HER2 Status in Gastric and Gastroesophageal Junction Cancer: Results of the Large, Multinational HER-EAGLE Study

Immune checkpoint inhibitors plus chemotherapy in the first-line treatment of young unresectable gastric cancer patients: a multicentre real-world study

Background

PD-1 inhibitors combined with chemotherapy have become the standard first-line treatment for advanced gastric cancer (GC), but their efficacy in young GC patients is unknown. This study aimed to evaluate the efficacy of immunotherapy in young GC patients and explore new treatment strategies for this population.

Methods

Clinicopathological data of young unresectable GC patients were collected from multiple centres. We defined young as ≤45 years. Statistical analyses were conducted with SPSS IBM for Windows version 24.0.

Results

In total, 225 young unresectable GC patients were registered. Their clinicodemographic characteristics included female predominance (60.9%), poor differentiation (86.7%), high family history of cancer (14.2%), low HER2 expression (12.2%), PD-L1 expression (43.0%) and mismatch repair (MMR) deficiency (1.0%), and a high proportion of peritoneal metastasis (49.3%). After screening, 134 patients were included for analysis: 63 received dual chemotherapy (mFOLFOX6, XELOX, SOX and two-drug containing paclitaxel), 32 PD-1 inhibitors plus dual chemotherapy (mFOLFOX6, XELOX, SOX and two-drug containing paclitaxel), and 39 triple regimens (two-drug chemotherapy combined with apatinib or trastuzumab, or triple chemotherapy based on platinum, fluorouracil and paclitaxel). The effectiveness analysis revealed no significant difference in the disease control rate (DCR) between the dual chemotherapy group and the PD-1 inhibitor plus dual chemotherapy group (P=0.787), but triple regimens led to the best DCR (71.4% vs. 68.8% vs. 94.9%, all P<0.05). Kaplan-Meier curves showed median progression-free survival (PFS) times of the three groups of 4.7, 4.7 and 9.2 months, respectively. The median overall survival (OS) was 13.9, 11.0 and 15.9 months, respectively. Multivariate analyses showed that triple regimens were an independent prognostic factor for PFS [hazard ratio (HR) 0.430, 95% confidence interval (CI) 0.263-0.700; P=0.001]. Detailed survival analysis demonstrated that patients receiving intraperitoneal infusion of paclitaxel followed by intravenous paclitaxel combined with S-1 and apatinib oral therapy had better PFS (P=0.014) and OS (P=0.013) than those receiving other regimens.

Conclusion

Young patients with GC have unique clinical characteristics and are not sensitive to immunotherapy. Triple regimens, especially intraperitoneal infusion of paclitaxel followed by intravenous paclitaxel combined with S-1 and apatinib oral therapy, deserve to be studied as first-line therapies.

Disitamab vedotin combined with apatinib in gastric cancer: A case report and review of literature

BACKGROUND

In patients with human epidermal growth factor receptor 2 (HER2)-overexpressing gastric cancer (GC), the combination of HER2 targeting and a standard first-line chemotherapy regimen has been demonstrated to significantly improve their prognosis. However, in a proportion of patients, cancer progresses within a short period of time, and there is currently no standard treatment after disease progression.

CASE SUMMARY

This study presents a case of a 51-year-old male with advanced GC who underwent radical resection (Billroth type II subtotal gastrectomy and gastrojejunostomy) and resection of liver metastases. Immunohistochemical staining revealed a HER2 score of 2+, a dMMR status, and a Ki67 proliferation index of 30% to 40%. The gene test results indicated the presence of ERBB2 amplification and a PD-L1 expression level of less than 5%. Since December 2021, the patient has experienced disease progression during both first-line (two cycles of KN026 combined with KN046) and second-line (five cycles of nivolumab combined with trastuzumab and SOX chemotherapy) treatment regimens. The patient's prognosis following the first and second lines of treatment was unfavorable, with progression occurring in a relatively short time. For third-line therapy, disitamab vedotin (RC48) plus apatinib was used. At the time of this report, the patient had achieved a progression-free survival (PFS) of 25.8 months, which exceeded the median survival time for patients with advanced GC.

CONCLUSION

Despite the unfavorable prognosis associated with advanced GC, the implementation of personalized treatment approaches may still prove beneficial for select patients. In patients with HER2-positive GC with extensive metastatic involvement, the use of the HER2-targeted combination with apatinib has demonstrated the potential to prolong both PFS and overall survival.

Current status of neoadjuvant immunotherapy for the treatment of gastric cancer

Gastric cancer is one of the most prevalent malignant tumors worldwide, characterized by high incidence and mortality rates. At present, comprehensive surgical treatment has enhanced the prognosis of locally advanced gastric cancer patients significantly. However, the postoperative recurrence rate remains high, and the long-term survival for patients is sub-optimal. In recent years, immunotherapy has garnered extensive attention as an innovative approach to the treatment of gastric cancer. Indeed, multiple studies have validated its therapeutic effects in advanced gastric cancer patients, leading to its incorporation into treatment guidelines. Currently, researchers are exploring the application of immunotherapy in the neoadjuvant setting globally in order to further adjust and refine neoadjuvant immunotherapy regimens for gastric cancer. This article summarizes the research progress and controversies associated with neoadjuvant immunotherapy in gastric cancer, aiming to optimize clinical benefits for gastric cancer patients undergoing this treatment approach. The retrieval methods of this study encompassed databases such as PubMed, Google Scholar, Web of Science, clinicaltrials.gov, etc. The retrieved articles included guidelines, consensus, meta-analyses, clinical trials, and reviews related to locally advanced gastric cancer published up to January 2024.

