HER2 Amplification Research Articles

The distribution of human epidermal growth factor receptor 2 (HER2) expression and the efficacy and safety of treatments in HER2-expressing advanced or metastatic gastroesophageal cancer: A systematic literature review (SLR).

405 Background: HER2 overexpression plays an important role in determining treatment options for patients with gastroesophageal cancer (GEC). HER2 overexpression has historically been defined dichotomously as HER2-positive (HER2+) or HER2-negative. An emerging potentially clinically relevant category is HER2-low, which could be targeted with HER2-directed antibody drug conjugates. However, data on the epidemiology and outcomes associated with HER2-low GEC are limited. Methods: An SLR of PubMed, Embase, and Cochrane Central Register of Controlled Trials databases was conducted to identify clinical trials, observational studies, and meta-analyses reporting clinical outcomes or distribution of HER2 expression by IHC and ISH in advanced or metastatic (a/m) GEC. Key inclusion criteria were: English language, published between 2013-2023, and sample size ≥100 HER2-expressing patients. HER2+ was defined as IHC score of 3+ or IHC 2+ and ISH+. HER2-low was defined as IHC 1+ or IHC 2+ and ISH-. Weighted averages were calculated for the proportion of patients who were HER2+ and HER2-low to estimate of the proportion of patients in each HER2 expression category. Results were categorized by patient population (all GEC or gastric cancer [GC] only). Results: Of 2,701 non-duplicated records screened, 174 studies met inclusion criteria. Distribution of HER2 expression was reported in 111 studies, 5 of which reported on the frequency of HER2 expression of IHC 1+ and/or IHC 2+ and ISH+. HER2 expression status varied by patient population, with a weighted average of 26.9% for HER2-low and 13.1-16.5% for HER2+ across groups (Table). Different cutoffs for HER2 amplification via ISH also affected the proportion of patients in each HER2 category across studies. Efficacy and safety outcomes were stratified by HER2 status or IHC results in 74 studies. However, only 3 observational studies reported outcomes separately for the HER2-low population, and results were inconclusive. Conclusions: The distribution of HER2 expression in a/m GEC in the identified studies is highly heterogenous, likely due to variability in IHC scoring and patient populations. Few studies with sufficient samples size (≥100 patients with HER2-expression a/mGEC) reported outcomes for HER2-low a/m GEC, and those that were identified were of low quality. The HER2-low a/m GEC population constitutes an unmet need for effective therapy. There is a need for consistent use of a standardized definition of HER2-low in a/mGEC and additional studies to better evaluate treatment options and outcomes for this patient population. [Table: see text]

Prevalence and treatment of human epidermal growth factor receptor 2-altered non-small cell lung cancer: a retrospective analysis and systematic literature review.

Human epidermal growth factor receptor 2 (HER2) is known for its oncogenic activities in diverse cancers, including non-small cell lung cancer (NSCLC). However, the prevalence of HER2 alterations in Malaysian NSCLC patients remains unreported. This study examined the prevalence and characteristics of HER2 mutations and amplification in a Malaysian cohort. Additionally, a systematic review was conducted to evaluate the global prevalence of HER2 alterations in NSCLC, as well as the efficacy of HER2-targeted therapies observed in clinical trials. NSCLC tumour samples received from October 2019 to December 2022 for next-generation sequencing diagnostics were included in the retrospective analysis. In this patient cohort, HER2 alteration was present in 5.8% of patients; 3.9% had HER2 mutations, 1.5% had HER2 amplifications and 0.4% were both HER2-mutated and amplified. HER2 exon 20 insertions were the most common HER2 variants, detected in 47/59 (79.7%) of HER2-mutated patients. Among cases with HER2 exon 20 insertions, the Y772_A775dup variant was found in 34 patient samples. HER2-mutated patients were significantly younger than non-HER2-mutants (61 versus 64 years old; p = 0.046) and were inclined to be female and never-smokers, albeit not statistically significant. Patients with HER2 amplification were more likely to have progressed post-tyrosine kinase inhibitor therapy (p = 0.015). The systematic review highlighted a global variation in the prevalence of HER2 alterations in NSCLC, ranging from 0.3% to 9.1% for mutations and 0.2% to 19% for amplification. Finally, phase II clinical trials involving HER2-altered NSCLC patients demonstrated promising treatment outcomes with trastuzumab deruxtecan, trastuzumab emtansine, pyrotinib, pyrotinib + apatinib and trastuzumab + pertuzumab + docetaxel. In conclusion, the prevalence of HER2 alteration among Malaysian NSCLC patients falls within the global range. A systematic review of clinical trials revealed promising treatment outcomes and Malaysian NSCLC patients with HER2 alterations are anticipated to similarly benefit from HER2-targeted therapies.

