HER2 mutations in lung adenocarcinomas: A report from the Lung Cancer Mutation Consortium

Molecular landscape of ERBB2 alterations in 3000 advanced NSCLC patients

ERBB2 (HER2) represents a newly recognized actionable oncogenic driver in non-small cell lung cancer (NSCLC), with approved targeted therapy available. Understanding the landscape of ERBB2 alterations and co-occurring mutations is essential for guiding treatment decisions. We conducted an analysis involving 3000 NSCLC patients with all types of ERBB2 alterations, drawn from two extensive retrospective cohorts: 1281 from Geneplus (Chinese) and 1719 from Guardant360 (the United States, US). The incidence of all types of ERBB2 alterations was found to be 5.6% in the Chinese group and 5.2% in the US group. In both cohorts, among oncogenic alterations of ERBB2, exon 20 insertion Y772_A775dupYVMA was the most frequent alteration (58% vs 41.6% in the Chinese vs the US), followed by G776delinsVC/LC/VV/IC (10.7% vs 9.7%), and S310X (10.5% vs 15.4%). EGFR ex20 insertions were identified in the A767-V774 region, whereas ERBB2 ex20 insertions were observed in the Y772-P780 region. Notably, EGFR ex20 insertions exhibited greater insertion diversity. Clinical characteristics of EGFR and ERBB2 ex20 NSCLC were similar, characterized by low tumor mutation burden (TMB), a predominant never-smoker population, and a majority of lung adenocarcinoma cases.

Protein Expression, Amplification, and Mutation of HER2 Gene in Canine Primary Pulmonary Adenocarcinomas: Preliminary Results

Recently, human epidermal growth factor receptor 2 (HER2) has emerged as a therapeutic target of interest for non-small-cell lung cancer in humans. The role of HER2 in canine pulmonary adenocarcinomas is poorly documented. To address this gap, this study employed three methodologies: immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and next-generation sequencing (NGS) to investigate the protein expression, gene amplification, and mutation of HER2 in 19 canine primary pulmonary adenocarcinomas. By IHC, 3 out of 19 cases were overexpressed 3+, 6 were 2+, and 10 were negative. With FISH, 2 cases were amplified (12.5%), 3 were inadequate for the analyses, and the others were non-amplified. With NGS, seven cases were inadequate. All other cases were wild-type, except for one IHC 3+ case, which was amplified with FISH and with a specific mutation already described in human pulmonary adenocarcinoma, V659E. This mutation is probably sensitive to tyrosine kinase inhibitory drugs. These results are similar to those in human medicine and to the few data in the literature on canine lung carcinomas; the presence of 12.5% of amplified cases in dogs lays the foundation for future targeted drugs against HER2 alterations.

Quantitative Measurement of HER2 Expression in Non-Small Cell Lung Cancer With a High-Sensitivity Assay

Recently, low human epidermal growth factor receptor 2 (HER2) protein expression has been proposed as a predictive biomarker for response to the antibody-drug conjugate trastuzumab deruxtecan (T-DXd) in metastatic breast cancer. HER2 expression in non-small cell lung cancer (NSCLC) patients has never been carefully measured, and little is known about the frequency of cases with unamplified but detectable levels of the protein. Although some HER2-targeted therapies have been studied in NSCLC patients, they have been restricted to those with genomic ERBB2 gene alterations, which only represent relatively rare cases of NSCLC. Still, emerging investigations of T-DXd in NSCLC have shown promise in patients with unamplified HER2. Taken together, we hypothesize that there may be many cases of NSCLC with levels of HER2 protein expression comparable with levels seen in breast cancer that benefit from T-DXd. Here, we used a previously validated, analytic, quantitative immunofluorescence (QIF) assay that is more sensitive than legacy clinical HER2 immunohistochemistry assays. We measured HER2 protein levels in NSCLC cases to determine the proportion of cases with detectable HER2 expression. Using cell line calibration microarrays alongside our QIF method enabled us to convert HER2 signal into units of attomoles per mm2. We found that over 63% of the 741 analyzed NSCLC cases exhibited HER2 expression above the limit of detection, with more than 17% of them exceeding the lower limit of quantification. Although the threshold for response to T-DXd in breast cancer is still unknown, many cases of NSCLC have expression in a range comparable to breast cancer cases with immunohistochemistry scores of 1+ or 2+. Our assay could potentially select NSCLC cases with a detectable target (ie, HER2) that might benefit from HER2 antibody-drug conjugates, irrespective of ERBB2 genomic alterations.

FDA approval summary: fam-trastuzumab deruxtecan-nxki for unresectable or metastatic non-small cell lung cancer with activating HER2 mutations

On August 11, 2022, FDA granted accelerated approval to fam-trastuzumab deruxtecan-nxki (DS-8201a, T-DXd, ENHERTU, Daiichi Sankyo) for adult patients with unresectable or metastatic non-small cell lung cancer (NSCLC) whose tumors have activating human epidermal growth factor receptor 2 (HER2) mutations, as detected by an FDA-approved test, and who have received a prior systemic therapy. The approval was based on a prespecified interim analysis of DESTINY-Lung02 (Study U206), a multi-center, randomized, dose-optimization trial in patients with NSCLC harboring activating HER2-mutations. At the approved dose of 5.4 mg/kg given intravenously every 3 weeks, the overall response rate (ORR) was 58% (95% confidence interval [CI]: 43, 71). The median duration of response was 8.7 months (95% CI: 7.1, not estimable). These results were consistent with response rates observed at the 6.4 mg/kg dose level. The most common (≥ 20%) adverse reactions were nausea, constipation, decreased appetite, vomiting, fatigue, and alopecia. The rate of interstitial lung disease (ILD) or pneumonitis was 6% at the 5.4 mg/kg dose level and 14% at the 6.4 mg/kg dose level. In the setting of similar efficacy and reduced toxicity, approval was granted for the 5.4 mg/kg dose level. The applicant conducted a randomized, dose-optimization study with guidance from the FDA Oncology Center of Excellence's Project Optimus. This is the first approval of a targeted therapy for HER2-mutated NSCLC.

Co-Occurring Driver Genomic Alterations in Advanced Non-Small-Cell Lung Cancer (NSCLC): A Retrospective Analysis

Background: Actionable driver mutations account for 40-50% of NSCLC cases, and their identification clearly affects treatment choices and outcomes. Conversely, non-actionable mutations are genetic alterations that do not currently have established treatment implications. Among co-occurring alterations, the identification of concurrent actionable genomic alterations is a rare event, potentially impacting prognosis and treatment outcomes. Methods: We retrospectively evaluated the prevalence and patterns of concurrent driver genomic alterations in a large series of NSCLCs to investigate their association with clinicopathological characteristics, to assess the prognosis of patients whose tumor harbors concurrent alterations in the genes of interest and to explore their potential therapeutic implications. Results: Co-occurring driver alterations were identified in 26 out of 1520 patients with at least one gene alteration (1.7%). Within these cases, the incidence of concurrent actionable gene alterations was 39% (0.7% of the overall cohort). Among compound actionable gene mutations, EGFR was the most frequently involved gene (70%). The most frequent association was EGFR mutations with ROS1 rearrangement. Front-line targeted treatments were the preferred approach in patients with compound actionable mutations, with dismal median PFS observed (6 months). Conclusions: Advances in genomic profiling technologies are facilitating the identification of concurrent mutations. In patients with concurrent actionable gene alterations, integrated molecular and clinical data should be used to guide treatment decisions, always considering rebiopsy at the moment of disease progression.

Chemoresistance Mechanisms in Non-Small Cell Lung Cancer-Opportunities for Drug Repurposing

Globally, lung cancer contributes significantly to the public health burden-associated mortality. As this form of cancer is insidious in nature, there is an inevitable diagnostic delay leading to chronic tumor development. Non-small cell lung cancer (NSCLC) constitutes 80-85% of all lung cancer cases, making this neoplasia form a prevalent subset of lung carcinoma. One of the most vital aspects for proper diagnosis, prognosis, and adequate therapy is the precise classification of non-small cell lung cancer based on biomarker expression profiling. This form of biomarker profiling has provided opportunities for improvements in patient stratification, mechanistic insights, and probable druggable targets. However, numerous patients have exhibited numerous toxic side effects, tumor relapse, and development of therapy-based chemoresistance. As a result of these exacting situations, there is a dire need for efficient and effective new cancer therapeutics. De novo drug development approach is a costly and tedious endeavor, with an increased attrition rate, attributed, in part, to toxicity-related issues. Drug repurposing, on the other hand, when combined with computer-assisted systems biology approach, provides alternatives to the discovery of new, efficacious, and safe drugs. Therefore, in this review, we focus on a comparison of the conventional therapy-based chemoresistance mechanisms with the repurposed anti-cancer drugs from three different classes-anti-parasitic, anti-depressants, and anti-psychotics for cancer treatment with a primary focus on NSCLC therapeutics. Certainly, amalgamating these novel therapeutic approaches with that of the conventional drug regimen in NSCLC-affected patients will possibly complement/synergize the existing therapeutic modalities. This approach has tremendous translational significance, since it can combat drug resistance and cytotoxicity-based side effects and provides a relatively new strategy for possible application in therapy of individuals with NSCLC.

