Epidermal growth factor receptor status and S-phase fractions in gastric carcinoma

Clinical Significance of Epidermal Growth Factor Receptor Content in Gastric Cancer

The objective of this work was to evaluate the epidermal growth factor receptor (EGFR) content in gastric cancer, its possible relationship with clinicopathological parameters of tumors and its prognostic significance. Membranous EGFR levels were examined by radioligand binding assays in 110 patients with gastric cancer. The mean follow-up period was 30.7 months. EGFR levels of tumors ranged widely, from 0.3 to 510 fmol/mg protein. EGFR levels were significantly higher (p<0.0005) in neoplastic tissue than in paired adjacent mucosa samples (median) (n= 84; 8.7 vs. 3.9 fmol/mg protein). Intratumoral EGFR levels were significantly correlated with tumor stage (p<0.05), and were higher in patients with stage III tumors (median) (7.6, 6.4, 12.3 and 7.5 fmol/mg protein for stages I, II, III and IV, respectively). In addition, the tumor/mucosa ratios of the EGFR content were significantly higher (p<0.05) in patients with stage III tumors (1, 1.8, 3.9, and 0.92, respectively). Although there was no significant relationship between EGFR levels of tumors and overall survival, the results suggest a role for EGFR in tumor progression of gastric cancer.

Effect of epidermal growth factor receptor status on the outcomes of patients with metastatic gastric cancer: A pilot study

The expression of epidermal growth factor receptor (EGFR) has been linked to clinical outcome in several solid tumors. However, the clinical significance of EGFR (c-erbB1) in gastric cancer remains unclear. The present study was designed to detect the clinical implications of EGFR in the Turkish population. Paraffin-embedded tissue microarrays containing gastric cancer tissue were obtained from 30 patients. EGFR expression was detected using immunohistochemistry. The correlation of this biomarker to the clinicopathological features and survival of patients with gastric cancer was studied. The overall positivity rate of EGFR was 63.3%. EGFR expression was significantly correlated with an improved progression-free survival (PFS) and overall survival (OS) rate (P=0.039 and 0.01, respectively). EGFR expression is a good prognostic marker for patients with gastric cancer.

Targeted therapies with chemoradiation in esophageal cancer: development and future directions

Targeted therapies have been studied in combination with chemoradiation therapy for esophageal and gastroesophageal junction cancers. To date, the Human Epidermal Growth Factor Receptor 2 (HER2) HER2, epidermal growth factor receptor, and vascular endothelial growth factor pathways have been most extensively studied in esophagogastric cancers. However, despite strong preclinical rationale and evidence of activity in other diseases, the efficacy of these agents has been mixed when studied in the metastatic setting or in combination with chemoradiation. In this review, the history of the development of targeted therapies in esophagogastric cancers is reviewed, with a specific focus on the incorporation of these agents with chemoradiation. Additionally, more recently identified targets of interest in esophagogastric cancers, including c-MET, heat shock protein 90, and Sonic hedgehog, are discussed in the context of chemoradiation.

Chemoradiation therapy: localized esophageal, gastric, and pancreatic cancer

Chemoradiation plays an important role in management of locally advanced gastrointestinal tumors. This article reviews data regarding chemoradiation for tumors of the upper gastrointestinal tract. For esophageal and gastroesophageal junction cancers, chemoradiation is standard of care in the preoperative setting. In gastric cancer, 2 standards have emerged: definitively treating with perioperative chemotherapy alone and using chemoradiation postoperatively. For pancreatic cancer, the benefit of radiation is less well defined. The future of treatment sites lies in trials evaluating new chemotherapy regimens, alternative systemic therapies, and different radiation fractionation schema. Because care of these patients is complex, multimodality team evaluation before treatment is encouraged.

