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Background: Non-small cell lung cancer (NSCLC) with human epidermal growth factor receptor 2 (HER2) alterations poses a substantial treatment challenge. Current HER2 -targeted therapies offer limited efficacy. Antibody-drug conjugates (ADCs) targeting HER2 have emerged as a promising therapeutic strategy. This study aimed to evaluate the clinical response to a novel ADC drug Disitamab vedotin (RC48) in advanced NSCLC with HER2 alterations. Methods: This study conducted a retrospective review of patients harboring HER2 alterations treated with RC48 in the real world. Clinical outcomes were evaluated in terms of objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS). Results: Out of 22 patients, 21 (95.5%) received RC48 combination therapy, while one received RC48 monotherapy. The ORR of all patients reached 45.5%, and the DCR stood at 90.9%. The median PFS (mPFS) was 7.5 months. Among patients receiving RC48 combination therapy, the ORR was 47.7%, and the mPFS of 8.1 months. The combination of RC48 with platinum+/- bevacizumab resulted in the highest ORR of 71.4% (5 out of 7 patients), with HER2 TKI following at a 50.0% ORR (4 out of 8 patients). First-line (1L) treatment with RC48 showed an ORR of 62.5% (5 out of 8 patients), second-line (2L) treatments had a 57.1% ORR (4 out of 7 patients), and beyond second-line (>2L) treatments exhibited a 14.3% ORR (1 out of 7 patients). Patients with 1L, 2L, or >2L treatment had a mPFS of 8.1 months, 7.2 months, and 7.4 months, respectively. Patients with HER2 mutations or amplifications, and those with concurrent mutations and amplifications at baseline, showed mPFS of 8.1 months, 9.4 months, and 7.4 months, respectively. The mPFS was significantly longer in patients with HER2 amplification. The most common adverse events included hand-foot syndrome (54.5%), asthenia (50.0%), decreased white blood cell count (45.5%), and liver impairment (45.5%). Grade 3 adverse events occurred in one (4.5%) patient. Conclusion: RC48, particularly in combination regimens, demonstrates promising efficacy in advanced NSCLC with HER2 alterations. These findings underscore the need for further research to validate RC48's application in clinical practice. [ABSTRACT FROM AUTHOR]

Simple Summary: Over the past years, the introduction of various anti-HER2 therapies has significantly improved the outcome for patients with HER2-positive breast and gastroesophageal carcinomas. HER2 protein overexpression is investigated using immunohistochemistry, gene amplification using fluorescence in situ hybridization, and gene mutation using next-generation sequencing. This review evaluated the predictive and prognostic role of HER2 status in various types of epithelial malignant cancers beyond breast and gastroesophageal cancers, focusing on the published studies, the scoring systems, and assays used and analyzing the clinical parameters and therapeutic approaches used. The evidence about prognostic and predictive roles of HER2 in carcinomas other than breast and gastroesophageal remains investigational but is increasing due to a tumor site-related prognostic and predictive value of the different types of HER2 alterations. The major limitation was that standardized and validated scoring system assays are not well-established for many organs. The oncogene ERBB2, also known as HER2 or c-ERB2, is located on chromosome 17 (q12). It encodes a tyrosine kinase receptor, the human epidermal growth factor receptor 2 (HER2), involved in neoplastic proliferation, tumor angiogenesis, and invasiveness. Over the past years, the introduction of various anti-HER2 therapies has significantly improved outcomes for patients with HER2-positive breast and gastroesophageal carcinomas. More recently, the introduction of a new antibody–drug conjugate, that is trastuzumab deruxtecan, expanded the therapeutic options to low-HER2 breast and gastroesophageal tumors. HER2 protein overexpression is investigated using immunohistochemistry, gene amplification using fluorescence in situ hybridization, and gene mutation using next-generation sequencing. This review evaluated the predictive and prognostic role of HER2 status in various types of epithelial malignant cancers beyond breast and gastroesophageal cancers. We critically analyzed the key published studies, focusing on utilized scoring systems and assays used, and analyzed clinical parameters and therapeutic approaches. Although the evidence about prognostic and predictive roles of HER2 in carcinomas other than breast and gastroesophageal has been widely increasing over the last decade, it still remains investigational, revealing a tumor site-related prognostic and predictive value of the different types of HER2 alterations. However, standardized and validated scoring system assays have not been well-established for many organs. [ABSTRACT FROM AUTHOR]

BackgroundNon-small cell lung cancer (NSCLC) with human epidermal growth factor receptor 2 (HER2) alterations poses a substantial treatment challenge. Current HER2-targeted therapies offer limited efficacy. Antibody-drug conjugates (ADCs) targeting HER2 have emerged as a promising therapeutic strategy. This study aimed to evaluate the clinical response to a novel ADC drug Disitamab vedotin (RC48) in advanced NSCLC with HER2 alterations.MethodsThis study conducted a retrospective review of patients harboring HER2 alterations treated with RC48 in the real world. Clinical outcomes were evaluated in terms of objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS).ResultsOut of 22 patients, 21 (95.5%) received RC48 combination therapy, while one received RC48 monotherapy. The ORR of all patients reached 45.5%, and the DCR stood at 90.9%. The median PFS (mPFS) was 7.5 months. Among patients receiving RC48 combination therapy, the ORR was 47.7%, and the mPFS of 8.1 months. The combination of RC48 with platinum+/- bevacizumab resulted in the highest ORR of 71.4% (5 out of 7 patients), with HER2 TKI following at a 50.0% ORR (4 out of 8 patients). First-line (1L) treatment with RC48 showed an ORR of 62.5% (5 out of 8 patients), second-line (2L) treatments had a 57.1% ORR (4 out of 7 patients), and beyond second-line (>2L) treatments exhibited a 14.3% ORR (1 out of 7 patients). Patients with 1L, 2L, or >2L treatment had a mPFS of 8.1 months, 7.2 months, and 7.4 months, respectively. Patients with HER2 mutations or amplifications, and those with concurrent mutations and amplifications at baseline, showed mPFS of 8.1 months, 9.4 months, and 7.4 months, respectively. The mPFS was significantly longer in patients with HER2 amplification. The most common adverse events included hand-foot syndrome (54.5%), asthenia (50.0%), decreased white blood cell count (45.5%), and liver impairment (45.5%). Grade 3 adverse events occurred in one (4.5%) patient.ConclusionRC48, particularly in combination regimens, demonstrates promising efficacy in advanced NSCLC with HER2 alterations. These findings underscore the need for further research to validate RC48’s application in clinical practice.

Simple Summary: In this study, scientists investigated how pathologists test for a protein called HER2 in a type of cancer called endometrial cancer (EC). They checked samples from 180 patients tested over the first two years following approval of the test in the clinic. They found that 28% of the samples had HER2 overexpression, which makes them eligible for HER2-targeted therapies. They also noticed that in some cases, the test results were different depending on the method used. This study shows that there are challenges in testing for HER2 in endometrial cancer and suggests that we need standardized guidelines to help doctors make better decisions about endometrial cancer treatment. HER2-targeted therapies have transformed the management of advanced or recurrent serous endometrial cancer (EC), leading to an increased clinical demand for HER2 testing. Despite its adoption in select academic centers, the global extent of such tumor testing is unclear. In this study, we report on the initial two-year experience of HER2 testing at a major academic center with a reference gynecologic oncology service and biomarker reference laboratory. All patients who underwent HER2 testing based on physician discretion, reflex HER2 testing, and reference laboratory requests were included. From February 2021 to October 2023, HER2 testing was performed on 192 tumor tissue samples from 180 EC patients. Serous carcinoma constituted 52% of samples, reflecting diagnostic challenges and limited therapeutic options for advanced EC. HER2 positivity was found in 28% of all cases and 30% of p53-aberrant cases. An immunohistochemistry (IHC) score of 3+ was found in 15% of samples, while IHC 2+ was found in 45% (13% IHC 2+/ISH+ and 32% IHC 2+/ISH−). The newly identified 'HER2-low' category comprised 46% of the samples. Heterogeneity was noted in 42% of HER2-positive cases, with complex patterns in 3%. NGS and HER2 IHC-FISH showed a 24% discordance, attributed to intratumoral heterogeneity, tumor cellularity, a small number of amplified cells, and the HER2/CEP17 ratio near the cut-off. This study offers real-world insights into HER2 testing in EC, highlighting the challenges and underscoring the need for standardized guidelines in specimen handling, proficiency testing, and scoring criteria to enhance patient management and therapeutic decision-making. [ABSTRACT FROM AUTHOR]

BackgroudHuman epithelial growth factor receptor 2 (HER2) amplification is an important mechanism of acquired resistance to anti-epidermal growth factor receptor (EGFR) therapy in non-small cell lung cancer (NSCLC) patients. For patients with both EGFR mutation and HER2 amplification, there is currently no unified standard treatment, and further exploration is needed on how to choose the therapy.Methods and resultsA female NSCLC patient developed bone and brain metastases 14 and 42 months after radical surgery, respectively. The second genetic sequencing detected EGFR L858R mutation and HER2 amplification, and therefore initiated treatment with almonertinib and pyrotinib. The patient achieved partial remission and did not show any further progression during the follow-up period.ConclusionFor NSCLC patients with both EGFR mutation and HER2 amplification, the combination of almonertinib and pyrotinib is a valuable therapy that can continuously reduce tumor burden and achieve long-term survival.

