Enzyme-linked immunosorbent assay of epidermal growth factor receptor in lung cancer: comparisons with immunohistochemistry, clinicopathological features and prognosis

A SERS/fluorescence dual-mode immuno-nanoprobe for investigating two anti-diabetic drugs on EGFR expressions

A surface-enhanced Raman scattering (SERS)/fluorescence dual-mode nanoprobe was proposed to assess anti-diabetic drug actions from the expression level of the epidermal growth factor receptor (EGFR), which is a significant biomarker of breast cancers. The nanoprobe has a raspberry shape, prepared by coating a dye-doped silica nanosphere with a mass of SERS tags, which gives high gains in fluorescence imaging and SERS measurement. The in situ detection of EGFR on the cell membrane surfaces after drug actions was achieved by using this nanoprobe, and the detection results agree with the enzyme-linked immunosorbent assay (ELISA) kit. Our study suggests that rosiglitazone hydrochloride (RH) may be a potential drug for diabetic patients with breast cancer, while the anti-cancer effect of metformin hydrochloride (MH) is debatable since MH slightly promotes the EGFR expression of MCF-7 cells in this study. This sensing platform endows more feasibility for highly sensitive and accurate feedback of pesticide effects at the membrane protein level.

Identification of EGFR as a Biomarker in Saliva and Buccal Cells from Oral Submucous Fibrosis Patients—A Baseline Study

Oral Submucous Fibrosis (OSMF) is a chronic debilitating disease more frequently encountered in the South-East Asian population. This disease represents a public health priority as it is grouped within oral potentially malignant disorders, with malignant transformation rates of around 7–19%. Hence, early identification of high-risk OSMF patients is of the utmost importance to prevent malignant transformation. Among various biomarkers, EGFR overexpression has an unfavorable clinical outcome, poor prognosis, and low survival rates in Oral Squamous Cell Carcinoma (OSCC). The current study aimed to evaluate the expression of EGFR in saliva and exfoliated buccal cells of OSMF. Immunoexpression of EGFR was observed in healthy controls (n = 11), OSCC (n = 106), and OPMD with dysplasia (n = 56), which showed significant expression with increasing grades of dysplasia and OSCC. EGFR expression was evaluated in saliva and exfoliated buccal cells of healthy controls (n = 15), OSMF (n = 24), and OSCC (n = 10) patients using ELISA, which revealed significant expression in OSMF and OSCC. Validation studies were also performed using real-time PCR (RT-PCR) to compare gene expression in healthy controls (n = 9), OSMF (n = 9), and OSCC (n = 25), which showed significant 18-fold upregulation in OSCC and three-fold upregulation in OSMF when compared to healthy controls. Hence, saliva and exfoliated buccal cells could be considered as potential non-invasive diagnostic samples for the evaluation of high-risk patients of OSMF using EGFR as a biomarker.

Optical Evidence for the Assembly of Sensors Based on Reduced Graphene Oxide and Polydiphenylamine for the Detection of Epidermal Growth Factor Receptor

Using Raman scattering and FTIR spectroscopy, new optical evidence for the assembly of sensors based on reduced graphene oxide (RGO) and polydiphenylamine (PDPA) for the electrochemical detection of the epidermal growth factor receptor (EGFR) are reported. The assembly process of the RGO sheets electrochemical functionalized with PDPA involves the chemical adsorption of 1,4-phenylene diisothiocyanate (PDITC), followed by an incubation with protein G in phosphate buffer (PB) solution and after that the interaction with EGFR antibodies solution. Taking into account the changes reported by Raman scattering and FTIR spectroscopy, a chemical mechanism of the assembling process for this sensor is proposed. The preliminary testing of the electrochemical activity of the sensors based on RGO and PDPA was reported by cyclic voltammetry.

Frequency Shift of a SH-SAW Biosensor with Glutaraldehyde and 3-Aminopropyltriethoxysilane Functionalized Films for Detection of Epidermal Growth Factor

The frequency shift of a shear-horizontal surface-acoustic-wave (SH-SAW) biosensor in which the concentration of biomolecule is determined by the amount of its adsorption on the sensing film was studied. Simulation results were compared with experimental results to investigate its sensitivity and to develop a model to estimate the concentration of a cancer-related biomarker antigen epidermal growth factor (EGF) in the sample, with two types of sensing films, 3-aminopropyltriethoxysilane (APTES) and glutaraldehyde. With the concentration of the targeted biomarker varying from 0.2 to 5 ng/mL, a typical exponential relationship was found between the concentration and the frequency shift of the SH-SAW sensor. Measurement results showed a clear response of this immunosensor to the mass-loading effects of the antibody–antigen. The sensitivity of the glutaraldehyde film is greater than that of the APTES film owing to the chemisorption of the antibody. In the simulation, a shift of the SH-SAW resonant frequency due to added mass occurred on applying an incremental surface mass density on the sensing film, while in real applications, the concentration of the targeted biomarker to be absorbed in the sensing film is demanded. An empirical model was proposed to calculate the frequency shift in the simulation of the SH-SAW biosensor, corresponding to the concentration of specific biomolecules absorbed on a specific film. From the semi-empirical model, the sensitivity level is found to be 0.641 and 1.709 kHz/(ng/mL) for APTES and glutaraldehyde sensing films, respectively, at a biomarker concentration of less than 1 ng/mL. The developed method is useful for quickly estimating the frequency shift with respect to the concentration of the target molecules in the simulation for SH-SAW sensors.

