Impact of expression of human epidermal growth factor receptors EGFR and ERBB2 on survival in stage II/III gastric cancer

Clinical impact of tumour biology in the management of gastroesophageal cancer

The characterization of oesophageal and gastric cancer into subtypes based on genotype has evolved in the past decade. Insights into the molecular landscapes of gastroesophageal cancer provide a roadmap to assist the development of new drugs and their use in combinations, for patient stratification, and for trials of targeted therapies. Trastuzumab is the only approved treatment for gastroesophageal cancers that overexpress HER2. Acquired resistance usually limits the duration of response to this treatment, although a number of new agents directed against HER2 have the potential to overcome or prolong the time until resistance occurs. Beyond that, anti-VEGFR2 therapy with ramucirumab was the first biological treatment strategy to produce a survival benefit in an unselected population of patients with chemotherapy-refractory gastroesophageal cancer. Large initiatives are starting to address the role of biomarker-driven targeted therapy in the metastatic and in the perioperative setting for patients with this disease. Immunotherapy also holds promise, and our understanding of subsets of gastroesophageal cancer based on patterns of immune response continues to evolve. Efforts are underway to identify more relevant genomic subsets through genomic screening, functional studies, and molecular characterization. Herein, we provide an overview of the key developments in the treatment of gastroesophageal cancer, and discuss potential strategies to further optimize therapy by targeting disease subtypes.

Synergistic combination of DT-13 and topotecan inhibits human gastric cancer via myosin IIA-induced endocytosis of EGF receptor in vitro and in vivo

Combination therapy has a higher success rate for many cancers compared to mono-therapy. The treatment of Topotecan (TPT) on gastric cancer (GC) is limited by its toxicity and the potential drug resistance. We found that the combination of the saponin monomer 13 from the dwarf lilyturf tuber (DT-13), performing anti-metastasis and anti-angiogenesis effects, with TPT synergistically induced apoptotic cytotoxicity in GCs with high EGF receptor (EGFR) expression, which was dependent on DT-13-induced endocytosis of EGFR. With TPT, DT-13 promoted EGFR ubiquitin--mediated degradation through myosin IIA-induced and Src/ caveolin-1 (Cav-1)-induced endocytosis of EGFR; inhibited EGFR downstream signalling and then increased the pro-apoptotic effects. Moreover, the synergistic pro-apoptotic efficacy of DT-13 and TPT in GCs with high EGFR expression was eliminated by both the NM II inhibitor (-)-blebbistatin and MYH-9 shRNA. The combination therapy of DT-13 with TPT showed stronger anti-tumour effects in vivo compared with their individual effects. Moreover, the results of combination therapy revealed selective upregulation of pro-apoptotic activity in TUNEL assays and cleaved caspase-3 and NM IIA in immunohischemical analysis; while specific downregulation of p-extracellular regulated kinase 1/2 (p-ERK1/2), EGFR and Cav-1 in immunohischemical analysis. Collectively, these findings have significant clinical implications for patients with tumours harbouring high EGFR expression due to the possible high sensitivity of this regimen.

Serum biomarker panels for diagnosis of gastric cancer

Purpose

Currently, serum biomarkers that are sufficiently sensitive and specific for early detection and risk classification of gastric adenocarcinomas are not known. In this study, ten serum markers were assessed using the Luminex system and enzyme-linked immunosorbent assay for the diagnosis of gastric cancer and analysis of the relation between prognosis and metastases.

Patients and methods

A training set consisting of 228 gastric adenocarcinoma and 190 control samples was examined. A Luminex multiplex panel with nine biomarkers, consisting of three proteins discovered through our previous studies and six proteins previously reported to be cancer-associated, was constructed. One additional biomarker was detected using a commercial kit containing EDTA. Logistic regression, random forest (RF), and support vector machine (SVM) were used to identify the panel of discriminatory biomarkers in the training set. After selecting five proteins as candidate biomarkers, multivariate classification analyses were used to identify algorithms for diagnostic biomarker combinations. These algorithms were independently validated using a set of 57 gastric adenocarcinoma and 48 control samples.

Results

Serum pepsinogen I, serum pepsinogen II, A Disintegrin And Metalloproteinase domain-containing protein 8 (ADAM8), vascular endothelial growth factor (VEGF), and serum IgG to Helicobacter pylori were selected as classifiers in the three algorithms. These algorithms differentiated between the majority of gastric adenocarcinoma and control serum samples in the training/test set with high accuracy (RF 79.0%, SVM 83.8%, logistic regression 76.2%). These algorithms also differentiated the samples in the validation set (accuracy: RF 82.5%, SVM 86.1%, logistic regression 78.7%).

Conclusion

A panel of combinatorial biomarkers comprising VEGF, ADAM8, IgG to H. pylori, serum pepsinogen I, and pepsinogen II were developed. The use of biomarkers is a less invasive method for the diagnosis of gastric adenocarcinoma. They may supplement clinical gastroscopic evaluation of symptomatic gastric cancer patients and enhance the diagnostic accuracy.

Prognostic significance and frequency of EGFR expression and amplification in surgically resected advanced gastric cancer

OBJECTIVE

The aim of this study is to find the frequency and the role of epidermal growth factor receptor expression as a prognostic biomarker in gastric cancer.

METHODS

We evaluated the prognostic value and frequency of epidermal growth factor receptor expression and amplification using immunohistochemistry and silver in situ hybridization in a large cohort of curatively resected gastric cancer.

RESULTS

Of the total of 935 cases, 294 (31.4%), 101 (10.8%) and 36 (3.9%) patients showed epidermal growth factor receptor 1+, 2+ and 3+ expression on immunohistochemistry, respectively. Epidermal growth factor receptor-positive (2+/3+) patients more frequently had intestinal type than epidermal growth factor receptor-negative (0/1+) patients (82.5 vs. 44.1%, P < 0.001). After adjusting for sex, age, stage and adjuvant chemotherapy, epidermal growth factor receptor-positive patients had a favorable overall survival outcome compared with epidermal growth factor receptor-negative patients (hazard ratio, 0.734; 95% confidence interval, 0.541-0.997; P = 0.047), especially in Stage III disease (hazard ratio, 0.676; 95% confidence interval, 0.472-0.968; P = 0.033). Among the 393 cases available for  in situ hybridization, the correlation between immunohistochemistry and in situ hybridization was statistically significant (P = 0.001). Thirteen patients with gene amplification (3.3%) did not show different survival outcome with others (P = 0.359).

CONCLUSION

Epidermal growth factor receptor positivity was an independent favorable prognostic factor for gastric cancer, especially in Stage III disease.

Lymph node ratio as a novel and simple prognostic factor in advanced gastric cancer

TNM staging is no doubt the most critical prognostic factors, representing tumor (T)/lymph node metastasis (N)/distant metastasis (M) in gastric cancer. Lymph node ratio-based N system (Nr) has been repeatedly reported to be of prognostic relevance in advanced gastric cancer independent of stage in the multivariate analysis world-wide, and proposed as more sophisticated than N with regard to predicting accurate prognosis. As a result, proposed TNrM system may predict survival more accurately than the present TNM staging system for patients undergoing limited lymph node analysis. It could adjust stage migration when the lymph node number was used as staging factor. Although correlation of the number of metastatic lymph nodes and lymph node ratio is obvious, biological characteristics other than that could also have been reflected on. It may indicate how successful the operation of lymph node dissection was, or it may be revealing the potential of the patient's lymph node immune-reaction. Recently, high lymph node ratio is closely associated with EGFR expression in advanced gastric cancer. When efficiency of applying lymph node ratio as a biomarker is verified and confirmed in an expansive research, and when cancer causing molecules are identified, as well as the competence as a treatment target is studied, the new biomarker, namely, lymph node ratio, could find itself in a limelight in gastric cancer treatment in the future.

Mucin glycosylating enzyme GALNT2 suppresses malignancy in gastric adenocarcinoma by reducing MET phosphorylation

Glycosylation affects malignancy in cancer. Here, we report that N- acetylgalactosaminyltransferase 2 (GALNT2), an enzyme that mediates the initial step of mucin type-O glycosylation, suppresses malignant phenotypes in gastric adenocarcinoma (GCA) by modifying MET (Hepatocyte growth factor receptor) activity. GALNT2 mRNA and protein were downregulated in GCAs, and this reduction was associated with more advanced disease stage and shorter recurrence-free survival. Suppressing GALNT2 expression in GCA cells increased cell growth, migration, and invasion in vitro, and tumor metastasis in vivo. GALNT2 knockdown enhanced phosphorylation of MET and decreased expression of the Tn antigen on MET. Inhibiting MET activity with PHA665752 decreased the malignant phenotypes caused by GALNT2 knockdown in GCA cells. Our results indicate that GALNT2 suppresses the malignant potential of GCA cells and provide novel insights into the significance of O-glycosylation in MET activity and GCA progression.