Comparison of Clinicopathogenomic Features and Treatment Outcomes of EGFR and HER2 Exon 20 Insertion Mutations in Non-Small Cell Lung Cancer: Single-Institution Experience

PURPOSE

Exon 20 insertion mutations (E20ins) in epidermal growth factor receptor (EGFR) or human epidermal growth factor receptor 2 (HER2) in non-small cell lung cancer (NSCLC) patients has become more important with emergence of novel agents targeting E20ins.

MATERIALS AND METHODS

Advanced/Metastatic NSCLC patients with E20ins were included. EGFR E20ins was identified by two methods, next-generation sequencing (NGS) or real-time polymerase chain reaction (PCR), while HER2 E20ins was done by NGS only.

RESULTS

Between December 2013 and July 2021, E20ins were identified in 107 patients at Asan Medical Center; 67 EGFR E20ins and 40 HER2 E20ins. Out of 32 patients with EGFR E20ins who had tested both PCR and NGS, 17 were identified only through NGS and the other 15 through both tests, giving a discordance rate of 53.1%. There was no clinically significant difference in clinicopathologic features between EGFR and HER2 E20ins; both were observed more frequently in adenocarcinoma, female and never-smokers. Brain metastases were evident at diagnosis in 31.8% of EGFR E20ins and 27.5% of HER2 E20ins, respectively. Platinum-based doublets demonstrated objective response rates (ORR) of 13.3% with a median progression-free survival (PFS) of 4.2 months for EGFR E20ins and 35.3% with 4.7 months for HER2 E20ins, respectively. In contrast, novel EGFR E20ins-targeted agents exhibited an ORR of 46.2% with a median PFS of 5.4 months, while HER2-targeted agents showed an ORR of 50% with that of 7.0 months.

CONCLUSION

Identification of EGFR and HER2 E20ins is more important as their targeted therapies improved outcomes. Upfront NGS test as a comprehensive molecular approach is strongly warranted.

Current status of molecular diagnostics for lung cancer

The management of lung cancer (LC) requires the analysis of a diverse spectrum of molecular targets, including kinase activating mutations in EGFR, ERBB2 (HER2), BRAF and MET oncogenes, KRAS G12C substitutions, and ALK, ROS1, RET and NTRK1-3 gene fusions. Administration of immune checkpoint inhibitors (ICIs) is based on the immunohistochemical (IHC) analysis of PD-L1 expression and determination of tumor mutation burden (TMB). Clinical characteristics of the patients, particularly age, gender and smoking history, significantly influence the probability of finding the above targets: for example, LC in young patients is characterized by high frequency of kinase gene rearrangements, while heavy smokers often have KRAS G12C mutations and/or high TMB. Proper selection of first-line therapy influences overall treatment outcomes, therefore, the majority of these tests need to be completed within no more than 10 working days. Activating events in MAPK signaling pathway are mutually exclusive, hence, fast single-gene testing remains an option for some laboratories. RNA next-generation sequencing (NGS) is capable of detecting the entire repertoire of druggable gene alterations, therefore it is gradually becoming a dominating technology in LC molecular diagnosis.

The rapidly changing field of predictive biomarkers of non-small cell lung cancer

Lung cancer is a leading cause of cancer-related death worldwide in both men and women, however mortality in the US and EU are recently declining in parallel with the gradual cut of smoking prevalence. Consequently, the relative frequency of adenocarcinoma increased while that of squamous and small cell carcinomas declined. During the last two decades a plethora of targeted drug therapies have appeared for the treatment of metastasizing non-small cell lung carcinomas (NSCLC). Personalized oncology aims to precisely match patients to treatments with the highest potential of success. Extensive research is done to introduce biomarkers which can predict the effectiveness of a specific targeted therapeutic approach. The EGFR signaling pathway includes several sufficient targets for the treatment of human cancers including NSCLC. Lung adenocarcinoma may harbor both activating and resistance mutations of the EGFR gene, and further, mutations of KRAS and BRAF oncogenes. Less frequent but targetable genetic alterations include ALK, ROS1, RET gene rearrangements, and various alterations of MET proto-oncogene. In addition, the importance of anti-tumor immunity and of tumor microenvironment has become evident recently. Accumulation of mutations generally trigger tumor specific immune defense, but immune protection may be upregulated as an aggressive feature. The blockade of immune checkpoints results in potential reactivation of tumor cell killing and induces significant tumor regression in various tumor types, such as lung carcinoma. Therapeutic responses to anti PD1-PD-L1 treatment may correlate with the expression of PD-L1 by tumor cells. Due to the wide range of diagnostic and predictive features in lung cancer a plenty of tests are required from a single small biopsy or cytology specimen, which is challenged by major issues of sample quantity and quality. Thus, the efficacy of biomarker testing should be warranted by standardized policy and optimal material usage. In this review we aim to discuss major targeted therapy-related biomarkers in NSCLC and testing possibilities comprehensively.

HER2-Mutant Advanced and/or Metastatic Non-Small-Cell Lung Cancer: A US Electronic Health Records Database Analysis of Clinical Characteristics, Treatment Practice Patterns, and Outcomes

BACKGROUND

Real-world data for advanced/metastatic non-small-cell lung cancer (NSCLC) with mutations in human epidermal growth factor 2 (HER2) are scarce. We aimed to assess treatment patterns and outcomes among patients with HER2-mutant advanced/metastatic NSCLC.

PATIENTS AND METHODS

This retrospective nationwide electronic health record study evaluated patient characteristics, treatment patterns, treatment duration, and overall survival for adults with HER2-mutant advanced/metastatic NSCLC without epidermal growth factor receptor mutation.

RESULTS

Of 55 included patients, median (quartile 1 [Q1]-quartile 3 [Q3]) age was 63.0 (58.0-72.0) years, 42 (76%) were women, and 39 (71%) were current/former smokers. In first-line therapy, 14 regimens were used for median (Q1-Q3) duration of 3.1 (2.4-6.2) months, with most patients (n = 39, 71%) receiving platinum-based chemotherapy alone or in combination with other agents. Median (95% CI) overall survival from first-line treatment initiation was 19.0 (12.2-not estimable) months, with no significant association with age, sex, or smoking status. Thirty-five (64%) patients received second-line therapy for median (Q1-Q3) duration of 3.3 (2.0-5.2) months. Fourteen second-line regimens were used; most commonly immunotherapy alone or in combination with other agents (n = 16, 46%). Sixteen (46%) patients received third-line therapy for median (Q1-Q3) duration of 1.9 (1.3-2.7) months. Nine third-line regimens were used, with 7 (44%) patients receiving HER2-directed agents.

CONCLUSION

First- and second-line treatments for HER2-mutant NSCLC varied widely and treatment duration was short. The approval of trastuzumab deruxtecan for NSCLC supports wider HER2 testing to identify eligible patients for HER2-directed therapy.

Molecular Testing in Lung Cancer: Recommendations and Update

Adoption of molecular testing in lung cancer is increasing. Molecular testing for staging and prediction of response for targeted therapy remain the main indications, and although utilization of blood-based testing for tumor is growing, the use of the diagnostic cytology and tissue specimens is equally important. The pathologist needs to optimize reflex testing, incorporate stage-based algorithms, and understand types of tests for timely and complete assessment in the majority of cases. When tissue is limited, testing should capture the most frequent alterations to maximize the yield of what are largely mutually exclusive alterations, avoiding the need for repeat biopsy.