Low sample volume origami-paper-based graphene-modified aptasensors for label-free electrochemical detection of cancer biomarker-EGFR

In this work, an electrochemical paper-based aptasensor was fabricated for label-free and ultrasensitive detection of epidermal growth factor receptor (EGFR) by employing anti-EGFR aptamers as the bio-recognition element. The device used the concept of paper-folding, or origami, to serve as a valve between sample introduction and detection, so reducing sampling volumes and improving operation convenience. Amino-functionalized graphene (NH₂-GO)/thionine (THI)/gold particle (AuNP) nanocomposites were used to modify the working electrode not only to generate the electrochemical signals, but also to provide an environment conducive to aptamer immobilization. Electrochemical characterization revealed that the formation of an insulating aptamer-antigen immunocomplex would hinder electron transfer from the sample medium to the working electrode, thus resulting in a lower signal. The experimental results showed that the proposed aptasensor exhibited a linear range from 0.05 to 200 ngmL^-1 (R ² = 0.989) and a detection limit of 5 pgmL^-1 for EGFR. The analytical reliability of the proposed paper-based aptasensor was further investigated by analyzing serum samples, showing good agreement with the gold-standard enzyme-linked immunosorbent assay.

A PET imaging approach for determining EGFR mutation status for improved lung cancer patient management

Tumor heterogeneity and changes in epidermal growth factor receptor (EGFR) mutation status over time challenge the design of effective EGFR tyrosine kinase inhibitor (TKI) treatment strategies for non-small cell lung cancer (NSCLC). Therefore, there is an urgent need to develop techniques for comprehensive tumor EGFR profiling in real time, particularly in lung cancer precision medicine trials. We report a positron emission tomography (PET) tracer, N-(3-chloro-4-fluorophenyl)-7-(2-(2-(2-(2-¹⁸F-fluoroethoxy) ethoxy) ethoxy) ethoxy)-6-methoxyquinazolin-4-amine (¹⁸F-MPG), with high specificity to activating EGFR mutant kinase. We evaluate the feasibility of using ¹⁸F-MPG PET for noninvasive imaging and quantification of EGFR-activating mutation status in preclinical models of NSCLC and in patients with primary and metastatic NSCLC tumors. ¹⁸F-MPG PET in NSCLC animal models showed a significant correlation (R² = 0.9050) between ¹⁸F-MPG uptake and activating EGFR mutation status. In clinical studies with NSCLC patients (n = 75), the concordance between the detection of EGFR activation by ¹⁸F-MPG PET/computed tomography (CT) and tissue biopsy reached 84.29%. There was a greater response to EGFR-TKIs (81.58% versus 6.06%) and longer median progression-free survival (348 days versus 183 days) in NSCLC patients when ¹⁸F-MPG PET/CT SUV_max (maximum standard uptake value) was ≥2.23 versus <2.23. Our study demonstrates that ¹⁸F-MPG PET/CT is a powerful method for precise quantification of EGFR-activating mutation status in NSCLC patients, and it is a promising strategy for noninvasively identifying patients sensitive to EGFR-TKIs and for monitoring the efficacy of EGFR-TKI therapy.

Two-dimensional porphyrin-based covalent organic framework: A novel platform for sensitive epidermal growth factor receptor and living cancer cell detection

A porphyrin-based covalent organic framework (denoted as p-COF) was synthesized by a simple oil-bath method and exploited as a novel sensing layer for immobilizing epidermal growth factor receptor (EGFR)-targeting aptamer strands to detect trace EGFR and living michigan cancer foundation-7 (MCF-7) cells for the first time. p-COF presented a nanosheet-like structure, large cavities, rich nitrogen-bearing groups, high electrochemical activity, excellent bioaffinity, low toxicity, and good stability in aqueous solution; the microstructural features of this material enabled strong immobilization of the aptamer strands. Interactions between the aptamer strands and EGFR significantly changed the electrochemical signals of the modified electrode due to the formation of an aptamer-EGFR complex. The p-COF-based aptasensor exhibited an extremely low detection limit (LOD) of 5.64 fg·mL^-1 obtained from differential pulse voltammetry and 7.54 fg·mL^-1 originated from electrochemical impedance spectroscopy with a broad linear detection range of 0.05-100 pg·mL^-1 of the EGFR concentration. When detecting living MCF-7 cells, the p-COF-based aptasensor showed an LOD of 61 cell·mL^-1 with a linear detection range of 500 × 10⁵ cell·mL^-1. The fabricated aptasensor exhibited high selectivity, good stability, reproducibility, acceptable recyclability, and favorable applicability in human serum samples. We believe that the developed p-COF-based aptasensor is a potential candidate for the sensitive detection of target cancer markers or living cells.