The Impact of Pembrolizumab as a Salvage Therapy Based on HER2 Expression in Advanced Gastric Cancer

Immune checkpoint inhibitors (ICIs) are used as salvage treatments for advanced gastric cancer (AGC) regardless of HER2 status. This study assessed the efficacy of ICIs based on HER2 expression in AGC patients who received pembrolizumab as salvage monotherapy at Samsung Medical Center from November 2017 to March 2023. HER2 status was determined via immunohistochemistry, and tumor response and survival outcomes were compared accordingly. Among the 113 patients analyzed, with a median age of 61 years and 64.6% being male, 12 patients (10.6%) were HER2-positive, and 101 patients (89.4%) were HER2-negative. Of 92 evaluable patients, none had a complete response. However, 50% of HER2-positive patients had a partial response, compared to 4.9% of HER2-negative patients (p < 0.001). The disease control rate was 70% in HER2-positive and 37.8% in HER2-negative patients (p = 0.086). Median progression-free survival was 5.53 months for HER2-positive patients versus 1.81 months for HER2-negative patients (p = 0.037). Pembrolizumab as a salvage chemotherapy for the treatment of AGC demonstrated superior effectiveness in HER2-positive patients compared with HER2-negative patients.

Advances in Diagnostic, Staging, and Restaging Evaluation of Esophageal and Gastric Cancer

The initial endoscopic and staging evaluation of esophagogastric cancers must be accurate and comprehensive in order to select the optimal therapeutic plan for the patient. Esophageal and gastric cancers (and treatment paradigms) are delineated by their proximity to the cardia (within 2 cm). The most frequent and important symptom that informs the initial staging evaluation is dysphagia, which is associated with at least cT3 or locally advanced disease. Endoscopic ultrasound is often needed if earlier stage disease is suspected, preferably in combination with endoscopic mucosal or submucosal resection or fine-needle aspiration of suspicious lymph nodes to enhance staging accuracy.

Risk factors and clinical significance of lower perigastric lymph node metastases in Siewert type II and III esophagogastric junction adenocarcinoma: a retrospective cohort study

BACKGROUND

No consensus has been concluded with regarding to the scope of lymph node (LN) dissection for Siewert type II and III adenocarcinoma of the esophagogastric junction (AEG). This study aimed to explore risk factors for lower perigastric LN (LPLN) metastases (including no. 4d, 5, 6, and 12a LN stations) and analyze the indications for LPLN dissection.

METHODS

In total, 302 consecutive patients with Siewert type II and III AEG who underwent total gastrectomy (TG) were enrolled. The logistic regression model was used to perform uni- and multivariate analyses of risk factors for LPLN metastases. Kaplan-Meier curves were used for survival analysis, and log-rank tests were used for group comparisons. Basing on the guidelines of Japanese Gastric Cancer Association, the LN metastases (LNM) as well as the efficiency index (EI) of each LN station was further evaluated.

RESULTS

The independent risk factors for LPLN metastases in patients with Siewert type II and III AEG were distance from the esophagogastric junction (EGJ) to the distal end of the tumor (> 4.0 cm), preoperative carcinoembryonic antigen (CEA) ( +), pT4 stage, and HER-2 ( +). LPLN metastases was an independent risk factor for overall survival following TG. The LNM and EI of LPLN were 8.6% and 2.31%, respectively. The LNM of LPLN > 10% under the stratification of the distance from the EGJ to the distal end of the tumor (> 4.0 cm), pT4, preoperative CEA ( +), and HER-2 ( +) exhibited EI values of 3.55%, 2.09%, 2.51%, and 3.64%, respectively.

CONCLUSIONS

LPLN metastases was a malignant factor for the prognosis of patients with Siewert type II and III AEG. For patients with preoperative CEA ( +), pT4 stage, HER-2 ( +), and the distance from the EGJ to the distal end of the tumor (> 4.0 cm), TG with LPLN dissection is prioritized for clinical recommendation.

Complete and rapid response with the combination of immunotherapy and chemotherapy in a young adult patient with microsatellite instability-high metastatic gastric cancer

ABSTRACT

Gastric cancer (GC) is an aggressive malignancy; 5.0% of GC patients are diagnosed before the age of 40. These patients are more aggressive and advanced stage at the diagnosis. Microsatellite instability-high (MSI-H) status is usually seen in relatively older patients. We report a 31-year-old male patient presenting with an intra-abdominal mass and spleen lesions that radiologically mimic a gastrointestinal stromal tumor (GIST). He underwent surgery. Histological examination revealed poorly differentiated adenocarcinoma starting from the deep gastric mucosa. After surgery, rapidly progressive disease was observed. The patient with MSI-H and combined positive score (CPS) of 65% was treated with a combination of immunotherapy and chemotherapy; complete response was observed in approximately 3 months. This is a very rare GC case in young adult age with MSI-H status and responds to treatment in a short time. Predictive markers for immunotherapy efficacy are still being discussed; this case supports the predictive role of high CPS score and MSI-H phenotype in demonstrating treatment efficacy.

Mechanism of pachymic acid in the treatment of gastric cancer based on network pharmacology and experimental verification

BACKGROUND

Pachymic acid (PA) is derived from Poria cocos. PA has a variety of pharmacological and inhibitory effects on various tumors. However, the mechanism of action of PA in gastric cancer (GC) remains unclear.

AIM

To investigate the mechanism of PA in treating GC via the combination of network pharmacology and experimental verification.