Clinicopathologic and Molecular Characteristics of HER2 (ERBB2)-Altered Non-Small Cell Lung Cancer: Implications for Precision Medicine

The heterogeneous relationship between protein expression, amplification, and mutations in human epidermal growth factor receptor 2 (HER2) in non-small cell lung cancer (NSCLC) and the optimal methods for detecting these alterations remain unclear. We aimed to elucidate the clinicopathological and molecular characteristics of HER2-altered NSCLC and investigate practical approaches for identifying patients who might benefit from HER2-targeted therapies. Using next-generation sequencing data from 1680 individuals, we searched for patients with HER2-altered NSCLCs, including amplifications and mutations. Clinicopathological data and tissue slides were reviewed. Immunohistochemistry (IHC) and silver in situ hybridization were performed according to the American Society of Clinical Oncology/College of American Pathologists guidelines. Our analysis identified 89 (5.3%) patients with HER2-altered NSCLCs, comprising 30 (1.8%) with amplification and 59 (3.6%) mutations, and they were compared with 165 control patients. Of the 59 HER2-mutated cases, 52 harbored tyrosine kinase domain (TKD) mutations, primarily HER2 exon 20 insertions. HER2 TKD alterations were associated with younger age, female sex, nonsmoking status, adenocarcinoma with a micropapillary pattern, lung-to-lung metastasis, and poor overall survival. The 33 patients with TKD mutations and 3 with non-TKD point mutations showed incomplete or complete membranous HER2 immunoreactivity (1+ and 2+, 61.07%). Six patients exhibiting amplifications had an IHC score of ≤2+ despite their high copy numbers and concomitantly displayed other actionable EGFR, KRAS, SMARCA4, and other HER2 mutations. These HER2-altered NSCLCs with molecular coalterations showed heterogeneous patterns through HER2 IHC and silver in situ hybridization. Therefore, next-generation sequencing should be used to identify HER2 mutations in patients with NSCLC who present with concomitant alterations. In addition, the above clinicopathological characteristics and HER2 IHC results can be valuable determinants for identifying patients with HER2-altered NSCLC. These insights hold promise for the development of more effective diagnostic and therapeutic strategies for this complex subset of NSCLC patients.

HER2-Altered Non-Small Cell Lung Cancer: A Journey from Current Approaches to Emerging Strategies

For patients diagnosed with advanced HER2-altered non-small cell lung cancer (NSCLC), the current standard of care is represented by a platinum-pemetrexed-based chemotherapy, eventually in combination with immunotherapy. Different pan-HER tyrosine kinase inhibitors have been evaluated in limited phase II trials, yielding generally unsatisfactory outcomes, although certain genotypes demonstrated some clinical benefit. Conversely, antibody-drug conjugates (ADCs) targeting HER2, particularly trastuzumab-deruxtecan, have shown promising results against HER2-mutant disease, including a great intracranial activity in patients with brain metastasis. Based on the results obtained from DESTINY-Lung01 and DESTINY-Lung02 trials, trastuzumab deruxtecan received regulatory approval as the first targeted therapy for pre-treated, HER2-mutant, advanced NSCLC patients. More recently, the Food and Drug Administration (FDA) granted the accelerated approval of trastuzumab deruxtecan for advanced, pre-treated HER2-positive solid tumours with no other treatment options. In this scenario, emerging evidence is increasingly pointing towards the exploration of combination regimens with synergistic effects in the advanced disease. In this review, we provide a detailed summary of current approaches and emerging strategies in the management of HER2-altered NSCLC, also focusing on unmet needs, including the treatment of patients with brain metastases.

Therapy for Stage IV Non-Small Cell Lung Cancer With Driver Alterations: ASCO Living Guideline, Version 2023.3

PURPOSE

To provide evidence-based recommendations for patients with stage IV non-small cell lung cancer with driver alterations.

METHODS

This ASCO living guideline offers continually updated recommendations based on an ongoing systematic review of randomized clinical trials (RCTs), with the latest time frame spanning February to October 2023. An Expert Panel of medical oncology, pulmonary, community oncology, research methodology, and advocacy experts were convened. The literature search included systematic reviews, meta-analyses, and randomized controlled trials. Outcomes of interest include efficacy and safety. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

This guideline consolidates all previous updates and reflects the body of evidence informing this guideline topic. Eight new RCTs were identified in the latest search of the literature to date.

RECOMMENDATIONS

Evidence-based recommendations were updated to address first, second, and subsequent treatment options for patients based on targetable driver alterations.Additional information is available at www.asco.org/living-guidelines.

Mechanisms of resistance to targeted therapy and immunotherapy in non-small cell lung cancer: promising strategies to overcoming challenges

Resistance to targeted therapy and immunotherapy in non-small cell lung cancer (NSCLC) is a significant challenge in the treatment of this disease. The mechanisms of resistance are multifactorial and include molecular target alterations and activation of alternative pathways, tumor heterogeneity and tumor microenvironment change, immune evasion, and immunosuppression. Promising strategies for overcoming resistance include the development of combination therapies, understanding the resistance mechanisms to better use novel drug targets, the identification of biomarkers, the modulation of the tumor microenvironment and so on. Ongoing research into the mechanisms of resistance and the development of new therapeutic approaches hold great promise for improving outcomes for patients with NSCLC. Here, we summarize diverse mechanisms driving resistance to targeted therapy and immunotherapy in NSCLC and the latest potential and promising strategies to overcome the resistance to help patients who suffer from NSCLC.

HSP90: A promising target for NSCLC treatments

The emergence of targeted therapies and immunotherapies has improved the overall survival of patients with nonsmall cell lung cancer (NSCLC), but the 5-year survival rate remains low. New drugs are needed to overcome this dilemma. Moreover, the significant correlation between various client proteins of heat-shock protein (HSP) 90 and tumor occurrence, progression, and drug resistance suggests that HSP90 is a potential therapeutic target for NSCLC. However, the outcomes of clinical trials for HSP90 inhibitors have been disappointing, indicating significant toxicity of these drugs and that further screening of the beneficiary population is required. NSCLC patients with oncogenic-driven gene mutations or those at advanced stages who are resistant to multi-line treatments may benefit from HSP90 inhibitors. Enhancing the therapeutic efficacy and reducing the toxicity of HSP90 inhibitors can be achieved via the optimization of their drug structure, using them in combination therapies with low-dose HSP90 inhibitors and other drugs, and via targeted administration to tumor lesions. Here, we provide a review of the recent research on the role of HSP90 in NSCLC and summarize relevant studies of HSP90 inhibitors in NSCLC.

Efficacy of immunotherapy in HER2-mutated non-small cell lung cancer: a single-arm meta-analysis

BACKGROUND

Non-small cell lung cancers (NSCLC) harboring Human Epidermal Growth Factor Receptor 2 (HER2) mutations represent a distinct subset with unique therapeutic challenges. Although immune checkpoint inhibitors (ICIs) have been transformative in lung cancer treatment, the efficacy of ICIs in HER2-mutated NSCLC remains to be established.

METHODS

We systematically searched for real-world studies investigating the use of ICIs in treating HER2-mutated NSCLC, sourced from the PubMed, Cochrane Library, and Embase databases. Outcomes including objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS) were extracted for further analysis.

RESULTS

Twelve studies involving 260 patients were enrolled in this meta-analysis. Pooled data revealed an ORR of 0.26 (95% CI 0.17-0.34), a DCR of 0.68 (95% CI 0.55-0.81), and a median PFS (mPFS) of 5.36 months (95% CI 3.50-7.21). Notably, in the subgroup receiving combined immune and chemotherapy, the ORR increased to 0.37 (95% CI 0.26-0.49), the DCR to 0.79 (95% CI 0.70-0.87), and the mPFS to 7.10 months (95% CI 5.21-8.99).

CONCLUSIONS

ICIs demonstrate promising anti-tumor activity and safety in patients with HER2-mutated NSCLC. Furthermore, the combined regimen of ICIs and chemotherapy may provide a significant therapeutic option for this patient population.

Pulmonary squamous cell carcinoma and lymphoepithelial carcinoma - morphology, molecular characteristics and differential diagnosis

Squamous cell carcinoma (SCC) comprises one of the major groups of non-small-cell carcinoma of the lung, and is subtyped into keratinising, non-keratinising and basaloid SCC. SCC can readily be diagnosed using histomorphology alone in keratinising SCC. Confirmatory immunohistochemical analyses should always be applied in non-keratinising and basaloid tumours to exclude differential diagnoses, most prominently adenocarcinoma and high-grade neuroendocrine carcinoma, which may have important therapeutic consequences. According to the World Health Organisation (WHO) classification 2015, the diagnosis of SCC can be rendered in resections of morphologically ambiguous tumours with squamous immunophenotype. In biopsies and cytology preparations in the same setting the current guidelines propose a diagnosis of 'non-small-cell carcinoma, favour SCC' in TTF1-negative and p40-positive tumours to acknowledge a possible sampling bias and restrict extended immunohistochemical evaluation in order to preserve tissue for molecular testing. Most SCC feature a molecular 'tobacco-smoke signature' with enrichment in GG > TT mutations, in line with the strong epidemiological association of SCC with smoking. Targetable mutations are extremely rare but they do occur, in particular in younger and non- or light-smoking patients, warranting molecular investigations. Lymphoepithelial carcinoma (LEC) is a poorly differentiated SCC with a syncytial growth pattern and a usually prominent lymphoplasmacytic infiltrate and frequent Epstein-Barr virus (EBV) association. In this review, we describe the morphological and molecular characteristics of SCC and LEC and discuss the most pertinent differential diagnoses.

