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Results for “HER2 amplification”

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PubMed2026

Co-Occurring EGFR L858R Mutation and HER2 Amplification in NSCLC Identified by Stepwise Molecular Profiling.

BACKGROUND The coexistence of multiple oncogenic drivers in non-small cell lung cancer (NSCLC) is a rare and diagnostically challenging molecular configuration. Conventional polymerase chain reaction (PCR)-based testing may fail to detect co-occurring genomic alterations, potentially limiting therapeutic options, particularly in resource-constrained settings. CASE REPORT We describe the case of a 54-year-old non-smoking woman diagnosed with Stage IIIA lung adenocarcinoma in 2020. Initial PCR-based molecular testing was negative for EGFR mutations. Following disease progression with brain metastases and severe chemotherapy toxicity, stepwise molecular profiling in a resource-limited setting identified HER2 (ERBB2) amplification via fluorescence in situ hybridization (FISH). The patient achieved 23 months of clinical and radiological stabilization on trastuzumab. Subsequent next-generation sequencing (NGS) analysis of archived tissue revealed a previously undetected estimated glomular filtration rate (EGFR) L858R mutation. In late April 2025, new lesions appeared in the lungs, indicating disease progression. Based on the previously verified EGFR L858R mutation, the treatment strategy was revised and gefitinib was initiated in May 2025. CONCLUSIONS This case illustrates that co-occurring EGFR and HER2 alterations can remain undetected following initial limited molecular testing, and that stepwise molecular profiling in a resource-constrained setting can facilitate identification of therapeutically actionable targets. The sequential clinical responses observed are consistent with the biological relevance of both alterations, although broader conclusions regarding diagnostic strategy or driver hierarchy cannot be drawn from a single observation.

Humans↗

PubMed2026

Eribulin versus taxane as first-line chemotherapy combined with dual HER2 blockade in patients with HER2-positive locally advanced or metastatic breast cancer: final survival outcomes of the JBCRG-M06/EMERALD study.

BACKGROUND: The phase III JBCRG-M06/EMERALD study was the first to show noninferior progression-free survival (PFS) of eribulin to taxane, combined with dual human epidermal growth factor receptor 2 (HER2) blockade (trastuzumab plus pertuzumab), as a first-line treatment for HER2-positive locally advanced breast cancer or metastatic breast cancer (LABC/MBC). We report final survival outcomes and biomarker analyses of the EMERALD trial. PATIENTS AND METHODS: Patients with HER2-positive LABC/MBC were randomly assigned 1:1 to either eribulin or physician-choice taxane (docetaxel or paclitaxel), both combined with trastuzumab plus pertuzumab, as first-line chemotherapy. PFS and overall survival (OS) were assessed through 30 June 2023 for PFS and 31 December 2024 for OS. Survival outcomes were compared between the eribulin and taxane groups and according to circulating tumor DNA (ctDNA) detection of PIK3CA mutations (PIK3CAm+; E542K, E545K, H1047R, and N345K single nucleotide variants) or HER2 amplification (HER2 amp+; ERBB2 copy number >2.5). RESULTS: Median OS was 78.5 months [95% confidence interval (CI) 64.3-not reached (NR)] for eribulin and was NR for taxane, with a hazard ratio of 1.25 (95% CI 0.92-1.71, log-rank P = 0.19). The 60-month OS rates were 59.7% and 65.2% for eribulin and taxane, respectively. Median OS and 60-month OS rates were numerically lower in ctDNA PIK3CAm+ patients, and greater in ctDNA HER2 amp+ patients for all patients and with stratification by treatment group. There were no statistical interactions between treatment group with either ctDNA PIK3CAm or ctDNA HER2 amp status. Similar patterns were observed for PFS. CONCLUSION: Final survival analysis revealed that median OS exceeded 6 years with eribulin or physician-choice taxane, combined with trastuzumab plus pertuzumab, as first-line chemotherapy for HER2-positive LABC/MBC, with no significant differences between the two groups. ctDNA PIK3CAm+ status was a poor prognostic factor. ctDNA HER2 amp+ was associated with longer survival.

Aged↗

PubMed2026

Trastuzumab Deruxtecan in Metastatic Urothelial Carcinoma with NGS-Detected ERBB2 Amplification: A Four-Patient Real-World Case Series.