METHODS

The GeneCards and OMIM databases were used to derive the GC targets, while the Pharm Mapper database provided the PA targets. Utilizing the STRING database, a protein-protein interaction network was constructed and core targets were screened. The analyses of Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis were conducted, and molecular docking and clinical correlation analyses were performed on the core targets. Ultimately, the network pharmacology findings were validated through in vitro cell assays, encompassing assessments of cell viability, apoptosis, cell cycle, cloning, and western blot analysis.

RESULTS

According to network pharmacology analysis, the core targets were screened, and the PI3K/AKT signaling pathway is likely to be the mechanism by which PA effectively treats GC, according to KEGG enrichment analysis. The experimental findings showed that PA could control PI3K/AKT signaling to prevent GC cell proliferation, induce apoptosis, and pause the cell cycle.

CONCLUSION

Network pharmacology demonstrated that PA could treat GC by controlling a variety of signaling pathways and acting on a variety of targets. This has also been supported by in vitro cell studies, which serve as benchmarks for further research.

Early-onset gasrtric cancer (review)

Objective. Early-onset gastric cancer (EOGC) constitutes a serious medical and social problem. Early-onset gastric cancer accounts for approximately 6% of all malignant epithelial neoplasms.

Material and Methods. We reviewed retrospective and prospective randomized trials using Medline and Elibrary databases.

Results. The applied significance of the molecular genetic classifications consist in the formation of groups for evaluating prognosis of the disease using multifactorial analysis. This classification indicates that EOGC diagnosed at a locally advanced stage and primary dissemination is most often caused by GS (TCGA) and MSS/EMT(ACRG) subtypes and is characterized by mutations in CDH1, RhoA, CLDN18-ARHGAP genes. These changes are accompanied by the prevalence of diffuse histological type of gastric cancer according to the Lauren classification and ulcerated or infiltrative type according to the Borrmann classification (type III and IV) with the presence of high-grade adenocarcinoma with a signet ring cell component.

Conclusion. Considering the aggressiveness of gastric cancer in young patients, who more frequently present with locally advanced and metastatic disease at the time of diagnosis, there is a need for increased cancer alertness among physicians of other specialties, early endoscopic controls to detect cancer at early stages and benefit from both surgical and multimodal treatment.

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

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.

Survival benefits of palliative gastrectomy for gastric cancer patients with liver metastasis: a population-based propensity score-matched cohort analysis

Background and aims

Palliative primary tumor resection (pPTR) can benefit colorectal cancer patients with liver metastasis. Whether pPTR benefiting gastric cancer (GC) patients with liver metastasis is still controversial.

Methods

Data on patients with metastatic GC diagnosed between 2010 to 2019 was extracted from SEER database. Propensity score analysis with 1:1 matching was performed. The univariable and multivariable Cox proportional hazards regression models were used to explore prognostic factors. Kaplan-Meier method was used to analyze survival outcomes.

Results

Of 5691 GC patients with liver metastasis, 468 were included in the matched cohorts. The results showed that the median survival time was 6 months in the non-surgery groups and 14.5 months in the surgery groups (p < 0.001). Multivariable analysis showed that surgery was a protective prognostic factor for overall survival [hazard ratio (HR) = 0.416] as well as cancer-specific survival (HR = 0.417). Also, pPTR was only recommended for GC patients with isolated liver metastasis. Moreover, pPTR combined with chemotherapy brought the greatest therapeutic effect.

Conclusion

pPTR benefits GC patients with isolated liver metastasis, and GC patients with liver metastasis receiving pPTR combined with chemotherapy had the best survival outcomes than any other therapeutic model.

Efficacy and survival of anti-PD-1 antibody in combination with trastuzumab and chemotherapy versus trastuzumab and chemotherapy as first-line treatment of HER2-positive metastasis gastric adenocarcinoma: a retrospective study

Background

The KEYNOTE-811 study exhibited promising preliminary results for HER2-positive metastasis gastric adenocarcinoma; however, long-term survival benefit remains to be determined.

Methods

In this single-center, controlled, retrospective study, patients with histologically confirmed HER2-positive unresectable or metastatic gastric/gastroesophageal adenocarcinoma received either anti-PD-1 antibody combined with trastuzumab and chemotherapy (cohort A) or trastuzumab and chemotherapy treatment (cohort B). The primary end points were progression-free survival (PFS) and overall survival (OS). The secondary end points were objective response rate (ORR), disease control rate (DCR), and duration of response (DoR).

Results

A total of 56 patients were eligible to join the study, with 30 patients in cohort A and 26 patients in cohort B. The median PFS (mPFS) was 16.2 months (95% CI, 15.093-17.307) in cohort A versus 14.5 months (95% CI, 9.491-19.509) in cohort B (p = 0.58). The median OS in cohort A was 28.1 months (95% CI, 17.625-38.575) versus 31.6 months (95% CI, 13.757-49.443) in cohort B (p = 0.534). ORRs were 66.7% and 50% in the two groups, respectively. DCRs were 90% and 84.6% in the two groups. Median DoR was not reached in cohort A and it was 16.3 (95% CI, 8.453-24.207) months in cohort B (p = 0.141). The most common irAEs were grade 1 hypothyroidism (33.3%) in cohort A. No treatment-related deaths occurred in this study.

Conclusions

This retrospective cohort study provided a preliminary picture on the long-term follow-up of combining anti-PD-1 antibody with trastuzumab and chemotherapy in HER2-positive GC, and a trend with longer DoR and ORR was identified. Further studies with larger sample sizes and more in-depth molecular investigation are needed.