Trastuzumab deruxtecan (DS8201) for advanced non-small cell lung cancer with HER2 exon 20 insertion mutation: a case report

An antibody-drug conjugate (ADC) of human epidermal growth factor receptor-2 (HER2) provides effective treatment for patients with HER2-positive non-small cell lung cancer (NSCLC). Exon 20 insertion mutations are the most common among HER2 mutations. This mutant subtype is highly drug-resistant, and patients receiving conventional treatment often have a poor prognosis. Trastuzumab deruxtecan (T-DXd), a novel anti-HER2 ADC, has emerged as a novel treatment option for HER2-positive (mutated, expressed, amplified, alternated) NSCLC, based on several studies and reported results. Herein, we report a case of stage IV NSCLC with HER2 exon 20 mutation in a 52-year-old male patient whose tumor recurred after radical resection of pulmonary carcinoma, who could not tolerate chemotherapy, and presented with bone metastasis. After treatment with T-DXd, the tumor significantly regressed and bone metastasis improved, maintaining a state of no progression for 21 months. This case report evidences the use of T-DXd in the treatment of NSCLC with HER2 exon 20 insertion mutation.

Path Less Traveled: Targeting Rare Driver Oncogenes in Non-Small-Cell Lung Cancer

Over the past decade, tremendous efforts have been made in the development of targeted agents in non-small-cell lung cancer (NSCLC) with nonsquamous histology. Pivotal studies have used next-generation sequencing to select the patient population harboring oncogenic driver alterations that are targetable with targeted therapies. As treatment paradigm rapidly evolves for patients with rare oncogene-driven NSCLC, updated comprehensive overview of diagnostic approach and treatment options is paramount in clinical settings. In this review article, we discuss the epidemiology, molecular testing, and landmark clinical trials addressing the targeted agents for ROS1 rearrangement, METex14 skipping mutation, EGFR exon 20 insertion, KRAS G12C mutation, HER2 mutation, RET fusion, NTRK fusion, and BRAF mutations.

HER2 Alterations in Non-Small Cell Lung Cancer: Biologico-Clinical Consequences and Interest in Therapeutic Strategies

Lung cancer stands as the first cause of death by cancer in the world. Despite the improvement in patients' outcomes in the past decades through the development of personalized medicine approaches, a substantial portion of patients remains ineligible for targeted therapies due to the lack of a "druggable" molecular target. HER2, a receptor tyrosine kinase member of the EGFR/ErbB family, is known to show oncogenic properties. In this review, we focus on the different HER2 dysregulation mechanisms that have been observed in non-small cell lung cancer (NSCLC): gene mutation, gene amplification, protein overexpression and protein hyper-phosphorylation, the latter suggesting that HER2 dysregulation can occur independently of any molecular aberration. These HER2 alterations inevitably have consequences on tumor biology. Here, we discuss how they are not only involved in abnormal proliferation and survival of cancer cells but also potentially in increased angiogenic properties, mesenchymal features and tumor immune escape. Finally, we review the impact of these HER2 alterations in various therapeutic approaches. While standard chemotherapy and groundbreaking immunotherapy seem rather ineffective for HER2-altered NSCLCs, the development of HER2-targeted therapies such as tyrosine kinase inhibitors, anti-HER2 antibodies and especially antibody-drug conjugates could provide new hopes for patients.

Management of HER2 alterations in non-small cell lung cancer - The past, present, and future

HER2 mutations, which account for 2-4% of non-small cell lung cancer (NSCLC), are distinct molecular alterations identified via next generation sequencing (NGS). Previously, treatment outcomes in HER2-mutant metastatic NSCLC were dismal, showing limited clinical benefit with platinum-based chemotherapy with or without immunotherapy. In contrast to HER2-altered breast and gastric cancer, HER2-mutant NSCLC does not benefit from HER2 targeting agents such as trastuzumab or TDM1. HER2 mutations are also inherently different from HER2 overexpression and amplification. Currently, trastuzumab deruxtecan, a HER2 targeting antibody drug conjugate (ADC) is the first and only approved treatment option for patients with HER2-mutant metastatic NSCLC after failure with standard treatment. In this review, we summarized the biology of HER2 and detection of HER2 overexpression, amplification and mutations, as well as general landscape of landmark and ongoing clinical trials encompassing from chemotherapy to targeted agents, including tyrosine kinase inhibitors (TKIs), ADCs and investigational agents.

Efficacy and safety of a pyrotinib-based regimen in non-small cell lung cancer patients harboring HER2 alterations: A real-world retrospective study

BACKGROUND

Pyrotinib, a novel irreversible pan-HER tyrosine kinase inhibitor, has been approved for the treatment of HER2-positive metastatic breast cancer in China. The aim of this study was to evaluate the efficacy and safety of pyrotinib in advanced nonsmall cell lung cancer (NSCLC) patients with HER2 alterations in real-world practice.

MATERIALS AND METHODS

A retrospective analysis of advanced NSCLC with HER2 mutations or amplifications who received pyrotinib-based treatment at the Qilu Hospital in Shandong University was performed. The primary end points were objective response rate and safety. The secondary end points were progression-free survival, disease control rate, and overall survival.

RESULTS

Twenty three eligible patients from a single center were enrolled between June 2019 and March 2023; among them, 21 had HER2 mutation and two harbored HER2 amplification. Evaluation of the efficacy in 21 patients revealed an objective response rate of 28.6% (6/21; 95% confidence interval [CI]: 7.5%-49.6%) and disease control rate of 85.7% (18/21). The median progression-free survival and overall survival were 7.7 months (95% CI: 6.07-9.33) and 20.8 months (95% CI: 8.42-33.18), respectively. The most common adverse events (AEs) included diarrhea (n = 14, 60.9%), nausea (n = 5, 21.7%), and liver dysfunction (n = 5, 21.7%). Seven patients (7/23, 30.4%) had grade 3-4 AE; no grade 5 AE was observed. Furthermore, one patient (1/23, 4.3%) experienced dose withdrawal and two (2/23, 8.7%) presented with dose reduction symptoms.

CONCLUSION

Pyrotinib-based therapy showed promising antitumor activity and acceptable safety in advanced NSCLC patients with HER2 alterations.

Current Status of Cancer Genomics and Imaging Phenotypes: What Radiologists Need to Know

Ongoing discoveries in cancer genomics and epigenomics have revolutionized clinical oncology and precision health care. This knowledge provides unprecedented insights into tumor biology and heterogeneity within a single tumor, among primary and metastatic lesions, and among patients with the same histologic type of cancer. Large-scale genomic sequencing studies also sparked the development of new tumor classifications, biomarkers, and targeted therapies. Because of the central role of imaging in cancer diagnosis and therapy, radiologists need to be familiar with the basic concepts of genomics, which are now becoming the new norm in oncologic clinical practice. By incorporating these concepts into clinical practice, radiologists can make their imaging interpretations more meaningful and specific, facilitate multidisciplinary clinical dialogue and interventions, and provide better patient-centric care. This review article highlights basic concepts of genomics and epigenomics, reviews the most common genetic alterations in cancer, and discusses the implications of these concepts on imaging by organ system in a case-based manner. This information will help stimulate new innovations in imaging research, accelerate the development and validation of new imaging biomarkers, and motivate efforts to bring new molecular and functional imaging methods to clinical radiology. Keywords: Oncology, Cancer Genomics, Epignomics, Radiogenomics, Imaging Markers Supplemental material is available for this article. © RSNA, 2023.

Understanding the feasibility of chemotherapeutic and immunotherapeutic targets against non-small cell lung cancers: an update of resistant responses and recent combinatorial therapies

Despite consistent progress in prompt diagnosis and curative therapies in the last decade, lung cancer (LC) continues to threaten mankind, accounting for nearly twice the casualties compared to prostate, breast, and other cancers. Statistics associate ~25% of 2021 cancer-related deaths with LC, more than 80% of which are explicitly caused by tobacco smoking. Prevailing as small and non-small cell pathologies, with respective occurring frequency of nearly 15% and 80-85%, non-small cell LCs (NSCLCs) are prominently distinguished into lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), subtypes. Since the first use of epidermal growth factor receptor (EGFR) inhibitor gefitinib for NSCLC treatment in 2002, immense progress has been made for targeted therapies with the next generation of drugs spanning across the chronological generations of small molecule inhibitors. The last two years have overseen the clinical approval of more than 10 therapeutic agents as first-line NSCLC medications. However, uncertain mutational aberrations as well as systemic resistant responses, and abysmal overall survival curtail the combating efficacies. Of late, immune checkpoint inhibitors (ICIs) against various molecules including programmed cell death-1 (PD-1) and its ligand (PD-L1) have been demonstrated as reliable LC treatment targets. Keeping these aspects in mind, this review article discusses the success of NSCLC chemo and immunotherapies with their characteristic effectiveness and future perspectives.