Epidermal growth factor receptor expression and gene copy number analysis in gastric carcinoma samples from Chinese patients

Epidermal growth factor receptor (EGFR) expression and gene copy number have been observed to be associated with a positive clinical response to EGFR inhibitors. The present study aimed to evaluate EGFR expression and gene copy number in samples of gastric carcinoma (GC) from Chinese patients. EGFR expression and gene copy number were detected using immunohistochemistry and fluorescence in situ hybridization, in tissue array slides containing 150 individual samples of GC tissue. The association between EGFR status, clinicopathological features and overall patient survival was analyzed. Out of the 150 cases of GC evaluated, 63 (42.00%) demonstrated weak EGFR expression and 20 (13.33%) demonstrated EGFR overexpression. EGFR expression was observed to be associated with tumor location (P<0.05). Out of 104 cases of GC, which produced a clear FISH signal, 6 (5.77%) exhibited EGFR gene amplification and 5 (4.80%) exhibited balanced polysomy. Patients exhibiting GC, who demonstrated weak EGFR expression, EGFR overexpression or increased EGFR gene copy number, possessed an unfavorable prognosis. Multivariate analysis revealed that EGFR expression, tumor/node/metastasis stage and tumor location were potential independent unfavorable prognostic factors for GC patients. In conclusion, EGFR overexpression, gene amplification and polysomy were observed in GC patients and were associated with an unfavorable prognosis. Evaluation of EGFR status may therefore facilitate the identification of a subset of GC patients sensitive to treatment with EGFR-targeted therapies.

Expression and Prognostic Significance of Human Epidermal Growth Factor Receptors 1 and 3 in Gastric and Esophageal Adenocarcinoma

Background

Gastric and esophageal adenocarcinomas are major global cancer burdens. These cancer forms are characterized by a poor prognosis and a modest response to chemo- radio- and targeted treatment. Hence there is an obvious need for further enhanced diagnostic and treatment strategies. The aim of this study was to examine the expression and prognostic impact of human epidermal growth factor receptor 1 (HER1/EGFR) and 3 (HER3), as well as the occurrence of EGFR and KRAS mutations in gastric and esophageal adenocarcinoma.

Methods

Immunohistochemical expression of EGFR and HER3 was analysed in all primary tumours and a subset of lymph node metastases in a consecutive cohort of 174 patients with adenocarcinoma of the stomach, cardia and esophagus. The anti-HER3 antibody used was validated by siRNA-mediated knockdown, immunohistochemistry and quantitative real-time PCR. EGFR and KRAS mutation status was analysed by pyrosequencing tecchnology.

Results and Discussion

High EGFR expression was an independent risk factor for shorter overall survival (OS), whereas high HER3 expression was associated with a borderline significant trend towards a longer OS. KRAS mutations were present in only 4% of the tumours and had no prognostic impact. All tumours were EGFR wild-type. These findings contribute to the ongoing efforts to decide on the potential clinical value of different HERs and druggable mutations in gastric and esophageal adenocarcinomas, and attention is drawn to the need for more standardised investigational methods.

Effect of EGFR and p-AKT Overexpression on Chromosomal Instability in Gastric Cancer

BACKGROUND

Molecular profiling in gastric cancer (GC) is important for diagnosis and treatment. In this study, we investigated signal transduction pathways that might induce chromosomal instability in GC.

METHODS

Epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and p-AKT expression were analyzed using immunohistochemistry, and chromosomal instability was assessed by DNA aneuploidy using laser scanning cytometry, in a total of 202 GC cases.

RESULTS

The rate of EGFR expression and p-AKT expression was 70.3 and 34.2 %, respectively, in GC patients. In total, 57.5 % of GC patients exhibited DNA aneuploidy, and p-AKT positively correlated with EGFR and HER2 (p = 0.0127 and p = 0.00031, respectively). Patients with EGFR overexpressing GC showed shorter disease-specific survival than the other cases (hazard ratio 2.00, 95 % confidence interval 1.19-3.53; p = 0.0104). Moreover, EGFR and p-AKT expression was significantly correlated with DNA aneuploidy (p = 0.0002 and p = 0.0302, respectively).

CONCLUSIONS

Our data showed that both EGFR and p-AKT overexpression were clearly associated with DNA aneuploidy. Aneuploidy could be a useful marker for therapies that target EGFR.

Tumor Infiltrative Pattern Predicts Sites of Recurrence After Curative Gastrectomy for Stages 2 and 3 Gastric Cancer

BACKGROUND

In East Asia, the tumor infiltrative pattern (INF) has been routinely evaluated by hematoxylin and eosin-stained sections as a pathologic characteristic of surgically resected specimens.

METHODS

The infiltrative pattern of gastric cancer (GC) has been histopathologically classified as INFa (expansive growth), INFb (intermediate type) and INFc (infiltrative growth) according to the Japanese Classification of Gastric Carcinoma. The prognostic value and characteristics of the disease recurrence pattern for each INF type were assessed in 785 patients with various stages of GC and also in 243 patients with stages 2 and 3 GC.

RESULTS

Comparison of the overall survival experienced by patients independently of stage showed that INF was significantly associated with prognosis. Specifically, peritoneal metastasis was present in 91 % of stage 4 patients in the INFc group, whereas hepatic metastasis was present in 39 % of stage 4 patients in the INFa and INFb group. After curative gastrectomy of patients with stages 2 or 3 GC, INF was not significantly associated with survival. The prevalence of peritoneal recurrence was significantly higher in the INFc group than in the INFa and INFb group, whereas the prevalence of hepatic recurrence was significantly higher in the INFa and INFb group than in the INFc group. Multivariate analysis identified INFc as an independent risk factor for peritoneal recurrence after curative gastrectomy. The association of the INF type with the incidence of peritoneal recurrence was observed with all disease stages regardless whether the patient was given adjuvant chemotherapy or not.

CONCLUSIONS

Evaluation of the INF type shows promise for its role as a predictor of postoperative recurrence sites in patients with GC.

Inhibition of non-small cell lung cancer (NSCLC) growth by a novel small molecular inhibitor of EGFR

The epidermal growth factor receptor (EGFR) is a therapeutic target (oncotarget) in NSCLC. Using in vitro EGFR kinase activity system, we identified a novel small molecule, WB-308, as an inhibitor of EGFR. WB-308 decreased NSCLC cell proliferation and colony formation, by causing G2/M arrest and apoptosis. Furthermore, WB-308 inhibited the engraft tumor growths in two animal models in vivo (lung orthotopic transplantation model and patient-derived engraft mouse model). WB-308 impaired the phosphorylation of EGFR, AKT, and ERK1/2 protein. WB-308 was less cytotoxic than Gefitinib. Our study suggests that WB-308 is a novel EGFR-TKI and may be considered to substitute for Gefitinib in clinical therapy for NSCLC.

Gene copy number gain of EGFR is a poor prognostic biomarker in gastric cancer: evaluation of 855 patients with bright-field dual in situ hybridization (DISH) method

BACKGROUND

EGFR overexpression is a prognostic biomarker and is expected to be a predictive biomarker for anti-EGFR therapies in gastric cancer. However, few studies have reported the clinical impact of EGFR gene copy number (GCN) and its correlation with EGFR overexpression.

METHODS

We used dual in situ hybridization (DISH) to detect EGFR GCN and chromosome 7 centromere (CEN7) in a set of tissue microarrays representing 855 patients with gastric cancer. These data were compared with those of immunohistochemical (IHC) analysis of EGFR expression to evaluate prognostic value.

RESULTS

EGFR GCN gain (≥ 2.5 EGFR signals per cell) was detected in 194 patients (22.7%) and indicated poor prognosis. Among 194 patients, EGFR amplification (EGFR/CEN7 ≥ 2.0) was observed in 29 patients (14.9%), which was almost identical to the IHC 3+ subgroup and worst prognostic subgroup. Patients with EGFR GCN gain but not amplification, including those exhibiting polysomy, also exhibited poorer prognosis than GCN non-gain patients and were distributed between IHC 0/1+ and 2+ subgroups. GCN gain was frequently observed in patients with more advanced disease, but served as an independent prognostic factor regardless of the pathological stage.

CONCLUSIONS

EGFR GCN gain is a more accurate prognostic biomarker than EGFR overexpression in patients with gastric cancer.

Prognostic impact of HER2, EGFR, and c-MET status on overall survival of advanced gastric cancer patients

BACKGROUND

This study was conducted to investigate whether human epidermal growth factor receptor 2 (HER2) status, epidermal growth factor receptor (EGFR) status, and c-MET status are independent prognostic factors for advanced gastric cancer patients who received standard chemotherapy.