Hongyi Zhou,1,* Xueping Cui,2,* Leilei Zhu,1 Zhuoqun Xu,1 Zhuo Wang,3 Jianfeng Shao4 1Department of Urology, The Affiliated Wuxi People’s Hospital of Nanjing Medical University, Wuxi, Jiangsu Province, 214023, People’s Republic of China; 2Department of Pharmacy, The Sixth Affiliated Hospital of Wenzhou Medical University, The People’s Hospital of Lishui, Lishui, Zhejiang Province, 323000, People’s Republic of China; 3Department of Geriatrics, The Affiliated Wuxi People’s Hospital of Nanjing Medical University, Wuxi, Jiangsu Province, 214023, People’s Republic of China; 4Department of Urology, Wuxi No. 2 People’s Hospital (Jiangnan University Medical Center), Wuxi, Jiangsu Province, 214023, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jianfeng Shao; Zhuo Wang, Email jianfenguro@163.com; wangzhuoausten@163.comBackground: 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.Methods: 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 performed to 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.Results: 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.Conclusion: circPVT1 is a tumor suppressor and novel prognostic biomarker for BLCA.Keywords: circPVT1, bladder cancer, biomarker, proliferation, HER2 amplification, BLCA

Introduction: Lacrimal sac squamous cell carcinoma (SCC) is a rare tumor. Only 241 cases of lacrimal sac SCC have been reported in the literature. However, the detailed molecular profile of this tumor is unknown. Case Presentation: Fifty-seven-year-old Caucasian male presented with a 6-month history of epiphora. Multimodal examination revealed a unilateral lacrimal sac SCC T4aN0M0. The patient underwent primary surgery with subsequent chemoradiotherapy. The patient was alive 18 months after the end of the treatment, with no signs of local or distant relapse. Complex molecular profiling revealed the FGFR p.G388R variant, HER2 amplification, and progression phenotype. Conclusion: Here, we describe a clinical case of a male patient with lacrimal sac SCC with a careful description of the disease history, treatment, and molecular-genetic patterns of the tumor. This is the first report of HER2-positive lacrimal sac SCC.

Purpose: Despite accumulating data regarding the genomic landscape of pancreatic ductal adenocarcinoma (PDAC), olaparib is the only biomarker-driven FDA-approved targeted therapy with a PDAC-specific approval. Treating ERBB2(HER2)-amplified PDAC with anti-HER2 therapy has been reported with mixed results. Most pancreatic adenocarcinomas have KRAS alterations, which have been shown to be a marker of resistance to HER2-targeted therapies in other malignancies, though the impact of these alterations in pancreatic cancer is unknown. We describe two cases of ERBB2-amplified pancreatic cancer patients treated with anti-HER2 therapy and provide data on the frequency of ERBB2 amplifications and KRAS alterations identified by clinical circulating cellfree DNA testing. Methods: De-identified molecular test results for all patients with pancreatic cancer who received clinical cell-free circulating DNA analysis (Guardant360) between 06/2014 and 01/2018 were analyzed. Cell-free circulating DNA analysis included next-generation sequencing of up to 73 genes, including select small insertion/deletions, copy number amplifications, and fusions. Results: Of 1,791 patients with pancreatic adenocarcinoma, 36 (2.0%) had an ERBB2 amplification, 26 (72.2%) of whom had a KRAS alteration. Treatment data were available for seven patients. Two were treated with anti-HER2 therapy after their cell-free circulating DNA result, with both benefiting from therapy, including one with a durable response to trastuzumab and no KRAS alteration detected until progression. Conclusion: Our case series illustrates that certain patients with ERBB2-amplified pancreatic adenocarcinoma may respond to anti-HER2 therapy and gain several months of prolonged survival. Our data suggests KRAS mutations as a possible mechanism of primary and acquired resistance to anti-HER2 therapy in pancreatic cancer. Additional studies are needed to clarify the role of KRAS in resistance to anti-HER2 therapy. [ABSTRACT FROM AUTHOR]

Introduction: Lacrimal sac squamous cell carcinoma (SCC) is a rare tumor. Only 241 cases of lacrimal sac SCC have been reported in the literature. However, the detailed molecular profile of this tumor is unknown. Case Presentation: Fifty-seven-year-old Caucasian male presented with a 6-month history of epiphora. Multimodal examination revealed a unilateral lacrimal sac SCC T4aN0M0. The patient underwent primary surgery with subsequent chemoradiotherapy. The patient was alive 18 months after the end of the treatment, with no signs of local or distant relapse. Complex molecular profiling revealed the FGFR p.G388R variant, HER2 amplification, and progression phenotype. Conclusion: Here, we describe a clinical case of a male patient with lacrimal sac SCC with a careful description of the disease history, treatment, and molecular-genetic patterns of the tumor. This is the first report of HER2-positive lacrimal sac SCC. [ABSTRACT FROM AUTHOR]

Abstract Background 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. Patients and Methods 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. Results 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. Conclusion 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.

PurposeDespite accumulating data regarding the genomic landscape of pancreatic ductal adenocarcinoma (PDAC), olaparib is the only biomarker-driven FDA-approved targeted therapy with a PDAC-specific approval. Treating ERBB2(HER2)-amplified PDAC with anti-HER2 therapy has been reported with mixed results. Most pancreatic adenocarcinomas have KRAS alterations, which have been shown to be a marker of resistance to HER2-targeted therapies in other malignancies, though the impact of these alterations in pancreatic cancer is unknown. We describe two cases of ERBB2-amplified pancreatic cancer patients treated with anti-HER2 therapy and provide data on the frequency of ERBB2 amplifications and KRAS alterations identified by clinical circulating cell-free DNA testing.MethodsDe-identified molecular test results for all patients with pancreatic cancer who received clinical cell-free circulating DNA analysis (Guardant360) between 06/2014 and 01/2018 were analyzed. Cell-free circulating DNA analysis included next-generation sequencing of up to 73 genes, including select small insertion/deletions, copy number amplifications, and fusions.ResultsOf 1,791 patients with pancreatic adenocarcinoma, 36 (2.0%) had an ERBB2 amplification, 26 (72.2%) of whom had a KRAS alteration. Treatment data were available for seven patients. Two were treated with anti-HER2 therapy after their cell-free circulating DNA result, with both benefiting from therapy, including one with a durable response to trastuzumab and no KRAS alteration detected until progression.ConclusionOur case series illustrates that certain patients with ERBB2-amplified pancreatic adenocarcinoma may respond to anti-HER2 therapy and gain several months of prolonged survival. Our data suggests KRAS mutations as a possible mechanism of primary and acquired resistance to anti-HER2 therapy in pancreatic cancer. Additional studies are needed to clarify the role of KRAS in resistance to anti-HER2 therapy.

Background: 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. Patients and Methods: 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. Results: 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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

Purpose: Our study intended to explore the correlation between HER2 alterations and 18F-FDG PET/CT metabolic parameters and their prognostic value in EGFR-negative non-small-cell lung cancer (NSCLC) patients detected by next-generation sequencing (NGS). Methods: NGS assay was performed in 1737 NSCLC patients, a total of 88 HER2 alterations and 176 negative HER2 with EGFR-negative patients were randomly selected for this study. Results: When the HER2 status with EGFR-negative group was analyzed, multivariate analysis showed that smoking status, primary tumor SUVmax (pSUVmax) < 13.03 and stage were the independent deterministic factors of HER2 alterations. Multivariate cox regression analysis revealed that HER2 status, age, smoking status and stage were independent risk factors for overall survival (OS) in EGFR-negative NSCLC patients with different HER2 status. When the HER2 alterations group was separately analyzed, multivariate analysis demonstrated that low pSUVmax < 15.32 and histology were the independent deterministic factors of HER2 mutation. Multivariate cox regression analysis revealed that pSUVmax, smoking status, nodal involvement and treatment methods were independent risk factors for OS in EGFR-negative NSCLC patients with HER2 alterations. Conclusion: The study revealed that low pSUVmax was associated with HER2 alterations in EGFR-negative NSCLC patients, moreover HER2 mutation and HER2 amplification exhibited distinct 18F-FDG metabolic and clinical characteristics. Furthermore, it explored the prognostic value of HER2 alterations and 18F-FDG PET/CT metabolic parameters of pSUVmax in EGFR-negative NSCLC patients. [ABSTRACT FROM AUTHOR]