Resonance Rayleigh scattering assay for EGFR using antibody immobilized gold nanoparticles

A highly selectivity determination of epidermal growth factor receptor (EGFR) has been described in the article. Antibody immobilized cysteamine (Cys) functionalized gold nanoparticles (AuNP) were proposed as immunosensors, and resonance Rayleigh scattering (RRS) was used for detection. First, Cys stabilized AuNPs (Cys-AuNP) were prepared by the reduction of chloroauric acid with sodium borohydride in the presence of Cys. Further, anti-EGFR antibody (Cetuximab, C225) was covalently linked to the Cys-AuNP by carbodiimide-mediated amidation protocol to yield the C225-AuNP immunoprobe. The prepared conjugations were characterized by ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Based on the specific binding of C225 to EGFR, an RRS method was established to determine the concentration of EGFR. Under the optimal conditions, the concentration of EGFR was related to the intensity of RRS in the range 30-130 ng ml^-1 with a low detection limit of 4.0 ng ml^-1 . Meanwhile, the proposed immunosensor exhibited excellent selectivity and anti-interference property. The method was applied to the determination of EGFR in human serum and cancer cell lysate samples with satisfactory results.

Highly sensitive detection of epidermal growth factor receptor in lung cancer cells by aptamer-based target-/probe-mediated cyclic signal amplification

We develop an antibody-free fluorescence method for the epidermal growth factor receptor (EGFR) assay using aptamer-based target-/probe-mediated cyclic signal amplification. The method is highly sensitive with a detection limit of 0.16 fM, and it can be applied to detect EGFR in lung cancer cells, holding great potential in clinical diagnosis.

Intercellular adhesion molecule-1 (ICAM-1) is upregulated in aggressive papillary thyroid carcinoma

BACKGROUND

Intercellular adhesion molecule-1 (ICAM-1) is implicated in carcinogenesis. In this study we examined the expression of ICAM-1 in papillary thyroid cancer (PTC). We hypothesized that ICAM-1 correlates with indicators of tumor aggressiveness in PTC.

METHODS

Thirty-five primary and metastatic PTCs, five follicular adenomas, five Hashimoto thyroiditis, five nodular hyperplasia, and eight normal thyroid tissue samples were analyzed for ICAM-1 gene expression using quantitative reverse-transcription polymerase chain reaction (RT-PCR). ICAM-1 gene expression was analyzed at protein level by immunohistochemistry (IHC) using a semiquantitative score. Gene expression and intensity levels were correlated with markers of tumor aggressiveness including BRAF V600E mutation, tumor size, extrathyroidal extension (ETE), angiolymphatic invasion, and lymph node metastasis.

RESULTS

ICAM-1 gene expression was higher in PTC (p = 0.01) and lymph node metastases (p = 0.03) when compared with benign tumors and Hashimoto's. Furthermore, PTCs exhibiting BRAF V600E mutation (p = 0.01), ETE (p < 0.01), and lymph node metastasis (p = 0.02) were associated with higher ICAM-1 levels. Gene expression correlated with protein levels on IHC. Additionally, poorly differentiated thyroid carcinoma had a higher ICAM-1 intensity score compared with well-differentiated carcinoma (p = 0.03).

CONCLUSIONS

ICAM-1 expression is upregulated in papillary thyroid carcinoma. Furthermore, ICAM-1 upregulation correlated with aggressive tumor features such as BRAF V600E mutation, ETE, and lymph node metastasis, suggesting that ICAM-1 plays a role in thyroid cancer progression.

Prognostic value of epidermal growth factor receptor expression in operable non-small cell lung carcinoma

Background and aim

Increased expression of the epidermal growth factor receptor (EGFR) in non-small cell lung cancer (NSCLC), supporting the tumor growth by a possible endocrine mechanism, affects patient survival negatively. We designed a study to test EGFR expression by immunohistochemistry (IHC) in resected stage I-II NSCLC and to correlate its overexpression with survival.

Methods

EGFR expression was evaluated in 98 consecutive NSCLC patients after complete resection (53 squamous cell carcinomas, 40 adenocarcinomas, 5 large cell carcinomas: stage I, 57 (58%) and stage II, 41 (42%). IHC was used to examine the expression of EGFR in resected lung tumor samples obtained from these patients, who had no pre- or post-operative chemotherapy or radiotherapy. Univariate and multivariate analyses were performed for factors influencing patient survival.

Results

EGFR was expressed in 51 (52%) of 98 NSCLC samples. More squamous tumors (61%) were EGFR-positive than adenocarcinomas (38%) (p = 0.038). There was a statistically significant correlation between EGFR expression and stage (p = 0.04). No difference was found between EGFR positive and negative tumors in the 5-year overall survival (57% vs. 73%, p = 0.13).

Conclusion

The level of EGFR expression in tumors was not a successful predictor of survival in resected NSCLC.

Increased MET gene copy number negatively affects survival of surgically resected non-small-cell lung cancer patients

PURPOSE

To investigate the prognostic role of genomic gain for MET and epidermal growth factor receptor (EGFR) genes in surgically resected non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

This retrospective study included 447 NSCLC patients with available tumor tissue from primary lung tumor and survival data. EGFR and MET status was evaluated by fluorescent in situ hybridization (FISH) in tissue microarray sections.

