Advances in HER2-Targeted Therapies: From monoclonal antibodies to dual inhibitors developments in cancer treatment

HER2 receptors, overexpressed in certain human cancers, have drawn significant attention in cancer research due to their correlation with poor survival rates. Researchers have developed monoclonal antibodies like Trastuzumab and Pertuzumab against HER2 receptors, which have proven highly beneficial in cancer therapy. Bispecific antibodies like Zanidatamab and antibody-drug conjugates like T-DM1 have been developed to overcome the resistance associated with monotherapy. Small molecules such as Lapatinib, Neratinib, and Pyrotinib were initially developed for treating breast cancer. However, ongoing research is investigating their potential use in other types of cancer, often in combination with other medications. EGFR/HER2 dual-targeted drugs have overcome drug resistance associated with HER2-targeted monotherapy. This comprehensive review covers the structural characteristics of HER2, the HER family signaling pathway mechanism, recent findings regarding HER2 receptor involvement in various cancers, and diverse HER2-targeted therapies. This information provides a comprehensive understanding of HER2-targeted strategies in the evolving field of cancer treatment.

HER2 overexpression in urothelial carcinoma with GATA3 and PPARG copy number gains

HER2, encoded by the ERBB2 gene, is an important druggable driver of human cancer gaining increasing importance as a therapeutic target in urothelial carcinoma (UC). The genomic underpinnings of HER2 overexpression in ERBB2 nonamplified UC are poorly defined. To address this knowledge gap, we investigated 172 UC tumors from patients treated at the University of California San Francisco, using immunohistochemistry and next-generation sequencing. We found that GATA3 and PPARG copy number gains individually predicted HER2 protein expression independently of ERBB2 amplification. To validate these findings, we interrogated the Memorial Sloan Kettering/The Cancer Genome Atlas (MSK/TCGA) dataset and found that GATA3 and PPARG copy number gains individually predicted ERBB2 mRNA expression independently of ERBB2 amplification. Our findings reveal a potential link between the luminal marker HER2 and the key transcription factors GATA3 and PPARG in UC and highlight the utility of examining GATA3 and PPARG copy number states to identify UC tumors that overexpress HER2 in the absence of ERBB2 amplification. In summary, we found that an increase in copy number of GATA3 and PPARG was independently associated with higher ERBB2 expression in patient samples of UC. This finding provides a potential explanation for HER2 overexpression in UC tumors without ERBB2 amplification and a way to identify these tumors for HER2-targeted therapies.

Claudin-18.2 immunohistochemical evaluation in gastric and gastroesophageal junction adenocarcinomas to direct targeted therapy: a practical approach

Claudin-18.2 (CLDN18.2) expression evaluated by immunohistochemistry is a new biomarker for gastric and gastroesophageal junction adenocarcinomas that will soon have market authorization for implementation into routine clinical practice. Despite successful testing in the setting of clinical trials, no specific practical testing guidelines have been proposed. Several pre-analytical and analytical variables may interfere with adequate CLDN18.2 staining interpretation, thus this article provides practical guidance on CLDN18.2 testing and scoring in gastric/gastroesophageal junction adenocarcinomas in order to identify patients who may respond to targeted therapy with monoclonal antibodies directed against CLDN18.2. Based on available data, moderate to strong (2+/3+) membrane staining in ≥75% of adenocarcinoma cells is the proposed cut-off for clinical use of the monoclonal antibody anti-CLDN18.2 (zolbetuximab).

Prognostic and predictive role of YKL-40 in anal squamous cell carcinoma: a serological and tissue-based analysis in a multicentric cohort

Introduction

Anal squamous cell carcinoma (ASC) is a rare gastrointestinal malignancy showing an increased incidence over the past decades. YKL-40 is an immune modulator and pro-angiogenetic factor that showed a promising prognostic and predictive potential in several malignancies, but limited data are available for ASC. This study aims to provide an extensive evaluation of the prognostic and predictive role of YKL-40 in a multicenter cohort of ASC patients.

Methods

We retrospectively retrieved 72 consecutive cases of ASC diagnosed between February 2011 and March 2021. Both serum and tissue protein expression of YKL-40 were assessed, the latter in ASC tumor cells and peritumor immune cells.

Results

Increased YKL-40 serum levels at the time of diagnosis were associated with older age (p = 0.035), presence of cardiovascular/metabolic comorbidities (p = 0.007), and death for any cause (p = 0.011). In addition, high serum levels of YKL-40 were associated with a poor prognosis (HR: 2.82, 95% CI: 1.01-7.84; p = 0.047). Protein expression of YKL-40 in ASC tumor cells was significantly associated with low tumor grade (p = 0.031), while the increased expression in peritumor immune cells was associated with a worse response of patients to chemoradiotherapy (p = 0.007). However, YKL-40 protein expression in ASC tumor cells or peritumor immune cells did not significantly impact patient overall survival.

Discussion

In conclusion, YKL-40 resulted a relevant prognostic (serum level) and predictive (tissue protein expression in peritumor immune cells) biomarker and can considerably improve ASC patient clinical management.

State of the art and upcoming trends in HER2-directed therapies in gastrointestinal malignancies

PURPOSE OF REVIEW

This review critically evaluates the evolution and current status of human epidermal growth factor receptor 2 (HER2)-directed therapies in upper gastrointestinal (GI) malignancies, a timely and relevant inquiry given the dynamic shifts in therapeutic strategies over the past decade. Initial enthusiasm following the Trastuzumab for Gastric Cancer (ToGA) study's demonstration of trastuzumab's efficacy, however, encountered hurdles due to subsequent trials showing limited progress, underscoring the necessity for a reevaluation of therapeutic approaches and the exploration of novel agents.

RECENT FINDINGS

The review highlights significant breakthroughs in the form of immune checkpoint inhibitors and innovative therapeutic technologies, which have redefined treatment paradigms and shown promising efficacy in HER2-positive cases. Emerging treatments such as trastuzumab deruxtecan (T-DXd), zanidatamab and evorpacept further illustrate the ongoing efforts to leverage unique mechanisms of action for improved HER2-positive antitumor activity.

SUMMARY

The advancements in HER2-directed therapies underscore a pivotal era in the management of upper GI malignancies. These developments not only reflect the profound impact of integrating novel therapeutic combinations but also highlight the critical role of ongoing research in overcoming resistance mechanisms and tailoring treatment to individual disease profiles.

HER2 evaluation for clinical decision making in human solid tumours: pearls and pitfalls

The significant clinical benefits of human epidermal growth factor receptor 2 (HER2)-targeted therapeutic agents have revolutionized the clinical treatment landscape in a variety of human solid tumours. Accordingly, accurate evaluation of HER2 status in these different tumour types is critical for clinical decision making to select appropriate patients who may benefit from life-saving HER2-targeted therapies. HER2 biomarker scoring criteria is different in different organ systems, and close adherence to the corresponding HER2 biomarker testing guidelines and their updates, if available, is essential for accurate evaluation. In addition, knowing the unusual patterns of HER2 expression is also important to avoid inaccurate evaluation. In this review, we discuss the key considerations when evaluating HER2 status in solid tumours for clinical decision making, including tissue handling and preparation for HER2 biomarker testing, as well as pathologist's readout of HER2 testing results in breast carcinomas, gastroesophageal adenocarcinomas, colorectal adenocarcinomas, gynaecologic carcinomas, and non-small cell lung carcinomas.

HER-2 directed therapies across gastrointestinal tract cancers - A new frontier

Gastrointestinal (GI) cancers are common and in the metastatic setting they have a poor prognosis. The current mainstay of treatment of GI cancers is chemotherapy; however, the biomarker-directed treatment landscape is evolving. HER-2 is overexpressed in a portion of GI cancers and is an emerging target for therapy, with recent FDA tumor agnostic approval for trastuzumab deruxtecan. Testing for HER-2 expression is not standardized across GI cancers, methodology requires further optimization and standardization as HER-2 targeted therapy emerges into the treatment landscape. There is established rationale for use of HER-2 targeted therapy in first line treatment of metastatic gastric cancer, and emerging evidence with variable benefit in bile duct, pancreatic and colorectal cancers.

Molecular classification and intratumoral heterogeneity of gastric adenocarcinoma

Gastric cancers frequently harbor striking histological complexity and diversity between lesions as well as within single lesions, known as inter- and intratumoral heterogeneity, respectively. The latest World Health Organization Classification of Tumors designated more than 30 histological subtypes for gastric epithelial tumors, assigning 12 subtypes for gastric adenocarcinoma (GAD). Meanwhile, recent advances in genome-wide analyses have provided molecular aspects to the histological classification of GAD, and consequently revealed different molecular traits underlying these histological subtypes. Moreover, accumulating knowledge of comprehensive molecular profiles has led to establishing molecular classifications of GAD, which are often associated with clinical biomarkers for therapeutics and prognosis. However, most of our knowledge of GAD molecular profiles is based on inter-tumoral heterogeneity, and the molecular profiles underlying intratumoral heterogeneity are yet to be determined. In this review, recently established molecular classifications of GAD are introduced in the aspect of pathological diagnosis and are discussed in the context of intratumoral heterogeneity.