Human epidermal growth factor receptor 2 (HER2)-low is a newly defined category with HER2 1+ or 2+ expression by immunohistochemistry (IHC) and lack of HER2 gene amplification measured by in situ hybridization (ISH). Much remains unknown about the HER2-low status across tumor types and changes in HER2 status between primary and metastatic samples. HER2 expression by IHC was evaluated in 4701 patients with solid tumors. We have evaluated the HER2 expression by IHC and amplification by ISH in paired breast and gastric/gastroesophageal (GEJ) primary and metastatic samples. HER2 expression was correlated with ERBB2 genomic alterations evaluated by next-generation sequencing (NGS) in non-breast, non-gastric/GEJ samples. HER2 expression (HER2 IHC 1-3+) was found in half (49.8%) of the cancers, with HER2-low (1 or 2+) found in many tumor types: 47.1% in breast, 34.6% in gastric/GEJ, 50.0% in salivary gland, 46.9% in lung, 46.5% in endometrial, 46% in urothelial, and 45.5% of gallbladder cancers. The concordance evaluation of HER2 expression between primary and metastatic breast cancer samples showed that HER2 3+ remained unchanged in 87.1% with a strong agreement between primary and metastatic samples, with a weighted kappa (Κ) of 0.85 (95% confidence interval 0.79-0.91). ERBB2 alterations were identified in 117 (7.5%) patients with non-breast, non-gastric/GEJ solid tumors who had NGS testing. Of 1436 patients without ERBB2 alterations, 512 (35.7%) showed any level HER2 expression by IHC. Our results show that HER2-low expression is frequently found across tumor types. These findings suggest that many patients with HER2-low solid tumors might benefit from HER2-targeted therapies. • HER2-low expression (1-2+ by IHC) was common across many solid tumors (41.1%). • A significant number of patients without ERBB2 alterations (35.7%) had HER2 expression (≥1+). • Changes between the primary and metastatic breast and gastric samples highlight the importance of HER2 re-testing. • HER2 protein expression by IHC complements genomics to identify actionable therapeutic targets. [ABSTRACT FROM AUTHOR]

Despite the high activity of selective RET inhibitors in RET-driven NSCLC, resistance eventually develops and there is unmet need to better define therapeutic options for patients. This is a case of a patient initially thought to have no targetable alterations, then found to have a RET fusion, and subsequently HER2 amplification on three distinct biopsies. She was treated initially with chemotherapy and immune therapy, then switched to selpercatinib, and eventually had fam-trastuzumab deruxtecan added to selpercatinib. She also developed neuroendocrine differentiation at time of progression in the context of a p53 mutation, which is a known factor that can lead to small cell transformation. This patient’s case highlights the need for comprehensive molecular testing at both diagnosis and progression, as unexpected resistance mechanisms may be identified particularly for patients with uncommon driver mutations.

Atypical ductal hyperplasia and low-grade ductal carcinoma in situ (DCIS) are regarded as precursor lesions of estrogen receptor (ER)-positive invasive breast cancer. In HER2 -amplified invasive breast cancer, a precursor lesion before DCIS has not yet been described. Here we introduce a case of HER2-positive lobules in the breast without histological abnormality. A 39-year-old premenopausal woman visited a hospital due to identification of microcalcifications on screening mammography. The subsequent biopsy confirmed high-grade DCIS. She underwent wide excision, and a residual high-grade DCIS with a size of 1.4 cm was found. The tumor cells were hormone receptor positive and HER2 negative on immunohistochemical (IHC) staining. Around DCIS, there were terminal duct lobular units (TDLUs) showing strong HER2 positivity on IHC. These HER2-positive lobules were 7 mm away from the high-grade DCIS and was 1.1 mm in size. These HER2-positive lobules showed no histologic abnormality and had no difference compared with the surrounding normal TDLUs. Nevertheless, in addition to showing HER2 overexpression in IHC, HER2 amplification was also identified in HER2 silver in situ hybridization. HER2 amplification plays an important role in breast cancer development, and HER2 amplification is known to occur as an early event in cancer development. There have been studies identifying driver mutations in normal tissues of other organs. These findings suggest that HER2 amplification in the breast without histological abnormality could occur, and the HER2-positive lobules could be "at risk" for transformation into the precursor lesion of HER2-positive breast cancer, although the biological significance of these findings is unclear. [ABSTRACT FROM AUTHOR]

Abstract Background Human epidermal growth factor receptor 2 (HER2) positive breast carcinomas due to HER2 amplification are associated with aggressive behavior and a poor prognosis. Anti-HER2-targeted therapies are widely used to treat HER2-positive breast carcinomas with excellent outcomes. Accurate identification of HER2 amplification status in breast carcinomas is of important diagnostic and treatment value. Currently, HER2 amplification status is routinely determined by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH) testing. This study will review our past HER2 data to determine and characterize discordant results between HER2 IHC and FISH. It will also determine a potential impact of HER2 amplification status by next-generation sequencing (NGS) on these patients. Methods We reviewed a total of 4884 breast carcinomas with coexisting HER2 IHC and HER2 FISH performed at our institution from 2010 to 2022. 57 cases also had a Next-Generation-Sequencing-based (NGS) gene panel performed. Given the advances in biostatic analysis pipelines, NGS methods were utilized to provide results on HER2 amplification status along with somatic mutations. Results While the majority (ranging from 98.5% with IHC score of 0 and 93.1% with IHC score of 1 +) of 4884 breast carcinomas had concordant results from HER2 IHC and HER2 FISH testing, a small percentage of patients (ranging from 1.5% in those with IHC score of 0, to 6.9% with IHC score of 1 +) had discordant results, with negative HER2 IHC and positive HER2 FISH results. These patients could be reported as HER2-negative breast carcinomas if only HER2 IHC testing has been performed according to a current cost-effective HER2 test strategy. 57 patients had HER2 amplification status determined by NGS, and all patients had concordant results between HER2 NGS and FISH tests. A HER2-amplified breast carcinoma by NGS had a negative IHC and a positive HER2 FISH result. This case was classified as a HER2-positive breast carcinoma, had anti-HER2-targeted therapy, and achieved a complete clinical response. Conclusions A small percentage of HER2-positive breast carcinomas are unidentified because of a negative HER2 IHC based on our current cost-effective HER2 test strategy. It is not feasible and affordable in routine clinical practice to perform HER2 FISH for the cases with negative HER2 IHC (IHC score 0 and 1 +). Therefore, NGS assays capable of simultaneously detecting both somatic mutations and HER2 amplification could provide a more comprehensive genetic profiling for breast carcinomas in a clinical setting. Identification of HER2 amplification by NGS in HER2-positive breast carcinomas with negative HER2 IHC results is important since these cases are concealed by our current cost-effective HER2 test strategy with IHC first (for all cases) and FISH reflex (only for cases with IHC score of 2 +), and would offer the opportunity for potentially beneficial anti-HER2-targeted therapies for these patients.

Despite the great progress made in the understanding of the biological behavior of certain types of invasive breast cancer, there is still no single histological or molecular classification that encompasses such diversity and accurately predicts the clinical course of distinct breast cancer subtypes. The long-lasting classification of breast cancer as HER2-positive vs. HER2-negative has recently come into question with the discovery of new antibody drug conjugates (ADC), which are proven to be remarkably efficient in treating HER2-low breast cancer. The HER2-low paradigm has challenged the traditional understanding of HER2 overexpression and emphasized the need for more robust HER2 testing in order to encompass HER2 intratumoral heterogeneity and spatial distribution more accurately. It is yet to be seen if low HER2 will remain merely a marker of HER2-equipped tumors targetable with ADCs or if distinctive molecular and phenotypic groups within HER2-low tumors will eventually be discerned. [ABSTRACT FROM AUTHOR]

Purpose: Human epidermal growth factor 2 (HER2) alterations are found in approximately 2%–5% of non-small cell lung cancer (NSCLC). This study aimed to evaluate the clinical characteristics of patients with NSCLC having HER2 alterations in China and the differences compared with Western counterparts and also perform a prognostic analysis. Material and Methods: A total of 1300 patients diagnosed with NSCLC from January 2017 to December 2020 were included. Their clinical characteristics were retrospectively recorded. The gene expression profiles and clinical information of 20 patients having altered HER2 were downloaded from the Cancer Genome Atlas database and compared, and the prognostic factors affecting the Chinese population were analyzed. If tissues were sufficient, the overexpression was assessed by immunohistochemical staining. Results: Among 39 (3.0%) patients with HER2 alterations, 31 patients (79.5%) had HER2 mutations. HER2 insertion mutation in exon 20 was the most common type (A775_G776 ins YVMA). Seven patients (17.9%) had amplification, and one had both. The HER2 kinase domain was most commonly mutated. A majority of patients in the study were young-aged with no smoking history; 66.7% had stage III/IV adenocarcinoma. Compared with Chinese patients, HER2 alterations in Western counterparts were mostly associated with old age, previous smoking, and stages I and II at diagnosis. The most common type of HER2 alteration was HER2 amplification; one patient had coexistence of HER2 gene amplification and fusion. The furin-like cysteine-rich region was most commonly mutated. The median overall survival (OS) of the Chinese patients was 41 months. The univariate analysis showed that age > 60 years, no surgical treatment, no liver or renal cysts on imaging, and maximum tumor diameter ≥ 4.25 cm were significantly associated with poor OS. The multivariate analysis showed that age, presence of surgery, and no hepatic or renal cysts were independent prognostic factors for OS. Chemotherapy achieved better outcomes, and HER2 mutations were not associated with HER2 amplification and overexpression. Conclusions: This study was novel in comprehensively investigating the clinical and molecular characteristics of patients in Chinese and Western populations, and in analyzing the factors affecting the prognosis of Chinese patients. It provided critical data for future therapies against HER2-altered NSCLC. [ABSTRACT FROM AUTHOR]