METHOD

Unresectable or recurrent gastric or gastroesophageal junction cancer patients with histologically confirmed adenocarcinoma treated with S-1 plus cisplatin as first-line chemotherapy were eligible. Formalin-fixed paraffin-embedded tumor samples were examined for HER2, EGFR, and c-MET status using immunohistochemistry (IHC). Additionally, gene amplification was examined using fluorescent in situ hybridization (FISH) for HER2. Positivity was defined as an IHC score of 3+ or an IHC score of 2+/FISH positive for HER2, and an IHC score of 2+ or 3+ for both EGFR and c-MET.

RESULTS

Of the 293 patients from nine institutions, 43 (15%) were HER2 positive, 79 (27%) were EGFR positive, and 120 (41%) were c-MET positive. Ten patients (3%) showed positive co-expression of HER2, EGFR, and c-MET. After a median follow-up time of 58.4 months with 280 deaths, there was no significant difference in overall survival (OS) in terms of HER2 and EGFR status. However, there was a significant difference in OS between c-MET-positive and c-MET-negative patients [median, 11.9 months vs 14.2 months; hazard ratio, 1.31 (95% confidence interval, 1.03-1.67); log-rank P = 0.024]. Multivariate analysis also showed that c-MET positivity was still a prognostic factor for OS [hazard ratio, 1.30 (95% confidence interval, 1.02-1.67); P = 0.037].

CONCLUSIONS

The study suggested that c-MET-positive status had poor prognostic value. These data could be used as the basis for future clinical trials for targeting agents for advanced gastric cancer patients.

Targeting HER 2 and angiogenesis in gastric cancer

Gastric cancer is one of the most commonly diagnosed and the second leading cause of cancer death worldwide. Surgery combined with multimodal therapy remains the only curative therapy. However, local relapse or distant metastases occur in more than 50% of radically resected patients. Due to molecular therapies, targeting HER2 and angiogenesis, major advances in the treatment of gastric cancer could be achieved. Nevertheless, development of resistance to monoclonal antibodies, such as trastuzumab, is arising. Currently a number of promising new therapeutic are under investigation, combining chemotherapy with newly developed agents to overcome cancer resistance. In this review we report current clinical applications of targeted therapies and overview ongoing trials, investigating the use of monoclonal antibodies in (HER2 positive) gastric cancer.

Impact of c-erbB-2 protein on 5-year survival rate of gastric cancer patients after surgery: a cohort study and meta-analysis

OBJECTIVE

To explore the association of c-erbB-2 protein expression with clinicopathological characteristics and prognosis of gastric cancer (GC) after surgery.

METHODS

A total of 133 patients undergoing surgical resection for GC between March 2006 and January 2009 in the Second Affiliated Hospital of Wenzhou Medical University were included in this study. c-erbB-2 protein expression was determined by immunohistochemistry. Afterwards, a meta-analysis was performed to further confirm the association between c-erbB-2 protein expression and GC by employing stringent inclusion and exclusion criteria. All data analyses were conducted with STATA 12.0 and SPSS 19.0.

RESULTS

There was no significant difference in c-erbB-2 expression among patients with various parameters including age, gender and histological types (all p>0.05). Among 133 GC patients, 32 patients presented c-erbB-2-positive expression and 101 presented c-erbB-2-negative expression (24.1% vs. 75.9%). The c-erbB-2-positive expression rate was significantly higher in GC tissues of patients with lymph node metastasis than those without. Similarly, a significant increase in c-erbB-2 expression was observed in well/moderately differentiated GC tissues compared with poorly differentiated GC. Patients with negative c-erbB-2 expression had a higher 5-year survival rate than those with positive c-erbB-2 expression, which was consistent with the results of the meta-analysis (OR = 0.54, 95% CI 0.37-0.80, p = 0.002).

CONCLUSIONS

Our study demonstrated that high expression of c-erbB-2 protein was strongly associated with lymph node metastasis, histological differentiation and 5-year survival rate in GC patients after surgery.

Molecular Dimensions of Gastric Cancer: Translational and Clinical Perspectives

Gastric cancer is a global health burden and has the highest incidence in East Asia. This disease is complex in nature because it arises from multiple interactions of genetic, local environmental, and host factors, resulting in biological heterogeneity. This genetic intricacy converges on molecular characteristics reflecting the pathophysiology, tumor biology, and clinical outcome. Therefore, understanding the molecular characteristics at a genomic level is pivotal to improving the clinical care of patients with gastric cancer. A recent landmark study, The Cancer Genome Atlas (TCGA) project, showed the molecular landscape of gastric cancer through a comprehensive molecular evaluation of 295 primary gastric cancers. The proposed molecular classification divided gastric cancer into four subtypes: Epstein-Barr virus–positive, microsatellite unstable, genomic stable, and chromosomal instability. This information will be taken into account in future clinical trials and will be translated into clinical therapeutic decisions. To fully realize the clinical benefit, many challenges must be overcome. Rapid growth of high-throughput biology and functional validation of molecular targets will further deepen our knowledge of molecular dimensions of this cancer, allowing for personalized precision medicine.

Combination therapy with zoledronic acid and cetuximab effectively suppresses growth of colorectal cancer cells regardless of KRAS status

Targeted molecular therapy is an effective anticancer strategy. Anti‐EGFR monoclonal antibodies such as cetuximab (CTX) have been approved for the treatment of various malignancies, including colorectal cancer (CRC) with wild‐type KRAS. However, their efficacy in patients with KRAS mutations has not been established. Therefore, we investigated whether CTX treatment was effective as a single agent or in combination with zoledronic acid (ZOL) in human CRC cell lines with different KRAS status. CRC cell lines SW48 (wild‐type KRAS) and LS174T (mutant KRAS) were treated with ZOL, CTX and a combination of both drugs. Cytotoxicity was measured using the MTT assay. Changes in the levels of intracellular signaling proteins were evaluated using western blot analysis. Finally, we evaluated the efficacy of the combination treatment in an in vivo xenograft model. We observed that ZOL apparently inhibited growth in both cell lines, whereas CTX showed little effect. ZOL also increased the levels of unprenylated RAS. Combined ZOL and CTX treatment was synergistic in both cell lines and was associated with inhibition of the RAS‐MAPK and AKT‐mTOR signaling pathways. Furthermore, the combination treatment was more effective in suppressing the growth of xenografts derived from both SW48 and LS174T cells; this effect was associated with increased apoptosis. These results demonstrate that ZOL inhibits the growth of colon cancer cells regardless of KRAS status, and combination therapy using ZOL and CTX enhances this growth suppression. These findings suggest a novel strategy for the treatment of CRC independent of KRAS mutational status.

What's new?

A new combination therapy could be the one‐two punch that takes out treatment‐resistant colorectal cancer. The anti‐EGFR antibody cetuximab works well against colorectal cancer, but tumors with KRAS mutations can fend it off. Zoledronic acid, which can treat osteoporosis, also thwarts various types of cancer, and in this article the authors evaluated whether it could boost cetuximab's effectiveness. They showed that not only did zoledronic acid suppress colorectal tumor growth, even in KRAS mutants, but that the combination of both agents works better than either alone, both in cultured cell and in mice.

Preferential HER2 expression in liver metastases and EGFR expression in peritoneal metastases in patients with advanced gastric cancer

BACKGROUND

Despite recent clinical trials, the sensitivity and resistance of metastatic gastric cancer to anti-HER2 and anti-EGFR therapy are still unclear.

MATERIALS AND METHODS

To clarify the HER2 and EGFR expression status in the metastatic sites, we immunohistochemically compared HER2 and EGFR expression between primary and metastatic tumors from 52 gastric cancer patients with liver metastases and 85 patients with peritoneal metastases.

RESULTS

The HER2 positivity rate of primary and metastatic tumors in patients with liver metastases, especially with intestinal-type histology (70.6 and 80.0 %, respectively), was significantly higher than in primary and metastatic tumors (22.4 and 16.4 %, respectively) in patients with peritoneal metastases. HER2 positivity of the primary tumor and liver metastases showed good concordance (87.5 %) in patients with liver metastases. In contrast, the EGFR positivity rate of metastatic tumors (70.1 %) in patients with peritoneal metastases was significantly higher than that of metastatic tumors (37.5 %) in patients with liver metastases. HER2 and EGFR expression tended to be mutually exclusive, and HER2/EGFR double-positive cases were rare in patients with liver or peritoneal metastases. In four such patients with HER2/EGFR double-positive primary tumors, the HER2- and EGFR-positive areas were separate, and corresponding liver metastasis was only positive for HER2 and peritoneal metastasis only positive for EGFR.

CONCLUSION

These results indicate that HER2 and EGFR are preferentially expressed in the liver and peritoneal metastases, respectively, which would be potential targets for anti-HER2 and anti-EGFR molecular therapy in metastatic gastric cancer patients.

Multicenter large-scale study of prognostic impact of HER2 expression in patients with resectable gastric cancer

BACKGROUND

Although some small-scale studies have suggested that human epidermal growth factor receptor 2 (HER2)-positive status in gastric cancer is associated with poor outcomes, the prognostic value of HER2 is still controversial. Since intratumoral HER2 heterogeneity is also an important issue, a multicenter large-scale study was conducted to evaluate the prognostic impacts of HER2 expression and intratumoral heterogeneity in gastric cancer.