Comparative evaluation of the diagnostic and prognostic performance of CNSide™ versus standard cytology for leptomeningeal disease.

This retrospective study compares the real-world performance of cerebrospinal fluid (CSF) CNSide™ versus cytology in leptomeningeal disease (LMD). Consecutive patients with suspected LMD who underwent lumbar punctures for CSF cytology and CNSide™ from January 2020 to December 2022 were reviewed. LMD was classified by EANO criteria. Descriptive statistics, confusion matrix, Kaplan-Meier curves, and Cox proportional regression were used. Median age for 87 evaluable patients was 63 years (range: 23-93); 82 (94%) met EANO criteria for possible/probable/confirmed LMD (EANO/LMD). The commonest primary cancers were breast (36,44.0%) and lung (34,41.5%). Primary lung harbored actionable mutations in 18 (53.0%); primary breast expressed hormone receptors in 27 (75%), and HER2 amplification in 8 (22%). Uncontrolled systemic disease was detected in 35 (40%), while 25 (46%) received systemic therapy with medium/high CNS penetrance at LMD diagnosis. The median time from initial cancer to LMD diagnosis was 31 months (range: 13-73). LMD was confirmed by CSF cytology in 23/82 (28%), all identified by CNSide™. CNSide™ identified 13 additional cases (36/82, 43.9%), increasing diagnostic yield by 56.5%. Median overall survival (mOS) was 31 weeks (95%CI: 21-43), significantly worse for CNSide™ positive versus negative: 4.0 versus 16.0 weeks, respectively (HR = 0.50, P = .010). While survival since LMD diagnosis did not differ by histology, time to LMD diagnosis from initial cancer diagnosis was longer for breast (48.5 months, IQR: 30.0-87.5) versus lung (8 months, IQR:0.5-16.0) cohorts. mOS was longer for patients eligible for intrathecal chemotherapy (HR: 0.189, 95%CI: 0.053-0.672, P = .010). This retrospective, real-world analysis of CNSide™ showed increased sensitivity versus cytology and provided clinically relevant molecular CSF analyses.

Genomic profiling of colorectal cancer in large-scale Chinese patients: amplification and somatic mutations in ERBB2.

Human epidermal growth factor receptor 2 (HER2)-targeted therapies have demonstrated potential benefits for metastatic colorectal cancer (mCRC) patients with HER2 amplification, but are not satisfactory in cases of HER2 mutant CRCs. Consequently, further elucidation of amplifications and somatic mutations in erythroblastic oncogene B-2 (ERBB2) is imperative. Comprehensive genomic profiling was conducted on 2454 Chinese CRC cases to evaluate genomic alterations in 733 cancer-related genes, tumor mutational burden, microsatellite instability, and programmed death ligand 1 (PD-L1) expression. Among 2454 CRC patients, 85 cases (3.46%) exhibited ERBB2 amplification, and 55 cases (2.24%) carried ERBB2 mutation. p.R678Q (28%), p.V8421 (24%), and p.S310F/Y (12%) were the most prevalent of the 16 detected mutation sites. In comparison to the ERBB2 altered (alt) group, KRAS/BRAF mutations were more prevalent in ERBB2 wild-type (wt) samples (ERBB2wt vs. ERBB2alt, KRAS: 50.9% vs. 25.6%, p < 0.05; BRAF: 8.5% vs. 2.3%, p < 0.05). 32.7% (18/55) of CRCs with ERBB2 mutation exhibited microsatellite instability high (MSI-H), while no cases with HER2 amplification displayed MSI-H. Mutant genes varied between ERBB2 copy number variation (CNV) and ERBB2 single nucleotide variant (SNV); TP53 alterations tended to co-occur with ERBB2 amplification (92.3%) as opposed to ERBB2 mutation (58.3%). KRAS and PIK3CA alterations were more prevalent in ERBB2 SNV cases (KRAS/PIK3CA: 45.8%/31.2%) compared to ERBB2 amplification cases (KRAS/PIK3CA: 14.1%/7.7%). Our study delineates the landscape of HER2 alterations in a large-scale cohort of CRC patients from China. These findings enhance our understanding of the molecular features of Chinese CRC patients and offer valuable implications for further investigation.