Abstract Background Although targeted agents have been gradually applied in the treatment of HER2-mutated non-small cell lung cancer (NSCLC) in recent years, patients’ therapeutic demands are far from being met. PATHER2 was the first phase 2 trial to explore the efficacy and safety of the HER2-targeted tyrosine kinase inhibitor (TKI) pyrotinib plus the antiangiogenic agent apatinib in previously treated HER2-altered metastatic NSCLC patients. Methods HER2-mutated or HER2-amplified metastatic NSCLC patients who had failed at least first-line chemotherapy or HER2-targeted TKIs received oral pyrotinib 400 mg plus apatinib 250 mg once daily until disease progression, intolerable toxicity, or death. The primary endpoint was the investigator-assessed objective response rate (ORR). Results Between March 2019 and December 2020, 33 patients were enrolled; 13 (39.4%) presented brain metastases, and 16 (48.5%) had received at least two lines of prior chemotherapy or HER2-targeted TKIs. As of September 20, 2021, the median follow-up duration was 11.3 (range, 3.5–26.0) months. The investigator-assessed ORR was 51.5% (17/33; 95% CI, 33.5 to 69.2%), and the disease control rate was 93.9% (31/33; 95% CI, 79.8 to 99.3%). The median duration of response, progression-free survival, and overall survival were 6.0 (95% CI, 4.4 to 8.6) months, 6.9 (95% CI, 5.8 to 8.5) months, and 14.8 (95% CI, 10.4 to 23.8) months, respectively. The most frequent grade ≥ 3 treatment-related adverse events included diarrhea (3.0%) and hypertension (9.1%). No treatment-related deaths were reported. Conclusions Pyrotinib plus apatinib demonstrated promising antitumor activity and a manageable safety profile in HER2-mutated or HER2-amplified metastatic NSCLC patients. Trial registration Chinese Clinical Trial Registry Identifier: ChiCTR1900021684 .

The association between human epidermal growth factor receptor-2 (HER2) amplification and brain metastasis (BM) in patients having colorectal cancer (CRC) has been suggested but not yet established. This study investigated the expression patterns of HER2, its association with BM, and its prognostic value in patients having CRC. We retrospectively identified 99 patients having metastatic CRC (mCRC) and BM (the BM cohort) and compared them with a cohort of 249 patients having mCRC and without BM (the stage IV cohort) by propensity score matching. Immunohistochemical studies of HER2 on all available paraffin-embedded tumour samples, either from the primary tumour, the metastasis (brain and/or extracranial sites) or both, were performed and analysed. HER2 fluorescent in situ hybridisation was applied when necessary. The expression of HER2 was compared and correlated with survival. HER2 amplifications were detected in 16 (18.4%) of 87 and 9 (3.6%) of 249 patients who had specimens available in the BM and stage IV cohorts, respectively (P <.001). After propensity score matching, HER2 amplification was significantly associated with BM (odds ratio: 5.38, P =.003). HER2 heterogeneity was frequently observed not only at the single tumour level but also in paired tumour samples. A marginally significant longer survival since BM was found in patients having HER2-amplified mCRC than in those without (P =.07). HER2 amplification was significantly associated with BM in patients having mCRC and might have prognostic value for survival since BM. Given the heterogeneity of HER2 expression, the testing of HER2 status on available tissues from both primary and metastatic tumours should be encouraged. • Propensity score matching examined HER2 amplification and brain metastases. • High frequency of HER2 amplification in patients having metastatic colorectal cancer and brain metastasis was demonstrated. • Intra-patient heterogeneities of HER2 amplification were observed. [ABSTRACT FROM AUTHOR]

Anti-HER2 therapies have dramatically improved the prognosis of human epidermal growth factor receptor 2 (HER2)-overexpressing cancers. However, the correlation between the HER2 copy number and the response rate to anti-HER2 remains unclear. Here, following the PRISMA method, we performed a meta-analysis in the neoadjuvant setting in breast cancer to study the association between the HER2 amplification level and the pathological complete response (pCR) to anti-HER2 therapies. Nine articles (four clinical trials, five observational studies) were retrieved after full-text screening, involving 11,238 women with locally advanced breast cancer in the neoadjuvant setting. The median HER2/CEP17 ratio cut-off value was 5.0 ± 5.0 (min-max = 1.0–14.0). For the overall population, the median pCR rate was 48% using the random effect model. The studies were categorized in quartiles as follows: ≤2 (Class 1); 2.1 to 5.0 (Class 2); 5.1 to 7.0 (Class 3); and >7.0 (Class 4). After grouping, the pCR rates were 33%, 49%, 57%, and 79%, respectively. When we excluded the study by Greenwell et al., which accounted for 90% of the patients, using the same quartiles, we still observed an increasing rate of pCR as the HER2/CEP17 ratio increased. This is the first meta-analysis demonstrating the relationship between the HER2 amplification level and the percentage of pCR in the neoadjuvant setting among women with HER2-overexpressing breast cancer, with potential therapeutic applications. [ABSTRACT FROM AUTHOR]

Cholangiocarcinoma is a deadly cancer comprising very heterogenous subtypes with a limited therapeutic arsenal in all comers. However, recent significant advances were made with immunotherapy in the first-line treatment of advanced cholangiocarcinoma, with the addition of durvalumab to cisplatin–gemcitabine chemotherapy showing a survival benefit. In the second line setting, only FOLFOX (5FU/folinic acid-oxaliplatin) is validated by a phase 3 trial, yet with a very modest benefit on survival; new options using 5FU with nanoliposomal-irinotecan may emerge in the next few years. The advent of molecular profiling in advanced cholangiocarcinoma in the last decade revealed frequent targetable alterations such as IDH1 mutations, FGFR2 fusions or rearrangements, HER2 amplification, BRAF V600E mutation and others. This strategy opened the way to personalised medicine for patients which are still fit after first-line treatment and the use of targeted inhibitors in first line constitutes a huge challenge with many ongoing trials to improve patients' care. This review exposes the recent clinical trial findings in non-molecularly selected advanced cholangiocarcinoma, offers a focus on how systematic molecular screening should be structured to allow patients to access to personalised medicine, and details which are the therapeutic options accessible in case of actionable alteration. • CISGEM-durvalumab is a new standard in advanced cholangiocarcinoma in first line. • Actionable alterations are present in up to 40–50% of patients, especially in iCCA. • Molecular profiling should be proposed to every ECOG 0–1 patients from the diagnosis. • Molecular profiling should integrate DNA and RNA next-generation sequencing techniques. [ABSTRACT FROM AUTHOR]

Simple Summary: Human epidermal growth factor receptor 2 (HER2) amplification has emerged as a biomarker of metastatic colorectal cancer (mCRC). Prospective clinical trials have demonstrated the efficacy of HER2-targeted therapies for HER2-positive mCRC and explored the underlying mechanisms. To improve the therapeutic efficacy of this strategy, many clinical trials with various HER2-targeted agents are ongoing. This review discusses the molecular basis of HER2-targeted therapeutic strategies for patients with HER2-positive mCRC. Human epidermal growth factor receptor 2 (HER2) amplification has emerged as a biomarker in colorectal cancer (CRC), occurring in 1–4% of metastatic CRC (mCRC). In addition to conventional methods, such as immunohistochemistry and fluorescence in situ hybridization, next-generation sequencing-based tissue or circulating tumor DNA analysis has recently been used to identify HER2 amplification and assess HER2 overexpression. Prospective clinical trials have demonstrated the efficacy of HER2-targeted therapies in HER2-positive mCRC. The TRIUMPH study, a phase II study of dual HER2 antibodies, i.e., pertuzumab plus trastuzumab, demonstrated promising efficacy for patients with HER2-positive mCRC confirmed by tissue-and/or blood-based techniques, which led to the regulatory approval of this combination therapy in Japan. The mechanisms associated with efficacy and resistance have also been explored in translational studies that incorporate liquid biopsy in prospective trials. In particular, HER2 copy number and co-alterations have repeatedly been reported as biomarkers related to efficacy. To improve the therapeutic efficacy of the current strategy, many clinical trials with various HER2-targeted agents are ongoing. This review discusses the molecular basis of HER2-targeted therapeutic strategies for patients with HER2-positive mCRC. [ABSTRACT FROM AUTHOR]