Prognostic Factors and Markers in Non-Small Cell Lung Cancer: Recent Progress and Future Challenges

Lung cancer is a highly aggressive neoplasm and, despite the development of recent therapies, tumor progression and recurrence following the initial response remains unsolved. Several questions remain unanswered about non-small cell lung cancer (NSCLC): (1) Which patients will actually benefit from therapy? (2) What are the predictive factors of response to MAbs and TKIs? (3) What are the best combination strategies with conventional treatments or new antineoplastic drugs? To answer these questions, an integrative literature review was carried out, searching articles in PUBMED, NCBI-PMC, Google Academic, and others. Here, we will examine the molecular genetics of lung cancer, emphasizing NSCLC, and delineate the primary categories of inhibitors based on their molecular targets, alongside the main treatment alternatives depending on the type of acquired resistance. We highlighted new therapies based on epigenetic information and a single-cell approach as a potential source of new biomarkers. The current and future of NSCLC management hinges upon genotyping correct prognostic markers, as well as on the evolution of precision medicine, which guarantees a tailored drug combination with precise targeting.

Single-Droplet Microsensor for Ultra-Short Circulating EFGR Mutation Detection in Lung Cancer Based on Multiplex EFIRM Liquid Biopsy

Liquid biopsy is a rapidly emerging field that involves the minimal/non-invasive assessment of signature somatic mutations through the analysis of circulating tumor DNA (ctDNA) shed by tumor cells in bodily fluids. Broadly speaking, the unmet need in liquid biopsy lung cancer detection is the lack of a multiplex platform that can detect a mutation panel of lung cancer genes using a minimum amount of sample, especially for ultra-short ctDNA (usctDNA). Here, we developed a non-PCR and non-NGS-based single-droplet-based multiplexing microsensor technology, "Electric-Field-Induced Released and Measurement (EFIRM) Liquid Biopsy" (m-eLB), for lung cancer-associated usctDNA. The m-eLB provides a multiplexable assessment of usctDNA within a single droplet of biofluid in only one well of micro-electrodes, as each electrode is coated with different probes for the ctDNA. This m-eLB prototype demonstrates accuracy for three tyrosine-kinase-inhibitor-related EGFR target sequences in synthetic nucleotides. The accuracy of the multiplexing assay has an area under the curve (AUC) of 0.98 for L858R, 0.94 for Ex19 deletion, and 0.93 for T790M. In combination, the 3 EGFR assay has an AUC of 0.97 for the multiplexing assay.

Prevalence and clinicopathological associations of HER2 expression in non-small cell lung cancer: a retrospective study in Jordanian patients

BACKGROUND

Human epidermal growth factor receptor 2 (HER2), a promising therapeutic target, can be mutated, amplified, or overexpressed in different malignancies, including non-small cell lung cancer (NSCLC). Although these alterations showed adverse prognostic effects in many cancers, their clinical significance in NSCLC is controversial. This study primarily assessed the prevalence of HER2 protein expression in NSCLC among Jordanian patients. In addition, the possible association between HER2 protein expression and clinicopathological variables was evaluated.

METHODS

A total of 100 surgically resected NSCLC cases treated at King Hussein Cancer Center (KHCC) between 2009 and 2021 were examined for HER2 protein expression using immunohistochemistry (IHC). The American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines for breast cancer were applied to interpret the results with a final score ranging from 0 to 3+, considering a score of 3 + as overexpression. Additionally, a separate subset of patients was tested for HER2 gene mutation. Fisher's exact test was used to assess the association between HER2 scores and the other variables. Kaplan-Meier method was used to calculate survival.

RESULTS

Of the 100 cases, Her2 overexpression (score 3+) was detected in 2 cases (2%), score 2 + in 10 cases (10%), score 1 + in 12 cases (12%), and score 0 in 76 cases (76%). The two positive cases were one adenocarcinoma and one squamous cell carcinoma; both patients were elderly male smokers. No significant association was identified between Her2 expression and age, gender, smoking, histological subtype, grade, stage, tumor size, and lymph node status. Our findings also showed no association between Her2 expression and survival; however, advanced tumor stages and positive lymph node metastasis were significantly associated with poor overall survival. All cases tested for the Her2 mutation were negative.

CONCLUSIONS

Her2 overexpression is uncommon in NSCLC among the Jordanian population. However, when the same scoring criteria are used, the rates are similar to other results found in Asian cohorts. Due to our study's relatively small sample size, a larger one is required to investigate the prognostic value and the molecular associations between the different Her2 alterations.

Pertuzumab Plus Trastuzumab in Patients With Lung Cancer With ERBB2 Mutation or Amplification: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry Study is a pragmatic basket trial evaluating antitumor activity of commercially available targeted agents in patients with advanced cancers harboring potentially actionable genomic alterations. Data from a cohort of patients with lung cancer and ERBB2 mutation or amplification treated with pertuzumab plus trastuzumab (P + T) are reported.

METHODS

Eligible patients had advanced lung cancer of any histology, no standard treatment options, measurable disease (RECIST v1.1), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and tumors with ERBB2 mutation or amplification. Simon's two-stage design was used with a primary end point of disease control (DC), defined as objective response (OR) per RECIST v. 1.1 or stable disease (SD) of at least 16 weeks duration (SD16+). Secondary end points included safety, duration of response, duration of SD, progression-free survival, and overall survival.

RESULTS

Twenty-eight patients with lung cancer (27 non-small-cell, 1 small-cell) and ERBB2 mutation (n = 15), ERBB2 amplification (n = 12), or both (n = 1) were enrolled from November 2016 to July 2020. All patients were evaluable for efficacy and toxicity. Three patients with partial response (two ERBB2 mutation; one both mutation and amplification) and seven patients with SD16+ (five ERBB2 mutation; two amplification) were observed for a DC rate of 37% (95% CI, 21 to 50; P = .005) and OR rate of 11% (95% CI, 2 to 28). Five patients had one or more grade 3 or 4 adverse or serious adverse events at least possibly related to P + T.

CONCLUSION

Combination P + T showed evidence of antitumor activity in heavily pretreated patients with non-small-cell lung cancer and ERBB2 mutation or amplification, particularly those with ERBB2 exon 20 insertion mutations.

Molecular alterations of driver genes in non-small cell lung cancer: from diagnostics to targeted therapy

Lung cancer is the leading cause of cancer death all over the world. The majority (80-85 %) of lung cancer cases are classified as non-small cell lung cancer (NSCLC). Within NSCLC, adenocarcinoma (AC) and squamous cell carcinoma (SCC) are the most often recognized. The histological and immunohistochemical examination of NSCLC is a basic diagnostic tool, but insufficient for comprehensive therapeutic decisions. In some NSCLC patients, mainly adenocarcinoma, molecular alterations in driver genes, like EGFR, KRAS, HER2, ALK, MET, BRAF, RET, ROS1, and NTRK are recognized. The frequency of some of those changes is different depending on race, and between smokers and non-smokers. The molecular diagnostics of NSCLC using modern methods, like next-generation sequencing, is essential in estimating targeted, personalized therapy. In recent years, a breakthrough in understanding the importance of molecular studies for the precise treatment of NSCLC has been observed. Many new drugs were approved, including tyrosine kinase and immune checkpoint inhibitors. Clinical trials testing novel molecules like miRNAs and trials with CAR-T cells (chimeric antigen receptor - T cells) dedicated to NSCLC patients are ongoing.

Metastatic HER2-amplified non-small-cell lung cancer treated with trastuzumab deruxtecan

Human epidermal growth factor receptor 2 (HER2) alterations can occur as gene mutations, gene amplification or protein overexpression. DESTINY-Lung01 and DESTINY-Lung02 demonstrated the efficacy of trastuzumab deruxtecan in the subsequent line setting in patients with unresectable or metastatic HER2-mutated non-small-cell lung cancer (NSCLC). Trastuzumab deruxtecan has not been studied in select patients with HER2-amplified NSCLC. Here, we present the first reported case of metastatic HER2-amplified NSCLC treated with trastuzumab deruxtecan with a durable response to therapy.