RESULTS

EGFR FISH results were obtained in 376 cases. EGFR gene amplification and high polysomy (EGFR FISH+) were observed in 10.4% and 32.4% of cases, respectively. EGFR FISH-positive patients had a nonsignificant shorter survival than EGFR FISH-negative patients (P = .4). Activating EGFR mutations were detected in 9.7% of 144 stage I-II disease with no impact on survival. MET FISH analysis was performed in 435 cases. High MET gene copy number (mean > or = 5 copies/cell) was observed in 48 cases (MET+, 11.1%), including 18 cases with true gene amplification (4.1%). MET+ status was associated with advanced stage (P = .01), with grade 3 (P = .016) and with EGFR FISH+ result (P < .0001). No patient with activating EGFR mutation resulted MET+. In the whole population, MET-positive patients had shorter survival than MET-negative patients (P = .005). Multivariable model confirmed that MET-negative patients had a significant reduction in the risk of death than MET-positive patients (hazard ratio, 0.66; P = .04).

CONCLUSION

MET increased gene copy number is an independent negative prognostic factor in surgically resected NSCLC. EGFR gene gain does not impact survival after resection.

Urokinase plasminogen activator and plasminogen activator inhibitor type-1 in nonsmall-cell lung cancer: relation to prognosis and angiogenesis

BACKGROUND

Urokinase plasminogen activator (uPA) and plasminogen activator inhibitor type-1 (PAI-1) have previously been suggested as prognostic markers in nonsmall-cell lung carcinomas (NSCLC). We investigate whether uPA and PAI-1 are prognostic markers in NSCLC and whether they are related to angiogenesis.

MATERIALS AND METHODS

Frozen tumour tissue from surgical specimens from 118 previously untreated patients diagnosed with NSCLC in the period 1984-1991 were investigated. All patients were treated with surgery, and no chemo- or radiotherapy was given. UPA and PAI-1 levels were assessed using a sandwich ELISA method.

RESULTS

Both uPA and PAI-1 were independent of classical histopathological parameters as well as of microvessel density and vascular pattern. Using death within the first 5 years as endpoint, neither of the factors were prognostic markers in univariate analysis, however, significantly higher levels of uPA and PAI-1 were seen in tumours with an angiogenic vascular pattern. In multivariate analysis, high disease stage (P<0.0001), adenocarcinoma (P=0.007), old age (P=0.02), and presence of an angiogenic pattern (P=0.05) were identified as independent markers of death within 5 years.

CONCLUSIONS

The present study investigated the prognostic role of the protein levels of uPA and PAI-1 in 118 tumour specimens from patients diagnosed with NSCLC. Neither of the factors were identified as prognostic markers when evaluated with survival as endpoint. However, in tumours previously identified as non-angiogenic we found significantly lower contents of both uPA and PAI-1 as compared to angiogenic tumours, thus we hypothesize that uPA and PAI-1 stimulate angiogenesis in NSCLC.

Activation state EGFR and STAT-3 as prognostic markers in resected non-small cell lung cancer

BACKGROUND

Total EGFR expression by immunohistochemistry (IHC) has failed to demonstrate prognostic importance. We hypothesized that activation (phosphorylated) state of EGFR (p-EGFR) and its activated downstream signal pathway (p-STAT-3) will have prognostic value in NSCLC.

METHODS

145 patients underwent lung resection for NSCLC at University Hospitals from 1998-2002. A database with TNM stage, gender, age, time to recurrence, and survival was established. p-EGFR and p-STAT-3 levels were quantified by IHC. Specimens were divided into negative, 1+, 2+, or 3+ (5-19%, 20-50%, >50% of tumor cells staining respectively). Cox proportional hazard model was used for multivariate analysis.

RESULTS

Median age was 70 years. 58% were female and 54% had adenocarcinoma. Pathologic stage was as follows: stage I: 54%, stage II: 31%, stage III: 15%. 32% were positive for p-EGFR (squamous 36%, adenocarcinoma 29%). p-STAT-3 staining was seen in 38% and was higher in adenocarcinoma (46%) versus squamous cell (27%, p=0.02) and was higher in patients >70 years than compared to those <70 years (p=0.06). There was a trend toward co-expression of p-EGFR and p-STAT-3 (p=0.09). The 5-year Kaplan-Meier probabilities of overall survival were not different amongst patients with activated versus no activation of EGFR and STAT-3.

CONCLUSIONS

Although EGFR is commonly expressed in NSCLC ( approximately 70%), p-EGFR is seen in only 1/3 of patients. p-EGFR and p-STAT-3 were commonly co-expressed in tumors compatible with known signal transduction pathways in lung cancer. However, EGFR and STAT-3 activation status does not provide prognostic information in resected disease.

EGFR expression: associations with outcome and clinicopathological variables in malignant pleural mesothelioma

Malignant mesothelioma (MM) is a fatal tumour of increasing incidence which is related to asbestos exposure. This work evaluated expression in MM of Epidermal Growth Factor Receptor (EGFR) by immunohistochemistry in 168 tumour sections and its correlations with clinicopathological and biological factors. The microvessel density (MVD) was derived from CD34 immunostained sections. Hematoxylin and eosin stained sections were examined for intratumoural necrosis. COX-2 protein expression was evaluated with semi-quantitative Western blotting of homogenised tumour supernatants (n=45). EGFR expression was correlated with survival by Kaplan-Meier and log rank analysis. Univariate and multivariate Cox proportional hazards models were used to compare the effects of EGFR with clinicopathological and biological prognostic factors and prognostic scoring systems. EGFR expression was identified in 74 cases (44%) and correlated with epithelioid cell type (p<0.0001), good performance status (p<0.0001), the absence of chest pain (p<0.0001) and the presence of TN (p=0.004), but not MVD or COX-2. EGFR expression was a good prognostic factor in univariate analysis (p=0.01). Independent indicators of poor prognosis in multivariate analysis were non-epithelioid cell type (p=0.0001), weight loss, performance status and WBC>8.3x10(9)L(-1). EGFR status was not an independent prognostic factor. EGFR expression in MM correlates with epithelioid histology and TN. EGFR may be a target for selective therapies in MM.