Advanced or recurrent mucinous carcinoma of the ovary minimally responds to current cytotoxic treatments and has a poor prognosis. Despite multimodal treatment with chemotherapy and surgery, most patients ultimately progress and require palliative systemic therapy. Anti-HER2 therapy has been demonstrated to be an effective strategy for the treatment of HER2-positive breast cancer. However, the role of anti-HER2 therapy in ovarian cancer remains largely unknown. Here, we report the case of a young woman with FIGO Stage IIIc recurrent mucinous ovarian carcinoma (MOC) who developed trastuzumab resistance and disease progression following cross-treatment with trastuzumab combined with pertuzumab. HER2 amplification was discovered using next-generation sequencing (NGS). The patient then received bevacizumab, and pyrotinib (an irreversible HER2 antagonist) plus capecitabine treatment, and achieved a long-term clinical benefit for 22 months. Pyrotinib combined with bevacizumab is a potential treatment for MOC patients who are heavily pretreated and harbor a HER2 amplification. Our case may provide valuable treatment information for patients with advanced or recurrent MOC. [ABSTRACT FROM AUTHOR]

Background: Human epidermal growth factor receptor 2 (HER2) positive breast carcinomas due to HER2 amplification are associated with aggressive behavior and a poor prognosis. Anti-HER2-targeted therapies are widely used to treat HER2-positive breast carcinomas with excellent outcomes. Accurate identification of HER2 amplification status in breast carcinomas is of important diagnostic and treatment value. Currently, HER2 amplification status is routinely determined by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH) testing. This study will review our past HER2 data to determine and characterize discordant results between HER2 IHC and FISH. It will also determine a potential impact of HER2 amplification status by next-generation sequencing (NGS) on these patients. Methods: We reviewed a total of 4884 breast carcinomas with coexisting HER2 IHC and HER2 FISH performed at our institution from 2010 to 2022. 57 cases also had a Next-Generation-Sequencing-based (NGS) gene panel performed. Given the advances in biostatic analysis pipelines, NGS methods were utilized to provide results on HER2 amplification status along with somatic mutations. Results: While the majority (ranging from 98.5% with IHC score of 0 and 93.1% with IHC score of 1 +) of 4884 breast carcinomas had concordant results from HER2 IHC and HER2 FISH testing, a small percentage of patients (ranging from 1.5% in those with IHC score of 0, to 6.9% with IHC score of 1 +) had discordant results, with negative HER2 IHC and positive HER2 FISH results. These patients could be reported as HER2-negative breast carcinomas if only HER2 IHC testing has been performed according to a current cost-effective HER2 test strategy. 57 patients had HER2 amplification status determined by NGS, and all patients had concordant results between HER2 NGS and FISH tests. A HER2-amplified breast carcinoma by NGS had a negative IHC and a positive HER2 FISH result. This case was classified as a HER2-positive breast carcinoma, had anti-HER2-targeted therapy, and achieved a complete clinical response. Conclusions: A small percentage of HER2-positive breast carcinomas are unidentified because of a negative HER2 IHC based on our current cost-effective HER2 test strategy. It is not feasible and affordable in routine clinical practice to perform HER2 FISH for the cases with negative HER2 IHC (IHC score 0 and 1 +). Therefore, NGS assays capable of simultaneously detecting both somatic mutations and HER2 amplification could provide a more comprehensive genetic profiling for breast carcinomas in a clinical setting. Identification of HER2 amplification by NGS in HER2-positive breast carcinomas with negative HER2 IHC results is important since these cases are concealed by our current cost-effective HER2 test strategy with IHC first (for all cases) and FISH reflex (only for cases with IHC score of 2 +), and would offer the opportunity for potentially beneficial anti-HER2-targeted therapies for these patients. [ABSTRACT FROM AUTHOR]

Simple Summary: The addition of chromosome 17 polysomy/HER2 amplification status to the updated EAU and AUA scores improves their accuracy, allowing molecular reclassification of EAU high-risk NMIBCs and G2 tumors. Based on this, we propose to reclassify the non-HER2 amplified, non-polysomic EAU 3–4 (high- and very high-risk) cases to the EAU 2 (intermediate) risk group to prevent unnecessarily strict follow-up and treatment for these patients. Furthermore, to classify Chr17 polysomic and/or HER2 amplified G2 tumors as high-grade (HG) and non-HER2 amplified, non-polysomic G2 tumors as low-grade (LG) NMIBCs (G1 and G3 tumors remain graded as low- and high-grade, respectively). Thus, the implementation of Chr17 polysomy/HER2 amplification testing would provide an immediate and simple solution to further refine the prognostic risk assessment of NMIBCs in the uro-oncology practice. Progression of non-muscle-invasive bladder cancer (NMIBC) to muscle-invasive disease (MIBC) significantly worsens life expectancy. Its risk can be assessed by clinicopathological factors according to international guidelines. However, additional molecular markers are needed to refine and improve the prediction. Therefore, in the present study, we aimed to predict the progression of NMIBCs to MIBC by assessing p53 expression, polysomy of chromosome 17 (Chr17) and HER2 status in the tissue specimens of the tumors of 90 NMIBC patients. Median follow-up was 77 months (range 2–158). Patients with Chr17 polysomy or HER2 gene amplification had a higher rate of disease progression (hazard ratio: 7.44; p < 0.001 and 4.04; p = 0.033, respectively; univariate Cox regression). Multivariable Cox regression models demonstrated that the addition of either Chr17 polysomy or HER2 gene amplification status to the European Association of Urology (EAU) progression risk score increases the c-index (from 0.741/EAU/ to 0.793 and 0.755, respectively), indicating that Chr17 polysomy/HER2 amplification status information improves the accuracy of the EAU risk table in predicting disease progression. HER2/Chr17 in situ hybridization can be used to select non-progressive cases not requiring strict follow-up, by reclassifying non-HER2-amplified, non-polysomic NMIBCs from the high- and very high-risk groups of EAU to the intermediate-risk group. [ABSTRACT FROM AUTHOR]

Background & Aims: ERBB2-pathway activation, through amplification or activating mutations, represents a new target for colon cancer (CC) treatment. We compared molecular methods to the gold-standard for assessing ERBB2 status and determined the prognostic value of ERBB2 amplification, mutations, and expression using data from two phase III trials involving nearly 3,000 stage III CC patients., Methods: In the PETACC8 trial, IHC/FISH, DNA, and RNA analysis were performed on 1813, 1719, and 1733 samples, respectively. In the IDEA-France trial, DNA and RNAseq were performed on 1129 and 1263 samples. The breast cancer SCAN-B cohort (n=3409) served as an external reference. A new molecular ERBB2-amplified status was defined using ERBB2 NGS-score, RNAseq expression, and clustering based on ERBB2 neighboring gene expression. Concordance between diagnostic techniques and the association between time-to-recurrence (TTR) and ERBB2-status were evaluated., Results: The prevalence of the molecular ERBB2-amplified group was 1.85% in PETACC8 and 1.5% in IDEA-France, with a concordance of 0.81 (95% CI [0.70-0.92]) with the gold-standard IHC/FISH method in PETACC8. A non-linear relationship was observed between TTR and ERBB2-expression, with extreme groups showing a less favorable prognosis (P<.0001) in both colon and breast cancers. Patients with molecular ERBB2-amplified status or mutations had the poorest prognosis, followed by low-expression and intermediate-expression groups (3-year TTR 67.0%, 71.2%, and 77.9%, respectively). In multivariate analysis, the low-expression group had a significantly shorter TTR (HR=1.28; 95%CI [1.07-1.52])., Conclusions: The molecular definition of ERBB2-status could represent a cost-effective alternative in stage III CC. ERBB2 alterations and low RNA expression significantly reduce TTR, highlighting the complex role of ERBB2., (Copyright © 2024 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Simple Summary: There are growing data on targeting HER2 alterations, which include gene mutations, gene amplifications, and protein overexpression, for non-small cell lung cancer (NSCLC). Currently, there are limited targeted therapies approved for NSCLC patients with HER2 alterations, and this remains an unmet clinical need. There has been an influx of research on antibody–drug conjugates, monoclonal antibodies, and tyrosine kinase inhibitors. This review discusses the diagnostic challenges of HER2 alterations in NSCLC and summarizes recent progress in HER2 targeted drugs for both clinicians and researchers treating this patient population. Human epidermal growth factor receptor 2 (HER2), a member of the ERBB family of tyrosine kinase receptors, has emerged as a therapeutic target of interest for non-small cell lung cancer (NSCLC) in recent years. Activating HER2 alterations in NSCLC include gene mutations, gene amplifications, and protein overexpression. In particular, the HER2 exon 20 mutation is now a well clinically validated biomarker. Currently, there are limited targeted therapies approved for NSCLC patients with HER2 alterations. This remains an unmet clinical need, as HER2 alterations are present in 7–27% of de novo NSCLC and may serve as a resistance mechanism in up to 10% of EGFR mutated NSCLC. There has been an influx of research on antibody–drug conjugates (ADCs), monoclonal antibodies, and tyrosine kinase inhibitors (TKIs) with mixed results. The most promising therapies are ADCs (trastuzumab-deruxtecan) and novel TKIs targeting exon 20 mutations (poziotinib, mobocertinib and pyrotinib); both have resulted in meaningful anti-tumor efficacy in HER2 mutated NSCLC. Future studies on HER2 targeted therapy will need to define the specific HER2 alteration to better select patients who will benefit, particularly for HER2 amplification and overexpression. Given the variety of HER2 targeted drugs, sequencing of these agents and optimizing combination therapies will depend on more mature efficacy data from clinical trials and toxicity profiles. This review highlights the challenges of diagnosing HER2 alterations, summarizes recent progress in novel HER2-targeted agents, and projects next steps in advancing treatment for the thousands of patients with HER2 altered NSCLC. [ABSTRACT FROM AUTHOR]