Pembrolizumab or pembrolizumab plus chemotherapy versus standard of care chemotherapy in patients with advanced gastric or gastroesophageal junction adenocarcinoma: Asian subgroup analysis of KEYNOTE-062

OBJECTIVE

First-line pembrolizumab with/without chemotherapy versus chemotherapy was evaluated in programmed death ligand 1 combined positive score ≥1, locally advanced/unresectable or metastatic gastric cancer/gastrooesophageal junction cancer in the KEYNOTE-062 study. We present results for patients enrolled in Asia.

METHODS

Eligible patients were randomly assigned 1:1:1 to pembrolizumab 200 mg, pembrolizumab plus chemotherapy (cisplatin + 5-fluorouracil or capecitabine) or placebo plus chemotherapy Q3W. End points included overall survival (primary) in combined positive score ≥1 and combined positive score ≥10 populations and safety and tolerability (secondary).

RESULTS

A total of 187 patients were enrolled in Asia (pembrolizumab, n = 62; pembrolizumab plus chemotherapy, n = 64; chemotherapy, n = 61). Compared with the global population, higher proportions of patients had Eastern Cooperative Oncology Group performance status 0 and a diagnosis of stomach cancer. In the programmed death ligand 1 combined positive score ≥1 population, median overall survival was numerically longer with pembrolizumab versus chemotherapy (22.7 vs 13.8 months; hazard ratio, 0.54; 95% confidence interval, 0.35-0.82) and pembrolizumab plus chemotherapy versus chemotherapy (16.5 vs 13.8 months; hazard ratio, 0.78; 95% confidence interval, 0.53-1.16). In the programmed death ligand 1 combined positive score ≥10 population, median overall survival was also numerically longer with pembrolizumab versus chemotherapy (28.5 vs 14.8 months; hazard ratio, 0.43; 95% confidence interval, 0.21-0.89) and pembrolizumab plus chemotherapy versus chemotherapy (17.5 vs 14.8 months; hazard ratio, 0.86; 95% confidence interval, 0.45-1.64). The grade 3-5 treatment-related adverse event rate was 19.4%, 75.8% and 64.9% for patients receiving pembrolizumab, pembrolizumab plus chemotherapy and chemotherapy, respectively.

CONCLUSIONS

This post hoc analysis showed pembrolizumab monotherapy was associated with numerically improved overall survival and a favourable tolerability profile versus chemotherapy in Asians with programmed death ligand 1-positive advanced gastric cancer/gastrooesophageal junction cancer.This study is registered with ClinicalTrials.gov, NCT02494583.

Prevalence of Her2-neu status and its clinicopathological association in newly diagnosed gastric cancer patients

Background

This study aimed to report the prevalence of HER2-neu in newly diagnosed early or metastatic gastric cancer (GC) patients, to determine the percentage of patients achieving various IHC scores correlating with the ISH results and to establish a database for GC patients in Lebanon.

Methods

This was a national, multicenter, descriptive and cross-sectional study in patients with histologically confirmed early or metastatic GC newly diagnosed. All eligible patients underwent the IHC and ISH tests in a central laboratory. Demographics, medical history and histopathology data were collected.

Results

One hundred fifty-seven patients were included (mean age at diagnosis: 63 ± 14.1 years) during a 3.5 year period. The prevalence of HER2-neu over expression was 21% (95% CI: 15.3–27.4) using ICH and ISH. Agreement between IHC and ISH results was significantly substantial (kappa = 0.681; p-value < 0.001). Over expressed HER2-neu status was significantly associated with high ECOG performance status only.

Conclusions

The prevalence of HER2-neu over expression in newly diagnosed early or metastatic GC patients seemed to be high in Lebanon. The database generated allows to monitor trends in the epidemiology and management of GC.

Dual block HER2 assessment increased HER2 immunohistochemistry positive rate in resected specimens of gastric cancer: a prospective multicenter clinical trial from China

Background

Former single center studies indicated that HER2 assessment with two primary tumor blocks (dual block HER2 assessment) could be an efficient and practical approach to overcome the adverse impact of heterogeneity and acquire a HER2 positive rate in gastric cancer (GC). This multicenter prospective clinical trial (NCT 02843412) was launched to verify its value and generality.

Methods

A total of 3806 participants with primary GCs have been enrolled from 8 hospitals in China. Two primary tumor blocks were selected and recorded as block 1 and block 2 after histological evaluation. An HER2 (4B5) rabbit monoclonal antibody was used for the immunohistochemistry (IHC) analysis.

Results

In total patients, HER2 IHC positive (3+) rate with dual block assessment (9.4%) was higher than that with single block assessment (block 1: 7.8%, block 2: 7.8%) (P < 0.001). Compared with single-block assessment, dual-block assessment increased the positive rate by approximate 20%. Similarly, HER2 equivocal (2+) rate was increased in dual block assessment (25.8%), which was higher than that in single block assessment (block 1: 20.3%, block 2: 20.9%) (P < 0.001). Conversely, dual block assessment demonstrated a lower HER2 negative (0/1+) rate (64.8%) than single block assessment (block1: 71.9%, block 2: 71.3%) (P < 0.001). These findings were also confirmed in individual hospitals.

Conclusions

Dual block HER2 assessment effectively increased HER2 IHC positive rate in resected specimens of GC. We recommended dual block HER2 assessment be promoted in routine clinical practice in GC.

Trial registration

ClinicalTrials.gov, NCT 02843412. Registered 1 July 2016 - Retrospectively registered.