Current and Future Biomarkers in Esophagogastric Adenocarcinoma

PURPOSE

Biomarker-based therapies have shown improved patient outcomes across various cancer types. The purpose of this review to summarize our knowledge of current and future biomarkers in esophagogastric adenocarcinoma (EGA).

METHODS

In this publication, we will review current standard biomarkers in patients with upper GI cancers. We will also discuss novel biomarkers that are under investigations and their associated therapies that are currently in clinical trials.

RESULTS

EGAa are a group of heterogeneous diseases, both anatomically and molecularly. There are several established biomarkers (HER2, PD-L1, microsattelite instability or mismatch repair protein expression) that allow for individualized treatments for patients with these cancers. There are also several emerging biomarkers for EGA, some of which have clinically relevant associated therapies. Claudin 18.2 is the furthest along among these. Anti-claudin antibody, zolbetuximab, improved overall survival in biomarker select patients with advanced GEA in two phase 3 studies. Other novel biomarkers, such as FGFR2b and DKN01, are also in the process of validation, and treatments based on the presence of these biomarkers are currently in clinical studies.

CONCLUSION

Ongoing efforts to identify novel biomarkers in EGA have led to enhanced subclassification of upper GI cancers. These advances, coupled with the strategic application of targeted therapies and immunotherapy when appropriate, hold promise to further improve patients outcomes.

Advances in Human Epidermal Growth Factor Receptor 2-Targeted Therapy in Upper Gastrointestinal Cancers

The Trastuzumab for Gastric Cancer (ToGA) trial marked a pivotal moment in the adoption of trastuzumab for treating advanced human epidermal growth factor receptor 2 (HER2)-positive esophagogastric (EG) cancer. The KEYNOTE-811 trial brought to light the synergistic effect of immune modulation and HER2 targeting. Additionally, the emergence of trastuzumab deruxtecan (T-DXd) highlighted the potential of new pharmaceutical technologies to extend response, particularly for patients who have advanced beyond initial HER2-targeted therapies. This review aims to navigate through both the successes and challenges encountered historically, as well as promising current trials on innovative and transformative therapeutic strategies, including promising first-in-class and novel first-in-human agents.

RAS/RAF mutations and microsatellite instability status in primary colorectal cancers according to HER2 amplification

HER2 amplification-associated molecular alterations and clinicopathologic features in colorectal cancers (CRCs) have not been well established. In this study, we assessed the prevalence of HER2 amplification and microsatellite instability (MSI) status of 992 patients with primary CRC. In addition, molecular alterations of HER2 amplified and unamplified CRCs were examined and compared by next-generation sequencing. HER2 amplifications were found in 41 (4.1%) of 992 primary CRCs. HER2 amplification was identified in 1.0% of the right colonic tumors, 5.1% of the left colonic tumors, and 4.8% of the rectal tumors. Approximately 95% of HER2 amplification was observed in the left colon and rectum. Seven (87.5%) of eight metastatic tumors showed HER2 amplification. Most clinicopathologic features were unrelated to HER2 amplification except tumor size and MSI status. All 41 HER2 amplified CRCs were microsatellite stable. In a molecular analysis of frequently identified somatic mutations in CRCs, HER2 amplified CRCs showed a lower rate of KRAS mutations (24.4%) but a higher rate of TP53 mutations (83%) than unamplified CRCs. No BRAF and NRAS mutations were identified in HER2 amplified CRCs. Our study suggests that HER2 amplified CRCs are mutually exclusive of MSI and harbor less frequent KRAS/NRAS/BRAF mutations but frequent T53 mutations.

Predicting human epidermal growth factor receptor 2 status of patients with gastric cancer by computed tomography and clinical features

Background

There have been no studies on predicting human epidermal growth factor receptor 2 (HER2) status in patients with resectable gastric cancer (GC) in the neoadjuvant and perioperative settings. We aimed to investigate the use of preoperative contrast-enhanced computed tomography (CECT) imaging features combined with clinical characteristics for predicting HER2 expression in GC.

Methods

We retrospectively enrolled 301 patients with GC who underwent curative resection and preoperative CECT. HER2 status was confirmed by postoperative immunohistochemical analysis with or without fluorescence in situ hybridization. A prediction model was developed using CECT imaging features and clinical characteristics that were independently associated with HER2 status using multivariate logistic regression analysis. Receiver operating characteristic curves were constructed and the performance of the prediction model was evaluated. The bootstrap method was used for internal validation.

Results

Three CECT imaging features and one serum tumor marker were independently associated with HER2 status in GC: enhancement ratio in the arterial phase (odds ratio [OR] = 4.535; 95% confidence interval [CI], 2.220-9.264), intratumoral necrosis (OR = 2.64; 95% CI, 1.180-5.258), tumor margin (OR = 3.773; 95% CI, 1.968-7.235), and cancer antigen 125 (CA125) level (OR = 5.551; 95% CI, 1.361-22.651). A prediction model derived from these variables showed an area under the receiver operating characteristic curve of 0.802 (95% CI, 0.740-0.864) for predicting HER2 status in GC. The established model was stable, and the parameters were accurately estimated.

Conclusions

Enhancement ratio in the arterial phase, intratumoral necrosis, tumor margin, and CA125 levels were independently associated with HER2 status in GC. The prediction model derived from these factors may be used preoperatively to estimate HER2 status in GC and guide clinical treatment.

Clinicopathological characteristics and prognosis of Epstein-Barr virus-associated gastric cancer

OBJECTIVE

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a distinct molecular subtype of gastric cancer (GC). At present, the clinical characteristics and prognostic implications of EBV infection and the potential clinical benefits of immune checkpoint blockade in GC remain to be clarified. Hence, this study was designed to analyze the clinical and pathological characteristics of GC patients with varying EBV infection states and compare their overall survival (OS).

METHODS

A retrospective study was performed on 1031 consecutive GC patients who underwent gastrectomy at the Affiliated Hospital of Xuzhou Medical University from February 2018 to November 2022. EBV-encoded RNA (EBER) in situ hybridization (ISH) was used for EBV assessment, and immunohistochemical staining was used for evaluation of human epidermal growth factor receptor 2 (HER2), programmed death ligand 1 (PD-L1), and Ki67 expression. EBVaGC was defined as tumors with EBV positivity. In addition, EBV-negative GC (EBVnGC) patients were matched with EBVaGC patients based on seven clinicopathological parameters (age, gender, anatomic subsite, tumor size, Lauren classification, degree of differentiation, and tumor-node-metastasis [TNM] stage). The correlations of clinical features with HER2, PD-L1, and Ki67 expression were evaluated statistically. The survival of patients was assessed through medical records, telephone, or WeChat communication, and prognostic analysis was performed using the logrank test as well as univariable and multivariable regression analysis.

RESULTS

Out of 1031 GC patients tested, 35 (3.4%) were diagnosed with EBVaGC. Notably, the EBVaGC group exhibited a distinct predominance of males and younger patients, significantly higher Ki67 and PD-L1 expression levels, and a lower prevalence of pericancerous nerve invasion than the EBVnGC group (P < 0.01). In the 35 EBVaGC cases, Ki67 expression was negatively correlated with age (P < 0.05), suggesting that a younger onset age was associated with higher Ki67 expression. In addition, PD-L1 expression was correlated with the degree of differentiation, T-stage, and clinical stage of the patient. Furthermore, PD-L1 expression was elevated in tumors with lower differentiation or at later stages (P < 0.05). Using univariate analysis, Ki67, PD-L1, and clinical stage were identified as significant factors influencing the overall survival (OS) of EBVaGC patients (P < 0.05). Moreover, multivariate survival analysis revealed that clinical stage and Ki67 expression were independent risk factors for the OS of the patients (P < 0.05), and the three-year OS rate of EBVaGC patients was 64.2%.

CONCLUSION

EBV-ISH is a practical and valuable method to identify EBVaGC. Owing to its unique etiological, pathological, and clinical characteristics, patients with EBVaGC might benefit from immune checkpoint blockade therapy.

Early endpoints of a randomized phase II trial of preoperative chemotherapy with S-1/CDDP with or without trastuzumab followed by surgery for HER2-positive resectable gastric or esophagogastric junction adenocarcinoma with extensive lymph node metastasis: Japan Clinical Oncology Group study JCOG1301C (Trigger Study)

BACKGROUND

This randomized phase II study explored the superiority of trastuzumab plus S-1 plus cisplatin (SP) over SP alone as neoadjuvant chemotherapy (NAC) for HER2-positive resectable gastric cancer with extensive lymph node metastasis.

METHODS

Eligible patients with HER2-positive gastric or esophagogastric junction cancer and extensive lymph node metastasis were randomized to receive three or four courses of preoperative chemotherapy with SP (arm A) or SP plus trastuzumab (arm B). Following gastrectomy, adjuvant chemotherapy with S-1 was administered for 1 year in both arms. The primary endpoint was overall survival, and the sample size was 130 patients in total. The trial is registered with the Japan Registry of Clinical Trials, jRCTs031180006.