Background: Although targeted agents have been gradually applied in the treatment of HER2-mutated non-small cell lung cancer (NSCLC) in recent years, patients' therapeutic demands are far from being met. PATHER2 was the first phase 2 trial to explore the efficacy and safety of the HER2-targeted tyrosine kinase inhibitor (TKI) pyrotinib plus the antiangiogenic agent apatinib in previously treated HER2-altered metastatic NSCLC patients.Methods: HER2-mutated or HER2-amplified metastatic NSCLC patients who had failed at least first-line chemotherapy or HER2-targeted TKIs received oral pyrotinib 400 mg plus apatinib 250 mg once daily until disease progression, intolerable toxicity, or death. The primary endpoint was the investigator-assessed objective response rate (ORR).Results: Between March 2019 and December 2020, 33 patients were enrolled; 13 (39.4%) presented brain metastases, and 16 (48.5%) had received at least two lines of prior chemotherapy or HER2-targeted TKIs. As of September 20, 2021, the median follow-up duration was 11.3 (range, 3.5-26.0) months. The investigator-assessed ORR was 51.5% (17/33; 95% CI, 33.5 to 69.2%), and the disease control rate was 93.9% (31/33; 95% CI, 79.8 to 99.3%). The median duration of response, progression-free survival, and overall survival were 6.0 (95% CI, 4.4 to 8.6) months, 6.9 (95% CI, 5.8 to 8.5) months, and 14.8 (95% CI, 10.4 to 23.8) months, respectively. The most frequent grade ≥ 3 treatment-related adverse events included diarrhea (3.0%) and hypertension (9.1%). No treatment-related deaths were reported.Conclusions: Pyrotinib plus apatinib demonstrated promising antitumor activity and a manageable safety profile in HER2-mutated or HER2-amplified metastatic NSCLC patients.Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR1900021684 . [ABSTRACT FROM AUTHOR]

Abstract Background Gastric cancer (GC) is one of the leading causes of cancer-related deaths worldwide. Human epidermal growth factor receptor 2 (HER2) amplification occurs in approximately 13–23% of all GC cases and patients with HER2 overexpression exhibit a poor prognosis. Lapatinib, a dual EGFR/HER2 tyrosine kinase inhibitor, is an effective agent to treat HER2-amplified breast cancer but it failed in gastric cancer (GC) clinical trials. However, the molecular mechanism of lapatinib resistance in HER2-amplified GC is not well studied. Methods We employed an unbiased, genome-scale screening with pooled CRISPR library on HER2-amplified GC cell lines to identify genes that are associated with resistance to lapatinib. To validate the candidate genes, we applied in vitro and in vivo pharmacological tests to confirm the function of the target genes. Results We found that loss of function of CSK or PTEN conferred lapatinib resistance in HER2-amplified GC cell lines NCI-N87 and OE19, respectively. Moreover, PI3K and MAPK signaling was significantly increased in CSK or PTEN null cells. Furthermore, in vitro and in vivo pharmacological study has shown that lapatinib resistance by the loss of function of CSK or PTEN, could be overcome by lapatinib combined with the PI3K inhibitor copanlisib and MEK inhibitor trametinib. Conclusions Our study suggests that loss-of-function mutations of CSK and PTEN cause lapatinib resistance by re-activating MAPK and PI3K pathways, and further proved these two pathways are druggable targets. Inhibiting the two pathways synergistically are effective to overcome lapatinib resistance in HER2-amplified GC. This study provides insights for understanding the resistant mechanism of HER2 targeted therapy and novel strategies that may ultimately overcome resistance or limited efficacy of lapatinib treatment for subset of HER2 amplified GC.

Pancreatic cancer has a high morbidity and mortality with the majority being PC ductal adenocarcinomas (PDAC). Whole genome sequencing provides a wide description of genomic events involved in pancreatic carcinogenesis and identifies putative biomarkers for new therapeutic approaches. However, currently, there are no approved treatments targeting driver mutations in PDAC that could produce clinical benefit for PDAC patients. A proportion of 5–10% of PDAC have a hereditary origin involving germline variants of homologous recombination genes, such as Mismatch Repair (MMR), STK11 and CDKN2A genes. Very recently, BRCA genes have been demonstrated as a useful biomarker for PARP-inhibitor (PARPi) treatments. In this study, a series of 21 FFPE PDACs were analyzed using OncoPan®, a strategic next-generation sequencing (NGS) panel of 37 genes, useful for identification of therapeutic targets and inherited cancer syndromes. Interestingly, this approach, successful also on minute pancreatic specimens, identified biomarkers for personalized therapy in five PDAC patients, including two cases with HER2 amplification and three cases with mutations in HR genes (BRCA1, BRCA2 and FANCM) and potentially eligible to PARPi therapy. Molecular analysis on normal tissue identified one PDAC patient as a carrier of a germline BRCA1 pathogenetic variant and, noteworthy, this patient was a member of a family affected by inherited breast and ovarian cancer conditions. This study demonstrates that the OncoPan® NGS-based panel constitutes an efficient methodology for the molecular profiling of PDAC, suitable for identifying molecular markers both for therapy and risk assessment. Our data demonstrate the feasibility and utility of these NGS analysis in the routine setting of PDAC molecular characterization. [ABSTRACT FROM AUTHOR]

Background: For cancer of unknown primary (CUP), non-selective empiric chemotherapy is usually used. However, patients suffering from CUP are generally assumed to have a dismal prognosis with median overall survival of less than 1 year. Therefore, clinicians eagerly await the establishment of effective strategies for diagnosis and treatment. In recent years, the remarkable advances in next-generation sequencing (NGS) technology have enabled the wide usage of DNA/RNA sequencing to comprehensively analyze the molecular information of individual tumors and identify potential targets for patients' diagnosis and treatment. Here, we describe a patient of CUP who was successfully diagnosed and treated with targeted therapy directed by comprehensive molecular profiling. Case Presentation: A 61-year-old Asian woman with a painless, slow-growing mass lesion in the mesosternum underwent fluorodeoxyglucose-positron emission tomography/computed tomography and was found to have malignant metastatic tumors in the mesosternum. Conventional pathological examination of metastatic lesions could not conclude the primary origin of the tumors. The patient was diagnosed with CUP at first. Then, comprehensive molecular profiling was employed to identify the tumor origin and genetic alterations. A gene expression-based tissue origin assay was performed using a tissue biopsy sample. The test result suggested that the lesion tumors might be breast cancer metastasis. Furthermore, liquid biopsy-based circulating tumor DNA profiling detected an ERBB2 copy number amplification. Subsequent surgery and additional postoperative pathology analysis confirmed that the primary tumor site was indeed located in the right outer upper quadrant of the breast. After local surgical resection, the patient received 8 cycles of Docetaxel + Carboplatin + Trastuzumab + Pertuzumab (TCbHP) chemotherapy with subsequent human epidermal growth factor receptor 2 (HER2)-targeted maintenance therapy. Currently, the patient is on regular follow-up and has achieved disease control for up to 6 months. Conclusion: Our findings suggest that molecular identification of the tumor origin and the detection of actionable molecular alterations may offer promise for improved diagnostic accuracy and important therapeutic implications for patients with the CUP syndrome. [ABSTRACT FROM AUTHOR]

HER2 amplification/overexpression is a common driver in a variety of cancers including gallbladder cancer (GBC). For patients with metastatic GBC, chemotherapy remains the standard of care with limited efficacy. The combination of HER2 antibody trastuzumab plus chemotherapy is the frontline treatment option for patients with HER2-positive breast cancer and gastric cancer. Recently, this regime also showed antitumor activity in HER2-positive GBC. However, resistance to this regime represents a clinical challenge. Camrelizumab is a novel PD-1 antibody approved for Hodgkin lymphoma and hepatocellular carcinoma in China. In this study, we presented a HER2-positive metastatic GBC patient who was refractory to trastuzumab plus chemotherapy but experienced significant clinical benefit after the addition of camrelizumab. Our case highlights the potential of immunotherapy in combination with HER2-targeted therapy in HER2-positive GBC. We also demonstrated that two immune-related adverse events (irAEs) associated with camrelizumab can be managed with an anti-VEGF agent apatinib. This case not only highlights the importance of irAE management in patients treated with camrelizumab, but also demonstrates the potential of PD-1 antibody plus trastuzumab in HER2-positive GBC patients who have developed resistance to chemotherapy and trastuzumab-based targeted therapy. [ABSTRACT FROM AUTHOR]