Deep Learning-Based Protein Features Predict Overall Survival and Chemotherapy Benefit in Gastric Cancer

Gastric cancer (GC) is one of the most common malignant tumors with a high mortality rate worldwide and lacks effective methods for prognosis prediction. Postoperative adjuvant chemotherapy is the first-line treatment for advanced gastric cancer, but only a subgroup of patients benefits from it. Here, we used 833 formalin-fixed, paraffin-embedded resected tumor samples from patients with TNM stage II/III GC and established a proteomic subtyping workflow using 100 deep-learned features. Two proteomic subtypes (S-I and S-II) with overall survival differences were identified. S-I has a better survival rate and is sensitive to chemotherapy. Patients in the S-I who received adjuvant chemotherapy had a significant improvement in the 5-year overall survival rate compared with patients who received surgery alone (65.3% vs 52.6%; log-rank P = 0.014), but no improvement was observed in the S-II (54% vs 51%; log-rank P = 0.96). These results were verified in an independent validation set. Furthermore, we also evaluated the superiority and scalability of the deep learning-based workflow in cancer molecular subtyping, exhibiting its great utility and potential in prognosis prediction and therapeutic decision-making.

Gastric Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Gastric cancer is the third leading cause of cancer-related deaths worldwide. Over 95% of gastric cancers are adenocarcinomas, which are typically classified based on anatomic location and histologic type. Gastric cancer generally carries a poor prognosis because it is often diagnosed at an advanced stage. Systemic therapy can provide palliation, improved survival, and enhanced quality of life in patients with locally advanced or metastatic disease. The implementation of biomarker testing, especially analysis of HER2 status, microsatellite instability (MSI) status, and the expression of programmed death-ligand 1 (PD-L1), has had a significant impact on clinical practice and patient care. Targeted therapies including trastuzumab, nivolumab, and pembrolizumab have produced encouraging results in clinical trials for the treatment of patients with locally advanced or metastatic disease. Palliative management, which may include systemic therapy, chemoradiation, and/or best supportive care, is recommended for all patients with unresectable or metastatic cancer. Multidisciplinary team management is essential for all patients with localized gastric cancer. This selection from the NCCN Guidelines for Gastric Cancer focuses on the management of unresectable locally advanced, recurrent, or metastatic disease.

Emerging biological drugs for the treatment of gastroesophageal adenocarcinoma

INTRODUCTION

Gastric cancer (GC) and gastroesophageal junction cancer (GOJC) patients have a poor prognosis with a 5-year relative survival rate of 6% in the metastatic setting. Despite the well-characterized molecular features, patients have been historically considered for treatment with universal and undistinguishing chemotherapies and targeted agents, except for the HER2-positive population and some immunological approaches.

AREAS COVERED

In this review, we discuss the intrinsic characteristics of GC/GOJC from an epidemiological, molecular, and clinical perspective with an exhaustive evaluation of the reported and ongoing phase II/III clinical trials with targeted therapies.

EXPERT OPINION

The absence of robust biomarkers, the difficulties in measuring it due to the well-recognized molecular heterogeneity, and in part nonoptimistic clinical trial designs have been a major cause of frequent failure. Current efforts should focus on proper recognition of the distinctive molecular and clinical features of each GC/GOJC patient. Sequencing both tumor tissue DNA and ctDNA could identify targetable alterations, including rare alterations, thus allowing GC/GOJC patients for a precision medicine benefit.

Novel Biomarkers of Gastric Adenocarcinoma: Current Research and Future Perspectives

Simple Summary

Gastric cancer is characterized by poor survival rates despite surgery and chemotherapy. Current research focuses on biomarkers to improve diagnosis and prognosis, and to enable targeted treatment strategies. The aim of our review was to give an overview over the wide range of novel biomarkers in gastric cancer. These biomarkers are targets of a specific treatment, such as antibodies against human epidermal growth factor receptor 2. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are vascular endothelial growth factor, programmed cell death protein 1, and Claudin 18.2. There is a vast number of biomarkers based on DNA, RNA, and protein expression, as well as detection of circulating tumor cells and the immune tumor microenvironment.

Abstract

Overall survival of gastric cancer remains low, as patients are often diagnosed with advanced stage disease. In this review, we give an overview of current research on biomarkers in gastric cancer and their implementation in treatment strategies. The HER2-targeting trastuzumab is the first molecular targeted agent approved for gastric cancer treatment. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are VEGF and Claudin 18.2. Expression of MET has been shown to be a negative prognostic factor in gastric cancer. Targeting the PD-1/PD-L1 pathway with immune checkpoint inhibitors has proven efficacy in advanced gastric cancer. Recent technology advances allow the detection of circulating tumor cells that may be used as diagnostic and prognostic indicators and for therapy monitoring in gastric cancer patients. Prognostic molecular subtypes of gastric cancer have been identified using genomic data. In addition, transcriptome profiling has allowed a comprehensive characterization of the immune and stromal microenvironment in gastric cancer and development of novel risk scores. These prognostic and predictive markers highlight the rapidly evolving field of research in gastric cancer, promising improved treatment stratification and identification of molecular targets for individualized treatment in gastric cancer.