Detailed curriculum vitae of HER2-targeted therapy

With the booming development of precision medicine, molecular targeted therapy has been widely used in clinical oncology treatment due to a smaller number of side effects and its superior accuracy compared to that of traditional strategies. Among them, human epidermal growth factor receptor 2 (HER2)-targeted therapy has attracted considerable attention and has been used in the clinical treatment of breast and gastric cancer. Despite excellent clinical effects, HER2-targeted therapy remains in its infancy due to its resulting inherent and acquired resistance. Here, a comprehensive overview of HER2 in numerous cancers is presented, including its biological role, involved signaling pathways, and the status of HER2-targeted therapy.

Activity of osimertinib in a patient with stage IV non-small cell lung cancer harboring HER2 exon 19, p.L755P mutation: case report

Background

Recurrent in-frame insertions within exon 20 causing duplication of amino acids Tyrosine-Valine-Methionine-Alanine (YVMA) represent 80% of all HER2 alterations in non-small cell lung cancer (NSCLC). HER2 tyrosine kinase inhibitors (TKI), anti-HER2 monoclonal antibodies and HER2 directed antibody-drug conjugates have been evaluated in patients with HER2 mutated NSCLC. Limited data are available regarding the activity of these agents in exon 19 alterations. Osimertinib, a 3rd generation EGFR-TKI, has been found in pre-clinical studies to decrease growth of NSCLC with HER2 exon 19 aberrations.

Case Description

A 68-year-old female with a past medical history of type 2 diabetes and minimal smoking was diagnosed with stage IV NSCLC. Next generation sequencing on tumor tissue demonstrated an ERBB2 exon 19 c.2262_2264delinsTCC, p.(L755P) mutation. After five lines of treatment that included chemotherapy, chemoimmunotherapy and investigational agents the patient's disease was progressing. At this time her functional status remained good, therefore clinical trials were explored however, none were available. Based on findings from pre-clinical studies, the patient was commenced on osimertinib 80 mg OD and achieved a partial response (PR) according to RESIST criteria both intra- and extracranially.

Conclusions

This is the first report to our knowledge to demonstrate activity of osimertinib in a patient with NSCLC harboring HER2 exon 19, p.L755P mutation resulting in intra- and extracranial response. In the future, osimertinib could become a targeted treatment for patients harboring exon19 ERBB2 point mutations.

HER2 exon 20 insertion mutations and myelosuppression in lung adenocarcinoma patient: a case report and response to trastuzumab deruxtecan

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) mutations occur in 2% of lung cancers.

CASE PRESENTATION

In this report, we presented a case of an Asian female who was diagnosed with lung adenocarcinoma. NGS results indicated HER2 exon 20 insertion mutation and PET/CT results showed multiple metastases in lower lobes of both lungs. Thereafter, she was treated with chemotherapy alone, combination of chemotherapy and targeted therapy and immunotherapy. Due to progressive disease, she was then received DS-8201. Imaging data indicated partial response to DS-8201 and tumor marker values decreased significantly, suggesting good efficacy. Nevertheless, DS-8201 was discontinued because of the development of myelosuppression (grade 3). Finally, she died at home due to platelet deficiency, white blood cell (grade 4), granulocytopenia, intracranial hemorrhage and gastrointestinal hemorrhage.

CONCLUSIONS

This was an important case since it exerted effective response to DS-8201. Meanwhile, myelosuppression is also found in the patient, which requires attention to pulmonary symptoms and careful monitoring.

A Case Report on the Efficacy of Trastuzumab Emtansine in a Patient With Human Epidermal Growth Factor Receptor 2 Exon 20-Mutated Adenocarcinoma of the Lung

Lung cancer is the foremost reason for cancer-related mortality among men and women. The ultimate goal of patient supervision post-diagnosis for advanced cases is to improve survival and quality of life with minimal treatment-associated side effects. With advancements in genomic medicine and a better understanding of cell signaling pathways, many actionable gene mutations have been identified in lung carcinoma, which drastically improve survival outcomes. Mutations in human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor together are observed in nearly 1-3% of cases and act as an oncogenic driver. In the case of HER2-mutant lung cancers, there are limited approved agents, and the treatment represents a critical unmet medical need because of the poorer survival outcomes compared to patients with additional oncogenic drivers. The recent standard of care of treatment is chemotherapy, but reports suggest that compared with cytotoxic chemotherapy, patients receiving HER2-directed therapies have relatively longer median survival duration. Here, we report a case of HER2 exon 20-mutated metastatic lung adenocarcinoma patient who received trastuzumab emtansine in the third-line setting and achieved durable disease control.

Targeting the EGF receptor family in non-small cell lung cancer-increased complexity and future perspectives

Lung cancer remains the leading cause of cancer-associated mortality worldwide, but with the emergence of oncogene targeted therapies, treatment options have tremendously improved. Owing to their biological relevance, members of the ERBB receptor family, including the EGF receptor (EGFR), HER2, HER3 and HER4, are among the best studied oncogenic drivers. Activating EGFR mutations are frequently observed in non-small cell lung cancer (NSCLC), and small molecule tyrosine kinase inhibitors (TKIs) are the established first line treatment option for patients whose tumors bear "typical/classical" EGFR mutations (exon 19 deletions, L858R point mutations). Additionally, new TKIs are rapidly evolving with better efficacy to overcome primary and secondary treatment resistance (e.g., that due to T790M or C797S resistance mutations). Some atypical EGFR mutations, such as the most frequent exon 20 insertions, exhibit relative resistance to earlier generation TKIs through steric hindrance. In this subgroup, newer TKIs, such as mobocertinib and the bi-specific antibody amivantamab have recently been approved, whereas less frequent atypical EGFR mutations remain understudied. In contrast to EGFR, HER2 has long remained a challenging target, but better structural understanding has led to the development of newer generations of TKIs. The recent FDA approval of the antibody-drug conjugate trastuzumab-deruxtecan for pretreated patients with HER2 mutant NSCLC has been an important therapeutic breakthrough. HER3 and HER4 also exert oncogenic potential, and targeted treatment approaches are being developed, particularly for HER3. Overall, strategies to inhibit the oncogenic function of ERBB receptors in NSCLC are currently evolving at an unprecedented pace; therefore, this review summarizes current treatment standards and discusses the outlook for future developments.

Deciphering the Impact of HER2 Alterations on Non-Small-Cell Lung Cancer: From Biological Mechanisms to Therapeutic Approaches

Despite the recent increase in the number of types of treatments, non-small-cell lung cancer (NSCLC) remains the major cause of death from cancer worldwide. So, there is an urgent need to develop new therapeutic strategies. The HER2 gene codes for tyrosine kinase receptor whose alterations are known to drive carcinogenesis. HER2 alterations, including amplification, mutations, and overexpression, have been mainly described in breast and gastric cancers, but up to 4% of NSCLC harbor actionable HER2 mutations. HER2-targeted therapy for NSCLC with trastuzumab, pertuzumab, and trastuzumab emtansine has failed to demonstrate an improvement in survival. Nevertheless, recent data from phase II trials have shed light on promising specific therapies for HER2-mutant NSCLC such as trastuzumab deruxtecan. Herein, we aimed to provide an updated review on the biology, epidemiology, molecular testing, and therapeutic strategies for NSCLC with HER2 molecular alterations.

Targeted therapy in lung cancer: Are we closing the gap in years of life lost?

PURPOSE

Patients with non-small cell lung cancer (NSCLC) that harbor driver mutations are associated with a cancer diagnosis at a younger age. While targeted therapies provide deep remissions and durable benefit in a subset of patients, it is unclear whether targeted therapies bridge the gap in years of life lost (YLL) in these younger NSCLC patients with targetable mutations in comparison to generally older NSCLC patients without actionable driver mutations.

MATERIALS AND METHODS

Retrospective cross-sectional study using landmark trials leading to the approval of targeted therapies in NSCLC with actionable mutations. We evaluated all targeted therapies as well as chemotherapy and IO regimens for the treatment of NSCLC through FDA Oncology Announcements and NCCN Guidelines for NSCLC (version 4.2021).