Role of HER2/neu in Colorectal Carcinoma: A Cross-sectional Study from a Tertiary Care Centre in West Bengal, India

Introduction: In many tumours, Human Epidermal Growth Factor Receptor 2 (HER2) expression and HER2 amplification are studied as therapeutic and prognostic factors. The incidence of HER2/neu expression and its consequences in patients with colorectal carcinoma has shown conflicting evidence. Aim: To evaluate the utility of HER2/neu expression in colorectal carcinoma and to find any association between HER2/neu expression, histological grade, and stage of the tumour. Materials and Methods: This cross-sectional study was conducted on 50 cases of colorectal carcinoma. Patients undergoing surgery for colorectal tumours were selected over an 18-month period (January 2020 to June 2021) in a tertiary care hospital in Kolkata, West Bengal, India. Various clinical and demographic parameters were obtained from the patients, and the specimens were subjected to Immunohistochemical (IHC) staining for HER2/neu. The results were analysed using Statistical Package for the Social Sciences (SPSS)software version 25.0 (IBM, Armonk, New York, USA). Results: On HER2/neu IHC examination, 30 cases (60%) showed a 3+ score, 4 cases (8%) showed a 2+ score, 7 cases (14%) showed a 1+ score, and the remaining 9 cases (18%) showed a score of 0. HER2/neu expression was found in 30 cases (60%) of colorectal carcinoma. HER2/neu expression showed a significant association with the histological grade of the tumour (p-value=0.020). HER2/neu expression also showed a significant association (p-value&lt;0.001) with histological subtypes of the tumour. Conclusion: This study revealed a significant association between HER2/neu expression and histological subtypes and grade of the tumour. Moderately differentiated adenocarcinoma showed the highest expression, while mucinous adenocarcinoma and undifferentiated carcinoma showed minimal or absent HER2/ neu expression. Thus, HER2/neu can serve as a prognostic and therapeutic marker in colorectal carcinoma. In conclusion, surgery alone is not curative for patients with colorectal cancer, and additional forms of management may be required to improve patient survival. In such cases, HER2/neu expression can guide new adjuvant therapy.

Semi-automated analysis of HER2 immunohistochemistry in invasive breast carcinoma using whole slide images: utility for interpretation in clinical practice.

Human epidermal growth factor receptor 2 (HER2) gene amplification and subsequent protein overexpression is a strong prognostic and predictive biomarker in invasive breast carcinoma (IBC). ASCO/CAP recommended tests for HER2 assessment include immunohistochemistry (IHC) and/or in situ hybridization (ISH). Accurate HER2 IHC scoring (0, 1+, 2+, 3+) is key for appropriate classification and treatment of IBC. HER2-targeted therapies, including anti-HER2 monoclonal antibodies and antibody drug conjugates (ADC), have revolutionized the treatment of HER2-positive IBC. Recently, ADC have also been approved for treatment of HER2-low (IHC 1+, IHC 2+/ISH-) advanced breast carcinoma, making a distinction between IHC 0 and 1+ crucial. In this focused study, 32 IBC with HER2 IHC scores from 0 to 3+ and HER2 FISH results formed a calibration dataset, and 77 IBC with HER2 IHC score 2+ and paired FISH results (27 amplified, 50 non-amplified) formed a validation dataset. H&E and HER2 IHC whole slide images (WSI) were scanned. Regions of interest were manually annotated and IHC scores generated by the software QuantCenter (MembraneQuant application) by 3DHISTECH Ltd. (Budapest, Hungary) and compared to the microscopic IHC score. H-scores [(3×%IHC3+) +(2×%IHC2+) +(1×%IHC1+)] were calculated for semi-automated (MembraneQuant) analysis. Concordance between microscopic IHC scoring and 3DHISTECH MembraneQuant semi-automated scoring in the calibration dataset showed a Kappa value of 0.77 (standard error 0.09). Microscopic IHC and MembraneQuant image analysis for the detection of HER2 amplification yielded a sensitivity of 100% for both and a specificity of 56% and 61%, respectively. In the validation set of IHC 2+ cases, only 13 of 77 cases (17%) had discordant results between microscopic and MembraneQuant images, and various artifacts limiting the interpretation of HER2 IHC, including cytoplasmic/granular staining and crush artifact were noted. Semi-automated analysis using WSI and microscopic evaluation yielded similar HER2 IHC scores, demonstrating the potential utility of this tool for interpretation in clinical practice and subsequent accurate treatment. In this study, it was shown that semi-automatic HER2 IHC interpretation provides an objective approach to a test known to be quite subjective.

CircPVT1 Inhibits the Proliferation and Aids in Prediction of the Prognosis of Bladder Cancer.