RESULTS

This report elucidates the early endpoints, including pathological findings and safety. The study was terminated early due to slow patient accruals. In total, 46 patients were allocated to arm A (n = 22) and arm B (n = 24). NAC was completed in 20 patients (91%) in arm A and 23 patients (96%) in arm B, with similar incidences of grade 3-4 hematological and non-hematological adverse events. Objective response rates were 50% in arm A and 84% in arm B (p = 0·065). %R0 resection rates were 91% and 92%, and pathological response rates (≥ grade 1b in Japanese classification) were 23% and 50% (p = 0·072) in resected patients, respectively.

CONCLUSIONS

Trastuzumab can be safely added to platinum-containing doublet chemotherapy as NAC, and it has the potential to contribute to higher antitumor activity against locally advanced, HER2-positive gastric or esophagogastric junction cancer with extensive nodal metastasis.

Human epidermal growth factor receptor-2 expression and subsequent dynamic changes in patients with ovarian cancer

Human epidermal growth factor receptor-2 (HER2)-targeting drugs are increasingly being incorporated into therapeutic paradigms for non-breast cancers, yet studies on HER2 expression in ovarian cancer (OC) are inadequate. Here, we studied the HER2 status and dynamic changes in OC by reviewing the records of patients who underwent HER2 testing at a single institution. Clinical parameters, including histology, BRCA status, and immunohistochemistry (IHC), were evaluated alongside HER2 expression, timing, and anatomical location. Among 200 patients, 28% and 6% exhibited expression scores of 2+ and 3+, respectively. HER2 3+ scores were observed in 23%, 11%, 9%, and 5% of mucinous, endometrioid, clear cell, and high-grade serous tumors, respectively, and were exclusively identified in BRCA-wildtype, mismatch repair-proficient, or PD-L1-low-expressing tumors. The TP53 mutation rate was low, whereas ARID1A, KRAS, and PIK3CA mutations were relatively more prevalent with HER2 scores of 2+ or 3+ than with 0 or 1+. Four of the five tumors with an HER2 3+ score exhibited ERBB2 amplification. Among 19 patients who underwent multiple time-lagged biopsies, 11 showed increased HER2 expression in subsequent biopsies. Patients with HER2-overexpressing OC exhibited distinct histological, IHC, and genomic profiles. HER2-targeting agents are potential options for BRCA-wildtype patients, particularly as later lines of treatment.

Targeting HER2 in Gastroesophageal Adenocarcinoma: Molecular Features and Updates in Clinical Practice

Gastroesophageal adenocarcinoma (GEA) is one of the principal causes of death related to cancer globally. Human epidermal growth factor receptor 2 (HER2) is a tyrosine kinase receptor which is found to be overexpressed or amplified in approximately 20% of GEA cases. In GEA, the identification of HER2-positive status is crucial to activate a specific anti-HER2 targeted therapy. The landmark ToGA trial demonstrated the superiority of adding trastuzumab to platinum-based chemotherapy, becoming the first-line standard of treatment. However, unlike breast cancer, the efficacy of other anti-HER2 drugs, such as lapatinib, pertuzumab, and T-DM1, has failed to improve outcomes in advanced and locally advanced resectable GEA. Recently, the combination of trastuzumab with pembrolizumab, along with chemotherapy, and the development of trastuzumab deruxtecan, with its specific bystander activity, demonstrated improved outcomes, renewing attention in the treatment of this disease. This review will summarise historical and emerging therapies for the treatment of HER2-positive GEA, with a section dedicated to the HER2 molecular pathway and the use of novel blood biomarkers, such as circulating tumour DNA and circulating tumour cells, which may be helpful in the future to guide treatment decisions.

HER2-Positive Gastric Cancer and Antibody Treatment: State of the Art and Future Developments

Despite a decreasing incidence in Western countries, gastric cancer is among the most common cancer subtypes globally and is associated with one of the highest tumor-related mortality rates. Biomarkers play an increasing role in the treatment against gastric cancer. HER2 was one of the first biomarkers that found its way into clinical practice. Since the ToGA trial, trastuzumab has been part of first-line palliative chemotherapy in metastatic or unresectable gastric cancer. HER2-targeting agents, such as the tyrosine kinase inhibitor lapatinib, the antibody drug conjugate (ADC) trastuzumab-emtansine or dual HER2 inhibition (pertuzumab and trastuzumab), have been investigated in the second-line setting but led to negative study results. More recently, the ADC trastuzumab-deruxtecan was authorized after the failure of trastuzumab-based treatment. However, further improvements in HER2-directed therapy are required as resistance mechanisms and HER2 heterogeneity limit the existing treatment options. This review aims to give an overview of the current standard-of-care HER2-directed therapy in gastric cancer, as well as its challenges and future developments.

Quantitative proteomic analysis of HER2 protein expression in PDAC tumors

Metastatic pancreatic adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the United States, with a 5-year survival rate of only 11%, necessitating identification of novel treatment paradigms. Tumor tissue specimens from patients with PDAC, breast cancer, and other solid tumor malignancies were collected and tumor cells were enriched using laser microdissection (LMD). Reverse phase protein array (RPPA) analysis was performed on enriched tumor cell lysates to quantify a 32-protein/phosphoprotein biomarker panel comprising known anticancer drug targets and/or cancer-related total and phosphorylated proteins, including HER2Total, HER2Y1248, and HER3Y1289. RPPA analysis revealed significant levels of HER2Total in PDAC patients at abundances comparable to HER2-positive (IHC 3+) and HER2-low (IHC 1+ /2+ , FISH-) breast cancer tissues, for which HER2 screening is routinely performed. These data support a critical unmet need for routine clinical evaluation of HER2 expression in PDAC patients and examination of the utility of HER2-directed antibody-drug conjugates in these patients.

Revolutionizing anti-HER2 therapies for extrahepatic cholangiocarcinoma and gallbladder cancer: Current advancements and future perspectives

Biliary tract cancers (BTCs) encompass a heterogeneous group of rare tumors, including intrahepatic cholangiocarcinoma (iCCA), extrahepatic cholangiocarcinoma (eCCA), gallbladder cancer (GBC) and ampullary cancer (AC). The present first-line palliative treatment regimen comprises gemcitabine and cisplatin in combination with immunotherapy based on two randomized controlled studies. Despite the thorough investigation of these palliative treatments, long-term survival remains low. Moving beyond conventional chemotherapies and immunotherapies, the realm of precision medicine has demonstrated remarkable efficacy in malignancies such as breast and gastric cancers, characterized by notable HER2 overexpression rates. In the context of biliary tract cancer, significant HER2 alterations are observed, particularly within eCCA and GBC, heightening the interest in precision medicine. Various anti-HER2 therapies, including trastuzumab, pertuzumab, trastuzumab-deruxtecan, zanidatamab and neratinib, have undergone investigation. The objective of this review is to summarize the current evidence and outline future directions of targeted HER2 treatment therapy in patients with biliary tract tumors, specially extrahepatic cholangiocarcinoma and gallbladder cancer.

The relationship between brain metastasis and HER2 expression status in gastric cancer

BACKGROUND

Brain metastasis (BM) in gastric cancer (GC) is underestimated, and human epidermal growth factor receptor 2 (HER2) overexpression is a durable poor prognostic factor. We explored the relationship between the two and made a survival analysis.

METHODS

HER2 expression and BM status were collected from GC patients who were diagnosed between December 2009 and May 2021. We collected GC patients diagnosed between 2010 and 2016 from the SEER database. The primary endpoint was survival from the diagnosis of BM. Multivariable logistic regression was used to determine potential risk factors of BM at diagnosis in SEER database. Survival analysis was performed using the Kaplan-Meier method.

RESULT

There were 513 HER2-positive GC patients, including 16 (3.1%) with BM. Among 38 brain metastasis GC patients we collected, 16 (42.1%) patients were HER2 positive. We collected 34,199 GC patients from the SEER database and there were 260 (0.76%) patients with BM at diagnosis. GC patients that are male, white, of younger age, with primary lesions located in the proximal stomach or with distant lymph nodes, liver, bone, or lung metastasis are more likely to develop BM. The median overall survival time from diagnosis of BM was 12.73 months, and the survival time from brain metastasis of HER2-positive patients was numerically shorter, though the difference was not significant (5.30 months vs.16.13 months, P = 0.28.) CONCLUSION: The incidence of BM in patients with HER2-positive gastric cancer is 4.08 times higher than that in general patients. The median overall survival time from BM is shorter for HER2-positive patients.

A systematic review and meta-analysis for human epidermal growth factor receptor 2 on upper tract urothelial carcinoma patients

OBJECTIVE

The expression and significance of human epidermal growth factor receptor 2 (Her2) in upper tract urothelial carcinoma (UTUC) remains controversial. Thus, we aimed to systemically review the Her2 expression in UTUC patients and its relationship with pathological characters and clinical outcomes with meta-analysis.

MATERIALS AND METHODS

A systematically computerized search in PubMed, Scopus, Embase and Cochrane was conducted. From a total of 454 related articles, 35 articles were finally reviewed and 16 papers were chosen for further analysis. Pathological characters included tumor stage, grade, lymph node metastasis (LNM) and lymphovascular invasion (LVI). The clinical outcomes included overall survival (OS), recurrence-free survival (RFS), cancer specific survival (CSS), metastatic-free survival (MFS) and progression-free survival (PFS). RevMan software was used for meta-analyses.