Intratumour heterogeneity fuels carcinogenesis and allows circumventing specific targeted therapies. HER2 gene amplification is associated with poor outcome in invasive breast cancer. Heterogeneous HER2 amplification has been described in 5–41% of breast cancers. Here, we investigated the genetic differences between HER2‐positive and HER2‐negative admixed breast cancer components. We performed an in‐depth analysis to explore the potential heterogeneity in the somatic mutational landscape of each individual tumour component. Formalin‐fixed, paraffin‐embedded breast cancer tissue of ten patients with at least one HER2‐negative and at least one HER2‐positive component was microdissected. Targeted next‐generation sequencing was performed using a customized 53‐gene panel. Somatic mutations and copy number variations were analysed. Overall, the tumours showed a heterogeneous distribution of 12 deletions, 9 insertions, 32 missense variants and 7 nonsense variants in 26 different genes, which are (likely) pathogenic. Three splice site alterations were identified. One patient had an EGFR copy number gain restricted to a HER2‐negative in situ component, resulting in EGFR protein overexpression. Two patients had FGFR1 copy number gains in at least one tumour component. Two patients had an 8q24 gain in at least one tumour component, resulting in a copy number increase in MYC and PVT1. One patient had a CCND1 copy number gain restricted to a HER2‐negative tumour component. No common alternative drivers were identified in the HER2‐negative tumour components. This series of 10 breast cancers with heterogeneous HER2 gene amplification illustrates that HER2 positivity is not an unconditional prerequisite for the maintenance of tumour growth. Many other molecular aberrations are likely to act as alternative or collaborative drivers. This study demonstrates that breast carcinogenesis is a dynamically evolving process characterized by a versatile somatic mutational profile, of which some genetic aberrations will be crucial for cancer progression, and others will be mere ‘passenger’ molecular anomalies.

Abstracts: Background: Human epidermal growth factor receptor 2(HER2) status is a crucial predictive factor for prognostic assessment and targeted therapy selection, which may be influenced by intratumor heterogeneity and molecular divergence between the primary site and different metastases. Therefore, we performed a prospective study to confirm the concordance of HER2 amplification in circulating tumor DNA(ctDNA) with primary tumor tissue and verified its clinical implications. Methods: A total of 105 breast cancer patients were enrolled, and dynamic monitoring of HER2 copy numbers in ctDNA was conducted in 31 participants during the treatment. Totally 186 plasma samples were prospectively obtained and blinded to test HER2 copy numbers in ctDNA based on low-coverage whole genome sequencing(WGS) by next-generation sequencing(NGS). Results: Comparing HER2 copy numbers in ctDNA collected before the initiation of next line of anticancer treatment with primary tumor tissue, the concordant rate of HER2 amplification was 86.5%(χ2 = 52.901, p

BackgroundFor cancer of unknown primary (CUP), non-selective empiric chemotherapy is usually used. However, patients suffering from CUP are generally assumed to have a dismal prognosis with median overall survival of less than 1 year. Therefore, clinicians eagerly await the establishment of effective strategies for diagnosis and treatment. In recent years, the remarkable advances in next-generation sequencing (NGS) technology have enabled the wide usage of DNA/RNA sequencing to comprehensively analyze the molecular information of individual tumors and identify potential targets for patients’ diagnosis and treatment. Here, we describe a patient of CUP who was successfully diagnosed and treated with targeted therapy directed by comprehensive molecular profiling.Case PresentationA 61-year-old Asian woman with a painless, slow-growing mass lesion in the mesosternum underwent fluorodeoxyglucose-positron emission tomography/computed tomography and was found to have malignant metastatic tumors in the mesosternum. Conventional pathological examination of metastatic lesions could not conclude the primary origin of the tumors. The patient was diagnosed with CUP at first. Then, comprehensive molecular profiling was employed to identify the tumor origin and genetic alterations. A gene expression-based tissue origin assay was performed using a tissue biopsy sample. The test result suggested that the lesion tumors might be breast cancer metastasis. Furthermore, liquid biopsy-based circulating tumor DNA profiling detected an ERBB2 copy number amplification. Subsequent surgery and additional postoperative pathology analysis confirmed that the primary tumor site was indeed located in the right outer upper quadrant of the breast. After local surgical resection, the patient received 8 cycles of Docetaxel + Carboplatin + Trastuzumab + Pertuzumab (TCbHP) chemotherapy with subsequent human epidermal growth factor receptor 2 (HER2)-targeted maintenance therapy. Currently, the patient is on regular follow-up and has achieved disease control for up to 6 months.ConclusionOur findings suggest that molecular identification of the tumor origin and the detection of actionable molecular alterations may offer promise for improved diagnostic accuracy and important therapeutic implications for patients with the CUP syndrome.

HER2 amplification/overexpression is a common driver in a variety of cancers including gallbladder cancer (GBC). For patients with metastatic GBC, chemotherapy remains the standard of care with limited efficacy. The combination of HER2 antibody trastuzumab plus chemotherapy is the frontline treatment option for patients with HER2-positive breast cancer and gastric cancer. Recently, this regime also showed antitumor activity in HER2-positive GBC. However, resistance to this regime represents a clinical challenge. Camrelizumab is a novel PD-1 antibody approved for Hodgkin lymphoma and hepatocellular carcinoma in China. In this study, we presented a HER2-positive metastatic GBC patient who was refractory to trastuzumab plus chemotherapy but experienced significant clinical benefit after the addition of camrelizumab. Our case highlights the potential of immunotherapy in combination with HER2-targeted therapy in HER2-positive GBC. We also demonstrated that two immune-related adverse events (irAEs) associated with camrelizumab can be managed with an anti-VEGF agent apatinib. This case not only highlights the importance of irAE management in patients treated with camrelizumab, but also demonstrates the potential of PD-1 antibody plus trastuzumab in HER2-positive GBC patients who have developed resistance to chemotherapy and trastuzumab-based targeted therapy.

Backgroud: Human epithelial growth factor receptor 2 (HER2) amplification is an important mechanism of acquired resistance to anti-epidermal growth factor receptor (EGFR) therapy in non-small cell lung cancer (NSCLC) patients. For patients with both EGFR mutation and HER2 amplification, there is currently no unified standard treatment, and further exploration is needed on how to choose the therapy., Methods and Results: A female NSCLC patient developed bone and brain metastases 14 and 42 months after radical surgery, respectively. The second genetic sequencing detected EGFR L858R mutation and HER2 amplification, and therefore initiated treatment with almonertinib and pyrotinib. The patient achieved partial remission and did not show any further progression during the follow-up period., Conclusion: For NSCLC patients with both EGFR mutation and HER2 amplification, the combination of almonertinib and pyrotinib is a valuable therapy that can continuously reduce tumor burden and achieve long-term survival., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Pan and Zhou.)

There are contradictory data regarding the correlation between HER2 amplification level determined by in situ hybridization and evolution after treatment with anti-HER2 therapies. The aim of this study was to correlate quantitative results of FISH (ratio HER2/CEP17 and number of HER2 signals/nucleus) with pathological response achieved after neoadjuvant treatment with trastuzumab and chemotherapy. For this purpose, we analysed 100 consecutive HER2-positive cases of breast carcinoma treated with neoadjuvant therapy. HER2 amplification determined by FISH was found in 92 of the 100 cases studied. pCR was obtained in 58% of the patients whose tumours presented amplification. In contrast, no pCR was obtained in the 8 patients with non-amplified tumours. A significant direct correlation between HER2 high amplification (HER2/CEP17 ratio > 5 or HER2 signals/nucleus > 10) and pCR was found. In conclusion, HER2 amplification levels are clinically relevant because they provide oncologists with valuable information on the possibilities of achieving pCR after neoadjuvant treatment. [ABSTRACT FROM AUTHOR]

Human epidermal growth factor receptor 2 (HER2) amplification/overexpression is an effective therapeutic target in breast and gastric cancer. Although HER2 positivity has been reported in other malignancies, previous studies generally focused on one cancer type, making it challenging to compare HER2 positivity across studies/malignancies. Herein, we examined 37,992 patient samples for HER2 expression (+/- amplification) in a single laboratory. All 37,992 patients were tested by immunohistochemistry (IHC); 21,642 of them were also examined for HER2 amplification with either fluorescent in situ hybridization (FISH) (11,670 patients) or chromogenic in situ hybridization (CISH) (9,972 patients); 18,262 patients had tumors other than breast or gastric cancer. All tissues were analyzed in a Clinical Laboratory Improvement Amendments (CLIA) laboratory (Caris Life Sciences) at the request of referring physicians. HER2 protein overexpression was found in 2.7 % of samples. Over-expressed HER2 was detected predominantly in malignancies of epithelial origin; for cancers derived from mesenchyme, neuroendocrine tissue, central nervous system, and kidney, HER2 expression and amplification were remarkably rare or non-existent. Bladder carcinomas, gallbladder, extrahepatic cholangiocarcinomas, cervical, uterine, and testicular cancers showed HER2 positivity rates of 12.4, 9.8, 6.3, 3.9, 3.0, and 2.4 %, respectively. HER2 overexpression and/or amplification is frequently found across tumor types. These observations may have significant therapeutic implications in cancers not traditionally thought to benefit from anti-HER2 therapies.