Proteomics provides individualized options of precision medicine for patients with gastric cancer

While precision medicine driven by genome sequencing has revolutionized cancer care, such as lung cancer, its impact on gastric cancer (GC) has been minimal. GC patients are routinely treated with chemotherapy, but only a fraction of them receive the clinical benefit. There is an urgent need to develop biomarkers or algorithms to select chemo-sensitive patients or apply targeted therapy. Here, we carried out retrospective analyses of 1,020 formalin-fixed, paraffin-embedded GC surgical resection samples from 5 hospitals and developed a mass spectrometry-based workflow for proteomic subtyping of GC. We identified two proteomic subtypes: the chemo-sensitive group (CSG) and the chemo-insensitive group (CIG) in the discovery set. The 5-year overall survival of CSG was significantly improved in patients who had received adjuvant chemotherapy after surgery compared with those who received surgery only (64.2% vs. 49.6%; Cox P-value=0.002), whereas no such improvement was observed in CIG (50.0% vs. 58.6%; Cox P-value=0.495). We validated these results in an independent validation set. Further, differential proteome analysis uncovered 9 FDA-approved drugs that may be applicable for targeted therapy of GC. A prospective study is warranted to test these findings for future GC patient care.

Remnant gastric cancer: a neglected group with high potential for immunotherapy

PURPOSE

The importance of targeted therapy and interest in the study of predictive markers in gastric cancer (GC) have increased in recent years with the use of anti-HER2 therapy and immunotherapy with anti-PD1/PD-L1 for microsatellite instability (MSI) and PD-L1 + tumors. However, the behavior of remnant GC (RGC) in this scenario is poorly reported. Thus, this study aims to evaluate the clinicopathological characteristics and prognosis of RGC and its association with the expression of current markers for targeted therapy.

METHODS

All RGC resections performed in a single center from 2009 to 2019 were retrospectively reviewed. As a comparison group, 53 primary proximal GC (PGC) who underwent total D2-gastrectomy were selected. HER2, MSI status and PD-L1 expression were analyzed by immunohistochemistry. Combined Positive Score (CPS) was used to determine PD-L1 positivity.

RESULTS

A total of 40 RGC were included. RGC patients were older (p = 0.001), had lower BMI (p = 0.001) and number of resected lymph nodes (p < 0.001) compared to the PGC. Regarding markers expression, MSI was higher in RGC than PGC (27.5% vs 9.4%, p = 0.022). The frequency of CPS-positive was 32.5% and 26.4% in RGC and PGC, respectively (p = 0.522). HER2 positivity was 17.5% and 22.6% for RGC and PGC, respectively (p = 0.543). In survival analysis, DFS was better for RGC CPS-positive than RGC CPS-negative (p = 0.039) patients. There was no difference in survival considering MSI status.

CONCLUSION

RGC had higher incidence of MSI than PGC, and CPS-positive RGC was associated with better survival. The immunological profile of RGC patients suggests that they would be good candidates for immunotherapy.

HER2 Heterogeneity in Gastric Cancer: A Comparative Study, Using Two Commercial Antibodies

BACKGROUND

Although amplification of the gene encoding human epidermal growth factor receptor 2 (HER2) is used as an indicator for response to trastuzumab, the reported response rate is low, and few patients with gastric cancer (GC) benefit from this individualized therapy. The aim of this study was to examine the expression of c-erbB-2 oncoprotein (HER2), in GC samples, using two commercial immunohistochemical (IHC) antibodies, and to validate the results by checking HER2 gene amplification by fluorescence in situ hybridization (FISH).

METHODS

We assessed the IHC expression of HER2 using the polyclonal antibody from Dako and CB11 clone from Leica, in 93 consecutive cases of GC samples. In all of the cases, FISH analysis was also performed using the BOND-MAX platform.

RESULTS

No significant difference was observed between the two HER2 antibodies. Of the 93 cases, 22.58% demonstrated at least focal and 1+ HER2 positivity. Seven cases (7.53%) exhibited 3+ expression, and another 7 carcinomas (7.53%) were equivocal (2+). HER2 amplification was seen in 11 cases (11.83%), 10 of which were differentiated adenocarcinomas. In 5 of the cases, 2-5 sections were examined, which proved the extremely high intratumorally/intraglandular heterogeneity. FISH heterogeneity was higher in cases with only 2+ positivity on IHC assessment, compared with those showing at least one small focus of 3+ overexpression. HER2 amplification proved to be an independent negative prognostic factor.

CONCLUSIONS

Due to the highly heterogeneous aspect of GC, at least 3-4 slides should be assessed by IHC, before considering a tumor to be HER2-negative. In cases with small 3+ foci representing less than 5% of tumor and in equivocal (2+) cases, FISH analysis remains the gold standard method.

Immune checkpoint inhibitor combination therapy for gastric cancer: Research progress

Gastric cancer is one of the most common types of cancer; notably, gastric cancer is one of the top five malignancies with regards to incidence and mortality rates. The symptoms of early gastric cancer are not typical, exhibiting only slight upper abdominal discomfort. When the symptoms become more obvious, the lesion has usually progressed to an advanced stage. Notably, >90% of inpatients already have locally advanced or metastatic gastric cancer at the time of initial diagnosis, with limited treatment options for advanced gastric cancer. These options include chemotherapy, targeted therapy and immune checkpoint inhibitors (ICIs). With regards to ICIs, the clinical benefit of monotherapy for advanced gastric cancer is limited; however, combinations of ICIs and other therapies may have clinical benefit. Relevant clinical studies have demonstrated that combinations of ICIs with chemotherapy, anti-vascular targeted therapy or other molecular targeted therapies, and the use of two ICIs, improve outcomes for patients with advanced gastric cancer. This article is a review of progress in the use of ICIs in combination with other therapies for the treatment of gastric cancer. The purpose of this article was to advance gastric cancer immunotherapy and to improve the overall therapeutic benefit for patients with advanced gastric cancer.