High predictive value of epidermal growth factor receptor phosphorylation but not of EGFRvIII mutation in resected stage I non-small cell lung cancer (NSCLC)

AIMS

Overexpression and mutation of epidermal growth factor regulator (EGFR) are frequently found in the carcinogenesis of non-small cell lung cancer (NSCLC). Because targeting of this receptor has proven therapeutic efficacy, studying EGFR has become a matter of particular scientific interest. The present study analysed the EGFR receptor, rate of EGFRvIII mutations, and rate of activated phosphorylated EGFR (pEGFR) by immunohistochemistry on cryostat sections.

METHODS

Surgically obtained tumour specimens of a series of 78 NSCLC patients and 66 adjacent tumour free specimens were examined immunohistochemically using monoclonal antibodies to stain EGFR, pEGFR, and EGFRvIII.

RESULTS

EGFRvIII and pEGFR expression was found in 42% and 26% of the tumours respectively and both were increased significantly compared with tumour free samples. EGFR, pEGFR, and EGFRvIII expression did not correlate with any of the previously tested markers (c-erbB-2, c-erbB-3, p53, ki-67, and microvessel density). Similar distributions of immunohistochemical profiles were seen, regardless of histological subtype, age, or sex. In stage I patients, EGFR phosphorylation at tyrosine residue 845 proved to be an independent prognostic factor.

CONCLUSION

Because pEGFR correlated with poor prognosis, it can be speculated that it plays a crucial biological role in the pathogenesis of NSCLC.

Survival impact of epidermal growth factor receptor overexpression in patients with non-small cell lung cancer: a meta-analysis

BACKGROUND

It is thought that overexpression of epidermal growth factor receptor (EGFR) in non-small cell lung cancer (NSCLC) might compromise patient survival, presumably by promoting tumour growth by an autocrine mechanism. However, conflicting results have been reported from various laboratories, and the clinical importance of EGFR overexpression remains unsettled.

METHODS

A meta-analysis of previous studies was performed to quantitatively review the effects of EGFR overexpression on survival in patients with NSCLC using a DerSimonian-Laird random effects model. Eighteen studies including 2972 patients were subjected to final analysis.

RESULTS

Overall, positivity for EGFR overexpression differed between histological types: 39% in adenocarcinomas, 58% in squamous cell carcinomas, 38% in large cell carcinomas, and 32% in cancers in a miscellaneous category (p<0.0001). The combined hazard ratio (HR) was 1.14 (95% CI 0.97 to 1.34; p = 0.103), indicating that EGFR overexpression has no significant impact on survival. When only the 15 immunohistochemistry based studies were considered, the combined HR was 1.08 (95% CI 0.92 to 1.28; p = 0.356), again suggesting that EGFR overexpression has no impact on survival. Heterogeneity testing indicated that there was heterogeneity between studies but publication bias was absent, which suggests that the summary statistics obtained may approximate the actual average.

CONCLUSIONS

EGFR overexpression was not associated with poorer survival in patients with NSCLC. Specific mutations of the EGFR gene will need further study in terms of survival implications.

Small tumor size and limited smoking history predicts activated epidermal growth factor receptor in early-stage non-small cell lung cancer

STUDY OBJECTIVE

Epidermal growth factor receptor (EGFR) signaling has been implicated in the pathogenesis of bronchial dysplasia and overt non-small cell lung cancer (NSCLC). We hypothesized that assaying for EGFR activity using an antibody that recognizes phosphorylated EGFR (pEGFR) may identify a subset of patients whose tumor cells are dependent on EGFR signaling. We also hypothesized that EGFR activity may be prognostic for early-stage NSCLC.

DESIGN

We constructed high-density tissue microarrays using tissues from 193 surgically resected stage I NSCLCs. These arrays were immunostained with a pEGFR antibody, and the intensity of staining was correlated with clinicopathologic variables, as well as disease-free and overall survival (OS). Staining was scored by intensity and the percentage of positively stained tumor cells in triplicate.

MEASUREMENTS AND RESULTS

We found the expression of pEGFR (with > 50% of tumor cells staining positive) in 51% of tumor tissues. We found an inverse correlation between pEGFR, and both tumor size and the degree of tobacco smoking. In addition, we found a trend in which pEGFR expression was inversely correlated with disease stage (IA higher than IB). There was no correlation with sex, histology, or disease-free or OS.

CONCLUSIONS

Our results suggest that pEGFR levels are present in early-stage NSCLC, especially in patients with small tumors and in those with short smoking histories, but there is no prognostic impact on a patient's disease course. Targeting EGFR may therefore have more promise in chemoprevention or in patients with smaller early-stage NSCLCs compared with those with more advanced disease.