METHODS

This study included 1,148 gastric cancer patients who underwent gastrectomy in 11 institutions. HER2 expression was centrally evaluated with immunohistochemistry and fluorescence in situ hybridization, and intratumoral HER2 heterogeneity was evaluated for HER2-positive tumors. Overall survival was compared between HER2-positive and HER2-negative patients and between the homogeneous and heterogeneous groups.

RESULTS

The HER2-positive rate was 15.7 %, and HER2 expression was significantly associated with histological type. HER2 expression scores obtained by immunohistochemistry showed a distinct influence on survival, and HER2-positive patients showed much poorer survival than HER2-negative patients [hazard ratio (HR) 1.59, 95 % confidence interval (CI) 1.24-2.02; P < 0.001). The subgroup analysis by pathological tumor stage showed a similar trend of poor survival in HER2-positive patients. Both intestinal type and diffuse type showed significant poor survival in HER2-positive patients. Cox multivariate analysis revealed that HER2 expression was an independent prognostic factor (HR 1.96, 95 % CI 1.51-2.55; P < 0.001). HER2 heterogeneity was observed in 75.4 % of HER2-positive cases, but the prognosis in the heterogeneous group was similar to that in the homogeneous group.

CONCLUSIONS

Our study demonstrated that HER2 overexpression is an independent prognostic factor in patients with any stage of resectable gastric cancer. Intratumoral HER2 heterogeneity did not affect prognosis.

Clinical significance of platelet derived growth factor-C and -D in gastric cancer

Platelet-derived growth factor (PDGF)-C and PDGF-D are frequently upregulated in human cancers and play important roles in tumor progression, angiogenesis and metastasis. However, the distribution, frequency and prognostic value of PDGF-C and PDGF-D expression in gastric cancer have not been clarified. The present study evaluated the association between expression of PDGF-C and PDGF-D, clinicopathological factors and outcomes, in patients with gastric cancer. Gastric adenocarcinoma tumor samples were obtained from 204 patients who underwent curative gastrectomy between 2003 and 2007. The expression of PDGF-C and PDGF-D was analyzed by immunohistochemical staining. High expression of PDGF-C and PDGF-D was detected in 114 (56%) and 151 (74%) tumors, respectively. PDGF-D expression was significantly associated with tumor depth (P=0.039), histopathology (P<0.01), tumor stage (P=0.01) and recurrence (P<0.01), whereas PDGF-C expression correlated only with histopathology (P=0.05). High PDGF-D expression was also associated with significantly shorter relapse-free survival (RFS) time (P<0.01), whilst high PDGF-C expression was associated with marginally, but not significantly, shorter RFS (P=0.10). On multivariate analysis, high PDGF-D expression was determined to be an independent prognostic factor (hazard ratio, 3.3; 95% confidence interval, 1.20–9.4; P=0.02). These findings indicate that high PDGF-D expression is strongly associated with tumor progression, recurrence, distant metastasis and poor outcomes in patients with gastric cancer. PDGF-D may therefore be an independent prognostic factor and a novel therapeutic target.

HER-2 incidence in gastric cancer, its association with prognosis and clinicopathological parameters

OBJECTIVE

Human epidermal growth factor-2 (HER-2) overexpression has prognostic value in breast cancer. However, the significance of HER-2 positivity in gastric cancer is controversial. In this study, we investigated the frequency of overexpression of HER-2 and its relationship with clinicopathological findings and impact on survival in gastric cancer.

MATERIAL AND METHODS

Gastric cancer patients, operated in Marmara University Faculty of Medicine, Pendik Training and Research Hospital, General Surgery Department, between January 2012-December 2013 were enrolled in this study. Medical records were retrospectively evaluated. Tissue samples were stained by immunohistochemistry (IHC) method, and were followed by fluorescence in situ hybridization (FISH) in those with positive results. HER-2 expression rates and its association with other histopathological features and survival have been analyzed.

RESULTS

135 patients were enrolled in the study, with 88 (65%) male and 47 (35%) female patients. The median age was 61 (29-84) years. Only 11 patients (8%) were positive for HER-2. HER-2 positive patients were similar to negative patients in terms of age, gender, tumor size, tumor location, tumor T stage, lymph node metastasis, histological type, differentiation, lymphovascular invasion, perinodal, perineural invasion and stage. No significant difference was detected on 1 and 2-year overall and disease-free survival rates between receptor positive and negative groups.

CONCLUSION

Consistent with the literature data, HER-2 positivity rate in this study was approximately 8%, but this positivity has not been found to be associated with either clinical and pathological parameters or overall and disease-free survival.

Patient-Derived Gastric Carcinoma Xenograft Mouse Models Faithfully Represent Human Tumor Molecular Diversity

Patient-derived cancer xenografts (PDCX) generally represent more reliable models of human disease in which to evaluate a potential drugs preclinical efficacy. However to date, only a few patient-derived gastric cancer xenograft (PDGCX) models have been reported. In this study, we aimed to establish additional PDGCX models and to evaluate whether these models accurately reflected the histological and genetic diversities of the corresponding patient tumors. By engrafting fresh patient gastric cancer (GC) tissues into immune-compromised mice (SCID and/or nude mice), thirty two PDGCX models were established. Histological features were assessed by a qualified pathologist based on H&E staining. Genomic comparison was performed for several biomarkers including ERBB1, ERBB2, ERBB3, FGFR2, MET and PTEN. These biomarkers were profiled to assess gene copy number by fluorescent in situ hybridization (FISH) and/or protein expression by immunohistochemistry (IHC). All 32 PDGCX models retained the histological features of the corresponding human tumors. Furthermore, among the 32 models, 78% (25/32) highly expressed ERBB1 (EGFR), 22% (7/32) were ERBB2 (HER2) positive, 78% (25/32) showed ERBB3 (HER3) high expression, 66% (21/32) lost PTEN expression, 3% (1/32) harbored FGFR2 amplification, 41% (13/32) were positive for MET expression and 16% (5/32) were MET gene amplified. Between the PDGCX models and their parental tumors, a high degree of similarity was observed for FGFR2 and MET gene amplification, and also for ERBB2 status (agreement rate = 94~100%; kappa value = 0.81~1). Protein expression of PTEN and MET also showed moderate agreement (agreement rate = 78%; kappa value = 0.46~0.56), while ERBB1 and ERBB3 expression showed slight agreement (agreement rate = 59~75%; kappa value = 0.18~0.19). ERBB2 positivity, FGFR2 or MET gene amplification was all maintained until passage 12 in mice. The stability of the molecular profiles observed across subsequent passages within the individual models provides confidence in the utility and translational significance of these models for in vivo testing of personalized therapies.

HER2 expression in locally advanced gastric cancer with extensive lymph node (bulky N2 or paraaortic) metastasis (JCOG1005-A trial)

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is likely overexpressed and/or amplified in locally advanced gastric cancer with extensive (bulky N2 or paraaortic) lymph node metastasis, and patients may benefit from treatment with anti-HER2 antibodies. This study evaluated the frequency of HER2 overexpression and amplification in The Japanese Gastric Cancer Association (JGCA)-N3 and JGCA-bulky N2 tumors and the correlation between HER2 status and survival.

METHODS

HER2 status was assessed using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in tumor tissue samples from 89 patients with gastric adenocarcinoma enrolled in the phase II JCOG0001 and JCOG0405 trials. HER2 positivity was defined as IHC3+ or IHC2+ with confirmatory FISH results.

RESULTS

Of the 89 tumor samples, 24 (27 %) showed HER2 positivity, including 16 scored as IHC3+ and 8 as IHC2+ and FISH positive. Multivariate analysis showed that the HER2 positivity rate was significantly higher in evaluable differentiated tumors than in undifferentiated tumors [18/44 (40.9 %) vs. 5/42 (11.9 %)]. Although the apparent OS curve of HER2 positive was superior to that of HER2 negative patients, HER2 status was not a statistically significant prognostic factor in multivariate analysis.

CONCLUSION

The HER2 positivity rate was relatively high in patients with JGCA-bulky N2 and JGCA-N3 gastric adenocarcinoma, suggesting that HER2 evaluation is essential to select the therapeutic regimen for neoadjuvant chemotherapy for this group of patients.

Postoperative adjuvant chemotherapy with S-1 alters recurrence patterns and prognostic factors among patients with stage II/III gastric cancer: A propensity score matching analysis

BACKGROUND

A phase 3 evidence indicates that S-1 adjuvant is beneficial among East Asian patients with stage II/III gastric cancer (GC). However, little is known about the changes in prognostic factors and recurrence patterns after it has become widespread as a standard of care. The present study compared prognostic factors of patients with stage II/III GC treated with or without S-1 adjuvant with formulate appropriate risk stratification strategies.