RESULTS

In total 16 studies from 1994 to 2020 were chosen, 14 studies used immunohistochemistry to assess the expression of Her2 and 5 studies used in situ hybridization, with a positive rate of 0 to 74.0% and 7.2 to 18.1%, respectively. Her2-positive was significantly associated with stage (pooled HR 1.86; 95 % CI 1.43-2.42), grade (pooled HR 2.81; 95 % CI 1.01-7.85) and LNM (pooled HR 1.93; 95 % CI 1.18-3.15). However, there was no statistically relationship between Her2-positive with LVI (pooled HR 1.48; 95 % CI 0.64-3.46) and RFS (pooled HR 1.41; 95 % CI 0.98-1.83).

CONCLUSIONS

This review indicated that UTUC patients with Her2-positive tended to develop higher stage and grade tumors and LNM. The Her2 expression in UTUC patients deserves further investigation in the future.

Implementing an On-Slide Molecular Classification of Gastric Cancer: A Tissue Microarray Study

Background and Objectives: Gastric cancer (GC) is one of the most commonly diagnosed cancers and the fourth cause of cancer death worldwide. Personalised treatment improves GC outcomes. A molecular classification is needed to choose the appropriate therapy. A classification that uses on-slide biomarkers and formalin-fixed and paraffin-embedded (FFPE) tissue is preferable to comprehensive genomic analysis. In 2016, Setia and colleagues proposed an on-slide classification; however, this is not in widespread use. We propose a modification of this classification that has six subgroups: GC associated with Epstein-Barr virus (GC EBV+), GC with mismatch-repair deficiency (GC dMMR), GC with epithelial-mesenchymal transformation (GC EMT), GC with chromosomal instability (GC CIN), CG that is genomically stable (GC GS) and GC not otherwise specified (GC NOS). This classification also has a provision for biomarkers for current or emerging targeted therapies (Her2, PD-L1 and Claudin18.2). Here, we assess the implementation and feasibility of this inclusive working classification. Materials and Methods: We constructed a tissue microarray library from a cohort of 79 resection cases from FFPE tissue archives. We used a restricted panel of on-slide markers (EBER, MMR, E-cadherin, beta-catenin and p53), defined their interpretation algorithms and assigned each case to a specific molecular subtype. Results: GC EBV(+) cases were 6%, GC dMMR cases were 20%, GC EMT cases were 14%, GC CIN cases were 23%, GC GS cases were 29%, and GC NOS cases were 8%. Conclusions: This working classification uses markers that are widely available in histopathology and are easy to interpret. A diagnostic subgroup is obtained for 92% of the cases. The proportion of cases in each subgroup is in keeping with other published series. Widescale implementation appears feasible. A study using endoscopic biopsies is warranted.

The prevalence and clinical significance of HER2 expression in prostate adenocarcinoma

AIMS

Abnormalities in HER2 are well-established oncogenic drivers and are approved therapeutic targets in various malignancies. Prior studies evaluating HER2 expression in prostate cancer (PCa) have yielded variable results. Most of these studies used immunohistochemistry scoring systems based on breast cancer data. The goal of this study was to determine the prevalence and clinical significance of HER2 expression using a scoring system that better reflects the HER2 staining pattern observed in PCa.

METHODS

We randomly selected similar numbers of localized low risk (AJCC stage I), locally advanced (AJCC stages II & III), and metastatic (AJCC stage IV) PCa patients treated at the DC VA Medical Center between 2000 and 2022. Among them, we included patients who had sufficient PCa tissue samples and clinical information required for this analysis. Two experienced pathologists independently scored HER2 expression (Ventana Pathway anti-HER2) according to a modified gastric cancer HER2 scoring system.

RESULTS

Out of the 231 patients included, 85 % self-identified as Black. 58.9 % of patients expressed HER2 (1+: 35.5 %; 2+: 18.2 %; 3+: 5.2 %). Validity of the results was confirmed using the HercepTest antibody. Higher HER2 expression was associated with a higher Gleason Score/Grade Group and advanced disease.

CONCLUSIONS

Our findings support the adverse prognostic impact on HER2 in PCa. We propose the use of a modified scoring system to evaluate HER2 expression in PCa. The observed high prevalence of HER2 expression supports the consideration of novel HER2-targeted therapies addressing even low levels of HER2 expression in future PCa trials.

Prediction of HER2 status via random forest in 3257 Chinese patients with gastric cancer

The accurate evaluation of human epidermal growth factor receptor 2 (HER2) is crucial for successful trastuzumab-based therapy in individuals with gastric cancer (GC). The present study, involving a retrospective cohort (N = 2865) from Wuhan Union Hospital and a prospective cohort (N = 392) from Renmin Hospital of Wuhan University, evaluated the benefits of clinical features using random forest and logistic regression models for the detection of HER2 status in patients with GC. Patients from the Union cohort were randomly assigned to either a training (N = 2005) or an internal validation (N = 860) group. Data processing and feature selection were done in Python, which was also used to build random forest and logistic regression models for the prediction of HER2 overexpression. The Renmin cohort (N = 392) was used as the external validation group. Ten features were closely correlated with HER2 overexpression, including age, albumin/globulin ratio, globulin, activated partial thromboplastin time, tumor stage, node stage, tumor node metastasis stage, tumor size, tumor differentiation, and neuron-specific enolase (NSE). Random forest and logistic regression had areas under the curve (AUC) of 0.9995 and 0.6653 in the training group and 0.923 and 0.667 in the internal validation group, respectively. When the two predictive models were validated using data from the Renmin cohort, random forest and logistic regression had AUCs of 0.9994 and 0.627, respectively. This is the first multicenter study to predict HER2 overexpression in individuals with GC, based on clinical variables. The random forest model significantly outperformed the logistic regression model.

HER2-low in gastro-oesophageal adenocarcinoma: a real-world pathological perspective

AIMS

In the DESTINY-Gastric01 trial, a novel HER2-targeted antibody-drug conjugate trastuzumab deruxtecan proved to be effective in HER2-low gastro-oesophageal adenocarcinomas. The aim of our study is to investigate the clinicopathological and molecular features of HER2-low gastric/gastro-oesophageal junction cancers in the real-world setting of a large multi-Institutional series.

METHODS

We retrospectively evaluated 1210 formalin-fixed paraffin-embedded samples of gastro-oesophageal adenocarcinomas which were analysed by immunohistochemistry for HER2 protein expression in 8 Italian surgical pathology units from January 2018 to June 2022. We assessed the prevalence of HER2-low (ie, HER2 1+ and HER2 2+ without amplification) and its correlation with clinical and histopathological features, other biomarkers' status, including mismatch repair/microsatellite instability status, Epstein-Barr encoding region (EBER) and PD-L1 Combined Positive Score.

RESULTS

HER2 status could be assessed in 1189/1210 cases, including 710 HER2 0 cases, 217 HER2 1+, 120 not amplified HER2 2+, 41 amplified HER2 2+ and 101 HER2 3+. The estimated prevalence of HER2-low was 28.3% (95% CI 25.8% to 31.0%) overall, and was higher in biopsy specimens (34.9%, 95% CI 31.2% to 38.8%) compared with surgical resection specimens (21.0%, 95% CI 17.7% to 24.6%) (p<0.0001). Moreover, HER2-low prevalence ranged from 19.1% to 40.6% among centres (p=0.0005).

CONCLUSIONS

This work shows how the expansion of the HER2 spectrum might raise problems in reproducibility, especially in biopsy specimens, decreasing interlaboratory and interobserver concordance. If controlled trials confirm the promising activity of novel anti-HER2 agents in HER2-low gastro-oesophageal cancers, a shift in the interpretation of HER2 status may need to be pursued.

The function and immune role of cuproptosis associated hub gene in Barrett's esophagus and esophageal adenocarcinoma

Barrett's esophagus (BE) is a precancerous lesion of esophageal adenocarcinoma (EAC), with approximately 3-5% of patients developing EAC. Cuproptosis is a kind of programmed cell death phenomenon discovered in recent years, which is related to the occurrence and development of many diseases. However, its role in BE and EAC is not fully understood. We used single sample Gene Set Enrichment Analysis (ssGSEA) for differential analysis of BE in the database, followed by enrichment analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO) and GSEA, Protein-Protein Interaction (PPI), Weighted Gene Co-expression Network Analysis (WGCNA), Receiver Operating Characteristic Curve (ROC) and finally Quantitative Real Time Polymerase Chain Reaction (qRT-PCR) and immunohistochemistry (IHC) of clinical tissues. Two hub genes can be obtained by intersection of the results obtained from the cuproptosis signal analysis based on BE. The ROC curves of these two genes predicted EAC, and the Area Under the Curve (AUC) values could reach 0.950 and 0.946, respectively. The mRNA and protein levels of Centrosome associated protein E (CENPE) and Shc SH2 domain binding protein 1 (SHCBP1) were significantly increased in clinical EAC tissues. When they were grouped by protein expression levels, high expression of CENPE or SHCBP1 had a poor prognosis. The CENPE and SHCBP1 associated with cuproptosis may be a factor promoting the development of BE into EAC which associated with the regulation of NK cells and T cells.

