Clinicopathologic features and prognostic implications of epidermal growth factor receptor (EGFR) gene copy number and protein expression in non-small cell lung cancer

Energy metabolism as the hub of advanced non-small cell lung cancer management: a comprehensive view in the framework of predictive, preventive, and personalized medicine

Energy metabolism is a hub of governing all processes at cellular and organismal levels such as, on one hand, reparable vs. irreparable cell damage, cell fate (proliferation, survival, apoptosis, malignant transformation etc.), and, on the other hand, carcinogenesis, tumor development, progression and metastazing versus anti-cancer protection and cure. The orchestrator is the mitochondria who produce, store and invest energy, conduct intracellular and systemically relevant signals decisive for internal and environmental stress adaptation, and coordinate corresponding processes at cellular and organismal levels. Consequently, the quality of mitochondrial health and homeostasis is a reliable target for health risk assessment at the stage of reversible damage to the health followed by cost-effective personalized protection against health-to-disease transition as well as for targeted protection against the disease progression (secondary care of cancer patients against growing primary tumors and metastatic disease). The energy reprogramming of non-small cell lung cancer (NSCLC) attracts particular attention as clinically relevant and instrumental for the paradigm change from reactive medical services to predictive, preventive and personalized medicine (3PM). This article provides a detailed overview towards mechanisms and biological pathways involving metabolic reprogramming (MR) with respect to inhibiting the synthesis of biomolecules and blocking common NSCLC metabolic pathways as anti-NSCLC therapeutic strategies. For instance, mitophagy recycles macromolecules to yield mitochondrial substrates for energy homeostasis and nucleotide synthesis. Histone modification and DNA methylation can predict the onset of diseases, and plasma C7 analysis is an efficient medical service potentially resulting in an optimized healthcare economy in corresponding areas. The MEMP scoring provides the guidance for immunotherapy, prognostic assessment, and anti-cancer drug development. Metabolite sensing mechanisms of nutrients and their derivatives are potential MR-related therapy in NSCLC. Moreover, miR-495-3p reprogramming of sphingolipid rheostat by targeting Sphk1, 22/FOXM1 axis regulation, and A2 receptor antagonist are highly promising therapy strategies. TFEB as a biomarker in predicting immune checkpoint blockade and redox-related lncRNA prognostic signature (redox-LPS) are considered reliable predictive approaches. Finally, exemplified in this article metabolic phenotyping is instrumental for innovative population screening, health risk assessment, predictive multi-level diagnostics, targeted prevention, and treatment algorithms tailored to personalized patient profiles-all are essential pillars in the paradigm change from reactive medical services to 3PM approach in overall management of lung cancers. This article highlights the 3PM relevant innovation focused on energy metabolism as the hub to advance NSCLC management benefiting vulnerable subpopulations, affected patients, and healthcare at large.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-024-00357-5.

Diarylheptanoid 35d overcomes EGFR TKI resistance by inducing hsp70-mediated lysosomal degradation of EGFR in EGFR-mutant lung adenocarcinoma

EGFR-mutant lung adenocarcinomas (LUAD) patients often respond to EGFR tyrosine kinase inhibitors (TKIs) initially, but eventually develop resistance to TKIs. The switch of EGFR downstream signaling from TKI-sensitive to TKI-insensitive is a critical mechanism driving resistance to TKIs. Identification of potential therapies to target EGFR effectively is a potential strategy to treat TKI-resistant LUADs. In this study, we developed a small molecule diarylheptanoid 35d, a curcumin derivative, that effectively suppressed EGFR protein expression, killed multiple TKI-resistant LUAD cells in vitro, and suppressed tumor growth of EGFR-mutant LUAD xenografts with variant TKI-resistant mechanisms including EGFR C797S mutations in vivo. Mechanically, 35d triggers hsp70-mediated lysosomal pathway through transcriptional activation of several components in the pathway, such as HSPA1B, to induce EGFR protein degradation. Interestingly, higher HSPA1B expression in LUAD tumors associated with longer survival of EGFR-mutant TKI-treated patients, suggesting the role of HSPA1B on retarding TKI resistance and providing a rationale for combining 35d with EGFR TKIs. Our data showed that combination of 35d significantly inhibits tumor re-progression on osimertinib and prolongs mice survival. Overall, our results suggest 35d as a promising lead compound to suppress EGFR expression and provide important insights into the development of combination therapies for TKI-resistant LUADs, which could have translational potential for the treatment of this deadly disease.

Anti-EGFR monoclonal antibody plus chemotherapy for treating advanced non-small cell lung cancer: A meta-analysis

BACKGROUND

The use of standard cytotoxic chemotherapy seems to have reached a "treatment plateau". The application of anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs) is a new strategy for non-small-cell lung cancer (NSCLC) therapy. We aimed to comprehensively assess the efficacy and safety of anti-EGFR-mAbs plus chemotherapy as first-line therapy for advanced NSCLC.