Circular RNA PVT1 (circPVT1) is aberrantly expressed in several cancers, but its functional role and clinical relevance in bladder urothelial carcinoma (BLCA) remain unknown. This study aimed to identify the expression level of circPVT1 in BLCA and investigated its functional relevance with BLCA progression both in vitro and in vivo. GEPIA, UALCAN, and OncoLnc were referred to presented data. Quantitative real-time PCR (qPCR) was used for the measurement of transnational expression of genes in BLCA specimens and cell lines. Immunohistochemistry (IHC) and fluorescence in situ hybridization analysis (FISH) assays were performedto detect HER2 amplification, Pearson's correlation analysis to analyze the correlation between circPVT1 expression and clinical characteristics, Cox regression and K-M survival analyses to analyze prognostic factors. A nomogram was constructed for predicting prognosis. The proliferation of cells was measured by CCK-8 and colony formation assay, and the proliferation in vivo was evaluated using nude mouse models. qPCR was used to detect the expression of proliferation-related genes. circPVT1 was but mRNA PVT1 was not significantly overexpressed in BLCA. A high circPVT1 expression was associated with a better survival and negative HER2, but not with age, gender, and T stage. circPVT1 was an independent prognostic factor for the overall survival of BLCA patients. Knocking down circPVT1 promoted BLCA proliferation in vitro and in vivo. Knocking down circPVT1 upregulated ERBB2, MKI67, and PCNA expression and downregulated TP53 expression, but exerted no influence on CCND1 and CCNB1 expression. circPVT1 is a tumor suppressor and novel prognostic biomarker for BLCA.

Automated Quantification of HER2 Amplification Levels Using Deep Learning.

HER2 assessment is necessary for patient selection in anti-HER2 targeted treatment. However, manual assessment of HER2 amplification is time-costly, labor-intensive, highly subjective and error-prone. Challenges in HER2 analysis in fluorescence in situ hybridization (FISH) and dual in situ hybridization (DISH) images include unclear and blurry cell boundaries, large variations in cell shapes and signals, overlapping and clustered cells and sparse label issues with manual annotations only on cells with high confidences, producing subjective assessment scores according to the individual choices on cell selection. To address the above-mentioned issues, we have developed a soft-sampling cascade deep learning model and a signal detection model in quantifying CEN17 and HER2 of cells to assist assessment of HER2 amplification status for patient selection of HER2 targeting therapy to breast cancer. In evaluation with two different kinds of clinical datasets, including a FISH data set and a DISH data set, the proposed method achieves high accuracy, recall and F1-score for both datasets in instance segmentation of HER2 related cells that must contain both CEN17 and HER2 signals. Moreover, the proposed method is demonstrated to significantly outperform seven state of the art recently published deep learning methods, including contour proposal network (CPN), soft label-based FCN (SL-FCN), modified fully convolutional network (M-FCN), bilayer convolutional network (BCNet), SOLOv2, Cascade R-CNN and DeepLabv3+ with three different backbones (p ≤ 0.01). Clinically, anti-HER2 therapy can also be applied to gastric cancer patients. We applied the developed model to assist in HER2 DISH amplification assessment for gastric cancer patients, and it also showed promising predictive results (accuracy 97.67 ±1.46%, precision 96.15 ±5.82%, respectively).

Research On Befortinib: Characteristics, Role, And Development of Fourth-Generation EGFR-Tkis

Lung cancer is one of the most common cancers in terms of morbidity and mortality. Among them, non-small cell lung cancer (NSCLC) accounts for 90% of lung cancer patients. Epidermal Growth Factor Receptor (EGFR) mutations are also the most common type of driver gene mutation in advanced NSCLC. In Chinese NSCLC patients, the proportion of EGFR mutations was 28.2%, and this proportion increased to 50.2% in lung adenocarcinoma. All three generations of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors (EGFR-TKI) are effective therapeutics for lung cancer patients carrying EGFR-sensitive mutations or T790M mutations, each of which has its own advantages and characteristics, as well as its own limitations and adverse reactions. Befortinib, which is new to the market in 2023, has better Median progression-free survival (mPFS). However, three generations of EGFR-TKI cannot completely overcome the resistance mechanism of lung cancer. In addition to the T790M mutation, there are other mutations or mechanisms that cause lung cancer to become resistant to third-generation EGFR-TKI, such as C797S mutation, MET amplification, HER2 amplification, etc. At present, the fourth-generation of EGFR-TKI is still under continuous research and development.

Treatment Options in Late-Line Colorectal Cancer: Lessons Learned from Recent Randomized Studies.

