDNA detectability was not associated with the outcome of patients showing CNS-only progression. In 6/6 cases with suspicion of non-neoplastic radiologic lung changes (mainly infection or pneumonitis), ctDNA results remained negative.

CONCLUSIONS

Positive blood-based liquid rebiopsies in ALK+ NSCLC characterize biologically more aggressive disease and are common with extracranial, but rare with CNS-only progression or benign radiologic changes. These results reconcile the increased detection of ALK resistance mutations with other features of the high-risk EML4-ALK V3-associated phenotype. Conversely, most oligoprogressive patients with negative liquid biopsies have a more indolent course without need for early change of systemic treatment.

Prevalence and Heterogeneity of PD-L1 Expression by 22C3 Assay in Routine Population-Based and Reflexive Clinical Testing in Lung Cancer

INTRODUCTION

Programmed death-ligand 1 (PD-L1) is used as a biomarker for anti-programmed cell death protein-1 (PD-1) or anti-PD-L1 immunotherapies in NSCLC. We report here the results of population-based PD-L1 testing using the 22C3 IHC pharmDx Assay (Agilent Technologies) in a large Canadian regional reference pathology laboratory.

METHODS

Testing was conducted reflexively on biopsies and resections for NSCLC during an 8-month period. Tumor proportion score (TPS) cutoffs for low and high expression were 1% and 50%, respectively.

RESULTS

Altogether, 2031 PD-L1 tests were performed on specimens from 1795 patients, with 107 inconclusive results (5.3%). Excluding cases with inconclusive/missing data, proportions for the remaining 1713 patients were 41.6% for TPS less than 1%, 28.6% for TPS 1% to 49%, and 29.8% for TPS greater than or equal to 50%. Higher PD-L1 expression rates were noted in EGFR wild-type versus mutant tumors (p < 0.001), squamous versus adenocarcinoma (p < 0.001), and metastatic versus primary tumors (p < 0.001). PD-L1 among 103 patients with paired biopsy and resection specimens revealed moderate concordance (κ = 0.67). A total of 52% (25 of 48) of biopsies with TPS less than 1% had TPS greater than 1% in resection, whereas 84.6% (22 of 26) of biopsies with TPS greater than or equal to 50% were concordant in resected tumors. Discordance rates between biopsy and resection were 71.4% for biopsies with less than 8 mm² total area, compared with 33.3% for biopsies with greater than or equal to 8 mm² area (p < 0.026). Concordance among 27 patients with paired primary lung and metastatic tumor biopsies revealed only weak concordance (κ = 0.48).

CONCLUSIONS

Intratumoral heterogeneity of PD-L1 expression may result in misclassification of PD-L1 status in a substantial proportion of PD-L1-negative small biopsy samples. Biopsy of metastatic site may increase proportion of patients with high PD-L1 expression.

De Novo Versus Secondary Metastatic EGFR-Mutated Non-Small-Cell Lung Cancer

Background

Metastatic epidermal growth factor receptor-mutated (EGFR⁺) non-small-cell lung cancer (NSCLC) can present de novo or following previous nonmetastatic disease (secondary). Potential differences between these two patient subsets are unclear at present.

Methods

We retrospectively analyzed characteristics of tyrosine kinase inhibitor (TKI)-treated patients with de novo vs. secondary metastatic EGFR⁺ NSCLC until December 2019 (n = 401).

Results

De novo metastatic disease was 4× more frequent than secondary (n = 83/401), but no significant differences were noted regarding age (median 66 vs. 70 years), sex (65% vs. 65% females), smoking history (67% vs. 62% never/light-smokers), and histology (both >95% adenocarcinoma). Patients with secondary metastatic disease showed a better ECOG performance status (PS 0-1 67%-32% vs. 46%-52%, p = 0.003), fewer metastatic sites (mean 1.3 vs. 2.0, p < 0.001), and less frequent brain involvement (16% vs. 28%, p = 0.022) at the time of stage IV diagnosis. Progression-free survival (PFS) under TKI (median 17 for secondary vs. 12 months for de novo, p = 0.26) and overall survival (OS, 29 vs. 25 months, respectively, p = 0.47) were comparable. EGFR alterations (55% vs. 60% exon 19 deletions), TP53 mutation rate at baseline (47% vs. 43%, n = 262), and T790M positivity at the time of TKI failure (51% vs. 56%, n = 193) were also similar. OS according to differing characteristics, e.g., presence or absence of brain metastases (19-20 or 30-31 months, respectively, p = 0.001), and ECOG PS 0 or 1 or 2 (32-34 or 20-23 or 5-7 months, respectively, p < 0.001), were almost identical for de novo and secondary metastatic disease.