Background: Next-generation sequencing (NGS)-detected ERBB2 amplification occurs in a subset of urothelial carcinomas, but its role as a treatment-selection marker for trastuzumab deruxtecan (T-DXd) remains uncertain. Methods: We retrospectively reviewed four patients with metastatic urothelial carcinoma treated with T-DXd in routine practice from 2024. Treatment selection was based on NGS-detected ERBB2 amplification because HER2 immunohistochemistry and in situ hybridization were unavailable. Results: Four men aged 65-76 years received T-DXd: one in the second line and three in the fourth or fifth line. The best radiological responses, abstracted from contemporaneous radiology reports and oncology medical records, were complete response in one patient, partial response in one, and stable disease in two. Three patients had previously received enfortumab vedotin. Documented adverse events included fatigue, anemia, diarrhea, rash, and leukopenia. No interstitial lung disease or pneumonitis was documented in the available records. Conclusions: These observations are descriptive and hypothesis-generating. They do not establish the efficacy or safety of T-DXd or validate ERBB2 amplification as a predictive biomarker, but they support prospective evaluation of genomic ERBB2 amplification when standard HER2 testing is unavailable.

Humans↗

PubMed2025

HER2 alterations across solid tumors: implications for comprehensive testing.

PURPOSE: ERBB2 (HER2) alterations (eg, overexpression, amplification, and mutations) are known to drive tumor progression. These changes, particularly in non-breast and gastric/gastroesophageal cancers, remain poorly characterized. With pan-tumor approval of HER2-targeted therapies like Trastuzumab deruxetecan (T-DXd), understanding ERBB2 alterations across diverse cancers is crucial. METHODS: HER2 analysis was conducted on 653 solid tumor specimens at the University of Alabama, using immunohistochemistry (IHC), copy number (CN) variation (CNV) assessment, and mutational profiling. The correlation between CN amplification and IHC expression was evaluated using Somers' D ordinal association. RESULTS: Of the 653 cases, HER2 IHC scores were distributed as 3+ (3.1%), 2+ (13.2%), and 1+ (19.8%), with 63.9% being IHC-negative. ERBB2 CN amplification was observed in 3.1%, with 75% exhibiting IHC3+. Pathogenic mutations were found in 3.1%, with low IHC3+ rates (5%). Among samples with ERBB2 mutations, only 3 had CN amplifications (1-positive, 2-intermediate). Somers'-D analysis revealed a strong association between CNV and IHC expression (D = 0.73, P < .001). CONCLUSION: This study highlights ERBB2 alterations across diverse cancers, demonstrating their heterogeneity and clinical significance. ERBB2 mutation-carrying tumors are less likely to have HER2 protein 3+ expression or CN amplification, indicating the need for comprehensive genomic analysis to identify those patients. In the context of pan-tumor approval of T-DXd for HER2, findings support integrating genomic and phenotypic data to enhance diagnostic precision and inform therapeutic decision-making. Comprehensive ERBB2 (HER2) testing across tumor types is essential to expand access to HER2-targeted therapies.

Humans↗

PubMed2026

Integrating NECTIN4 Amplification With Membranous Nectin-4 Expression to Develop a Scoring System for Predicting Enfortumab Vedotin Response in Urothelial Carcinoma.

PURPOSE: Enfortumab vedotin (EV) is standard therapy for metastatic urothelial carcinoma (mUC), yet the predictive relevance of NECTIN4 expression-especially membranous versus cytoplasmic-remains unclear. Here, we sought to extend previous findings on NECTIN4 gene amplification in parallel with a systematic subcellular evaluation of NECTIN4 expression. EXPERIMENTAL DESIGN: We retrospectively analyzed 179 EV-treated mUC patients. NECTIN4 amplification was assessed by FISH and NECTIN4 protein levels by IHC. A four-tier membranous scoring algorithm (0,1+,2+,3+) adapted from CAP HER2 gastric guidelines was benchmarked against H-score. We integrated amplification status with membranous staining to refine predictive stratification and compared associations with objective response rate (ORR) to EV-301 data. RESULTS: Combining membranous and cytoplasmic compartments resulted in a median composite H-score of 260 (78.2% ≥150), closely matching NECTIN4 expression prevalence reported in EV-301 (median 250; 82.6% ≥ 150). A ≥150 cut-off enriched for EV responders in both cohorts; in EV-301 with ORR of 45.8% vs. 20% (P = 0.001). High membranous expression based on the scoring (2+/3+) predicted response (ORR 55.1% vs. 25.5%; P < 0.001), with longer PFS (7.1 vs. 2.9 months; HR 0.45) and OS (12.3 vs. 6.9 months; HR 0.57), whereas cytoplasmic expression lacked predictive value. NECTIN4-amplified tumors showed particularly favorable outcomes (PFS 12.2 months; OS 30.1 months). An integrated three-tier model-amplified, non-amplified/high-membranous, and non-amplified/low-membranous-yielded ORRs of 77.2%, 42.9%, and 26.1% and separated survival outcomes. CONCLUSIONS: Our NECTIN4 scoring system integrating NECTIN4 amplification with membranous NECTIN4 expression accurately predicts outcomes, supporting combined genomic and membranous assessment as complementary biomarkers for optimizing EV selection.