Clinicopathologic features and prognostic value of claudin 18.2 overexpression in patients with resectable gastric cancer

Claudin 18.2 has emerged as a promising therapeutic target in gastric cancer based on phase 3 studies. However, clinicopathologic features associated with claudin 18.2 overexpression have not been comprehensively studied specifically for patients with resectable gastric cancer. This retrospective study included 299 patients with stage I-III resectable gastric cancer who underwent curative surgical resection. Possible associations between claudin 18.2 overexpression (moderate-to-strong expression in ≥ 75% by the 43-14A clone) and clinicopathologic features and survival outcomes were analyzed. There were 90 (30.1%), 96 (32.1%), and 113 (37.8%) patients with stage I, II, and III disease, respectively. Claudin 18.2 overexpression was noted in 139 out of 299 patients (46.5%). Claudin 18.2 overexpression was associated with a younger age, a lower invasion depth limited to the mucosa/submucosa, and less frequent lymphovascular invasion. Claudin 18.2 overexpression was also associated with Borrmann type 4 among patients with advanced gastric cancer and the diffuse histological type. Claudin 18.2 overexpression was not an independent factor for survival outcomes. In conclusion, claudin 18.2 was overexpressed in almost half of resectable gastric cancer patients. Claudin 18.2 overexpression was associated with some clinicopathological characteristics, but was not an independent prognostic factor in a localized setting.

Genetic landscape and PD-L1 expression in Epstein-Barr virus-associated gastric cancer according to the histological pattern

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a distinct molecular subtype of gastric cancer. This study aims to investigate genomic and clinicopathological characteristics of EBVaGC according to the histological pattern. We retrospectively collected 18 specimens of surgically resected EBVaGCs. Whole-exome sequencing was performed for all cases. Moreover, PD-L1 expression and tumor-infiltrating lymphocyte (TIL) percentage were investigated. Among 18 EBVaGCs, 10 cases were of intestinal histology, 3 were of poorly cohesive histology, and the remaining 5 were of gastric carcinoma with lymphoid stroma histology. Whole-exome sequencing revealed that EBVaGCs with intestinal histology harbored pathogenic mutations known to frequently occur in tubular or papillary adenocarcinoma, including TP53, KRAS, FBXW7, MUC6, ERBB2, CTNNB1, and ERBB2 amplifications. One patient with poorly cohesive carcinoma histology harbored a CDH1 mutation. Patients with EBVaGCs with intestinal or poorly cohesive carcinoma histology frequently harbored driver mutations other than PIK3CA, whereas those with EBVaGCs with gastric carcinoma with lymphoid stroma histology lacked other driver mutations. Moreover, the histological pattern of EBVaGCs was significantly associated with the levels of TILs (P = 0.005) and combined positive score (P = 0.027). In conclusion, patients with EBVaGCs with different histological patterns exhibited distinct genetic alteration, PD-L1 expression, and degree of TILs.

Prognostic Potential of Nectin Expressions in Colorectal Cancer: An Exploratory Study

Colorectal cancer (CRC) is a pressing global health challenge, with an estimated 1.9 million new cases in 2020. Ranking as the third most diagnosed cancer globally, CRC accounts for nearly 930,000 cancer-related deaths annually. Nectins, immunoglobulin-like adhesion molecules, are pivotal in intercellular adhesion formation and cellular function regulation. Altered nectin expression patterns have been identified in various cancers. However, the intricacies of their role in cancer development and progression remain underexplored. This study aimed to evaluate the expression of specific nectins in CRC tumors, explore their association with clinicopathological factors, and ascertain their potential as prognostic indicators for CRC patients post-resection. We retrospectively analyzed the medical records of 92 CRC patients who underwent surgical treatment between 2013 and 2014. Tumor specimens were re-evaluated to determine nectin expression using immunohistochemistry. The study identified heterogeneous expressions of nectin-2, -3, and -4 in 58%, 62.6%, and 87.9% of specimens, respectively. Elevated nectin-4 expression correlated with worse 5-year and overall survival rates, presenting a negative prognostic value (HR = 4, 95% CI: 2.4-6.8, p < 0.001). Conversely, reduced nectin-3 expression was linked to poorer CRC prognosis (HR = 0.54; 95% CI: 0.31-0.96; p = 0.036). Nectin-4 expression positively correlated with elevated carcinoembryonic antigen (CEA) levels and advanced disease stages. In contrast, nectin-3 expression negatively correlated with CEA levels, tumor size, presence of distant metastases, and disease stage. Notably, tumors in the right colon were statistically more likely to express nectin-2 compared to those in the left. This study underscores the potential prognostic significance of nectins in CRC. The high prevalence of nectin-4-expressing cells offers promising avenues for further evaluation in targeted therapeutic interventions with already available agents such as PADCEV.

New treatment options for metastatic HER2-low breast cancer : Consequences for histopathological diagnosis

The overexpression of HER2 in breast cancer is a classic example for molecular targeted therapy, and it has been shown that classical anti-HER2 therapeutics were only effective in patients with HER2 overexpressing tumors. Therefore, in recent decades, pathologists have been focused on the reliable identification of HER2 overexpressing tumors. Based on the results of recent clinical trials in metastatic breast cancer with antibody-drug conjugates (ADCs), this diagnostic strategy for evaluation of HER2 is currently changing. It has been shown that the ADC trastuzumab-deruxtecan is effective not only against tumors with classical HER2 overexpression, but also against HER2-low tumors. These clinical trial results lead to a paradigm shift in the treatment of patients whose tumours were previously classified as HER2 negative. In addition to the identification of HER2 (score 3+) overexpressing tumors, it is necessary to identify HER2-low expressing tumors (defined as an immunohistochemistry (IHC) score of 1+ or IHC2+ with negative in situ hybridization).Due to the therapeutic consequences, it is important to quickly adapt the diagnostic workup and reporting to the new requirements. In addition, the new therapeutic options for anti-HER2 therapy lead to new challenges for standardization as well as to new scientific questions for the characterization of tumors with low HER2 expression.

HER2 Genetic Intratumor Heterogeneity Is Associated With Resistance to Trastuzumab and Trastuzumab Emtansine Therapy in Recurrent High-Grade Endometrial Cancer

Anti-HER2 targeted therapies have recently demonstrated clinical activity in the treatment of high-grade endometrial carcinomas (ECs), particularly serous carcinomas with HER2 amplification and/or overexpression. Intratumor heterogeneity of HER2 amplification or HER2 genetic intratumor heterogeneity (G-ITH) has been associated with resistance to anti-HER2 therapies in breast and gastroesophageal cancers; however, its clinical relevance in EC is unknown. To characterize HER2 G-ITH in EC, archival specimens from a clinically annotated cohort of 57 ECs treated with trastuzumab or trasutuzmab emtansine in the recurrent (n = 38) or adjuvant (n = 19) setting were subjected to central pathology review, HER2 assessment by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), and next-generation sequencing. HER2 G-ITH, defined as HER2 amplification in 5% to 50% of tumor cells examined by FISH, was identified in 36% (19/53) of ECs and was associated with lower HER2 copy number and levels of protein expression. HER2 IHC revealed spatially distinct areas of strong expression juxtaposed with areas of low/absent expression in tumors with the "cluster" pattern of G-ITH, whereas the "mosaic" pattern was typically associated with a diffuse admixture of cells with variable levels of HER2 expression. HER2 G-ITH was frequently observed in cases with IHC/FISH or FISH/next-generation sequencing discrepancies and/or with an equivocal/negative FISH result (9/13, 69%). Although the objective response rate to anti-HER2 therapy in recurrent ECs was 52% (13/25) for tumors lacking HER2 G-ITH, none (0%, 0/10) of the patients with HER2 G-ITH achieved a complete or partial response (P = .005). HER2 G-ITH was significantly associated with worse progression-free survival (hazard ratio, 2.88; 95% CI, 1.33-6.27; P = .005) but not overall survival. HER2 IHC score, HER2/CEP17 ratio, HER2 copy number, histologic subtype, and other genetic alterations, including PIK3CA hotspot mutations, were not significantly associated with therapeutic response or survival outcomes. Treatment responses were not restricted to serous carcinomas, supporting consideration of anti-HER2 therapy in patients with HER2-positive high-grade ECs of non-serous histology. Our results demonstrate that HER2 G-ITH is an important determinant of response to trastuzumab and trastuzumab emtansine in EC, providing a rationale for the development of novel therapeutic strategies to target HER2-nonamplified resistant tumor subpopulations, such as HER2 antibody-drug conjugates with bystander effects.