METHODS

We enrolled 171 patients with stage II/III GC, 92 patients who underwent gastrectomy alone, and 79 patients treated with S-1 adjuvant. To balance more strictly the essential variables including stage of progression, we conducted propensity score analysis and 70 pairs of patients were generated from each group. Prognostic factors were compared between the groups and initial recurrence patterns were investigated to explore reasons for the change.

RESULTS

In concordance with the previous phase 3 trial, overall and recurrence-free survival were better for the S-1 adjuvant group. In the surgery alone group, carcinoembryonic antigen ≥ 5 ng/mL, total gastrectomy, vessel invasion, pT4, and stage 3 were identified as significant prognostic factors. In striking contrast, macroscopic tumor size ≥ 50 mm was the only significant prognostic factor for the S-1 adjuvant group. The lower overall recurrence rate of the S-1 adjuvant group was attributable mainly to a significant decrease of peritoneal recurrence.

CONCLUSION

Prognostic factors changed substantially after implementation of S-1 adjuvant treatment. Macroscopic tumor size should be considered for patient stratification and selection of treatment options for patients with stage II/III GC.

Clinicopathologic and molecular features associated with patient age in gastric cancer

AIM: To compare characteristics and prognosis of gastric cancer based on age.

METHODS: A retrospective study was conducted on clinical and molecular data from patients (n = 1658) with confirmed cases of gastric cancer in Seoul National University Bundang Hospital (Seoul, South Korea) from 2003 to 2010 after exclusion of patients diagnosed with lymphoma, gastrointestinal stromal tumor, and metastatic cancer in the stomach. DNA was isolated from tumor and adjacent normal tissue, and a set of five markers was amplified by polymerase chain reaction to assess microsatellite instability (MSI). MSI was categorized as high, low, or stable if ≥ 2, 1, or 0 markers, respectively, had changed. Immunohistochemistry was performed on tissue sections to detect levels of expression of p53, human epidermal growth factor receptor (HER)-2, and epidermal growth factor receptor. Statistical analysis of clinical and molecular data was performed to assess prognosis based on the stratification of patients by age (≤ 45 and > 45 years).

RESULTS: Among the 1658 gastric cancer patients, the number of patients with an age ≤ 45 years was 202 (12.2%; 38.9 ± 0.4 years) and the number of patients > 45 years was 1456 (87.8%; 64.1 ± 0.3 years). Analyses revealed that females were predominant in the younger group (P < 0.001). Gastric cancers in the younger patients exhibited more aggressive features and were at a more advanced stage than those in older patients. Precancerous lesions, such as atrophic gastritis and intestinal metaplasia, were observed less frequently in the older than in the younger group (P < 0.001). Molecular characteristics, including overexpression of p53 (P < 0.001), overexpression of HER-2 (P = 0.006), and MSI (P = 0.006), were less frequent in gastric cancer of younger patients. Cancer related mortality was higher in younger patients (P = 0.048), but this difference was not significant after adjusting for the stage of cancer.

CONCLUSION: Gastric cancer is distinguishable between younger and older patients based on both clinicopathologic and molecular features, but stage is the most important predictor of prognosis.

Single nucleotide polymorphisms in AREG and EREG are prognostic biomarkers in locally advanced gastric cancer patients after surgery with curative intent

OBJECTIVE

Amphiregulin (AREG) and epiregulin (EREG) are important ligands to the epithelial growth factor receptor, which is involved in the regulation of progression and stemness in gastric cancer (GC). This study investigated whether frequent single nucleotide polymorphisms (SNPs) in genes of AREG and EREG are associated with recurrence-free survival and overall survival in patients with locally advanced GC.

METHODS

SNPs with a minor allele frequency of at least 10% were analyzed using direct DNA sequencing in two independent study populations.

RESULTS

The minor allele of AREG rs1615111 was associated with a significantly higher 3-year recurrence rate and lower 3-year survival rate [hazard ratio (HR)=2.21 and 2.35, respectively] compared with patients homozygous for the dominant allele G. The value for overall survival could be validated with a HR of 2.54 (P=0.018) in an independent cohort. Patients homozygous for the minor allele A of EREG rs12641042 had a significantly higher 3-year survival rate than patients with allele C (HR 0.48; P=0.034), but significance was lost in multivariable analysis (P=0.066). The value of rs12641042 could not be validated (P=0.98). Exploratory multivariable subgroup analysis showed the strongest prognostic value for rs1615111 in tumors with a diffuse histology (Pfor interaction=0.004).

CONCLUSION

AREG rs1615111, located in the AREG genomic region, can significantly define different prognostic cohorts in locally advanced GC. This value is most evident in GC patients with diffuse histology, which might be relevant as none of the trials testing epithelial growth factor receptor inhibitors has been enriched for diffuse histology or a molecularly defined population.

Current and Future Therapies for Advanced Gastric Cancer

The treatment of patients with advanced gastric cancer remains a challenging area of oncology. Extensive trials of differing chemotherapy regimens have yielded no international consensus on the optimal combination, and overall survival with chemotherapy alone remains poor. Recently an improved understanding of the molecular drivers of the disease has opened up promising new avenues of treatment through the use of biological targeted agents. The anti-HER2 monoclonal antibody trastuzumab was the first targeted agent to significantly prolong survival in the first-line treatment of a molecularly-selected subgroup of patients. More recently the anti-vascular endothelial growth factor receptor 2 monoclonal antibody ramucirumab has demonstrated a modest survival benefit in previously treated patients as both a monotherapy and in combination with chemotherapy. Immunotherapy and the use of checkpoint inhibitors are a further exciting area of development with promising preliminary results for the activity of the anti-Programmed Death 1 Receptor antibody pembrolizumab and ongoing trials of a number of immune-modulating agents. Continuing research to identify novel targets and therapies aims to make further incremental gains in survival. In this review we outline the evidence base supporting current chemotherapy regimens and describe the latest advances in the development and use of molecularly targeted and immune-modulating agents.

S-1 and Cisplatin With or Without Nimotuzumab for Patients With Untreated Unresectable or Metastatic Gastric Cancer: A Randomized, Open-Label Phase 2 Trial

This open-label, randomized phase II trial was performed to compare the efficacy and safety of nimotuzumab plus S-1 and cisplatin (NCS) versus S-1 and cisplatin (CS) alone in patients with untreated unresectable or metastatic gastric cancer in the first-line setting. Eligible participants were randomly assigned (1:1) to receive either NCS or CS. The treatment consisted of 3-week cycles of twice-daily S-1 40 mg/m² (on days 1-14) and intravenous cisplatin 30 mg/m² (on days 1, 2), with or without weekly nimotuzumab (200 mg/m²). The primary endpoint was objective response rate (ORR). The second endpoint included progression-free survival (PFS), overall survival (OS), safety and association between efficacy and tumor epidermal growth factor receptor (EGFR) expression. Between October, 2009, and February, 2012, we enrolled 62 patients in Cancer Hospital Chinese Academy of Medical Sciences (CAMS). The ORR for 31 patients allocated NCS was 54.8% compared with 58.1% for 31 patients who were allocated to receive CS alone (P = 0.798). Median PFS for patients in CS arm was significantly improved than that in NCS arm [7.2 months vs. 4.8 months HR = 2.136 (95% CI 1.193-3.826), P = 0.011]. There was also a trend toward better overall survival for patients in CS arm compared with NCS arm [14.3 months vs. 10.2 months; HR = 1.776 (95% CI 0.972-3.246), P = 0.062]. In the EGFR 2+/3+ subgroup, adding nimotuzumab also failed to show additional benefit than chemotherapy alone. Both groups were well tolerated. Less than 10% of patients in both arms developed grade 3/4 toxicity. Combination of nimotuzumab and S-1-cisplatin provided no additional benefit than chemotherapy alone in the first-line treatment of unresectable or metastatic gastric cancer.

HER2/neu-directed therapy for biliary tract cancer

Background

Biliary cancers are highly aggressive tumors that are often diagnosed an advanced disease stage and have a poor outcome with systemic therapy. Recent efforts towards molecular characterization have identified a subset of biliary patients that have HER2/neu amplification or mutation. HER2/neu amplification is associated with response to HER2/neu-directed therapy in breast and gastric cancers. However, the efficacy of HER2/neu-targeted therapy in biliary cancers is unknown.

Patients and methods

We retrospectively reviewed cases of advanced gallbladder cancer and cholangiocarcinoma with HER2/neu genetic aberrations or protein overexpression who received HER2/neu-directed therapy between 2007 and 2014. Clinical data were retrieved from medical records, and imaging studies were independently reviewed.