Current Management of Advanced Non-Small Cell Lung Cancer: Targeted Therapy

Lung cancer is one of the most frequent causes of cancer-related death in the United States. For patients with advanced non-small cell lung cancer (NSCLC), chemotherapy, alone or in combination with radiation therapy, is considered the standard treatment. Although this treatment may result in a modest improvement in patient survival, overall prognosis of these patients remains dismal, and the treatment is nonspecific, nonselective, and toxic. Therefore, new therapeutic strategies are needed. During the past decade, several molecules that contribute to lung cancer progression and metastasis have been identified. Growth factors and proangiogenic factors have been the focus of intense research in cancer since therapeutic approaches for their inhibition do exist. The role of these factors was studied in different organs and tumors and was found to be phenotypically distinct. Several molecular targeted therapies have shown efficacy and had been approved for treatment of specific cancers. Most advanced in clinical research for lung cancer are targeted therapies that inhibit the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor (VEGF) signaling pathways. Others are signaling pathway inhibitors. The first targeted therapy for lung cancer is gefitinib, an EGFR inhibitor, which was approved in several countries in 2003. Goals of molecular targeted therapy studies include the following: better understanding of the exact role of particular growth factors in specific tumors; establishment of new clinical study designs for biological agents; and tailoring appropriate combinations of conventional chemotherapy and/or radiotherapy with biological therapy for specific patients. Achievement of these goals will hopefully lead to incorporation of biological therapy into the current anticancer arsenal, for the benefit of lung cancer patients.

Clinical significance of biological differences between cavitated and solid form of squamous cell lung cancer

Recently, Kolodziejski et al. [Kołodziejski LS, Dyczek S, Duda K, Goralczyk KJ, Wysocki MW, Lobaziewicz W. Cavitated tumor as a clinical subentity in squamous cell lung cancer patients. Neoplasma 2003;50:66--73] have shown, that patients with cavitated form of squamous cell lung cancer (c-SqCLC) treated by surgery had shorter survival than patients with solid form (s-SqCLC) despite having similar stage, histological features and causes of deaths. Therefore, we decided to check if tumour biological features are responsible for the difference in patients' response. The aim of the study was to assess tumour proliferation rate (MIB-1 labelling index, MIB-1 LI), tumour proliferation pattern and expression of epidermal growth factor receptor (EGFR labelling index, EGFR LI) in solid and cavitated SqCLCs. A total of 81 patients with SqCLC were analysed; 18 c-qCLC (with cavity identified at X-ray examination) and 63 s-SqCLC. Expression of Ki-67 protein (MIB-1 LI) and proliferation pattern based on this staining and EGFR LI was visualized in formalin-fixed paraffin-embedded sections, using immunohistochemistry. s-SqCLC showed faster proliferation than c-SqCLC. Mean MIB-1 LI for the first group was higher-39.2% (range, 12.7--65.6) than for the second group--26.1% (range, 7.1--45.6) (P=0.000). In c-SqCLC subgroup, eight tumours with intermediate type of proliferation, six with random and four with mixed pattern were identified. However, in the s-SqCLC there were 18 with intermediate, 22 with random and 22 with mixed type of proliferation. The difference between architecture of proliferation and histological grade was seen (P=0.040). Mean EGFR LI did not differ between c-SqCLC (31.1%) and s-SqCLC (29.3%); however, median value was non-significantly lower for c-SqCLC (14.0%) than in s-SqCLC (21.0%). Univariate Kaplan-Meier analysis revealed that patients with s-SqCLC and a lower pTNM, faster tumour proliferation (MIB-1 LI>39%) and 13%</=EGFR LI<80% had significantly longer survival. Cox multivariate analysis performed for the whole analysed group showed that proliferation rate, expression of EGF receptor (EGFR LI); pTNM and form of SqCLC were significant in respect of patients' survival. However, when the analysis was performed separately for s-SqCLC and c-SqCLC it appeared that biological parameters (EGFR LI and proliferation pattern) were significant only for solid and not for cavitated SqCLC form. For the latter, only clinical (TNM) and pathological stage (pTNM) appeared to be important and therefore adjuvant systemic chemotherapy after surgery may be more indicated.

Phase I/II trial evaluating the anti-vascular endothelial growth factor monoclonal antibody bevacizumab in combination with the HER-1/epidermal growth factor receptor tyrosine kinase inhibitor erlotinib for patients with recurrent non-small-cell lung cancer

PURPOSE

Bevacizumab (Avastin; Genentech, South San Francisco, CA) is a recombinant, humanized anti-vascular endothelial growth factor monoclonal antibody. Erlotinib HCl (Tarceva, OSI-774; OSI Pharmaceuticals, New York, NY) is a potent, reversible, highly selective and orally available HER-1/epidermal growth factor receptor tyrosine kinase inhibitor. Preclinical data in various xenograft models produced greater growth inhibition than with either agent alone. Additionally, both agents have demonstrated benefit in patients with previously treated non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

A phase I/II study in two centers examined erlotinib and bevacizumab (A+T) in patients with nonsquamous stage IIIB/IV NSCLC with > or = one prior chemotherapy. In phase I, erlotinib 150 mg/day orally plus bevacizumab 15 mg/kg intravenously every 21 days was established as the phase II dose, although no dose-limiting toxicities were observed. Phase II assessed the efficacy and tolerability of A+T at this dose. Pharmacokinetic parameters were evaluated. ResultsForty patients were enrolled and treated in this study (34 patients at phase II dose); the median age was 59 years (range, 36 to 72 years), 21 were female, 30 had adenocarcinoma histology, nine were never-smokers, and 22 had > or = two prior regimens (three patients had > or = four prior regimens). The most common adverse events were mild to moderate rash, diarrhea, and proteinuria. Preliminary data showed no pharmacokinetic interaction between A + T. Eight patients (20.0%; 95% CI, 7.6% to 32.4%) had partial responses and 26 (65.0%; 95% CI, 50.2% to 79.8%) had stable disease as their best response. The median overall survival for the 34 patients treated at the phase II dose was 12.6 months, with progression-free survival of 6.2 months.