Phase I study of matuzumab in combination with 5-fluorouracil, leucovorin and cisplatin (PLF) in patients with advanced gastric and esophagogastric adenocarcinomas

BACKGROUND

To evaluate the safety and tolerability of two different weekly doses of the fully humanized epidermal growth factor receptor (EGFR)-targeting monoclonal antibody matuzumab combined with high-dose 5-fluorouracil, leucovorin and cisplatin (PLF) in the first-line treatment of patients with EGFR-positive advanced gastric and esophagogastric adenocarcinomas.

METHODS

Patients were treated in two matuzumab dose groups with the first cohort of patients receiving 400 mg matuzumab in combination with PLF. Based on the safety observations the next cohort of patients received 800 mg matuzumab. The study was conducted in two parts, with phase A, designed to assess the safety and tolerability of the combination, and phase B designed to be a treatment continuation for those patients benefiting from treatment. Treatment cycles were 7 weeks each. Each patient received the dose of matuzumab they were assigned to at study entry for the duration of the study.

RESULTS

Fifteen EGFR-positive patients were enrolled into the two matuzumab dose groups; 400 mg dose n=7; 800 mg dose n=8. All patients experienced at least one adverse event (AE). No patient experienced any serious AE which was considered to be related to matuzumab. Two grade 3 AEs possibly related to matuzumab occurred in 2 different patients (13.3 %), both in the 800 mg dose group. No dose-limiting toxicity (DLT) was observed in the 400 mg group. The maximum tolerated dose of matuzumab was not reached. The best confirmed overall response rate was 26.7 %.

CONCLUSION

Matuzumab, in combination with PLF, demonstrated an acceptable safety profile with modest anti-tumor activity.

Targeted therapies for gastric cancer: current status

Gastric cancer represents one of the most common cancers internationally. Unfortunately the majority of patients still present at an advanced stage, and despite advances in diagnostic and treatment strategies, outcomes still remain poor with high mortality rates despite a decline in incidence. Whilst the utility of classical chemotherapy agents has been explored thoroughly (and continues to be investigated, alone or in various combinations), advances have been slow and the efficacy of these agents has reached a plateau. As such, the focus of recent study has shifted toward developing a greater understanding of the molecular biology of carcinogenesis and the cancer cell phenotype, and, in turn, the development of rationally designed drugs that target molecular aberrancies in signal transduction pathways specific to gastric cancer. These targets include circulating growth and angiogenic factors, cell surface receptors, and other molecules that comprise downstream intracellular signalling pathways, including receptor tyrosine kinases. Therapeutic advances in this area significantly lag behind other solid organ malignancies such as breast and colorectal cancer. This article reviews the role of targeted therapies in gastric cancer, including rationale and mechanism of action, current and emerging data, as single-agent therapy or in combination regimens. A recently published randomized phaseIII trial supporting the use of trastuzumab, an anti-human epidermal growth factor receptor 2 (HER2)/neu monoclonal antibody, in a selected population of patients is discussed. Therapies that have been evaluated in phase II trials are also reviewed, as well as promising new therapies currently being investigated in preclinical or phase I studies. There is optimism that targeted therapies, whether as single-agent therapy or in combination with traditional therapies, including chemotherapy, radiotherapy and surgery, may yet have an impact on improvement of the overall prognosis of gastric cancer.

Matuzumab plus epirubicin, cisplatin and capecitabine (ECX) compared with epirubicin, cisplatin and capecitabine alone as first-line treatment in patients with advanced oesophago-gastric cancer: a randomised, multicentre open-label phase II study

BACKGROUND

Clinical data showed promising antitumour activity with feasible tolerability for matuzumab plus epirubicin, cisplatin and capecitabine (ECX) chemotherapy in untreated advanced oesophago-gastric (OG) cancer. The aim was to evaluate the efficacy of matuzumab plus ECX versus ECX alone.

PATIENTS AND METHODS

In this multicentre, randomised open-label phase II study, 72 patients with metastatic OG cancer were randomly assigned to either 800 mg matuzumab weekly plus epirubicin 50 mg/m², cisplatin 60 mg/m² on day 1 and capecitabine 1250 mg/m² daily in a 21-day cycle (ECX) or the same ECX regimen alone. The primary end point was objective response. Secondary end points included progression-free survival (PFS), overall survival (OS), quality of life, safety and tolerability.