Systemic treatment of metastatic colorectal cancer (mCRC) has improved considerably over the past 20 years. First- and second-line combinations of 5FU, oxaliplatin, and irinotecan, with or without anti-angiogenic and/or anti-EGFR antibodies, were approved shortly after the turn of the millennium. Further triumphs were not seen for almost 10 years, until the approval of initially regorafenib and shortly after trifluridine/tipiracil. A growing understanding of tumor biology through molecular profiling has led to further treatment options. Here, we review the most recent clinical data for late-line treatment options in mCRC, focusing on randomized trials if available. We include recommendations for options in unselected patients and therapies that should only be offered in patients with distinct tumor profiles (e.g., BRAF mutations, KRAS G12C mutations, HER2 amplification, deficient MMR, or NTRK gene fusions).

HER2 amplification level by in situ hybridization predicts survival outcome in advanced HER2-positive breast cancer treated with pertuzumab, trastuzumab, and docetaxel regardless of HER2 IHC results

BackgroundThe role of HER2 amplification level in predicting the effectiveness of HER2-directed therapies has been established. However, its association with survival outcomes in advanced HER2-positive breast cancer treated with dual HER2-blockade remains unexplored.MethodsThis is a single-center retrospective study of patients with advanced HER2-positive breast cancer treated with first-line pertuzumab, trastuzumab, and docetaxel. The primary objective was to ascertain the relationship between treatment outcomes and the level of HER2 amplification by in situ hybridization (ISH).ResultsA total of 152 patients were included with a median follow-up duration of 50.0 months. Among the 78 patients who received ISH, a higher HER2/CEP17 ratio correlated significantly with longer PFS (HR 0.50, p = 0.022) and OS (HR 0.28, p = 0.014) when dichotomized by the median. A higher HER2 copy number also correlated significantly with better PFS (HR 0.35, p < 0.001) and OS (HR 0.27, p = 0.009). In multivariate analysis, the HER2/CEP17 ratio was an independent predictive factor for PFS (HR 0.66, p = 0.004) and potentially for OS (HR 0.64, p = 0.054), along with HER2 copy number (PFS HR 0.85, p = 0.004; OS HR 0.84, p = 0.049). Furthermore, the correlation between HER2 amplification level by ISH with PFS and OS was consistent across the HER2 IHC 1+/2+ and 3+ categories.ConclusionsThis is the first study to report that a higher level of HER2 amplification by ISH is associated with improved PFS and OS in advanced HER2-positive breast cancer treated with dual HER2-blockade. Notably, HER2 amplification level had a predictive role regardless of IHC results. Even in patients with HER2 protein expression of 3+, treatment outcome to HER2-directed therapy was dependent on the level of HER2 gene amplification.

Comparison of an amplicon-based large panel next generation sequencing (NGS) assay with conventional testing methods for MET and HER2 amplification in lung and breast cancers

The frequency of MET and HER2 amplification being detected by next generation sequencing (NGS) is increasing due to NGS being increasingly adopted for molecular profiling of cancers. However, the accuracy of NGS in detecting these gene amplifications remains uncertain due to conflicting reports in the scientific literature. We studied the accuracy of an amplicon-based large panel NGS assay in detecting MET and HER2 amplification in lung and breast cancers, respectively, by comparing it against conventional testing methods. Amongst 48 lung cancers, four of five cancers that were MET amplified on fluorescence in situ hybridisation (FISH) were classified as amplified on NGS while 42 of the remaining 43 non-amplified cancers were classified as non-amplified on NGS, giving a sensitivity of 80%, specificity of 97.7% and overall concordance of 95.8%. Of the 46 breast cancers tested, only six of the nine cancers that were HER2-positive on immunohistochemistry (IHC)/FISH were HER2-positive on NGS, while all the remaining HER2-negative cases were negative on NGS, giving a sensitivity of 66.7%, specificity of 100% and overall concordance of 93.5%. All the false-negative cases had low level gene amplification (MET:CEP7 or HER2:CEP17 FISH ratio of <3). The low sensitivity for HER2 amplification may be confounded by the small sample size and disproportionate number of cases with low level amplification. In summary, the NGS assay has good concordance with conventional testing methods but may be less sensitive in detecting low level gene amplification.

The genomic and immune landscapes of gastric cancer and their correlations with HER2 amplification and PD-L1 expression.