Results

Nine patients with gallbladder cancer and five patients with cholangiocarcinoma had received HER2/neu-directed therapy (trastuzumab, lapatinib, or pertuzumab) during the study period. In the gallbladder cancer group, HER2/neu gene amplification or overexpression was detected in eight cases. These patients experienced disease stability (n = 3), partial response (n = 4), or complete response (n = 1) with HER2/neu-directed therapy. One patient had HER2/neu mutation and experienced a mixed response after lapatinib therapy. The duration of response varied from 8+ to 168 weeks (median 40 weeks), and three patients are still on therapy. One patient developed HER2/neu amplification as a secondary event after FGFR-directed therapy for FGF3-TACC3 gene fusion. The cholangiocarcinoma cases treated in this series had a higher proportion of HER2/neu mutations, and no radiological responses were seen in these patients despite HER2/neu-directed therapy.

Conclusions

HER2/neu blockade is a promising treatment strategy for gallbladder cancer patients with gene amplification and deserves further exploration in a multi-center study.

Targeted therapy in gastric cancer

Gastric cancer is often diagnosed at an advanced stage. Although chemotherapy prolongs survival and improves quality of life, the survival of gastric cancer patients with advanced disease is short. Thanks to recent insights into the molecular pathways involved in gastric carcinogenesis, new targeted treatment options have become available for gastric cancer patients. Trastuzumab, an antibody targeted to HER-2, was shown to improve survival of advanced gastric cancer patients harboring HER-2 overexpression due to gene amplification in their tumor cells, and is currently also explored in adjuvant and neoadjuvant settings. Another agent with promising results in clinical trials is ramucirumab, an antibody targeting VEGFR-2. No clear survival benefit, however, were experienced with agents targeting EGFR (cetuximab, panitumumab), VEGF-A (bevacizumab), or mTOR (everolimus). Drugs targeting c-MET/HGF are currently under investigation in biomarker-selected cohorts, with promising results in early clinical trials. This review will summarize the current status of targeted treatment options in gastric cancer.

Adjuvant therapy for gastric cancer: What have we learned since INT0116?

Gastric cancer is one of the main cancer-related causes of death worldwide. The curative treatment of gastric cancer consists of tumor resection and lymphadenectomy. However, surgical treatment alone is associated with high recurrence rates. Adjuvant treatment strategies have been studied over the last decades, but there have been controversial results from the initial studies. The pivotal INT0116 study demonstrated that the use of adjuvant chemoradiotherapy with 5-fluorouracil increases relapse-free and overall survival, and it has been adopted across the Western world. The high toxicity of radiochemotherapy and suboptimal surgical treatment employed, with fewer than 10% of the patients submitted to D2 lymphadenectomy, were the main study limitations. Since its publication, other adjuvant treatment modalities have been studied, and radiochemotherapy is being refined to improve its efficacy and safety. A multimodal approach has been demonstrated to significantly increase relapse-free and overall survival, and it can be offered in the form of perioperative chemotherapy, adjuvant chemoradiotherapy or adjuvant chemotherapy, regardless of the extent of lymphadenectomy. The objective of the present review is to report the major advances obtained in the last decades in the adjuvant treatment of gastric cancer as well as the perspectives of treatment based on recent knowledge of the molecular biology of the disease.

Expression profiles of HER2, EGFR, MET and FGFR2 in a large cohort of patients with gastric adenocarcinoma

BACKGROUND

Some tyrosine kinase receptors (RTKs) play critical roles in gastric cancer progression. Not only trastuzumab, but also several other agents targeting RTKs are being investigated for gastric cancer therapy. However, the simultaneous expression of multiple RTKs, which may interfere with the effectiveness of therapeutic agents, has not been evaluated in a large cohort with gastric adenocarcinoma (GAC).

METHODS

We performed a tissue microarray analysis in 950 patients with GAC who underwent a gastrectomy without preoperative chemotherapy. The protein expressions of HER2, EGFR, MET and FGFR2 were evaluated using immunohistochemistry, and the gene amplifications of HER2, EGFR and MET were examined using dual-color in situ hybridization.

RESULTS

The frequency of overexpression was 11.8% for HER2, 23.5% for EGFR, 24.9 % for MET and 31.1% for FGFR2. Whereas strong staining for each of the RTKs was heterogeneous, tumors with homogeneously strong staining areas often exhibited gene amplification. Strong EGFR expression was significantly associated with a poor outcome, but no prognostic correlations were observed in other RTKs. The overexpression of single and multiple RTKs was observed in 40.4 and 22.7% of the cases, respectively. HER2, EGFR, MET and FGFR2 predominance was observed in 10.1, 13.9, 16.1 and 22.9% of the GACs, respectively.

CONCLUSIONS

Approximately two-thirds of patients with GAC exhibited the expression of at least one RTK and would be candidates for targeted therapies. Moreover, one-third of at least one RTK overexspressing cases showed multiple RTKs expression. Our results may be useful for selecting the most suitable patients for each targeted therapy.

External Validation of a Score Predictive of Recurrence after Radical Surgery for Non-Cardia Gastric Cancer: Results of a Follow-Up Study

BACKGROUND

A score predictive of tumor recurrence after radical surgery for non-cardia gastric cancer was previously developed in Italian centers. The aim of this study was to validate the score in a consecutive cohort with prospectively collected follow-up data.

STUDY DESIGN

Of 1,178 patients surgically treated between 1998 and 2006, six hundred and thirty-five patients who fulfilled the selection criteria and completed the follow-up program were available for analysis. The score value for each patient was calculated using the formula obtained from a logistic regression model. Discrimination and calibration of the score in the validation group were evaluated and compared with the data of 438 patients in the study group where the score was developed.

RESULTS

Most patients in both groups had very low or very high score values. In the validation group, the observed recurrence rates ranged from 5% to 92% in different score strata. The area under the receiver operating characteristic curve was 0.889 (95% CI, 0.864-0.914; p < 0.001), indicating a high discrimination value of the score for recurrence. A good calibration was observed by comparing the predicted risk with the actual risk of recurrence. With a score cut-off value of 50, sensitivity, specificity, and overall accuracy were 74%, 86%, and 81%, respectively. An inverse correlation between the time to recurrence and score level was also estimated (R(2) = 0.119; p < 0.001).

CONCLUSIONS

The high predictive value of the score was validated in a consecutive cohort. These results might allow the introduction of the score in clinical practice for Western patients.

Decreased expression of Bauhinia purpurea lectin is a predictor of gastric cancer recurrence

PURPOSE

Molecular markers as indicators for gastric cancer recurrence are urgently required. The aim of this study was to identify lectins that can be used to predict gastric cancer recurrence after gastrectomy.

METHODS

We created lectin expression profiles by microarray analysis for 60 patients, who underwent surgery for gastric cancer at the Oita University Hospital between January, 2005 and December, 2007. Lectin expression and clinicopathological factors in patients who suffered gastric cancer recurrence and those who did not were compared by univariate and multivariate analyses.

RESULTS

Thirteen lectins showed a significant increase in binding to cancer tissues, whereas 11 lectins showed a significant decrease in binding to cancer tissues, when compared with binding to normal epithelia. Multivariate analysis revealed that lymph node metastasis and low Bauhinia purpurea lectin (BPL)-binding signals were independent predictive factors for recurrence. All patients with low BPL expression had significantly worse relapse-free survival than those with high BPL expression.

CONCLUSIONS

Our results using a novel lectin microarray system provide the first solid evidence that BPL expression is a predictor of gastric cancer recurrence.

Protein expression of HER2, 3, 4 in gastric cancer: correlation with clinical features and survival

BACKGROUND AND AIMS

Despite significant improvements in targeted therapies for patients with advanced gastric cancer (GC), the prognosis of those patients remains poor. This study explores the expression and clinicopathological significance of human epidermal growth factor receptor 2, 3 and 4 (HER2, HER3, HER4) in GC, in order to find more prognostic biomarkers of GC and putative targets of therapy.

METHODS

Immunohistochemistry was performed for HER2, HER3 and HER4 in 498 patients with GC using tissue microarray. Correlations between the receptor expression and clinicopathological features, as well as prognosis of the patients were statistically analysed.

RESULTS

The high expression rates of HER2, HER3 and HER4 proteins in the patients were 8.6% (43/498), 20.7% (103/498) and 13.3% (66/498), respectively. High expression of HER2 and HER3 was correlated with proximal GC of the cardia (p<0.05). High expression of HER3 was associated with the tumour depth, tumour node metastasis (TNM) stage and lymph node metastasis (p<0.05). High expression of HER4 was associated with TNM stage (p<0.05) only. According to a regression model, high expression of HER3 was significantly associated with patients' poor survival (p=0.004). High expression rates of HER2, HER3 and HER4 were correlated with each other, but they were all associated merely with histologically intestinal-type adenocarcinoma of GC (p<0.05).

CONCLUSIONS

HER3 is correlated with the malignant biological behaviour of GC. Expression of HER3 is a significant predictor of poor survival in GC. Therefore, the development of HER3-targeted agents may provide new possibilities in the treatment of GC.