RESULTS

Following random assignment, 35 patients (median age 59 years) received ECX/matuzumab and 36 patients (median age 64 years) ECX. The addition of matuzumab to ECX did not improve objective response: 31% for ECX/matuzumab [95% confidence interval (CI) 17-49] compared with 58% for the ECX arm (95% CI 41-74) P = 0.994 (one sided). There was no significant difference in median PFS: 4.8 months (95% CI 2.9-8.1) for ECX/matuzumab versus 7.1 months (95% CI 4.4-8.5) for ECX, or in median OS: 9.4 months (95% CI 7.5-16.2), compared with 12.2 months (95% CI 9.8-13.8 months). Grade 3/4 treatment-related toxicity was observed in 27 and 25 patients in the ECX/matuzumab and ECX groups, respectively.

CONCLUSION

Matuzumab 800 mg weekly combined with ECX chemotherapy does not increase response or survival for patients with advanced OG cancer. Therefore, ECX/matuzumab should not be examined further in phase III trials.

Impact of insulin-like growth factor type 1 receptor, epidermal growth factor receptor, and HER2 expressions on outcomes of patients with gastric cancer

PURPOSE

Expression levels of insulin-like growth factor type 1 receptor (IGF-IR), epidermal growth factor receptor (EGFR), and HER2 expressions have been linked to clinical outcomes in several solid tumors. However, the clinical significance of these biomarkers in gastric cancer (GC) remains unclear. This study was designed to delineate the clinical implications of these three biomarkers in GC.

EXPERIMENTAL DESIGN

The study group comprised 87 patients who underwent gastrectomy at National Cancer Center Hospital and subsequently received chemotherapy for recurrent or residual tumors. Using immunohistochemical techniques, we analyzed the expressions of IGF-IR, EGFR, and HER2 on formalin-fixed paraffin-embedded specimens of surgically removed primary tumors.

RESULTS

IGF-IR expression (defined as >10% membranous staining) was found in 67 tumors (77%), EGFR expression in 55 (63%), and HER2 expression in 16 (18%). Positive coexpression of IGF-IR and EGFR was found in 48 tumors (55%), that of IGF-IR and HER2 in 16 (18%), and that of EGFR and HER2 in 13 (15%). Multivariate survival analysis showed that IGF-IR-positive expression [hazard ratio (HR) 2.14, 95% confidence interval (95% CI) 1.20-3.82; P = 0.01], performance status 1 or 2 (HR 1.83, 95% CI 1.15-2.91; P = 0.01), and diffuse type tumors (HR 1.71; 95% CI 1.08-2.70; P = 0.02) were significant predictors of poor survival.

CONCLUSIONS

IGF-IR expression in surgical GC specimens, poor performance status, and diffuse type tumors are significant predictors of poor outcomes in patients with GC. Our data suggest that anti-IGF-IR strategies may prove valuable in such patients.

Clinical significance of the epidermal growth factor receptor and HER2 receptor in resectable gastric cancer

BACKGROUND

Epidermal growth factor receptor (EGFR or HER1) and its homolog c-erbB-2 (HER2) are membrane receptors. Both EGFR and HER2 genes are overexpressed in a variety of solid human cancers and are related to poor prognosis of the patients. The objective of this work was to evaluate the EGFR and HER2 contents in resectable gastric cancer, their possible relationship with clinicopathologic parameters of tumors, and their prognostic significance.

METHODS

This was a prospective analysis of 63 patients with resectable gastric carcinomas, with a mean follow-up period of 40.7 months. Membranous EGFR levels were examined by radioligand binding assays, and cytosolic HER2 levels were examined by means of an immunoenzymatic assay.

RESULTS

There was a wide variability of EGFR (1-1,239 fmol/mg of protein) and HER2 (7-20,863 NHU/mg of protein) levels in tumors. There was no significant correlation between these levels and patient or tumor characteristics. However, high levels of EGFR and HER2 were significantly associated with a shorter overall survival period (P =.03 and P =.02, respectively).