Journal Article↗

PubMed2025

Molecular features influencing clinical outcome of advanced HER2-positive gastric cancer receiving trastuzumab plus chemotherapy.

BACKGROUND: Less than half of the human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC) patients respond to trastuzumab plus chemotherapy, and the outcomes are unsatisfactory. Understanding the underlying mechanisms remains crucial for identifying patients who are more likely to benefit from treatment. PATIENTS AND METHODS: We performed targeted DNA sequencing on paired pre-treatment and progressive tumour tissues from 22 HER2-positive advanced GC patients undergoing first-line treatment with trastuzumab and chemotherapy. Clinicopathological and genomic characteristics were assessed for the correlation with clinical outcomes. RESULTS: A performance status (PS) of 0-1 was associated with improved progression-free survival (PFS) and overall survival (OS) than a PS of 2. Poorly differentiated tumours exhibited shorter PFS than moderate or moderate-poor ones. Pre-treatment amplification of MYC or TOP2A gene was association with increased PFS, and suggested a potential benefit for OS. Patients with higher tumour mutation burden (TMB) experienced significantly worse PFS, while higher chromosome instability (CIN) appeared to be correlated with longer PFS. Compared to non-responders, responders had a higher CIN but similar TMB and intratumoural heterogeneity (ITH). PS and MYC amplification emerged as independent factors related to PFS according to multivariate survival analysis. Additionally, after treatment, TMB significantly increased in non-responders, while CIN significantly decreased in responders. CONCLUSIONS: Pre-treatment MYC amplification and PS were independently associated with clinical outcomes in HER2-positive advanced GC patients treated with first-line trastuzumab plus chemotherapy. Dynamic post-treatment changes in TMB and CIS provide valuable insights into the relationship between therapeutic response and distinct evolutionary trajectories.

Humans↗

PubMed2025

Molecular Landscape, Genomic Shift, and Prediction in the Neoadjuvant Setting of Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer.

The amplification or overexpression of human epidermal growth factor receptor 2 (HER2) defines a breast cancer subtype, which benefits from neoadjuvant HER2-targeted therapy. However, at least 40% of patients respond poorly or do not respond to treatment. We analyzed the main genomic alterations of 64 HER2+ patients by next-generation sequencing to identify new predictors of response and correlate them with clinicopathological parameters. We also compared the genomic alterations between primary and residual tumors after neoadjuvant treatment. The TP53 gene was the most frequently mutated gene, and in combination with ERBB2 overexpression, the 2 were predictive of residual cancer burden (P = .001). Furthermore, the combination of their immunohistochemical counterpart (p53 mutant and score 3+ for HER2) can predict complete pathological response and the grade of response (P = .038 and P = .031, respectively). Therefore, p53 could be included in the initial panel of breast cancer biomarkers to help therapeutic decision-making in HER2+ cases.

Humans↗

PubMed2026

Efficacy of S-1 Monotherapy for Salivary Duct Carcinoma With MYC Amplification.

BACKGROUND/AIM: Salivary duct carcinoma (SDC) is a rare, highly aggressive subtype of salivary gland carcinoma, commonly characterized by overexpression of erb-b2 receptor tyrosine kinase 2 [ERBB2, commonly known as human epidermal growth factor receptor 2 (HER2)] and androgen receptor positivity. Anti-HER2 therapy, platinum-based chemotherapy, and androgen-deprivation therapy (ADT) are commonly provided as standard systemic treatments for advanced SDC; however, effective therapeutic options after failure of these treatments remain limited. The clinical efficacy of S-1 monotherapy in SDC and its predictive biomarkers are not well established. Herein, we present a case in which S-1 monotherapy showed efficacy in a case of SDC after resistance to anti-HER2 therapy, platinum-based chemotherapy, and ADT. CASE REPORT: The patient was a 70-year-old man diagnosed with HER2-positive and androgen receptor-positive SDC of the submandibular gland, who presented with multiple lung metastases. He initially received trastuzumab plus docetaxel as first-line therapy, followed by platinum-based chemotherapy and ADT, but experienced disease progression after each treatment. Comprehensive genomic profiling revealed amplifications of ERBB2 and MYC proto-oncogene bHLH transcription factor (MYC). S-1 monotherapy was started as a late-line therapy. Computed tomography scans 2 months later showed shrinkage of lung and liver metastases, with disease control maintained for more than 5 months. CONCLUSION: S-1 monotherapy may represent a treatment option for patients with advanced SDC refractory to anti-HER2 therapy, platinum-based chemotherapy, and ADT, particularly in cases harboring MYC amplification.