RESULTS

We estimated the YLL for each driver mutation, cumulative median duration of response (DOR) with targeted therapies by mutation type, and percentage of estimated improvement in YLL from NSCLC targeted therapies. The median ages at diagnosis (in years) for patients whose tumors express targetable mutations were: 47.6 (NTRK); 52.0 (ALK); 62.0 (HER2); 57.0 (ROS1); 61.4 (RET); 63.0 (BRAF); 69.0 (EGFR); and 72.0 (MET). For comparison, the median age at diagnosis for patients without driver mutations, regardless of PD-L1 status was 71 years. The median DOR (in years) for patients whose tumors express the same mutations include: 0.9 (NTRK); 3.9 (ALK); 0.6 (HER2); 6.2 (ROS1); 2.2 (RET); 1.5 (BRAF); 3.1 (EGFR); and 2.4 (MET). The median DOR for patients without driver mutations was 1.2 years. The cumulative estimated survival time (years; median age at diagnosis plus the median DOR or OS) for patients whose tumors express targetable mutations were: 48.5 (NTRK); 55.9 (ALK); 62.6 (HER2); 63.2 (ROS1); 63.6 (RET); 64.5 (BRAF); 72.1 (EGFR); and 74.4 (MET). The cumulative estimated survival time for patients without driver mutations, regardless of PD-L1 status, was 72.2 years of age. We calculated the number of years NSCLC is diagnosed earlier in patients with targetable mutations as follows: 23.4 (NTRK), 19 (ALK), 14 (ROS1), 11 (EGFR), 9.6 (RET), 9 (HER2), and 8 (BRAF). The percent difference (%) ameliorated in YLL by mutation type is as follows: 44.3 (ROS1), 28.2 (EGFR), 22.9 (RET), 20.5 (ALK), 18.8 (BRAF), 6.4 (HER2), and 3.7 (NTRK).

CONCLUSION

Although targeted therapies have paved the way for significant progress toward providing a survival benefit to many young patients with advanced NSCLC with actionable mutations, it is evident that these therapies still leave a wide gap in the YLL in these younger patients compared to generally older individuals with advanced NSCLC without targetable mutations.

NSCLC as the Paradigm of Precision Medicine at Its Finest: The Rise of New Druggable Molecular Targets for Advanced Disease

Standard treatment for advanced non-small cell lung cancer (NSCLC) historically consisted of systemic cytotoxic chemotherapy until the early 2000s, when precision medicine led to a revolutionary change in the therapeutic scenario. The identification of oncogenic driver mutations in EGFR, ALK and ROS1 rearrangements identified a subset of patients who largely benefit from targeted agents. However, since the proportion of patients with druggable alterations represents a minority, the discovery of new potential driver mutations is still an urgent clinical need. We provide a comprehensive review of the emerging molecular targets in NSCLC and their applications in the advanced setting.

Trastuzumab and pertuzumab combination therapy for advanced pre-treated HER2 exon 20-mutated non-small cell lung cancer

INTRODUCTION

In 1-3% of non-small cell lung cancer (NSCLC) human epidermal growth factor 2 (HER2) mutations are identified as a genomic driver. Nevertheless, no HER2-targeted treatment is approved for NSCLC. In the Drug Rediscovery Protocol (DRUP), patients are treated with off-label drugs based on their molecular profile. Here, we present the results of the cohort 'trastuzumab/pertuzumab for HER2 exon20 mutation positive (HER2m+) NSCLC'.

METHODS

Patients with treatment refractory, advanced HER2m+ NSCLC with measurable disease (RECISTv1.1) were eligible. Treatment with intravenous trastuzumab combined with pertuzumab every 3 weeks was administered. The primary end-point was clinical benefit (CB: either objective response or stable disease ≥ 16 weeks). Patients were enrolled using a Simon-like 2-stage design, with 8 patients in stage 1 and up to 24 patients in stage 2 if at least 1 patient had CB in stage 1. At baseline, a biopsy for biomarker analysis, including whole genome sequencing, was obtained.

RESULTS

Twenty-four evaluable patients were enrolled and treated between May 2017 and August 2020. CB was observed in 9 patients (38%); including an objective response rate of 8.3% (2 patients had a partial response) and 7 patients with stable disease ≥ 16 weeks. The most frequently observed HER2 mutation was p.Y772_A775dup (71%, n = 20). Median follow-up was 13 months, median progression-free survival and overall survival 4 (95% CI 3-6) and 10 months (95% CI 4 - not reached), respectively. Whole genome sequencing data (available for 67% of patients) confirmed the inclusion mutation in all cases. No unexpected toxicity was observed.

CONCLUSION

Despite the fact that the study did meet its primary end-point, trastuzumab/pertuzumab was only marginally active in a subset of patients with heavily pre-treated HER2m+ NSCLC.

Characterization of ERBB2 (HER2) Alterations in Metastatic Non-small Cell Lung Cancer and Comparison of Outcomes of Different Trastuzumab-based Regimens

INTRODUCTION

About 3%-5% of mNSCLC have ERBB2 (HER2) alterations, but currently, there are no FDA-approved targeted therapies for this indication. We compared treatment response between trastuzumab-based and non-targeted regimens in ERBB2-mutant mNSCLC.

METHODS

This retrospective, single-institution study included patients with mNSCLC with ERBB2 alterations identified by next-generation sequencing. Best overall response was determined using Response Evaluation Criteria in Solid Tumors 1.1.

RESULTS

We identified 3 groups of patients: ERBB2-mutant/EGFR-wildtype mNSCLC (n = 33), ERBB2-amplified/EGFR-wildtype mNSCLC without concurrent ERBB2 mutations (n = 6), and ERBB2-altered/EGFR-mutant mNSCLC (n = 8). Observed mutations included A775_G776insYVMA (n = 23), Gly778_Pro780dup (n = 4), Ser310Phe (n = 3), and others (n = 5). Among the 33 with ERBB2-mutant/EGFR-wildtype mNSCLC, those with and without A775_G776insYVMA had significantly different median overall survival (OS) of 17.7 and 52.9 months, respectively (Cox regression multivariable HR: 5.03, 95% CI: 1.37-18.51, P = .02). In those with mNSCLC with A775_G776insYVMA, trastuzumab-based therapies were associated with greater OS (20.3 vs. 9.8 months; multivariable HR: 0.19, 95% CI: 0.04-0.87, P = .032). Objective response and disease control rates (median tumor size change) in the 33 patients with ERBB2-mutant/EGFR-wildtype mNSCLC were 40.0% and 80.0% (-35.8%), respectively, for patients treated with trastuzumab deruxtecan; 0% and 30.0% (-5.2%) for trastuzumab emtansine; and 7.1% and 50.0% (-13.0%) for trastuzumab/chemotherapy combinations.

CONCLUSION

In ERBB2-mutant/EGFR-wildtype mNSCLC, while most trastuzumab-based regimens had modest activity in this real-world analysis, trastuzumab deruxtecan had highest response rates and best tumor size reduction. Receipt of any trastuzumab-based regimen was associated with greater OS with A775_G776insYVMA. There remains an unmet need for approved targeted therapies for ERBB2-mutant/EGFR-wildtype NSCLC.

Response of Leptomeningeal Metastasis of Breast Cancer With a HER2/neu Activating Variant to Tucatinib: A Case Report

Metastatic breast cancer demonstrates HER2/neu amplification approximately 15% of the time. However, HER2 mutations, which often stimulate tumor growth, occur in only 3% to 5% of patients, and are seen more frequently in metastatic versus primary tumors. They are more frequent in lobular carcinoma, including triple-negative lobular cancer. Many of these variants are resistant to trastuzumab and lapatinib. However, neratinib can be efficacious, and recent data suggest that antibody-drug conjugates (ADCs) such as ado-trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan may also be helpful. Laboratory and clinical data raise the possibility that simultaneous treatment with ADCs plus neratinib may be even more efficacious. Tucatinib, which has demonstrated significant activity in the central nervous system, has also been shown in vitro to be active against a number of these HER2 variants. This report describes a patient with metastatic estrogen receptor-positive, HER2-nonamplified breast cancer with an activating HER2 mutation whose tumor became resistant to neratinib as well as capecitabine, but whose subsequent leptomeningeal disease had a dramatically successful response to tucatinib plus capecitabine. As the frequency of HER2 mutations increases during the evolution of metastatic breast cancer, it is important to obtain genomic evaluation on these tumors with either repeat tissue or liquid biopsy as they progress over time.

HER2-Altered Non-Small Cell Lung Cancer: Biology, Clinicopathologic Features, and Emerging Therapies

Multiple oncogenic molecular alterations have been discovered that serve as potential drug targets in non-small cell lung cancer (NSCLC). While the pathogenic and pharmacological features of common targets in NSCLC have been widely investigated, those of uncommon targets are still needed to be clarified. Human epidermal growth factor receptor 2 (HER2, ERBB2)-altered tumors represent a highly heterogeneous group of diseases, which consists of three distinct situations including mutation, amplification and overexpression. Compared with breast and gastric cancer, previous studies have shown modest and variable results of anti-HER2 treatments in lung cancers with HER2 aberrations, thus effective therapies in these patients represent an unmet medical need. By far, encouraging efforts towards novel treatment strategies have been made to improve the clinical outcomes of these patients. In this review, we describe the biological and clinicopathological characteristics of HER2 alterations and systematically sum up recent studies on emerging therapies for this subset of patients.