An Overview of Current Biomarkers, the Therapeutic Implications, and the Emerging Role of hERG1 Expression in Gastric Cancer: A Literature Review

Gastric cancer remains one of the most commonly diagnosed cancers in the world. It carries a high mortality rate, with cases being more prevalent in the developing world, and has been linked to diet and Helicobacter pylori infection. It is a highly heterogeneous disease, with most cases being of a sporadic nature. Most patients present at an advanced stage due to the asymptomatic nature of the early stages of the disease. A multidisciplinary approach is often best implemented to help decide how to best manage individual cases. However, the overall clinical outcome and survival of patients with advanced gastric cancer remain poor. Recent therapeutic advancements focus on the identification of molecular biomarkers associated with gastric cancer that have predictive, diagnostic, and prognostic implications. This enables the development of specific targeted therapies that have shown efficacy in numerous trials, either as monotherapy or in combination with standard chemotherapy. Despite this, tumour heterogeneity and treatment resistance are still issues leading to poor survival outcomes. An emerging approach is focusing efforts on the bidirectional crosstalk between tumour cells and the microenvironment through targeting ion channels. A key player in this is human ether-á-go-go-related gene 1 (hERG1). This voltage-gated potassium ion channel has been shown to have predictive, diagnostic, and prognostic significance, enabling the stratification of high-risk individuals. In addition, targeting hERG1 in combination with chemotherapy has been shown to potentiate tumour regression. This comprehensive literature review will aim to consolidate our understanding of current biomarkers in gastric cancer. The relevance of hERG1 in gastric cancer as a useful novel biomarker and the potential therapeutic implications as targeted therapy will be explored. This offers a new and personalised approach to helping to manage patients with gastric cancer.

The risk of weekend biopsy: Impact of specimen source and fixation status on HER2 assessment in the treatment of advanced gastric cancer (The HER_WEEKEND study)

Accurate evaluation of human epidermal growth factor receptor type 2 (HER2) expression is crucial for determining chemotherapy regimens in gastric cancer. However, formalin fixation status has been identified as an important factor affecting HER2 assessment reliability. This retrospective cohort study aimed to investigate the correlation between sample collection day (weekday vs. weekend) and source (biopsy vs. surgical specimens) in assessing HER2 expression in patients with unresectable advanced/recurrent gastric cancer. Data were collected from gastric cancer patients who received chemotherapy at a single public hospital in Japan from 2008 to 2021. The analysis included 177 patients (109 men, 68 women) with a median age of 68.0 (21-88) years, and the primary outcome was the HER2 positivity rate. The overall HER2 positivity rate was 18.1%, with higher rates on weekdays (20.0%) compared to weekends (12.8%). Biopsies had higher positivity rates on weekdays (23.9%) but lower rates on weekends (11.1%) than surgical specimens. Significant differences were observed in formalin fixation times between weekdays and weekends for both biopsies and surgical samples. The study findings suggest that longer formalin fixation times on weekends may lead to underestimating HER2 expression, particularly in biopsies. Therefore, it is crucial to be cautious of excessive formalin fixation when collecting samples, especially during weekend biopsies.

Exploring the molecular characteristics of the malignant potential of gastric adenocarcinoma with enteroblastic differentiation

AIMS

Gastric adenocarcinoma with enteroblastic differentiation (GAED) is a rare subset of alpha-fetoprotein (AFP)-producing carcinomas with poor prognosis. However, the molecular features associated with the malignant potential of GEAD remain partially elucidated.

METHODS AND RESULTS

In this study, the relationship between clinicopathological parameters and aggressive biological behaviour was analysed in 37 patients with GAED. The results showed that GAED tended to infiltrate the deep layer of the gastric wall and possessed more frequent vascular invasion than conventional gastric adenocarcinoma (CGA) (P < 0.001). All distant metastases were observed in the GAED group, not the CGA group (P < 0.001). High HER2 expression was found in nearly 24.32% of the informative cases, and none showed EBV-encoded RNA positivity or deficient mismatch repair. The most frequently mutated gene in GAED was p53. Programmed cell death-ligand 1 (PD-L1) immunostaining revealed 13 patients with a combined positive score (CPS) ≥ 5 (65%, 13 of 20). Thus, based on these molecular markers (immunostaining, in situ hybridisation and mutation analysis), GAED may be classified as a unique subgroup of the chromosomal instability subtype with HER2+ /EBV- /MSS/TP53+ /PD-L1+ . Next-generation sequencing analyses showed that mutations in the TOPI, ELOA and NOTCH3 genes were found only in GAED, and abnormally expressed genes in GAED were significantly enriched in hepatocellular carcinoma-, gland development-, and gastric cancer-related pathways.

CONCLUSION

The HER2+ /EBV- /MSS/TP53+ /PD-L1+ profile and hepatocellular carcinoma-related pathways may be significant in the malignant potential of GAED. In addition to anti-HER2 therapy, immune check-point inhibitors may be an effective treatment option for patients with GAED.

A study of human epidermal growth factor receptor 2 overexpression by immunohistochemistry in patients with gastric adenocarcinoma

Gastric cancer is one of the leading causes of cancer-related deaths across the world and in the Middle East. Human epidermal growth factor receptor 2 (HER2) overexpression has been observed in gastric cancers. Trastuzumab, a recombinant monoclonal antibody targeting HER2 protein, is being used for treatment of metastatic gastric cancer. To study the frequency and association of HER2 overexpression with age, gender, histopathological subtype and grade of differentiation in patients with gastric adenocarcinoma from Basra, Iraq. This cross-sectional single-center study collected demographic (age, gender), histopathological (histological subtype, grade of differentiation) and immunohistochemical (HER2 overexpression status) data from 100 consenting adult patients (male: 56) with histopathologically confirmed gastric adenocarcinoma from samples obtained through endoscopy or surgery. HER2 overexpression (ToGA score 3+) was observed in 6/100 (6%) of patients, with another 6 showing 'equivocal' HER2 expression (2+). Out of 20 patients with moderately differentiated gastric cancer, 4 (20%) showed HER2 overexpression (p=0.008). Other factors considered (age, gender, histological subtype) did not show statistically significant correlation with HER2 overexpression. More females showed HER2 overexpression than males (4 vs. 2), and more patients with intestinal type gastric cancer showed HER2 overexpression than diffuse gastric cancer (5 vs. 1), but the difference was not statistically significant in both variables. HER2 overexpression was 6% in this population; statistically significant correlation was found with histological grade. Statistically non-significant correlations were observed between HER2 overexpression and gender, age, and histological subtype.

Current Laboratory Testing Practices for Assessment of ERBB2/HER2 in Endometrial Serous Carcinoma and Colorectal Carcinoma

CONTEXT.—

Therapy targeted at human epidermal growth factor receptor 2 (HER2; also known as ERBB2) was used initially for breast and gastroesophageal carcinoma and has more recently been adopted for endometrial serous carcinoma (ESC) and colorectal carcinoma (CRC). There is evidence that predictive biomarker testing algorithms for HER2 must be tumor type specific and that an algorithm validated for one tumor type cannot be applied to another.

OBJECTIVE.—

To describe current laboratory practices for HER2 assessment in ESC and CRC.

DESIGN.—

We surveyed laboratories participating in the 2021 College of American Pathologists (CAP) HER2 immunohistochemistry proficiency testing program.

RESULTS.—

The survey was distributed to 1548 laboratories and returned by 1195, of which 83.5% (998) were in the United States. For ESC, 24.0% (287) of laboratories reported performing in-house testing for HER2 by immunohistochemical staining and/or in situ hybridization; of these, 44.3% (127) performed it reflexively on all cases of ESC. The most common criterion for evaluating HER2 was the American Society of Clinical Oncology/CAP 2018 guideline for breast carcinoma (69.0%; 194 of 281), whereas only 16.0% (45) of laboratories used guidelines specific to ESC. For CRC, 20.2% (239 of 1185) of laboratories performed in-house HER2 testing, and 82.0% of these (196) did the test only at the clinician's request. A plurality (49.4%; 115 of 233) used gastroesophageal cancer guidelines when scoring CRC, 30.0% (70) used the CRC scoring system from the HERACLES trial, and 16.3% (38) used the American Society of Clinical Oncology/CAP 2018 guideline for breast carcinoma.

CONCLUSIONS.—

Laboratories vary in their approach to HER2 testing in ESC and CRC. Most laboratories did not report using tumor type-specific recommendations for HER2 interpretation. The lack of standardization could present a challenge to evidence-based practice when considering targeted therapy for these diseases.

p70S6K/Akt dual inhibitor DIACC3010 is efficacious in preclinical models of gastric cancer alone and in combination with trastuzumab

The PI3K-Akt-mTOR (PAM) pathway is implicated in tumor progression in many tumor types, including metastatic gastric cancer (GC). The initial promise of PAM inhibitors has been unrealized in the clinic, presumably due, in part, to the up-regulation of Akt signaling that occurs when the pathway is inhibited. Here we present that DIACC3010 (formerly M2698), an inhibitor of two nodes in the PAM pathway, p70S6K and Akt 1/3, blocks the pathway in in vitro and in vivo preclinical models of GC while providing a mechanism that inhibits signaling from subsequent Akt up-regulation. Utilizing GC cell lines and xenograft models, we identified potential markers of DIACC3010-sensitivity in Her2-negative tumors, i.e., PIK3CA mutations, low basal pERK, and a group of differentially expressed genes (DEGs). The combination of DIACC3010 and trastuzumab was evaluated in Her2-positive cell lines and models. Potential biomarkers for the synergistic efficacy of the combination of DIACC3010 + trastuzumab also included DEGs as well as a lack of up-regulation of pERK. Of 27 GC patient-derived xenograft (PDX) models tested in BALB/c nu/nu mice, 59% were sensitive to DIACC3010 + trastuzumab. Of the 21 HER2-negative PDX models, DIACC3010 significantly inhibited the growth of 38%. Altogether, these results provide a path forward to validate the potential biomarkers of DIACC3010 sensitivity in GC and support clinical evaluation of DIACC3010 monotherapy and combination with trastuzumab in patients with HER2- negative and positive advanced GCs, respectively.