Conclusions

Despite the survival advantage reported in the pre-TKI era for relapsed NSCLC, molecular features and outcome of TKI-treated metastatic EGFR⁺ tumors are currently independent of preceding nonmetastatic disease. This simplifies design of outcome studies and can assist prognostic considerations in everyday management of patients with secondary metastatic EGFR⁺ tumors.

Case Report: A Case Report of a Histological Transformation of ALK-Rearranged Adenocarcinoma With High Expression of PD-L1 to Squamous Cell Carcinoma After Treatment With Alectinib

We report an anaplastic lymphoma kinase (ALK)-positive patient shows a poor response to the ALK inhibitor alectinib due to the high expression of programmed death-ligand 1 (PD-L1). After treatment with alectinib, the pathological form changed from adenocarcinoma into squamous cell carcinoma without novel genetic changes. This case may reveal a direct relationship between ALK mutation and a high level of PD-L1 expression.

Therapeutic Sequencing in ALK+ NSCLC

Anaplastic lymphoma kinase-rearranged non-small-cell lung cancer (ALK⁺ NSCLC) is a model disease for the use of targeted pharmaceuticals in thoracic oncology. Due to higher systemic and intracranial efficacy, the second-generation ALK tyrosine kinase inhibitors (TKI) alectinib and brigatinib have irrevocably displaced crizotinib as standard first-line treatment, based on the results of the ALEX and ALTA-1L trials. Besides, lorlatinib and brigatinib are the preferred second-line therapies for progression under second-generation TKI and crizotinib, respectively, based on the results of several phase II studies. Tissue or liquid rebiopsies at the time of disease progression, even though not mandated by the approval status of any ALK inhibitor, are gaining importance for individualization and optimization of patient management. Of particular interest are cases with off-target resistance, for example MET, HER2 or KRAS alterations, which require special therapeutic maneuvers, e.g., inclusion in early clinical trials or off-label administration of respectively targeted drugs. On the other hand, up to approximately half of the patients failing TKI, develop anatomically restricted progression, which can be initially tackled with local ablative measures without switch of systemic therapy. Among the overall biologically favorable ALK⁺ tumors, with a mean tumor mutational burden uniquely below 3 mutations per Mb and the longest survival among NSCLC currently, presence of the EML4-ALK fusion variant 3 and/or TP53 mutations identify high-risk cases with earlier treatment failure and a need for more aggressive surveillance and treatment strategies. The potential clinical utility of longitudinal ctDNA assays for earlier detection of disease progression and improved guidance of therapy in these patients is a currently a matter of intense investigation. Major pharmaceutical challenges for the field are the development of more potent, fourth-generation TKI and effective immuno-oncological interventions, especially ALK-directed cell therapies, which will be essential for further improving survival and achieving cure of ALK⁺ tumors.

ALK variants, PD-L1 expression, and their association with outcomes in ALK-positive NSCLC patients

It remains unclear how programmed death-ligand 1 (PD-L1) expression interacts with anaplastic lymphoma kinase (ALK) mutation, its variants, and the outcome of treatment. One hundred and twenty four out of 1255 patients (9.9%) were deemed ALK-positive by the Ventana IHC assay. PD-L1 status and ALK variants were available in 100 and 59 patients, respectively. PD-L1 positive (TPS ≥ 1%) and strong positive (TPS ≥ 50%) rate was 50% and 16%, respectively. A total of 64 variant types were detected in 59 patients. V1 (32.8%) and V3a/b (28.1%) were the most common variants. There was no significant association between ALK variants and the PD-L1 expression. The presence of V3a/b subtype independently predicted a worse overall survival in patients receiving ALK inhibitor(s) (aHR 5.10 [95% CI 1.22–21.25], P = 0.025) and platinum plus pemetrexed (aHR 9.62 [95% CI 1.90–48.80], P = 0.006). While incorporating ALK variants and PD-L1 expression together, patients with non-V3a/b/positive PD-L1 showed a trend towards longer OS. In conclusion, ALK-positive NSCLC patients possess a high PD-L1 expression rate. Although there was no significant association between PD-L1 expression and ALK variants, the outcome of ALK-positive patients could be sorted by these two biomarkers.