Biomarkers for gastric cancer: Progression in early diagnosis and prognosis (Review)

Gastric cancer is one of leading causes of cancer-related mortality worldwide and is a notable disease due to its heterogeneity. Recently, numerous studies have investigated the molecular basis of gastric cancer, involving the alteration of pathogenesis, and invasion and metastasis. With the development of modern technologies, various novel biomarkers had been identified that appear to possess diagnostic and prognostic value; therefore, the present review describes our current knowledge of biomarkers for the early diagnosis and prognosis of gastric cancer. Classic biomarkers for gastric cancer diagnosis include carcinoembryonic antigen and cancer antigen 19-9, while microRNA and DNA hypomethylation are proposed as novel biomarkers. Excluding classical biomarkers, biomarkers for determining the progression and prognosis of gastric cancer focus on targeting microRNAs, epigenetic alterations and genetic polymorphisms.

Recent advances in the HER2 targeted therapy of gastric cancer

Recent advances in molecular targeted therapies, including targeting human epidermal growth factor receptor 2 (HER2), had a major forward step in the therapy for gastric cancer patients. Application of HER2-targeted therapies, in particular trastuzumab in combination with chemotherapy in metastatic HER2-positive gastric cancers, resulted in improvements in response rates, time to progression and overall survival. Nevertheless, as with breast cancer, many patients with gastric cancer develop resistance to trastuzumab. Several promising therapies are currently being developed in combination with chemotherapy to increase the efficacy and overcome the cancer-resistance. Here we review the current overview of clinical application of agents targeting HER2 in gastric cancer. We also discuss the ongoing trials supporting the use of HER2-targeted agents combined with cytotoxic agents or other monoclonal antibodies.

Randomized phase II trial of nimotuzumab plus irinotecan versus irinotecan alone as second-line therapy for patients with advanced gastric cancer

BACKGROUND

This multicenter, randomized phase II trial was conducted to compare the efficacy and safety of nimotuzumab plus irinotecan (N-IRI) versus irinotecan alone (IRI) in patients with advanced gastric cancer (AGC) showing disease progression after previous 5-fluorouracil-based therapy.

METHODS

Irinotecan-naive patients (n = 82) received N-IRI (nimotuzumab 400 mg weekly plus irinotecan 150 mg/m(2) biweekly) or IRI (irinotecan 150 mg/m(2) biweekly) until disease progression. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival (OS), response rate (RR), safety, tolerability, and the correlation between efficacy and tumor epidermal growth factor receptor (EGFR) expression.

RESULTS

Of 83 patients, 40 and 43 patients were randomly assigned to the N-IRI and IRI groups, respectively. In the N-IRI/IRI treatment group, median PFS was 73.0/85.0 days (P = 0.5668), and median OS and RR at 18 months were 250.5/232.0 days (P = 0.9778) and 18.4/10.3 %, respectively. Median PFS and OS in the EGFR 2+/3+ subgroups were 118.5/59.0 and 358.5/229.5 days, respectively. The RR was 33.3/0.0 % in the N-IRI/IRI treatment group. The incidence of grade 3 or higher adverse events was 77.5/64.3 %. No adverse events of grade 3 or higher skin rash or grade 3 or higher infusion-related reaction were reported.

CONCLUSIONS

There was no superiority of N-IRI over IRI alone in terms of PFS in 5-fluorouracil-refractory AGC patients. However, N-IRI showed potential improvement in the EGFR 2+/3+ subgroup based on improved RR, PFS, and OS.

Impact of the expression of thymidylate synthase and dihydropyrimidine dehydrogenase genes on survival in stage II/III gastric cancer

BACKGROUND

The efficacy of 5-fluorouracil (5FU)-based therapy, which remains the cornerstone of gastrointestinal cancer treatment, depends upon the expression of enzymes involved in pyrimidine metabolism, including thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP), and orotate phosphoribosyltransferase (OPRT). We analyzed the expression of these genes in patients enrolled in the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer (ACTS-GC) and their possible roles as biomarkers for treatment outcomes.

METHODS

Formalin-fixed, paraffin-embedded specimens were available for 829 of a total of 1,059 (78.3 %) patients. TS, DPD, TP, and OPRT expression was measured by RT-PCR in manually microdissected tumor specimens and normalized to the reference gene, β-actin. The expression level of each gene was categorized as low or high using cutoffs at the 33.3rd, 50th, or 66.7th percentiles.

RESULTS

The hazard ratio (HR) for overall survival (OS) after S-1 treatment versus surgery alone was significantly lower in high (>66.7th percentile; HR = 0.370; 95 % CI 0.221-0.619) compared to low (<66.7th percentile; HR = 0.757; 95 % CI 0.563-1.018) TS expression groups (P = 0.015). Similarly, the HR for OS after S-1 therapy versus surgery alone was significantly lower in high (>33.3rd percentile; HR = 0.520, 95 % CI 0.376-0.720) compared to low (<33.3rd percentile; HR = 0.848, 95 % CI 0.563-1.276) DPD expression groups (P = 0.065). There was no interaction between TP or OPRT expression and OS.

CONCLUSIONS

This large biomarker study showed that high TS and DPD gene expression in tumors was associated with enhanced benefit from postoperative adjuvant S-1 treatment in gastric cancer. There was no interaction between TP and OPRT expression and S-1 treatment.

Assessment and prognostic analysis of EGFR, HER2, and HER3 protein expression in surgically resected gastric adenocarcinomas

Aim

To investigate the significance of epidermal growth factor receptor (EGFR), human epidermal growth factor receptor (HER)2, and HER3 expression on survival outcomes in Chinese gastric cancer patients.

Materials and methods

Formalin-fixed, paraffin-embedded specimens from 121 patients who underwent gastrectomy at Shanghai Renji Hospital from 2007–2010 were retrospectively examined. Fluorescence in situ hybridization and immunohistochemistry techniques were used to identify gene amplification and protein overexpression. Correlations between the expression or amplification of HER family genes and clinicopathological parameters were then determined using statistical analysis.

Results

EGFR protein overexpression, an increase in HER2 copy number and gene amplification, and HER3 protein overexpression were identified in 33.1%, 17.4%, and 62.0% of samples, respectively. Statistical analysis showed a significant association between EGFR expression and tumor invasion depth or tumor stage. HER2 was also shown to be significantly associated with the tumor grade. In addition, EGFR protein overexpression was found to be significantly associated with worse overall survival (P=0.03).

Conclusion

The HER family members showed a high expression in gastric cancer. EGFR protein expression was associated with overall survival.

Immunohistochemical analysis of RTKs expression identified HER3 as a prognostic indicator of gastric cancer

Standard treatment in Japan for the 13th Japanese Gastric Cancer Association stage II/III advanced gastric cancer is postoperative adjuvant S-1 administration after curative surgery. High expression of receptor type tyrosine kinases (RTKs) has repeatedly represented poor prognosis for cancers. However it has not been demonstrated whether RTKs have prognostic relevance for stage II/III gastric cancer with standard treatment. Tumor tissues were obtained from 167 stage II/III advanced gastric cancer patients who underwent curative surgery and received postoperative S-1 chemotherapy from 2000 to 2010. Expression of the RTKs including EGFR, HER2, HER3, IGF-1R, and EphA2 was analyzed using immunohistochemistry (IHC). Analysis using a multivariate proportional hazard model identified the most significant RTKs that represented independent prognostic relevance. When tumor HER3 expression was classified into IHC 1+/2+ (n = 98) and IHC 0 (n = 69), the cumulative 5-year Relapse Free Survival (5y-RFS) was 56.5 and 82.9%, respectively (P = 0.0034). Significant prognostic relevance was similarly confirmed for IGF-1R (P = 0.014), and EGFR (P = 0.030), but not for EphA2 or HER2 expression. Intriguingly, HER3 expression was closely correlated with IGF-1R (P < 0.0001, R = 0.41), and EphA2 (P < 0.0001, R = 0.34) expression. Multivariate proportional hazard model analysis identified HER3 (IHC 1+/2+) (HR; 1.53, 95% CI, 1.11–2.16, P = 0.0078) as the sole RTK that was a poor prognostic factor independent of stage. Of the 53 patients who recurred, 40 patients (75.5%) were HER3-positive. Thus, of the RTKs studied, HER3 was the only RTK identified as an independent prognostic indicator of stage II/III advanced gastric cancer with standard treatment.

Causes and consequences of microsatellite instability in gastric carcinogenesis

Loss of DNA mismatch repair (MMR) function, due to somatic or germline epi/genetic alterations of MMR genes leads to the accumulation of numerous mutations across the genome, creating a molecular phenotype known as microsatellite instability (MSI). In gastric cancer (GC), MSI occurs in about 15% to 30% of the cases. This review summarizes the current knowledge on the molecular mechanisms underlying the acquisition of MSI in GC as well as on the clinic, pathologic and molecular consequences of the MSI phenotype. Additionally, current therapeutic strategies for GC and their applicability in the MSI subset are also discussed.