Prognostic Significance of ARID1A Expression Patterns Varies with Molecular Subtype in Advanced Gastric Cancer

Background/Aims

AT-rich interactive domain 1A (ARID1A) is frequently mutated in gastric cancer (GC), especially Epstein-Barr virus (EBV)-associated and microsatellite instability high GC. The loss of ARID1A expression has been reported as a poor prognostic marker in GC. However, the relationships between ARID1A alteration and EBV-associated and microsatellite instability high GC, which are known to have a favorable prognosis, has hampered proper evaluation of the prognostic significance of ARID1A expression in GC. We aimed to analyze the true prognostic significance of ARID1A expression by correcting confounding variables.

Methods

We evaluated the ARID1A expression in a large series (n=1,032) of advanced GC and analyzed the relationships between expression pattern and variable parameters, including clinicopathologic factors, key molecular features such as EBV-positivity, mismatch repair protein deficiency, and expression of p53 and several receptor tyrosine kinases including human epidermal growth factor receptor 2, epidermal growth factor receptor, and mesenchymal-epithelial transition factor. Survival analysis of the molecular subtypes was done according to the ARID1A expression patterns.

Results

Loss of ARID1A expression was found in 52.5% (53/101) of mutL homolog 1 (MLH1)-deficient and 35.8% (24/67) of EBV-positive GCs, compared with only 9.6% (82/864) of the MLH1-proficient and EBV-negative group (p<0.001). The loss of ARID1A expression was associated only with MLH1 deficiency and EBV positivity. On survival analysis, the loss of ARID1A expression was associated with worse prognosis only in MLH1-proficient and EBV-negative GC. Multivariate analysis revealed that both loss of ARID1A and decreased ARID1A expression were independent worse prognostic factors in patients with advanced GC.

Conclusions

Only in MLH1-proficient and EBV-negative GC, the loss of ARID1A expression is related to poorer prognosis.

PET/CT and SPECT/CT Imaging of HER2-Positive Breast Cancer

HER2 (Human Epidermal Growth Factor Receptor 2)-positive breast cancer is characterized by amplification of the HER2 gene and is associated with more aggressive tumor growth, increased risk of metastasis, and poorer prognosis when compared to other subtypes of breast cancer. HER2 expression is therefore a critical tumor feature that can be used to diagnose and treat breast cancer. Moving forward, advances in HER2 in vivo imaging, involving the use of techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT), may allow for a greater role for HER2 status in guiding the management of breast cancer patients. This will apply both to patients who are HER2-positive and those who have limited-to-minimal immunohistochemical HER2 expression (HER2-low), with imaging ultimately helping clinicians determine the size and location of tumors. Additionally, PET and SPECT could help evaluate effectiveness of HER2-targeted therapies, such as trastuzumab or pertuzumab for HER2-positive cancers, and specially modified antibody drug conjugates (ADC), such as trastuzumab-deruxtecan, for HER2-low variants. This review will explore the current and future role of HER2 imaging in personalizing the care of patients diagnosed with breast cancer.

Next generation immuno-oncology biomarkers in gastrointestinal cancer: what does the future hold?

INTRODUCTION

Gastrointestinal (GI) cancers pose a significant health burden worldwide, necessitating advancements in diagnostic and treatment approaches. One promising avenue is the utilization of next-generation biomarkers, which hold the potential to revolutionize GI cancer management.

AREAS COVERED

This review explores the latest breakthroughs and expert opinions surrounding the application of next-generation immunotherapy biomarkers. It encompasses various aspects of the currently utilized biomarkers of immunotherapy in the context of GI cancers focusing on microsatellite stable cancers. It explores the promising research on the next generation of biomarkers addressing the challenges associated with integrating them into clinical practice and the need for standardized protocols and regulatory guidelines.

EXPERT OPINION

Immune profiling, multiplex immunohistochemistry, analysis of immune cell subsets, and novel genomic and epigenomic markers integrated with machine-learning approaches offer new avenues for identifying robust biomarkers. Liquid biopsy-based approaches, such as circulating tumor DNA (ctDNA) and exosome-based analyses, hold promise for real-time monitoring and early detection of treatment response.

Molecular characterization and potential therapeutic roles of miR125a in HER-2 positive gastric cancer

Introduction

miR-125a-3p could have a role in gastric cancer by targeting HER2. This study aimed to investigate the expression pattern of miR-125a-3p, identify the expression level of its target gene in gastric carcinoma, and test its effect in HER-2 positive gastric carcinoma cells.

Materials and Methods

The levels of miR-125a-3p in both cancer and noncancer tissues were measured by using Quantitative real-time polymerase chain in 70 gastric carcinomas. Immunohistochemical study was used to measure the expression of HER2 protein in these carcinomas. In addition, the level of expression of this miRNA is correlated to different pathological and clinical parameters. The effects of miR-125a-3p alone and in combination with 5-FU (fluorouracil) on the growth of HER2 positive (NUGC4) and HER2 negative (ECC10) gastric carcinoma cells were also analyzed by in vitro studies.

Results

Most gastric cancer tissues samples showed downregulation of miR-125a-3p (84%) when compared to their noncancer tissues. Significant correlations of downregulation of miR-125a-3p with cancer recurrence and pathological staging of gastric carcinoma (P = 0. 02 and 0.02, respectively) were noted. HER2 protein expression correlated significantly and inversely with miR-125a-3p expression (P < 0.05). A reduction in cell growth rate was noted significantly in miR-125a-3p transfected gastric carcinoma cells when 5-FU was added to them in comparison to other control cells (P < 0.01). When both gastric carcinoma cell lines were transfected with miR-125a-3p, a significantly higher growth inhibition percentage in HER2 positive (NUGC4) cell line was seen in comparison to the HER2 negative (ECC10) cells (P < 0.01).

Conclusion

miR-125a-3p plays a significant role in the pathogenesis of gastric carcinoma. Therapeutic transfection of miR-125a-3p in HER2 positive gastric cancer cells resulted in reduced cell proliferation and potentiate the effect of 5-FU.

Human epidermal growth factor 2 overexpressed alpha-fetoprotein-producing-gastric cancer

PURPOSE

This study aimed to elucidate the clinicopathological characteristics of α-fetoprotein (AFP)-producing gastric carcinoma (AFP-GC) with human epidermal growth factor receptor (HER)2 overexpression to extend the treatment strategy for AFP-GC.

METHODS

We analyzed 41 patients with AFP-GC who underwent surgical resection or chemotherapy from 1989 to 2019, and who had over 20ng/mL of serum AFP or positive immunohistochemical AFP expression. HER2 expression status was investigated by immunohistochemistry (IHC) for all patients and by fluorescence in situ hybridization (FISH) for cases with an IHC score of 2+. AFP-GC with an IHC score of 3 + or 2 + and FISH positivity was defined as HER2 overexpressed AFP-GC. The correlation between HER2 status and clinicopathological characteristics and prognosis in AFP-GC was analyzed.

RESULTS

HER2 overexpression was detected in 17.1% of AFP-GC patients. The prognosis of the patients with HER2 overexpressed AFP-GC was not significantly different compared to HER2 non-overexpressed AFP-GC. HER2 overexpressed AFP-GC consisted of heterogeneous histology with a higher proportion of mixed-type tumors (p = 0.002). The clinical outcome of AFP-GC with mixed-type of histology tended to be better than other intestinal or diffuse types (p = 0.05).

CONCLUSION

HER2 overexpressed AFP-GC consisted of a mixed type of histology, which showed a better prognosis. The results presented that HER2 status in AFP-GC is one of the molecular candidates to improve the prognosis.

Targeted Therapies and Developing Precision Medicine in Gastric Cancer

Gastric cancer is an aggressive disease with survival remaining poor in the advanced setting. More than a decade after the first targeted treatment was approved, still only HER2, MSI and PDL-1 status have reached everyday practice in terms of guiding treatment options for these patients. However, various new targets and novel treatments have recently been investigated and have shown promise in improving survival outcomes. In this review, we will summarise previous and currently ongoing studies on predictive biomarkers, possible new targeted treatments, potential reasons for conflicting trial results and hope for the future of precision medicine in gastric cancer.

Assessment of the expression pattern of HER2 and its correlation with HER2-targeting antibody-drug conjugate therapy in urothelial cancer

Background

Human epidermal growth factor receptor 2 (HER2) overexpression is related to anti-HER2 therapy in many tumors. RC48- antibody-drug conjugate (ADC) has shown promising efficacy in patients with HER2-positive locally advanced or metastatic urothelial carcinoma (UC). The characteristic expression and scoring systems of HER2 are nonexistent in UC. We aimed to explore HER2 status and its correlation with the efficacy of HER2-targeting ADC therapy in UC.

Methods

A total of 137 and 43 patients were enrolled in cohort 1 and cohort 2, respectively, from March 2009 to December 2018. The patients in cohort 2 were enrolled in a phase II study of RC48-ADC. UC samples were tested for HER2 status using immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH). The 2018 ASCO/CAP HER2 scoring system was adopted and modified to score HER2 expression in UC.