CONCLUSION

Encouraging antitumor activity and safety of A + T support further development of this combination for patients with advanced NSCLC and other solid tumors.

Biomarkers in non-small cell lung cancer prevention

Identification of biomarkers is one of the most promising approaches for the detection of early malignant or even premalignant lesions with the chance of diagnosing early stages of non-small cell lung cancer that could be treated curatively. Alterations of chromosomes (3p, 5q, 9p), genes (Rb, C-myc, C-mos, hTERT), proteins (p16, p53, K-ras, hnRNP A2/B1, MCM2, EGFR, erbB-2, erbB-3, erbB-4) and others can be found in lung cancer. Some of these occur at early stages of the disease and few could serve as potential screening markers. The actual literature is reviewed and the relevance of the different biomarkers for early lung cancer detection is discussed.

Molecular mechanisms of ZD1839-induced G1-cell cycle arrest and apoptosis in human lung adenocarcinoma A549 cells

Epithelial growth factor receptor (EGFR) has been proposed as a target for anticancer therapy. ZD1839 (Iressa) is a quinazoline derivative that selectively inhibits the EGFR tyrosine kinase activity and is under clinical use in cancer patients. However, the molecular mechanisms involved in ZD1839-mediated anticancer effects remain largely uncharacterized. In this study, exposure of human lung adenocarcinoma A549 cells to ZD1839 caused G1 arrest, and subsequently induced apoptosis. Moreover, ZD1839 increased the protein levels of p27(KIP1) and retinoblastoma-related Rb2/p130 while decreased the expression of cyclin-dependent kinase-2 (CDK2), CDK4, CDK6 and cyclin-D1, cyclin-D3. In vitro kinase assay showed that ZD1839 decreased these CDKs expression in A549 cells, leading to significantly reduce their kinase activities. In addition, ZD1839-induced death of A549 cells with characteristics of apoptosis including apoptotic morphological changes, DNA fragmentation and enhancement of TUNEL-positive cell. These events were accompanied by a marked increase of Fas protein expression, and activation of caspase-2, -3, -8. Co-treatment of cells with Fas antagonist antibody significantly blocked ZD1839-induced apoptosis. Caspase-8 and caspase-3 inhibitors, but not a caspase-9 inhibitor, were also capable of restoring cell viability. Our results indicate that downregulation of the expression and function of CDK2, CDK4, CDK6, cyclin-D1 and cyclin-D3, as well as upregulation of p27(KIP1) and pRb2/p130, are strong candidates for the cell cycle regulator that arrests ZD1839-treated A549 cells at G1 phase. Furthermore, upregulation of Fas appears to play a major role in the initiation of ZD1839-induced apoptosis, activation of caspase-8/caspase-3 cascade is involved in the execution phase of this death program.

Epidermal growth factor receptor as a target to improve treatment of lung cancer

Despite considerable efforts to reduce tobacco use, lung cancer remains the most common cancer in both men and women. Recent advances in radiation therapy and chemotherapy for lung cancer have yielded encouraging results, but survival in patients with locally advanced non-small-cell lung cancer (NSCLC) remains poor. As more and more molecular changes and their importance in malignant tissues continue to be characterized, approaches to target those aberrant pathways are being actively explored. The epidermal growth factor receptor (EGFR) is commonly overexpressed in NSCLC, particularly squamous cell carcinoma, and has been implicated in the development and progression of this disease, although a clear correlation with prognosis has not been established. Several different strategies have been developed to target and block the EGFR and its downstream effects, and some of them have been intensively studied in preclinical and clinical studies as a single-agent approach or in combination with radiation therapy or chemotherapy. In this article, we review the role of EGFR in lung cancer, as well as preclinical and clinical data on strategies to interfere with EGFR signaling alone or in combination with chemotherapy, radiation, or both.

Epidermal growth factor receptor (EGFR) expression in operable non-small cell lung carcinoma

This study was performed to assay the expression of epidermal growth factor receptor (EGFR) in non-small cell lung carcinoma (NSCLC), and to investigate the relationship between EGFR status and various clinicopathologic features of NSCLC, including angiogenesis and proliferative activity. The expression of EGFR, microvessel count (MVC) measured by CD31 monoclonal antibody, and proliferative activity using Ki-67 labeling index were immunohistochemically analyzed in formalin-fixed and paraffin-embedded tissue specimens from 65 patients with completely resected stage II-IIIA NSCLC. Pathologic and clinical records of all patients were retrospectively reviewed. EGFR was expressed in 18 (28%) of 65 NSCLC samples. More squamous tumors (35%) were EGFR-positive than other NSCLCs (23%) (p-value 0.308). There was a statistically significant correlation between EGFR expression and Ki-67 labeling index (p-value 0.042), but no correlation was observed between EGFR expression and tumor histology, stage, or MVC. There were no differences between EGFR positive and negative tumors in 5-yr disease-free survival (60% vs. 52%, p-value 0.5566) and 5-yr overall survival (53% vs. 45%, p-value 0.3382) rates. In conclusion, our findings suggest that NSCLC proliferative activity may be dependent on EGFR expression, but that EGFR expression had no significant impact on survival in curatively resected NSCLC.