CONCLUSIONS

There is a wide variability in membranous EGFR levels and in cytosolic HER2 levels in gastric cancer, which seems to be related to the biological heterogeneity of these tumors. In addition, high tumor EGFR and HER2 levels were associated with an unfavorable outcome in patients with resectable gastric cancer.

Tyrosine kinases and gastric cancer

Carcinoma of the stomach is one of the most prevalent cancer types in the world today. Two major forms of gastric cancer are distinguished according to their morphological and clinicopathological classifications (well differentiated/intestinal type and poorly differentiated/diffuse type), characteristics that could also be attributed to the altered expression of different types of oncogenes or tumor suppressor genes. Significant differences exist for gastric cancer incidence comparing people of different ethnic origins, implicating various genetic and epigenetic factors for gastric oncogenesis. There are only a limited number of molecular markers available for gastric cancer detection and prognostic evaluation, among which are tyrosine kinases. There is convincing evidence that tyrosine kinases are involved in oncogenesis and disease progression for many human cancers. Amplifications of certain tyrosine kinases (c-met, k-sam and erbB2/neu) have been associated with human gastric cancer progression. Alternatively spliced transcripts and enhanced protein-expression levels for some of these tyrosine kinases are correlated with clinical outcomes for gastric cancer patients. With advent of high throughput techniques, it is now possible to detect nearly all expressed tyrosine kinases in a single screen. This increases the chance to identify additional tyrosine kinases as predictive markers for gastric cancers. In this article, we will first review the literature data concerning certain tyrosine kinases implicated in gastric carcinogenesis and then summarize more recent work which provide comprehensive tyrosine kinase profiles for gastric cancer specimens and cell lines. Two new gastric cancer molecular markers (tie-1 and mkk4) have been identified through the use of these profiles and demonstrated effective as clinical prognostic indicators.

Bombesin/gastrin-releasing peptide antagonists RC-3095 and RC-3940-II inhibit tumor growth and decrease the levels and mRNA expression of epidermal growth factor receptors in H-69 small cell lung carcinoma

BACKGROUND

Antagonists of bombesin/gastrin-releasing peptide (BN/GRP) have been developed to block the autocrine stimulatory effect of BN/GRP on tumors such as small cell lung carcinoma (SCLC). Although several studies have addressed the intracellular events that follow the formation of the receptor-ligand complex, the mechanism of action of BN/GRP antagonists remains unclear.

METHODS

In this study the authors investigated the effect of synthetic BN/GRP antagonists RC-3095 and RC-3940-II on tumor growth and the expression of epidermal growth factor receptors (EGF-R) in H-69 SCLC. Athymic nude mice xenografted with H-69 SCLC were treated subcutaneously for 5 weeks with RC-3095 and RC-3940-II at the dose of 10 microg/animal/day.

RESULTS

RC-3095 decreased tumor volume by approximately 50% (P < 0.05) and RC-3940-II by 70-60% (P < 0.01). Tumor burden also was significantly decreased in the groups treated with RC-3095 and RC-3940-II. Receptor analyses demonstrated high affinity binding sites for BN/GRP and EGF on the untreated H-69 SCLC tumors. After treatment with RC-3095 and RC-3940-II, the concentration of receptors for BN/GRP was decreased by 29.0% and 36.5%, respectively (both, P < 0.01) compared with controls, and EGF-R levels were reduced by 62.3% and 63.0%, respectively (both, P < 0.01). Reverse transcriptase-polymerase chain reaction and Southern blot analyses revealed that the levels of mRNA for EGF-R in tumors were lowered by 31% (P < 0.05) and 43% (P < 0.01), respectively, after treatment with RC-3095 and RC-3940-II.

CONCLUSIONS

This study indicates that the inhibition of growth of H-69 SCLC by BN/GRP antagonists RC-3095 and RC-3940-II is accompanied by a marked decrease in the levels and mRNA expression of EGF-R.