Anti-PD1/PD-L1 antibody plus human epidermal growth factor receptor 2 (HER2) antibody and chemotherapy have become the new first-line therapy for HER2 overexpression-positive advanced gastric cancers (GC), suggesting that HER2 and PD-L1 play a vital role in guiding systemic treatment for patients with GC. This study aimed to depict the genomic and immune landscapes of Chinese patients with GC and investigate their correlations with HER2 amplification and PD-L1 expression. Next-generation targeted sequencing and PD-L1 immunohistochemistry were performed on tumor samples from 735 patients with pathologically diagnosed GC. The genomic and immune landscapes and their correlations with HER2 amplification and PD-L1 expression were analyzed. The most commonly mutated genes in Chinese GC were TP53 (64%), CDH1 (20%), ARID1A (18%), HMCN1 (15%), KMT2D (11%), and PIK3CA (11%). Seventy-six (10%) patients were HER2 amplification, and 291 (40%) had positive PD-L1 expression. Classifying the total population based on HER2 amplification and PD-L1 expression level, 735 patients were divided into four subgroups: HER2+/PD-L1+ (4.5%), HER2+/PD-L1- (5.9%), HER2-/PD-L1+ (35.1%), and HER2-/PD-L1- (54.5%). The HER2+/PD-L1- and HER2+/PD-L1+ subgroups exhibited dramatically higher rate of TP53 mutations, CCNE1 and VEGF amplifications. The HER2+/PD-L1- subgroup also had a markedly higher rate of MYC amplification and KRAS mutations. The HER2-/PD-L1+ subgroup had significantly higher rate of PIK3CA mutations. HER2+/PD-L1- subgroup had the highest TMB level and HER2-/PD-L1+ subgroup had the highest proportion of patients with microsatellite instability-high than other subgroups. Furthermore, we observed that different HER2 amplification levels had distinct impacts on the correlations between PD-L1 expression and therapeutic genomic alterations, but no impact on the prognosis. The combination of HER2 amplification and PD-L1 expression in Chinese patients with GC could stratify the total populations into several subgroups with distinctive genomic and immune landscapes, which should be considered when making personalized treatment decisions.

Diagnostic Accuracy of Immunohistochemistry for HER2-Positive Breast Cancer.

Currently, human epidermal growth factor receptor 2 (HER2)-positive breast cancer cells are diagnosed under the American Society of Clinical Oncology (ASCO) and College of American Pathologists (CAP) 2018 guidelines. The guideline combined the results of in situ hybridization (DISH) and immunohistochemistry (IHC) techniques. The IHC technique is easy, cheap, and suitable for developing country. Therefore, in this study, we validated the use of IHC alone compared to the results of HER2 amplification under ASCO/CAP 2018 guidelines in diagnosed HER2 positive breast cancer cells. A total of 510 breast cancer tissue samples from Rajavithi Hospital in Bangkok, Thailand, from January 1st, 2022, to May 31st, 2023, were analyzed by IHC, followed by dual ISH (DISH). We selected 58 samples of IHC equivocal (score 2+) and 98 samples of IHC positive (score 3+) to analyze the diagnostic values by comparing them to the results of HER2 amplification. The HER2 IHC score was found to agree with HER2 amplification with a sensitivity of 87.96%, a specificity of 93.75%, a positive predictive value of 96.94%, a negative predictive value of 77.59%, a positive likelihood ratio of 14.07, a negative likelihood ratio of 0.13, and an accuracy of 89.74%. The promising outcomes suggest that a positive IHC test result (score 3+) could potentially stand alone for patients with breast cancer undergoing anti-HER2 treatment, even without DISH confirmation.

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

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

Abstract B017: Clinical utility of next generation sequencing in advanced colorectal cancer: The earlier the better