Background: Gastric cancer (GC) is one of the leading causes of cancer-related deaths worldwide. Human epidermal growth factor receptor 2 (HER2) amplification occurs in approximately 13-23% of all GC cases and patients with HER2 overexpression exhibit a poor prognosis. Lapatinib, a dual EGFR/HER2 tyrosine kinase inhibitor, is an effective agent to treat HER2-amplified breast cancer but it failed in gastric cancer (GC) clinical trials. However, the molecular mechanism of lapatinib resistance in HER2-amplified GC is not well studied.Methods: We employed an unbiased, genome-scale screening with pooled CRISPR library on HER2-amplified GC cell lines to identify genes that are associated with resistance to lapatinib. To validate the candidate genes, we applied in vitro and in vivo pharmacological tests to confirm the function of the target genes.Results: We found that loss of function of CSK or PTEN conferred lapatinib resistance in HER2-amplified GC cell lines NCI-N87 and OE19, respectively. Moreover, PI3K and MAPK signaling was significantly increased in CSK or PTEN null cells. Furthermore, in vitro and in vivo pharmacological study has shown that lapatinib resistance by the loss of function of CSK or PTEN, could be overcome by lapatinib combined with the PI3K inhibitor copanlisib and MEK inhibitor trametinib.Conclusions: Our study suggests that loss-of-function mutations of CSK and PTEN cause lapatinib resistance by re-activating MAPK and PI3K pathways, and further proved these two pathways are druggable targets. Inhibiting the two pathways synergistically are effective to overcome lapatinib resistance in HER2-amplified GC. This study provides insights for understanding the resistant mechanism of HER2 targeted therapy and novel strategies that may ultimately overcome resistance or limited efficacy of lapatinib treatment for subset of HER2 amplified GC. [ABSTRACT FROM AUTHOR]

HER2 amplification, which results in overexpression of the receptor tyrosine kinase HER2, has been described in a wide variety of malignancies. HER2‐targeting agents have been incorporated into the treatment paradigms for HER2‐overexpressing breast and gastric cancer. More recently, these agents have shown promise in other gastrointestinal malignancies, such as colon cancer and biliary tract tumors. This study discusses two patients with gallbladder carcinoma and a third with ampullary carcinoma who were able to achieve marked responses to HER2‐directed therapy. These cases underscore the importance of molecular analysis for HER2 amplification/HER2 overexpression, irrespective of tumor histology, and highlight a need for further investigation of HER2‐directed therapy beyond breast and gastroesophageal cancers. Key Points: Current guidelines recommend molecular assessment for HER2 overexpression exclusively in breast and gastric adenocarcinoma.The focus of this report is on three cases (two biliary tract and one ampullary carcinoma) in which amplification of HER2 or overexpression of HER2 was detected and treatment with HER2‐directed therapy resulted in robust responses.These cases exemplify responsiveness of non‐breast/gastric histologies to HER2‐directed therapies, highlighting several promising new settings for these agents.Testing for amplification of HER2 or overexpression of HER2 should be considered especially in rare diseases with limited treatment options. This article presents three unique cases, two patients with gallbladder carcinoma and one patient with ampullary carcinoma, whose tumors overexpressed HER2 and responded remarkably well to HER2‐directed therapy. [ABSTRACT FROM AUTHOR]

HER2 amplification is seen in 20–25% of primary breast cancer cases, and HER2 detection is performed routinely in primary operable, as well as metastatic breast cancer patients. Currently, HER2 is the only gene of which amplification is routinely assayed by fluorescent in situ hybridization (FISH) and/or immunohistochemistry (IHC). However, histochemical assay (FISH/IHC) of multiple target genes is laborious and time-consuming, and simultaneous amplification by microarray is preferred. OncoScan™ is a microarray-based assay capable of whole-genome copy number analysis using DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues. In the current study, we aimed to investigate the impact of tumor cellularity on the accuracy of OncoScan™ in the determination of HER2 amplification. Our results demonstrated that HER2 amplification by OncoScan™ is accurate, and has a high concordance rate of 93.3% with FISH. However, the concordance rate is poor (66.7%) in cases with a tumor cellularity < 20%. Nevertheless, the addition of FISH to breast tumors with a tumor cellularity < 20% and a HER2 copy number of 4 appears to be useful to minimize false-negative results by OncoScan™. [ABSTRACT FROM AUTHOR]

Background: The recent advancement in massively parallel sequencing technologies has empowered liquid biopsies, in particular circulating tumor DNA (ctDNA) analysis, to be the new paradigm in personalized cancer management. Plasma ctDNA detection overcomes the current limitations in tumor tissue procurement and serves as a convenient and non-invasive method to capture tumor heterogeneity and genetic evolution along patients' cancer journey. Summary of findings: In breast cancer, the current clinical application of ctDNA includes real-time monitoring of tumor response, detection of drug-resistant clones, assessing dynamic variations in tumor mutational landscape, identifying actionable mutations, detecting minimal residual disease and screening of early tumor. Purpose: This review aims to summarize the current clinical evidence of ctDNA application in the management of breast cancer. [ABSTRACT FROM AUTHOR]

Purpose: HER2 overexpression and gene amplification are routinely tested by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively. In addition, HER2 mRNA expression is also tested by the Oncotype DX assay. Discordance between laboratories among the different assays remains a problem. To improve the routine HER2 reporting, the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) updated their guidelines in 2018. Our study will compare concordance of HER2 status by IHC and FISH using ASCO/CAP 2013 and 2018 guidelines with Oncotype DX. Methods: We retrospectively reviewed 657 estrogen receptor positive primary breast cancer cases with available Oncotype DX tests between 2011 and 2018. Medical records were reviewed for HER2 results by IHC, FISH, and Oncotype DX. The HER2 results by different assays and between 2013 and 2018 guidelines were compared. Results: Of the 657 cases, 280 were tested by IHC, FISH, and Oncotype DX. HER2-equivocal cases by IHC 2013 guidelines were all negative (67/67, 100%) by FISH 2018 guidelines and by Oncotype DX. HER2-equivocal cases by FISH 2013 guidelines were all negative (16/16, 100%) by FISH 2018 guidelines, while 15/16 (93.8%) negative and 1/16 (6.2%) equivocal by Oncotype DX. The HER2-equivocal and HER2-negative groups were similar in age, gender, histology, grade, and Ki67 score. Conclusions: HER2 concordance was highest between Oncotype DX (99.6%) and FISH per 2018 guidelines. This suggests that the ASCO/CAP 2018 guidelines improved the accurate stratification of HER2-equivocal cases. [ABSTRACT FROM AUTHOR]

Pancreatic cancer has a high morbidity and mortality with the majority being PC ductal adenocarcinomas (PDAC). Whole genome sequencing provides a wide description of genomic events involved in pancreatic carcinogenesis and identifies putative biomarkers for new therapeutic approaches. However, currently, there are no approved treatments targeting driver mutations in PDAC that could produce clinical benefit for PDAC patients. A proportion of 5–10% of PDAC have a hereditary origin involving germline variants of homologous recombination genes, such as Mismatch Repair (MMR), STK11 and CDKN2A genes. Very recently, BRCA genes have been demonstrated as a useful biomarker for PARP-inhibitor (PARPi) treatments. In this study, a series of 21 FFPE PDACs were analyzed using OncoPan®, a strategic next-generation sequencing (NGS) panel of 37 genes, useful for identification of therapeutic targets and inherited cancer syndromes. Interestingly, this approach, successful also on minute pancreatic specimens, identified biomarkers for personalized therapy in five PDAC patients, including two cases with HER2 amplification and three cases with mutations in HR genes (BRCA1, BRCA2 and FANCM) and potentially eligible to PARPi therapy. Molecular analysis on normal tissue identified one PDAC patient as a carrier of a germline BRCA1 pathogenetic variant and, noteworthy, this patient was a member of a family affected by inherited breast and ovarian cancer conditions. This study demonstrates that the OncoPan® NGS-based panel constitutes an efficient methodology for the molecular profiling of PDAC, suitable for identifying molecular markers both for therapy and risk assessment. Our data demonstrate the feasibility and utility of these NGS analysis in the routine setting of PDAC molecular characterization.

Human epidermal growth factor receptor2 (HER2) overexpression/amplification is associated with high malignancy, rapid disease progression and poor overall survival in breast cancer. The application of anti-HER2 drugs has greatly improved the survival of patients with HER2-positive breast cancer, but drug resistance issues affect the long-term efficacy. The HER2 mutation is considered to be one of the reasons for resistance to anti-HER2 therapy, and there is currently no standard treatment. We report for the first time the detection of HER2 amplification with R157W mutation by second-generation sequencing (NGS) in a 57-year-old hormone receptor-negative, HER2-positive woman with advanced breast cancer who was resistant to multi-line anti-HER2 therapies. She subsequently received pyrotinib combined with capecitabine treatment and achieved partial response. The small-molecule pan-HER family irreversible inhibitor pyrotinib combined with capecitabine has shown a promising effect in the treatment of HER2 mutation-induced resistance, but the molecular mechanism and efficacy need to be further verified. [ABSTRACT FROM AUTHOR]