Increased estrogen receptor and epidermal growth factor receptor gene product co-expression in surgically resected gastric adenocarcinomas

BACKGROUND

Evidence exists that estrogens influence the action of epidermal growth factor (EGF) and its receptor (EGF-R) at multiple levels. Estrogen and antiestrogen action on gastric and other gastrointestinal malignancies has been evaluated by several groups with conflicting results, and EGF-R has been implicated in the current growth factor-mediated models for gastric cancer progression.

METHODS

ERs and EGF-Rs were detected immunohistochemically in a total of 53 advanced gastric carcinomas using monoclonal antibodies (mAbs) to human ERs and EGF-Rs.

RESULTS

ERs were expressed in 30 (56%) and EGF-Rs in 20 (38%) of the gastric tumors. ER(+) gastric tumors were closely associated with the intestinal type (P < 0.01), whereas EGF-R(+) tumors were significantly correlated with poor differentiation status and ER(+) expression (P < 0.01). Of EGF-R(+) tumors, 85% were also ER(+). EGF-R and ER co-expression was demonstrated in 17 tumors (32% of the group). These cases were significantly corelated with poor differentiation and large tumor size upon resection (P < 0.05).

CONCLUSIONS

ER and EGF-R co-expression indicates that a functional interaction between estrogens and EGF may exist in gastric cancer and that when such an interaction becomes operative, it may lead to dedifferentiation and increased tumor growth.

Clinical significance of epidermal growth factor (EGF), EGF receptor, and c-erbB-2 in human gastric cancer

The EGF stimulation system for growth regulation is implicated in normal and neoplastic cell proliferation. The role of EGF, the EGF receptor, and c-erbB-2 in human gastric cancer is reviewed on the basis of several reports, which have been mainly oriented toward their clinical significance. EGF has been shown immunohistochemically to be present in 26% of gastric cancers (n = 395). The presence of EGF in gastric cancer is correlated with the degree of gastric wall invasion and lymph node metastasis. The 5-year survival of patients with EGF-positive tumors is worse than that of patients with EGF-negative tumors. The presence of EGF in human gastric cancer may therefore represent a higher malignant potential. Fifteen percent of gastric cancers (n = 352) were also shown to be positive for both EGF and the EGF receptor immunohistochemically, and the simultaneous occurrence of EGF and the EGF receptor suggests that these tumors grow in an autocrine fashion. Tumors exhibiting EGF and the EGF receptor simultaneously show a greater degree of local invasion and lymph node metastasis. Increased expression of EGF receptor protein in gastric cancer appears to be related to biologic aggressiveness, although gene amplification has occurred only to a small extent. Twelve percent of gastric cancers (n = 486) were found to be positive for c-erbB-2. This type of tumor has a frequent metastasis, and patients with c-erbB-2-positive cancer have a poorer prognosis than those with c-erbB-2-negative tumors. Selective blockade of the EGF receptor and c-erbB-2 from their ligands with monoclonal antibodies (MoAbs) inhibits the growth of human gastric cancer xenografts. These MoAbs may therefore be effective antitumor agents against gastric cancer showing overexpression of EGF receptors or c-erbB-2.

Establishment and characterization of TSGH9201, a human gastric carcinoma cell line that is growth inhibited by epidermal growth factor

A human signet ring gastric carcinoma cell line TSGH9201 was established in vitro. The cells grew in vitro as a monolayer with polygonal morphology and had a population doubling time of 34 hours. The cells secreted tumor markers CEA and CA 125. They were, however, not tumorigenic in athymic nude mice. Karyotypic analysis demonstrated a near tetraploidy with a modal chromosome number of 98. Northern blotting and immunocytochemical analysis revealed the expression of both transforming growth factor alpha and high levels of epidermal growth factor receptor. Cell growth was inhibited by the epidermal growth factor in vitro. The cell line may be a useful tool to study autocrine growth regulation through the epidermal growth factor receptor.