Prognostic significance of EGFR and Her-2 in oral cavity cancer in betel quid prevalent area cancer prognosis

Although several studies have found overexpression of epidermal growth factor receptor (EGFR) proteins EGFR and Her-2 in head and neck cancers, the clinical relevance of the finding varies. We examined the expression and clinical association of these molecules with oral squamous cell carcinoma in an area where betel chewing is prevalent. EGFR and Her-2 proteins were measured in 59 paired (grossly normal and cancer) tissues by an enzyme immunoassy method. The cutoff value for gene overexpression was defined as the level of mean expression in normal tissue plus two s.d. A total of 59% of the patients consumed alcohol, 90% smoked tobacco, and 90% chewed betel quid. Of the patients assayed, 34 (58%) and 24 (41%) had EGFR and Her-2 overexpression, with average 3.5- and 1.5-fold elevations. EGFR overexpression has been shown to be statistically associated with T stage, N stage, overall TMN stage, primary tumour depth, lymph node extra-capsular spread, and poor survival. Her-2 overexpression, however, did not demonstrate a similar association with clinicopathological parameters or therapeutic outcome. On multivariant analysis, EGFR overexpression (P=0.041) and N stage (P=0.024) were the only independent factors for overall survival. These results indicate that the molecular targeting therapy to EGFR may be a treatment for oral cavity cancer in the betel quid-chewing prevalent area.

Frequent overexpression of the c-kit protein in large cell neuroendocrine carcinoma of the lung

Overexpression of receptor-type tyrosine kinases in various cancers is associated with an aggressive tumor phenotype and poor outcome, but their expression had never been evaluated in large cell neuroendocrine carcinoma (LCNEC) of the lung. In the present study, we investigated the expression of three receptor tyrosine kinases, epidermal growth factor receptor (EGFR), c-erbB-2, and c-kit protein, by comparing surgically resected 40 LCNECs with other neuroendocrine (NE) lung tumors: 9 typical carcinoids (TCs), 5 atypical carcinoids (ACs), and 13 small cell lung carcinomas (SCLCs). None of the NE lung tumors showed expression of EFGR or c-erbB-2, but c-kit was overexpressed in 55% of the LCNEC tumor cells and 46% of the SCLC tumor cells. None of the clinicopathologic factors in either the LCNEC or SCLC patients correlated with c-kit overexpression. The finding that c-kit expression in LCNEC is similar to its expression in SCLC suggests that inhibition of c-kit may be effective as a therapy targeting LCNEC as well as SCLC.

The Role of Apoptosis-Related Genes in non—small-Cell Lung Cancer

Both intrinsic and acquired resistance to chemotherapeutic drugs are major obstacles in the treatment of non-small-cell lung cancer. Apart from classical drug resistance mechanisms, the failure of tumor cells to undergo apoptosis also plays an important role in drug resistance. Mutations and defects in the apoptotic pathway are, therefore, additional factors that determine drug resistance. The tumor suppressor gene p53, the retinoblastoma gene, and the bcl-2 family members are important factors in this pathway. Recently much attention has been drawn to different apoptotic pathways induced by naturally occurring death receptor ligands (such as tumor necrosis factor, Fas ligand, and tumor necrosis factor-related apoptosis-inducing ligand) or induced by drugs that affect the downstream pathway from the epidermal growth factor receptor. Insight regarding the proteins that determine sensitivity for chemotherapeutic drugs could provide new targets for cancer treatment, which may help to at least partly overcome drug resistance in non-small-cell lung cancer

Molecular staging of lung and esophageal cancer

In both esophageal and NSCLC, the TNM stage at diagnosis remains the most important determinant of survival. Significant research to investigate the biology of NSCLC and esophageal carcinoma is ongoing, and the roles of proto-oncogenes, tumor suppressor genes, angiogenic factors, extracellular matrix proteases, and adhesion molecules are being elucidated. While evidence is accumulating that various markers are involved in NSCLC and esophageal tumor virulence, the current studies are compromised by small sample sizes, heterogeneous populations, and variations in techniques. Large prospective studies with homogenous groups designed to evaluate the role of these various markers should clarify their potential involvement in NSCLC and esophageal cancer. Identification of occult micrometastases in lymph nodes and bone marrow using immunohistochemical techniques and rt-PCR is intriguing. These techniques are promising as a method to more accurately stage patients, and therefore to predict outcomes and to determine therapies. Perhaps the most promising area of research is the development of novel drugs whose mechanism of action targets the pathways of various molecular markers. Molecular biologic substaging offers an opportunity to individualize a chemotherapeutic regimen based on the molecular profile of the tumor, thus providing the potential for improved outcomes with less morbidity in patients with both NSCLC and esophageal cancer.