Identification of Recurrent Insertions and Deletions in Exon 18 and 19 of Human Epidermal Growth Factor Receptor 2 as Potential Drivers in Non-Small-Cell Lung Cancer and Other Cancer Types

PURPOSE

Human epidermal growth factor receptor 2 (HER2) belongs to the same family as epidermal growth factor receptor (EGFR) and is known as an important cancer driver gene. Insertions and deletions (indels) are frequent driver mutations in both EGFR and HER2. The most common HER2 indels are the exon 20 insertions within the kinase domain, while others are rarely reported. Our study aimed to investigate other indels of HER2 that may act as driver mutations in Chinese patients with different cancer types.

METHODS

In this retrospective study, patient samples were subjected to targeted sequencing covering HER2 and other cancer-related genes. Mutation profiles of patients harboring HER2 exon 18/19 indels were described. Identified HER2 exon 18/19 indels in our study were compared with external data from COSMIC. In silico and in vitro analyses were performed on selected indels of HER2 exon 18 and 19, respectively.

RESULTS

A total of 25 indels in HER2 exon 18/19, 17 of which being recurrent, were identified in 20 of 53,591 patients with lung cancer (0.037%), two of 5,888 patients with colorectal cancer (0.034%), two of 3,774 patients with breast cancer (0.053%), and one of 14 patients with urothelial carcinoma of the renal pelvis (7.1%). Most patients harboring HER2 exon 18/19 indels were absent of known driver mutations. In lung cancer, mutation profiles were comparable between patients carrying HER2 exon 18/19 indels and the two established HER2 drivers (exon 20 insertions and S310 mutations). The in silico and in vitro analyses suggested an activated state conferred by HER2 exon 18/19 indels, which could be targeted by different tyrosine kinase inhibitors.

CONCLUSION

Our study revealed a class of rare but unique indels in HER2 exon 18/19, which may act as driver mutations in several cancer types.

HER2 exon 18/19 indels identified in a small subset of patients may act as a novel class of cancer drivers.

Consensus for HER2 alterations testing in non-small-cell lung cancer

Human epidermal growth factor receptor 2 (HER2) is a transmembrane glycoprotein receptor with intracellular tyrosine kinase activity. Its alterations, including mutation, amplification and overexpression, could result in oncogenic potential and have been detected in many cancers such as non-small-cell lung cancer (NSCLC). Such alterations are, in general, considered markers of poor prognosis. Anti-HER2 antibody-drug conjugates, e.g. trastuzumab deruxtecan (T-DXd, DS-8201) and disitamab vedotin (RC48), were recently approved for HER2-positive breast and gastric cancers. Meanwhile, several HER2-targeted drugs, such as T-DXd, neratinib, afatinib, poziotinib and pyrotinib, have been evaluated in patients with advanced NSCLC, with several of them demonstrating clinical benefit. Therefore, identifying HER2 alterations is pivotal for NSCLC patients to benefit from these targeted therapies. Recent guidelines on HER2 testing were developed for breast and gastric cancer, however, and have not been fully established for NSCLC. The expert group here reached a consensus on HER2 alteration testing in NSCLC with the focus on clinicopathologic characteristics, therapies, detection methods and diagnostic criteria for HER2-altered NSCLC patients. We hope this consensus could improve the clinical management of NSCLC patients with HER2 alterations.

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Human epidermal growth factor receptor 2 (HER2) alterations lead to poor prognosis in non-small-cell lung cancer (NSCLC).

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Identifying HER2 alterations is pivotal to guide the anti-HER2-targeted therapies in NSCLC.

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The requirements for HER2 mutation, amplification or expression testing are distinct in NSCLC.

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This consensus fills the gap in the criteria for HER2 alteration testing in NSCLC.

Association of EGFR mutations in second primary lung cancer and HER2 expression in breast cancer survivors

Background

The incidence of second primary lung cancer (SPLC) is increasing with longer survival rates from breast cancer. Despite of studies to suggest the mutual exclusivity of epidermal growth factor receptor (EGFR) and human epidermal growth receptor 2 (HER2) in several cancers, the effect of HER2 expression in breast cancer on EGFR mutations in SPLC is unclear. Therefore, this study aimed to determine the association between HER2 expression and EGFR mutations.

Methods

We conducted a retrospective cohort study of breast cancer survivors diagnosed with SPLC after breast cancer treatment between 1997 and 2018. We investigated the association between HER2 expression in breast cancer and EGFR mutations in SPLC, specifically focusing on negative correlations by using logistic regression analysis.

Results

EGFR mutations in SPLC were detected in 19 of 38 patients. Analysis for HER2 revealed a statistically significant difference in the proportion of EGFR mutations between patients with SPLC and previous HER2 positive breast cancer (43.5%) and those with SPLC and previous HER2 negative breast cancer (90.0%; P=0.021). The ratio of EGFR mutations decreased with the degree of HER2 expression in patients with previous breast cancer (90.0%: for no HER2 expression, 62.5% for HER2 1+, 0.0% for HER2 2+, and 41.7% for HER2 3+; P=0.018). Multivariate logistic analyses revealed that EGFR mutations in SPLC were significantly associated with age [odds ratio (OR): 1.11, 95% confidence interval (CI): 1.01-0.23, P=0.039] and HER2 positive status (OR: 0.04, 95% CI: 0.01-0.56, P=0.017).

Conclusions

This study suggests that the frequency of EGFR mutations in SPLC may be associated with low HER2 expression in previous breast cancer.

Epstein-Barr Virus Infection in Lung Cancer: Insights and Perspectives

Lung cancer (LC) is the leading cause of cancer death worldwide. Tobacco smoke is the most frequent risk factor etiologically associated with LC, although exposures to other environmental factors such as arsenic, radon or asbestos are also involved. Additionally, the involvement of some viral infections such as high-risk human papillomaviruses (HR-HPVs), Merkel cell polyomavirus (MCPyV), Jaagsiekte Sheep Retrovirus (JSRV), John Cunningham Virus (JCV), and Epstein-Barr virus (EBV) has been suggested in LC, though an etiological relationship has not yet been established. EBV is a ubiquitous gamma herpesvirus causing persistent infections and some lymphoid and epithelial tumors. Since EBV is heterogeneously detected in LCs from different parts of the world, in this review we address the epidemiological and experimental evidence of a potential role of EBV. Considering this evidence, we propose mechanisms potentially involved in EBV-associated lung carcinogenesis. Additional studies are warranted to dissect the role of EBV in this very frequent malignancy.

Trastuzumab Deruxtecan in HER2-Mutant Non-Small-Cell Lung Cancer

BACKGROUND

Human epidermal growth factor receptor 2 (HER2)-targeted therapies have not been approved for patients with non-small-cell lung cancer (NSCLC). The efficacy and safety of trastuzumab deruxtecan (formerly DS-8201), a HER2 antibody-drug conjugate, in patients with HER2-mutant NSCLC have not been investigated extensively.

METHODS

We conducted a multicenter, international, phase 2 study in which trastuzumab deruxtecan (6.4 mg per kilogram of body weight) was administered to patients who had metastatic HER2-mutant NSCLC that was refractory to standard treatment. The primary outcome was objective response as assessed by independent central review. Secondary outcomes included the duration of response, progression-free survival, overall survival, and safety. Biomarkers of HER2 alterations were assessed.

RESULTS

A total of 91 patients were enrolled. The median duration of follow-up was 13.1 months (range, 0.7 to 29.1). Centrally confirmed objective response occurred in 55% of the patients (95% confidence interval [CI], 44 to 65). The median duration of response was 9.3 months (95% CI, 5.7 to 14.7). Median progression-free survival was 8.2 months (95% CI, 6.0 to 11.9), and median overall survival was 17.8 months (95% CI, 13.8 to 22.1). The safety profile was generally consistent with those from previous studies; grade 3 or higher drug-related adverse events occurred in 46% of patients, the most common event being neutropenia (in 19%). Adjudicated drug-related interstitial lung disease occurred in 26% of patients and resulted in death in 2 patients. Responses were observed across different HER2 mutation subtypes, as well as in patients with no detectable HER2 expression or HER2 amplification.

CONCLUSIONS

Trastuzumab deruxtecan showed durable anticancer activity in patients with previously treated HER2-mutant NSCLC. The safety profile included interstitial lung disease that was fatal in two cases. Observed toxic effects were generally consistent with those in previously reported studies. (Funded by Daiichi Sankyo and AstraZeneca; DESTINY-Lung01 ClinicalTrials.gov number, NCT03505710.).