In situ evaluation of the relationship between epidermal-growth-factor-receptor status and tumor-cell proliferation in colon carcinomas

The association between the expression of the epidermal-growth-factor receptor (EGFR) and tumor proliferation was studied in 69 resected human adenocarcinomas of the colon. EGFR was detected immunohistochemically using the monoclonal antibody (MAb) EGFRI. Tumor-cell proliferation was assessed with the MAb Ki-67 directed against a proliferation-associated nuclear antigen expressed only in proliferating cells. The percentage of Ki-67-positive tumor cells (Ki-67 index) was evaluated by the point-counting method. Forty-seven carcinomas contained detectable EGFR immunoreactivity. Statistical analysis failed to reveal correlations between the EGFR status and T, N and M stages or tumor differentiation. The mean Ki-67 index did not differ between EGFR-positive and -negative carcinomas. Seven tumors contained clearly distinguishable areas with different EGFR staining intensity. In these tumors with a locally heterogeneous EGFR expression, tumor proliferation also did not correlate with EGFR immunoreactivity. These in situ observations suggest that EGFR expression may not play an important role in the growth regulation of human colonic carcinomas.

Expression of c-erbB-2 oncoprotein in gastric carcinoma. Immunoreactivity for c-erbB-2 protein is an independent indicator of poor short-term prognosis in patients with gastric carcinoma

Correlations of c-erbB-2 protein expression with clinical outcomes of gastric carcinomas were studied in 189 gastric carcinomas. There were 23 (12.2%) carcinomas with evidence of c-erbB-2 protein in which the reaction was localized to the cell membrane. There was no significant association between c-erbB-2 staining and the macroscopic or histologic type of the carcinomas. c-erbB-2-stained tumors were more likely to be associated with serosal invasion, nodal involvement, and peritoneal metastasis, than c-erbB-2-unstained ones. In addition, c-erbB-2 was stained in none of early gastric carcinomas. The 5-year survival rates of the c-erbB-2 protein-positive and the protein-negative group were 11% and 50%, respectively. When the c-erbB-2 tissue status and seven clinicopathologic variables as conventional prognostic factors were entered simultaneously into the Cox regression model, serosal invasion, hepatic metastasis, peritoneal metastasis, nodal status, and c-erbB-2 tissue status emerged as independent prognostic variables. The results suggested that c-erbB-2 protein expression might be enhanced in advanced stages during the progression of gastric carcinoma. In this particular group of patients, immunoreactivity for c-erbB-2 protein is an indicator of poor short-term prognosis.

Growth factors and oncogenes in human solid tumors: clinical aspects

Growth factors, growth factor receptors and oncogenes have been extensively studied in human tumors for some years. The purpose of this paper is to review the clinical results obtained in human cancers and their predisposing conditions or high risk groups as well as their relation with clinical, pathological characteristics and their prognosis.

Relation of proliferative activity to survival in patients with gastric carcinoma

The prognostic significance of proliferative activity in 167 gastric carcinomas was studied by means of an in vitro labeling method with bromodeoxyuridine (BrdU), using specimens obtained by endoscopic biopsy, and the results were correlated with conventional prognostic factors. The BrdU labeling indicates (BrdU LI) varied from 2.1 to 45%. When the in vitro BrdU LI were plotted against in vivo BrdU LI, a significant correlation was found between in vitro and in vivo BrdU LI (P less than .01). These results show that the in vitro BrdU LI of specimens obtained by endoscopic biopsy indicate accurate proliferative activities of gastric cancers. The BrdU LI were closely correlated with nodal status, vessel invasion, and tumor size. With regard to the correlation of BrdU LI and prognosis, patients whose tumors had a high BrdU LI (BrdU greater than LI less than 10%). When the BrdU LI and all the pathologic findings were entered simultaneously into the regression model, nodal status, tumor size, serosal involvement, and BrdU LI emerged as independent prognostic parameters. The present studies demonstrated the usefulness of the in vitro BrdU-labeling method to estimate the malignancy of gastric cancer preoperatively, and this method may be useful in designing the operative procedure and multimodal therapy for individual patients.