Gastric Cancer in Young Adults: A Different Clinical Entity from Carcinogenesis to Prognosis

Approximately 5.0% of gastric cancer (GC) patients are diagnosed before the age of 40 and are not candidates for screening programs in most countries and regions. The incidence of gastric cancer in young adults (GCYA) has declined over time in most countries except in the United States. Genetic alterations, environmental factors, and lifestyle may predispose some young adults to GC. According to molecular classifications, the cancer of most GCYA patients belongs to the genomically stable or microsatellite stable/epithelial-mesenchymal transition subtype, with the common genetic aberrations being mutations in CDH1. What characterizes GCYA are a higher prevalence in females, more aggressive tumor behaviors, diagnosis at advanced stages, fewer comorbidities and being better treatment candidates, and a similar or better survival outcome when compared with older patients. Considering the greater loss of life-years in younger patients, lowering the incidence of GC and diagnosing at a relatively early stage are the two most effective ways to decrease GC mortality. To achieve these goals, the low awareness of GCYA among general people, policy-makers, clinicians, and researchers should be changed.

The age variation of HER2 immunohistochemistry positive rate in biopsy specimens of gastric cancer

AIMS

The aim of this study was to explore HER2 status and characteristics in biopsy specimens of gastric cancer (GC) in Chinese population.

METHODS AND RESULTS

A total of 27,787 biopsy specimens of GC from 103 hospitals were obtained. Immunohistochemistry (IHC) staining of HER2 was performed. Overall HER2 IHC positive rate was 11.2 %. HER2 positive rate elevated with the increase of age in total patients and both genders. The rates were 7.1 %, 8.1 %, 9.0 %, 10.9 %, 11.8 %, 12.6 %, and 12.1 % when patient age was ≤30, 31-40, 41-50, 51-60, 61-70, 71-80, and >80, respectively (P < 0.001). In male, the rates were 6.5 %, 8.4 %, 9.6 %, 11.5 %, 12.4 %, 13.3 %, and 12.1 % (P < 0.001). In female, the rates were 7.4 %, 7.9 %, 8.0 %, 9.0 %, 9.6 %, 10.6 %, and 11.9 % (P = 0.128). The changes in male were more dramatic than in female (P < 0.001). Furthermore, the proportion of the intestinal type GCs increased with age in total patients and both genders (P < 0.001), and in male the changes were more dramatic (P < 0.001). While the proportion of the diffuse type showed the opposite tendency to that of the intestinal type (P < 0.001). HER2 IHC positive rate showed a positive correlation with the proportion of the intestinal type (r=0.986, P < 0.001), and a negative correlation with the proportion of the diffuse type (r=0.984, P < 0.001).

CONCLUSIONS

The HER2 IHC positive rate showed age variation in biopsy specimens of GC. In male the variation was more dramatic than in female. The variation of HER2 positive rate can be attributed to the age variation of the Lauren subtypes.

Treatment strategies for metastatic gastric cancer: chemotherapy, palliative surgery or radiotherapy?

Aim: This study explored whether chemotherapy combined with palliative surgery and/or radiotherapy is a possible treatment for metastatic gastric cancer. Materials & methods: Patients were divided into groups according to treatments. COX models were used to explore prognostic factors. Kaplan-Meier models and log-rank tests were used to analyze outcomes. Outcomes were analyzed before and after propensity score matching. Results: Chemotherapy combined with gastrectomy or metastasectomy prolongs the survival time compared with chemotherapy alone (p < 0.05). Chemotherapy combined with gastrectomy plus metastasectomy and/or radiation therapy also prolongs the survival time (p < 0.05). Conclusion: Chemotherapy combined with gastrectomy could be a more effective treatment for metastatic gastric cancer. Chemotherapy combined with gastrectomy plus metastasectomy and/or radiation therapy could also be a promising treatment.

Prognostic significance of Human epidermal growth factor receptor-2 expression in patients with resectable gastric adenocarcinoma

BACKGROUND

The purpose of this study was to investigate the correlation between human epidermal growth factor receptor 2 (HER2) overexpression and clinicopathologic factors and overall survival rate in patients who underwent curative gastrectomy for gastric adenocarcinoma.

METHODS

Among patients who underwent curative gastrectomy for gastric adenocarcinoma at Inje University Paik Hospital from January 2012 to December 2015, 782 patients underwent an immunohistochemical analysis to evaluate HER2 expression levels. Clinicopathologic records that were collected from a gastric cancer database were retrospectively reviewed to identify clinicopathologic factors and survival rates of the patients.

RESULTS

HER2 overexpression was detected in 166 patients (21.2%). There was a statistically significant correlation between HER2 expression level and sex (p = 0.013), histologic differentiation (p < 0.001), Lauren classification (p < 0.001), and T pathologic stage (p = 0.022). There were no statistically significant relationships between HER2 expression level and overall 5-year survival rate (p = 0.775) and overall 5-year survival rate of gastric adenocarcinoma classified according to the TNM stage (stage I: p = 0.756, stage II: p = 0.571, stage III: p = 0.704). The HER2 expression level was not affected by the overall 5-year survival rate in the uni- and multivariate analyses.

CONCLUSIONS

In this study, the HER2 overexpression rate in gastric adenocarcinoma was 21.2% and was observed in well- and moderately differentiated types according to histologic differentiation, intestinal type according to the Lauren classification, male, and low T stage. There was no correlation between HER2 expression level and overall 5-year survival rate, and HER2 expression level was not associated with independent prognostic factors.