Identification of EGFR expression status association with metastatic lymph node density (ND) by expression microarray analysis of advanced gastric cancer

Metastatic lymph node density (ND) has been reproducibly proven to be a prognostic factor in gastric cancer. The molecular mechanisms that underlie this aggressiveness are underexplored. Here, we aimed to identify molecules associated with this unique phenotype. Tumor specimens from patients with stage III gastric cancer with high or low ND (n = 4 for both) were compared at the mRNA level using Affymetrix microarray (harboring 54,675 genes). The expression data were prioritized, and genes that correlated with ND were selected. Ultimately, the EGFR was validated as such a candidate molecule in patients with primary advanced gastric cancer who underwent standard treatment (n = 167). Expression data of the microarray were prioritized based on gene expression ratio and frequency of gene expression. The first priority genes to be selected were genes that are known to be amplified in cancer, which included NKX2.1, CHST9, CTNND2, SLC25A27, FGFR2, EGFR, and PTGER1. Of these genes, the EGFR gene was of particular interest. EGFR expression in primary gastric cancer was examined using immunohistochemistry (IHC). The Student's t-test elucidated a significant difference in EGFR expression between IHC 2+/3+ and IHC 1+ according to ND (P = 0.0035). The Chi-square test also indicated a significant difference between high and low levels of EGFR immunohistochemical staining (IHC2+/3+ and IHC1+, respectively) and ND status (P = 0.0023). According to the least squares method, as ND increased, the risk that EGFR staining levels changed from IHC 1+ to IHC 2+ also increased. In this study, we determined that high EGFR expression may underlie the aggressive mechanism of advanced gastric cancer with high ND.

Comparison of HER2 status between surgically resected specimens and matched biopsy specimens of gastric intestinal-type adenocarcinoma

HER2 protein overexpression and gene amplification are important biomarkers for identifying gastric cancer patients who may respond to HER2-targeted therapy using trastuzumab. The aim of this study was to evaluate the concordance between HER2 protein expression and gene amplification in both surgically resected tumors and matched biopsy specimens of gastric cancer. Formalin-fixed, paraffin-embedded sections of 207 surgically resected tumors and 158 biopsy specimens from 207 cases of invasive intestinal-type gastric cancer were analyzed. Protein expression was assessed using immunohistochemistry and graded by the modified scoring criteria for gastric cancer. Gene amplification was evaluated by fluorescence in situ hybridization (FISH). HER2 overexpression was observed in 17 % of both surgically resected tumors (35/207) and biopsy specimens (26/158). HER2 gene amplification was detected in 31 % (61/200) of surgically resected tumors and 32 % (47/147) of biopsy specimens. Except for immunohistochemistry (IHC) equivocal (2+) cases, the concordance rates between IHC and FISH was 90.9 % in surgically resected tumors and 90.2 % in biopsy specimens. In IHC 2+ cases, the rate of HER2 gene amplification was 56 and 38 % in surgically resected tumors and biopsy specimens, respectively. IHC-FISH discordance was mainly due to intratumoral heterogeneity and low-level gene amplification. The concordance rate of IHC results between surgically resected specimens and the corresponding biopsy specimen was 57.0 % (κ = 0.224), and in discordant cases, HER2 positivity in biopsies and HER2 negativity in surgically resected tumors were most common. The concordance rate of FISH results between surgically resected tumors and biopsy specimens was 72.7 % (κ = 0.313). Polysomy 17 was detected in 5.5 and 7.5 % of surgically resected tumors and biopsy specimens and significantly correlated with IHC score, but polysomy 17 could explain one IHC score 3+ and FISH-negative tumor only. Although high concordance rates between HER2-protein expression and gene amplification were observed in both surgically resected tumors and biopsy specimens, the agreement levels were evaluated to be fair. Polysomy 17 was infrequent and seemed to have limited impact on gastric HER2 testing. Further investigations are required for an appropriate biopsy method to reduce false results of HER2 testing and to clarify the clinical significance of intratumoral heterogeneity in HER2 status.

Prognostic impact of major receptor tyrosine kinase expression in gastric cancer

BACKGROUND

Various kinds of molecular targeted drugs to inhibit receptor tyrosine kinases (RTKs) have been recently developed. The relationship between the expression status of major RTKs and prognosis in gastric cancer remains unclear. We conducted a multicenter study to evaluate the prognostic impact of the expression of epidermal growth factor receptor (EGFR), c-Met, platelet-derived growth factor receptor (PDGFR), and c-Kit in gastric cancer.

METHODS

This study included 153 gastric cancer patients who underwent gastrectomy at 9 institutions between 2000 and 2006. Expression status of EGFR, c-Met, PDGFR, and c-Kit were evaluated with immunohistochemistry (IHC) centrally. Overall survival based on RTK expression status was statistically compared. Cox multivariate analysis was conducted to adjust for potentially confounding factors.

RESULTS

The positive rates for EGFR, c-Met, PDGFR, and c-Kit were 14.4, 24.8, 41.2, and 11.1 %, respectively. Significant interactions with expression status were observed for pathological N stage with EGFR; HER2-status with c-Met; tumor location, histology, and pathological N stage with PDGFR; and no examined variables with c-Kit. Concomitant HER2 positivity was observed for 0.7 % of tumors positive for EGFR, 3.9 % for c-Met, 4.6 % for PDGFR, and 1.3 % for c-Kit. There were some differences in overall survival between patients with or without RTK expression, but only c-Kit expression showed a significant survival difference in Cox multivariate analysis (P = 0.046).

CONCLUSIONS

Our multicenter study indicated that IHC expression of 4 RTKs had some prognostic impact and that c-Kit-positive status may be a significant indicator of good prognosis in gastric cancer patients.

Prognostic significance of HER2 expression based on trastuzumab for gastric cancer (ToGA) criteria in gastric cancer: an updated meta-analysis

The prognostic significance of HER2 expression in patients with gastric cancer remains controversial, partially due to the significant heterogeneity of the approaches and criteria used for HER2 assessment among different studies. We therefore conducted a meta-analysis enrolling only studies defining HER2 status by trastuzumab for gastric cancer (ToGA) criteria. Published studies investigating the association between HER2 expression and survival were identified. Only publications that defined HER2 expression using ToGA criteria were enrolled. Meta-analyses were performed by Revman 5.2. Pooled hazard ratio (HR) and its 95 % confidence interval (CI) were calculated to evaluate the risk of disease. A total of 11 studies were enrolled in meta-analyses. Pooled data of nine studies using univariate analysis showed that HER2 expression is not associated with overall survival (OS; pooled HR, 0.97; 95 % CI, 0.84-1.12; P=0.63), which are maintained in six studies of multivariate analysis (pooled HR, 1.01; 95 % CI, 0.75-1.35; P=0.95). The Q statistic test for nine studies of univariate analysis and for six studies of multivariate analysis showed no and low heterogeneity (I (2)=22 % and P=0.25; I (2)=41 % and P=0.13, respectively). Furthermore, pooled data of four studies without heterogeneity (I (2)=0 %, P=0.74) showed that HER2 expression were not associated with relapse-free survival as well, with a pooled HR of 1.08 (95 % CI, 0.84-1.37; P=0.55) in patients with HER2 expression. In conclusion, this meta-analysis indicated that HER2 expression based on ToGA criteria is not related to the survival in patients with gastric cancer.

FGFR2 amplification has prognostic significance in gastric cancer: results from a large international multicentre study

BACKGROUND

In preclinical gastric cancer (GC) models, FGFR2 amplification was associated with increased tumour cell proliferation and survival, and drugs targeting this pathway are now in clinical trials.

METHODS

FGFR2 FISH was performed on 961 GCs from the United Kingdom, China and Korea, and the relationship with clinicopathological data and overlap with HER2 amplification were analysed.

RESULTS

The prevalence of FGFR2 amplification was similar between the three cohorts (UK 7.4%, China 4.6% and Korea 4.2%), and intratumoral heterogeneity was observed in 24% of FGFR2 amplified cases. FGFR2 amplification was associated with lymph node metastases (P<0.0001). FGFR2 amplification and polysomy were associated with poor overall survival (OS) in the Korean (OS: 1.83 vs 6.17 years, P=0.0073) and UK (OS: 0.45 vs 1.9 years, P<0.0001) cohorts, and FGFR2 amplification was an independent marker of poor survival in the UK cohort (P=0.0002). Co-amplification of FGFR2 and HER2 was rare, and when high-level amplifications did co-occur these were detected in distinct areas of the tumour.

CONCLUSION

A similar incidence of FGFR2 amplification was found in Asian and UK GCs and was associated with lymphatic invasion and poor prognosis. This study also shows that HER2 and FGFR2 amplifications are mostly exclusive.