Results

The HER2-positive (IHC 2+ or 3+) rate was 24.1% (33/137). In HER2 IHC 2+ or 3+ patients, the HER2 gene amplification rate was 31% (13/42). The objective response rates (ORRs) in RC48-ADC-treated patients with IHC 3+, IHC 2+ and FISH+, IHC 2+ and FISH- were 58.8%, 66.7% and 40%, respectively. The ORR showed a trend toward a better benefit for RC48-ADC therapy in patients with HER2 amplification than in those without amplification (61.5% vs. 44.8%, P = 0.059). The heterogeneity of HER2 expression in the primary tumor was 55.5% (15/27), and the ORR was not significantly different between patients with tumor heterogeneity and homogeneity.

Conclusions

IHC testing should be performed to assess the HER2 status before the initiation of HER2-ADC therapy. There was a trend toward a better benefit for patients with HER2 amplification, and tumor heterogeneity did not influence the drug efficacy.

Prognostic Factors in Patients with Advanced HER2-Positive Gastric Cancer Treated with Trastuzumab-Based Chemotherapy: a Cohort Study

PURPOSE

Prognostic factors for the survival of patients with advanced HER2-positive gastric cancer treated with trastuzumab-based chemotherapy remain controversial. The aim of this study was to identify the clinical factors that predict prognosis in patients with advanced HER2-positive gastric cancer.

METHODS

We retrospectively reviewed the medical records of HER2-positive gastric cancer patients treated with trastuzumab-based chemotherapy at our institution. Clinical features and laboratory test results that considered prognostic factors were re-examined. Overall survival (OS) was estimated using the Kaplan-Meier method. Univariate analysis was performed with the log-rank test and multivariate analysis was performed using Cox's proportional hazard regression model.

RESULTS

A total of 133 patients with advanced HER2-positive gastric cancer were enrolled. The median OS in this cohort was 18.7 months. Four prognostic factors: visceral metastasis (lung or liver), levels of hemoglobin (Hb) (< 11.6 g/dl), lactate dehydrogenase (LDH) (> 222 mg/dl), and C-reactive protein (CRP) (> 0.14 mg/dl), were identified as independent prognostic factors. The patients were placed into three groups according to their number of prognostic factors. These included low (0, 1), moderate (2, 3), and high (4) risk factors. The OS was separated into three categories with a median OS of 32.0, 18.7, and 10.1 months, respectively. Compared to the low-risk group, hazard ratios for the moderate- and high-risk groups were 1.75 and 3.49, respectively.

CONCLUSION

Visceral metastasis and abnormal Hb, LDH, and CRP levels were associated with unfavorable OS. These findings may be beneficial for the management of advanced HER2-positive gastric cancer treated with trastuzumab-based chemotherapy.

Assessment of HER2 in Gastric-Type Endocervical Adenocarcinoma and its Prognostic Significance

As the most common type of human papillomavirus-independent endocervical adenocarcinomas (ECAs), gastric-type endocervical adenocarcinomas (GEAs) account for approximately 10% of all ECAs. Although anti-HER2 therapy has been proven effective in many cancers, it has not been used in ECAs, including GEAs, which is at least partly due to the lack of a well-defined guideline. Limited available data regarding HER2 in GEAs and ECAs have considerable variations likely caused by variations in the tumor type selection, testing methods, and scoring criteria. Here, we selected 58 GEA cases to examine the HER2 status using immunohistochemistry and fluorescent in situ hybridization and investigate the prognostic value and their association with other known or potential prognostic factors. When strong complete or lateral/basolateral membranous reactivity in ≥10% tumor cells was used to define HER2 positivity, relatively high prevalence of HER2 overexpression (10/58[17.2%]) and amplification (9/58 [15.5%]), as well as high immunohistochemistry-fluorescent in situ hybridization concordance rate (9/10 [90%]) was found in GEAs. A lateral/basolateral staining pattern ("U-shaped") was observed, at least focally, in most of HER2-positive (3+) and equivocal (2+) tumors. Notably, considerable heterogeneity of HER2 expression was observed in HER2 positive and equivocal cases (80.0% and 83.3%, respectively). HER2 overexpression and amplification were associated with worse progression-free survival (P = .047 and P = .032, respectively). Programmed death-ligand 1 expression was associated with worse progression-free survival (P = .032), whereas mutant-type p53 demonstrated no prognostic significance. Our work laid a solid foundation for the eventual development of a future standard HER2 testing guideline for GEAs.

Molecular and clinical correlates of HER3 expression highlights its potential role as a therapeutic target in melanoma

Overexpression of the epidermal growth factor receptor family member HER3 (erbB3) has been implicated in several types of cancer and recently drugs targeting HER3 have shown promising clinical activity. In melanoma, HER3 overexpression has been linked to both metastasis formation and resistance to drug therapy in cell culture models. Here, we sought to characterise the expression of HER3 in 187 melanoma biopsies (149 cutaneous, 38 mucosal) using immunohistochemistry, as well as to analyse the association between HER3 expression and molecular, clinical and pathological variables. A subset of the cutaneous melanoma specimens was taken prior to treatment with immune checkpoint blockade therapy (pre-ICB) (n=79). HER3 expression (≥1+) was observed in 136 of 187 samples (∼73%). HER3 expression was found to be markedly lower in the mucosal melanomas, with 17 of the 38 tumours (∼45%) demonstrating no HER3 expression. In cutaneous melanomas, there was a negative association between HER3 expression and mutational load, a positive association with NRAS mutational status, and a trend of negative association with PD-L1 expression. In the pre-ICB cohort, an association was found between high HER3 expression (≥2+) and overall survival after anti-PD-1-based immunotherapy. Overall, our results indicate that HER3 is a promising therapeutic avenue in cutaneous melanoma worthy of further clinical evaluation.

Impact of HER2 on prognosis and benefit from adjuvant chemotherapy in stage II/III gastric cancer patients: a multicenter observational study

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is a well-developed therapeutic target in breast and gastric cancer (GC). However, the impact of HER2 on survival and benefit from fluorouracil-based adjuvant chemotherapy remains unclear in patients with GC.

MATERIALS AND METHODS

This multicenter cohort study involved 5622 consecutive stage II/III GC patients. HER2 expression was assessed prospectively via immunohistochemistry (IHC). The staining intensity was graded on a scale of 0 to 3+. An IHC score of 2+or 3+was defined as high expression, and a score of 3+was defined as overexpression.

RESULTS

HER2 overexpression was independently associated with a lower 5-year overall survival (OS) in stage II [hazard ratio (HR), 2.10; 95% CI: 1.41-3.11], but not in stage III GC (HR, 1.00; 95% CI, 0.82-1.20). Further analysis revealed that stage II patients with high HER2 expression showed a poorer response to chemotherapy than stage II patients with low HER2 expression ( Pinteraction =0.024). The HRs for 5-year OS were 0.51 (95% CI, 0.38-0.70) for stage II patients with low HER2 expression, 0.58 (95% CI, 0.51-0.66) for stage III patients with low HER2 expression, 1.13 (95% CI, 0.61-2.09) for stage II patients with high HER2 expression, and 0.47 (95% CI, 0.36-0.61) for stage III patients with high HER2 expression.

CONCLUSIONS

Fluorouracil-based adjuvant chemotherapy is insufficient for stage II GC patients with high HER2 expression, indicating that prospective trials are required to validate alternative HER2-targeted adjuvant therapies in the individuals above.

Assessment of the Impact of Alternative Fixatives on HER2 Detection in Breast Cancer and Gastric Cancer Tumor Specimens

The type of fixative used for preserving tumor specimens can significantly impact the performance of the immunohistochemistry and in situ hybridization assays used for assessing human epidermal growth factor receptor 2 (HER2) status. This study reports the prevalence of the use of alternative fixatives other than the guideline-recommended 10% neutral buffered formalin (NBF) during HER2 testing in a real-world setting. The effects of alternative fixatives [20% NBF and 10% unbuffered formalin (UBF) fixatives] on HER2 testing of breast cancer (BC) and gastric cancer (GC) cell lines and tissues are also assessed. Overall, 117,636 tumor samples received at a central laboratory from >8000 clinical trial sites across 60 countries were reviewed to determine the prevalence of alternative fixative usage. To investigate the impact of alternative fixatives, 27 cell lines (21 BC and 6 GC) and 76 tumor tissue samples (50 BC and 26 GC) were fixed in 10% NBF, 20% NBF, or 10% UBF, and evaluated for HER2 status by immunohistochemistry and in situ hybridization. Real-world data showed that 9195 (7.8%) tumor samples were preserved using an alternative fixative. In cell lines, overall percentage agreement, negative percentage agreement, and positive percentage agreement among the 3 fixatives were 100%. In tumor tissues, the agreement among 10% NBF, 20% NBF, and 10% UBF ranged between 94.7% and 96.6% for negative percentage agreement and 90.9% for overall percentage agreement compared with a range of 58.3% to 66.7% for positive percentage agreement. These results suggest that alternative fixatives may have the potential to convert HER2 status in tissues from positive to negative.