Abstract Background. Since next generation sequencing (NGS) was approved in solid tumor in Korea, it has been usually performed when patients were progressed on standard chemotherapy in advanced colorectal cancer (CRC). Recently, new targeted agents have been developed rapidly, so the NGS is recommended as early as possible. In this study, we analyzed NGS results and investigated clinical benefit in advanced CRC. Patient and method. Between October 2018 to December 2022, NGS data in 85 advanced CRC patients in St. Vincent’s Hospital, Suwon, Korea were retrospectively analyzed. Results. Seven patients had metachronous, and others had synchronous metastasis. The median age was 58 (34-84), and 59 (69.4%) were male. Fourteen (16.5%) were right-side, 40 (47.1%) were left-side colon, and 30 (35.3%) were rectum. The median time from diagnosis of advanced CRC to NGS was 13 (0-81) months, and median time to death after NGS was 8 (0.3-43.0) months. NGS platform were ‘Oncomine comprehensive assay Plus’ in 71 (83.5%), and the others were various platforms in K-master project. NGS analyses revealed new therapeutic target in 17 (20%): high tumor mutational burden (n = 2), KRAS G12C (n = 4), KRAS (n = 1) or BRAF (n = 2) mutation not routinely screened at initial, BRAF class II mutation (n = 2), Her2/3 mutation (n = 2), and NTRK fusion (n = 1). Among those, two patients with KRAS G12C mutation enrolled in clinical trial of KRAS G12 inhibitor, and one patient with NTRK fusion received NTRK inhibitor (3.5% of total). Among RAS wild type population (n=30), we identified hyperselected patients (n = 18, [60%], absence of either KRAS, NRAS, PTEN, and extracellular domain EGFR mutations, HER2 and MET amplifications, and ALK, RET or NTRK1 fusions by PARADIGM trial), which showed longer survival in cetuximab-treated population (p&amp;lt;0.001). Specific mutation including KRAS, NRAS, BRAF, TP53, or APC did not impact on prognosis. High TMB (≥10Mut/Mb) were associated with longer survival (p = 0.020). For patients with oligometastasis, hyperselected patients (p = 0.062) showed good prognosis. Conclusion. The NGS results provided additional predictive or prognostic information in advanced CRC patients. Application of NGS as early as possible might help to make a clinical decision. Citation Format: Ho Jung An, Hyunho Kim, Hyung Soon Park, Hyeon-Min Cho, Bong-Hyeon Kye, Ri Na Yoo, Ji-Yeon Moon, Sung Hwan Kim, Jonghoon Lee, Hyo Chun Lee. Clinical utility of next generation sequencing in advanced colorectal cancer: The earlier the better [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B017.

Prevalence and Therapeutic Targeting of High-Level ERBB2 Amplification in NSCLC

IntroductionERBB2 amplification in lung cancer remains poorly characterized. HER2 (encoded by ERBB2) is a transmembrane tyrosine kinase capable of ligand-independent dimerization and signaling when overexpressed, and a common cause of HER2 overexpression is ERBB2 amplification. Here, we evaluated the clinicopathologic and genomic characteristics of ERBB2-amplified NSCLC and explored a HER2 antibody–drug conjugate (ADC) therapeutic strategy. MethodsOur institutional next-generation DNA sequencing data (OncoPanel) from 5769 NSCLC samples (5075 patients) were queried for cases having high-level ERBB2 amplification (≥6 copies). Clinical and demographic characteristics were extracted from the electronic medical records. Efficacy of the pan-ERBB inhibitor afatinib or HER2 ADCs (trastuzumab deruxtecan and trastuzumab emtansine) was evaluated in NSCLC preclinical models and patients with ERBB2 amplification. ResultsHigh-level ERBB2 amplification was identified in 0.9% of lung adenocarcinomas and reliably predicted overexpression of HER2. ERBB2 amplification events are detected in two distinct clinicopathologic and genomic subsets of NSCLC: as the sole mitogenic driver in tumors arising in patients with a smoking history or as a concomitant alteration with other mitogenic drivers in patients with a light or never smoking history. We further reveal that trastuzumab deruxtecan is effective therapy in in vitro and in vivo preclinical models of NSCLC harboring ERBB2 amplification and report two cases of clinical activity of an anti-HER2 ADC in patients who acquired ERBB2 amplification after previous targeted therapy. ConclusionsHigh-level ERBB2 amplification reliably predicts HER2 overexpression in patients with NSCLC, and HER2 ADC is effective therapy in this population.

HER2 amplification in cases with low HER2 expression by immunohistochemistry (IHC): A Single Institutional Experience