Humans↗

PubMed2024

Molecular and Clinical Determinants of Acquired Resistance and Treatment Duration for Targeted Therapies in Colorectal Cancer.

PURPOSE: Targeted therapies have improved outcomes for patients with metastatic colorectal cancer, but their impact is limited by rapid emergence of resistance. We hypothesized that an understanding of the underlying genetic mechanisms and intrinsic tumor features that mediate resistance to therapy will guide new therapeutic strategies and ultimately allow the prevention of resistance. EXPERIMENTAL DESIGN: We assembled a series of 52 patients with paired pretreatment and progression samples who received therapy targeting EGFR (n = 17), BRAF V600E (n = 17), KRAS G12C (n = 15), or amplified HER2 (n = 3) to identify molecular and clinical factors associated with time on treatment (TOT). RESULTS: All patients stopped treatment for progression and TOT did not vary by oncogenic driver (P = 0.5). Baseline disease burden (≥3 vs. <3 sites, P = 0.02), the presence of hepatic metastases (P = 0.02), and gene amplification on baseline tissue (P = 0.03) were each associated with shorter TOT. We found evidence of chromosomal instability (CIN) at progression in patients with baseline MAPK pathway amplifications and those with acquired gene amplifications. At resistance, copy-number changes (P = 0.008) and high number (≥5) of acquired alterations (P = 0.04) were associated with shorter TOT. Patients with hepatic metastases demonstrated both higher number of emergent alterations at resistance and enrichment of mutations involving receptor tyrosine kinases. CONCLUSIONS: Our genomic analysis suggests that high baseline CIN or effective induction of enhanced mutagenesis on targeted therapy underlies rapid progression. Longer response appears to result from a progressive acquisition of genomic or chromosomal instability in the underlying cancer or from the chance event of a new resistance alteration.

Humans↗

PubMed2026

Landscape of acquired resistance alterations in gastrointestinal malignancies after genomically targeted therapy.

BACKGROUND: Targeted therapies directed at specific genomic alterations have transformed the management of gastrointestinal (GI) cancers; however, acquired resistance remains inevitable. Circulating tumor DNA (ctDNA) analysis via liquid biopsy provides a non-invasive approach to characterize genomic mechanisms of resistance. We therefore evaluated patterns of acquired genomic resistance in patients with GI cancers treated with targeted therapies. METHODS: Patients with GI cancers treated with standard of care or investigational therapies targeting EGFR, HER2, FGFR, MET, KRAS, BRAF for at least 60 days who underwent both baseline comprehensive genomic profiling and post-progression ctDNA sequencing were retrospectively evaluated. RESULTS: Of 106 patients meeting inclusion criteria, 45 had biliary tract cancer (BTC), 42 colorectal cancer (CRC), and 19 other GI malignancies. At least one putative resistance-associated alteration was detected in ctDNA in 53% of cases. Resistance patterns were heterogeneous with 47% showing no detectable alterations and 33% harboring ≥2 resistance alterations. Among 164 total alterations, the majority were single nucleotide variants (82%), followed by amplifications (17%). Overall, 48% were classified as 'bypass' alterations-activating alternative oncogenic pathways, most commonly MAPK signaling-while 52% were 'on-target' alterations involving secondary changes within the drug target. RAS alterations represented a key mechanism of bypass resistance, accounting for 28% of all resistance alterations. Interestingly, in CRC, bypass alterations predominated (69%), whereas in BTCs, on-target alterations were more frequent (61%). CONCLUSIONS: Liquid biopsies frequently identify acquired resistance following targeted therapy across GI cancers, often revealing multiple concurrent alterations. Patterns of resistance varied by tumor type, with both on-target and bypass mechanisms observed. These findings highlight common themes of resistance and support the growing clinical role of ctDNA analysis in defining resistance and guiding management in GI malignancies.

Gastrointestinal malignancies↗