Updates in Effusion Cytology

Effusion cytology plays multiple roles in the management of benign and malignant disease, from primary diagnosis to tissue allocation for ancillary diagnostic studies and biomarker testing of therapeutic targets. This article summarizes recent advances in pleural effusion cytology, with a focus on the practical application of immunohistochemical markers, cytogenetic techniques, flow cytometry, and molecular techniques for the diagnosis and management of primary and secondary neoplasms of the pleura.

Molecular biomarkers in gastro-esophageal cancer: recent developments, current trends and future directions

Gastro-esophageal adenocarcinomas (GEA) represent a severe global health burden and despite improvements in the multimodality treatment of these malignancies the prognosis of patients remains poor. HER2 overexpression/amplification has been the first predictive biomarker approved in clinical practice to guide patient selection for targeted treatment with trastuzumab in advanced gastric and gastro-esophageal junction cancers. More recently, immunotherapy has been approved for the treatment of GEA and PD-L1 expression is now a biomarker required for the administration of pembrolizumab in these diseases. Significant progress has been made in recent years in dissecting the genomic makeup of GEA in order to identify distinct molecular subtypes linked to distinct patterns of molecular alterations. GEA have been found to be highly heterogeneous malignances, representing a challenge for biomarkers discovery and targeted treatment development. The current review focuses on an overview of established and novel promising biomarkers in GEA, covering recent molecular classifications from TCGA and ACRG. Main elements of molecular heterogeneity are discussed, as well as emerging mechanisms of primary and secondary resistance to HER2 targeted treatment and recent biomarker-driven trials. Future perspectives on the role of epigenetics, miRNA/lncRNA and liquid biopsy, and patient-derived xenograft models as a new platform for molecular-targeted drug discovery in GEA are presented. Our knowledge on the genomic landscape of GEA continues to evolve, uncovering the high heterogeneity and deep complexity of these tumors. The availability of new technologies and the identification of promising novel biomarker will be critical to optimize targeted treatment development in a setting where therapeutic options are currently lacking. Nevertheless, clinical validation of novel biomarkers and treatment strategies still represents an issue.

HER2 testing of gastro-oesophageal adenocarcinoma: a commentary and guidance document from the Association of Clinical Pathologists Molecular Pathology and Diagnostics Committee

The use of biologics targeted to the human epidermal growth factor receptor 2 (HER2) protein is the latest addition to the armamentarium used to fight advanced gastric or gastro-oesophageal junction adenocarcinoma. The decision to treat with the biologic trastuzumab is completely dependent on HER2 testing of tumour tissue. In 2017, the College of American Pathologists, American Society for Clinical Pathology and the American Society of Clinical Oncology jointly published guidelines for HER2 testing and clinical decision making in gastro-oesophageal adenocarcinoma. The Association of Clinical Pathologists Molecular Pathology and Diagnostics Committee has issued the following document as a commentary of these guidelines and, in parallel, to provide guidance on HER2 testing in National Health Service pathology departments within the UK. This guidance covers issues related to case selection, preanalytical aspects, analysis and interpretation of such HER2 testing.

HER2 is frequently overexpressed in hepatoid adenocarcinoma and gastric carcinoma with enteroblastic differentiation: a comparison of 35 cases to 334 gastric carcinomas of other histological types

AIMS

α-Fetoprotein (AFP)-producing gastric carcinoma (AFPGC) is one of the most aggressive GC subtypes. Frequent expression of human epidermal growth factor receptor 2 (HER2) has previously been reported in hepatoid adenocarcinoma (HAC), a major histological subtype of AFPGC originating from common-type GC (CGC). However, HER2 expression levels in other AFPGC histological subtypes are unknown. In this study, we analysed HER2 expression in GCs with primitive phenotypes in addition to HAC.

METHODS

HER2 expression was evaluated in representative complete sections from 16 HACs, 19 GCs with enteroblastic differentiation (GCEDs) and 334 GCs of other histological types as controls. The Ruschoff/Hofmann method was used to score HER2 immunohistochemistry. Samples with a HER2 score of 2+ were further assessed using fluorescence in situ hybridisation. Oncofetal protein (OFP) expression in HAC and GCED was tested via immunohistochemical staining for AFP, glypican 3 and Sal-like protein 4.

RESULTS

Thirty of 35 HAC/GCED cases comprised more than two histological patterns. The HER2 positivity rates of each histological component in the HACs/GCEDs were 25.0% for HAC (n=16), 34.6% for GCED (n=26) and 48.1% for CGC (n=27), which were higher than those of the control group (13.8%). Additionally, the majority of CGC components in HACs/GCEDs were positive for OFP (88.9%).

CONCLUSIONS

HER2 is frequently overexpressed not only in HAC but also in GCED and CGC components of HACs/GCEDs, which suggests an association between HER2 and OFP expression. Moreover, our findings suggest that HER2-positive CGC has a higher risk of progression to HAC/GCED than HER2-negative GC.

Trastuzumab in the management of gastroesophageal cancer: patient selection and perspectives

The addition of trastuzumab to the treatment of a subset of patients with advanced gastric and gastroesophageal junction cancers showing HER2 positivity has been shown to confer clinical benefit; however, questions remain over the optimal methods for defining and selecting such patients. This review provides an overview of current standards for assessing HER2 positivity, the evolving treatment landscape for HER2-positive gastric and esophageal cancers and the challenges and potential future directions in optimal patient selection for HER2-targeted therapy.