Abstract Introduction/Objective HER2 testing in invasive breast carcinoma (IBC) is the standard of care to determine patient eligibility for HER2 directed therapy with trasuzumab. Initial testing of tissue by HER2 immunohistochemistry (IHC) can be positive, negative, or equivocal. In equivocal cases as well as negative cases in our institution HER2 FISH is also performed. According to ASCO/CAP guidelines a subset of equivocal and negative IHC cases are considered HER2 positive if they meet criteria for increased HER2/CEP17 ratio and HER2 copy number by FISH, allowing more patients to be treated with HER2 directed therapies. HER2 grouping per ASCO is as follows; Group 1: HER2 copy number ≥4 signals/cell, Group 2: &amp;lt;4.0 signals/cell, Group 3: ≥6 signals/cell, Group 4: HER2 copy number ≥4 and &amp;lt;6 signals/cell, Group 5: HER2 copy number &amp;lt;4 signals/cell Methods/Case Report All cases of IBC resection with HER2 IHC and FISH results from Jan 2018-Dec 2021 were included in this study. All cases positive for HER2 by IHC alone (3+ staining) were excluded. The ASCO/CAP 2018 guidelines for HER2 testing in breast cancer were used to evaluate HER2 positivity by FISH and the relation to IHC scores Results (if a Case Study enter NA) A total of 2630 IBC cases with both HER2 IHC and FISH testing were included. Of these, 131 (5.0%) were in FISH group 1, 17 (0.7%) in group 2, 11 (0.4%) in group 3, 161 (6.1%) in group 4, and 2310 (87.8%) in group 5. A total of 142 (5.4%) cases that were HER2 equivocal or negative by IHC were HER2 positive by FISH. Specifically, 0.3% of cases with an IHC score of 0, 1.4% with a score of 1+, and 14.6% of cases with a score of 2+ were positive by FISH. Of the 14.6% IHC 2+ cases that were FISH positive 13.3% were in FISH group 1 (115 cases) and 1.3% (11 cases) in FISH group 3. Of FISH positive cases 1.4% had an IHC score of 0, 9.9% had an IHC score of 1 and 88.7% had a score of 2 Conclusion At our institution 14.6% of IBC with equivocal HER2 staining on IHC, 1.4% of cases with negative (1+) staining and 0.3% of cases with negative (0) were HER2 FISH positive. Since HER2 FISH is not reflexively performed on cases HER2 negative by IHC, this additional 1.7% will qualify for HER2 targeted therapy Interpretation of low HER2 expression by IHC by traditional IHC assay may miss a small percentage of cases eligible for HER2 directed therapy. Accurate interpretation of HER2 low by IHC is critical as recent clinical trials have shown that low HER2 expression with IHC scores of 1+ or 2+ without gene amplification by FISH could benefit from Trastuzumab Deruxtecan

Decreased HER2 expression in endometrial cancer following anti-HER2 therapy.

Trastuzumab has demonstrated clinical efficacy in the treatment of HER2-positive serous endometrial cancer (EC), which led to its incorporation into standard-of-care management of this aggressive disease. Acquired resistance remains an important challenge, however, and its underlying mechanisms in EC are unknown. To define the molecular changes that occur in response to anti-HER2 therapy in EC, targeted next-generation sequencing (NGS), HER2 immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) were performed on pre- and post-treatment tumour samples from 14 patients with EC treated with trastuzumab or trastuzumab emtansine. Recurrent tumours after anti-HER2 therapy acquired additional genetic alterations compared with matched pre-treatment ECs and frequently showed decreased HER2 protein expression by IHC (7/14, 50%). Complete/near-complete absence of HER2 protein expression (score 0/1+) observed post-treatment (4/14, 29%) was associated with retained HER2 gene amplification (n = 3) or copy number neutral status (n = 1). Whole-exome sequencing performed on primary and recurrent tumours from the latter case, which exhibited genetic heterogeneity of HER2 amplification in the primary tumour, revealed selection of an early HER2-non-amplified clone following therapy. Our findings demonstrate that loss of target expression, by selection of HER2-non-amplified clones or, more commonly, by downregulation of expression, may constitute a mechanism of resistance to anti-HER2 therapy in HER2-positive EC. © 2023 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Immunoexpression of HER2 pathway related markers in HER2 invasive breast carcinomas treated with trastuzumab

PurposeWe evaluated the immunoexpression of potential markers involved in the HER2 pathway in invasive breast carcinoma with HER2 amplification treated with trastuzumab. MethodsSamples of ninety patients diagnosed and treated at two public Brazilian hospitals with overexpressed invasive carcinoma between 2009 and 2018 were included. Several markers (Bcl-2, CDK4, cyclin D1, EGFR, IGF1, IGF-1R, MDM2, MUC4, p16, p21, p27, p53, PTEN, RA, TNFα, and VEGF) were immune analyzed in the tumor by immunohistochemistry and then correlated with clinicopathological variables. ResultsTumor sample expression results determined potential markers of good prognosis with statistically significant values: cyclin D1 with a nuclear grade, and recurrence; IGF-1 with tumor size, and death; p16 with a response after treatment; PTEN with a response after treatment, and death. Markers of poor prognosis: p53 with histological, and nuclear grade; IGF-1R with a compromised lymph node. The treatment resistance rate after trastuzumab was 40%; the overall survival was 4.13 years (95% CI 5.1–12.5) and the disease-free survival was 3.6 years (95% CI 5.1–13.1). ConclusionsThe tumor samples profile demonstrated that cyclin D1, IGF-1, p16, and PTEN presented the potential for a good prognosis and p53 and IGF-1R for worse.