METHODS

According to inclusion and exclusion criteria, we conducted a comprehensive literature search of electronic databases. From the included trials, information on overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and adverse events (AEs) was extracted.

RESULTS

The research showed that compared with chemotherapy alone, anti-EGFR-mAb plus chemotherapy combinations significantly improved OS (HR = 0.88, 95%CI: 0.83-0.94, P < .0001), PFS (HR = 0.89, 95%CI: 0.83-0.95, P = 0.0004) and ORR (OR = 1.39, 95%CI: 1.13-1.69, P = .001). Meta subgroup analyses manifested that the OS of patients with squamous NSCLC treated with anti-EGFR-mAb plus chemotherapy combinations was notably better than that of patients with non-squamous NSCLC treated with the same combinations (HR = 0.82, 95%CI: 0.73-0.92, P = .0005). Compared with the chemotherapy group, combination of chemotherapy and anti-EGFR mAb showed increase in incidences of severe AEs (> = grade 3) that mainly include, leukopenia (OR = 1.53, 95%CI: 1.28-1.82, P < .00001), febrile neutropenia (OR = 1.35, 95%CI: 1.06-1.71, P = .02), hypomagnesemia (OR = 5.68, 95%CI: 3.54-9.10, P < .00001), acneiform rash (OR = 35.88, 95%CI: 17.37-74.10, P < .00001), fatigue (OR = 1.24, 95%CI: 1.02-1.49, P = .03), diarrhea (OR = 1.69, 95%CI: 1.16-2.47, P = .006), and infusion-related reactions (OR = 3.78, 95%CI: 1.93-7.41, P = .0001).

CONCLUSION

Adding an anti-EGFR-mAb to the standard platinum-based chemotherapy regimens used for the first-line treatment of advanced NSCLC resulted in statistically notable improvements in OS, PFS, and ORR. In particular, anti-EGFR-mAb and chemotherapy combinations achieved greater survival benefits in patients with squamous NSCLC than in those with non-squamous NSCLC. In addition, the safety profile of chemotherapy plus anti-EGFR-mAb combinations was acceptable compared to that of chemotherapy alone.

Concurrent Chemoradiation Therapy With or Without Nimotuzumab in Locally Advanced Squamous Cell Lung Cancer: A Phase 2 Randomized Trial

PURPOSE

The study aimed to evaluate the efficacy and safety of concurrent chemoradiation therapy (CCRT) combined with nimotuzumab in patients with unresectable stage III squamous cell lung cancer (SqCLC).

METHODS AND MATERIALS

A prospective, single-center, open-label, randomized phase 2 trial was performed in patients with unresectable stage III SqCLC. Patients were randomized to receive 65 Gy thoracic radiation over 5 weeks concurrent with docetaxel and cisplatin or the same CCRT regimen combined with 200 mg of nimotuzumab (NIMO-CCRT), administered weekly by intravenous infusion. The primary endpoint was overall survival. The secondary endpoints were progression-free survival, objective response rate, failure patterns, and treatment-related toxicity.

RESULTS

From August 2015 to June 2020, 126 patients with SqCLC were randomized. Four patients withdrew consent before the start of treatment, and 122 patients were included for analysis, including 57 in the NIMO-CCRT group and 65 in the CCRT group. The median OS was 24.9 months in the NIMO-CCRT group and 23.5 months in the CCRT group (P = .655). The median PFS was 12.1 months in the NIMO-CCRT group and 13.7 months in the CCRT group (P = .968). The NIMO-CCRT group had a significantly lower risk of brain metastasis, with adjusted subdistribution hazard ratio of 0.099 (95% confidence interval, 0.012-0.81; P = .031). The incidence of grade ≥3 pneumonitis (P = .894) and esophagitis (P = .974) was similar between the 2 arms. There was no grade 2 or higher skin toxicity in NIMO-CCRT group.

CONCLUSIONS

The coincident application of nimotuzumab with CCRT was well tolerated for locally advanced SCCL. The NIMO-CCRT group had an OS and PFS similar to that in the CCRT group, but a lower risk of brain metastasis. Further investigations are warranted.

Integrated analysis of the prognostic value of TP53 dependent etoposide-induced gene 24 in non-small cell lung cancer

BACKGROUND

Etoposide-induced gene 24 (EI24) is an induction target of TP53-mediated apoptosis in human cancer cells. The hypothesis of this study is that EI24 might be a prognostic biomarker of non-small cell lung carcinoma (NSCLC).

MATERIAL AND METHODS

Fourteen gene expression NSCLC datasets with follow-up information (a total of 2582 accessible cases) were collected from Asia, Europe and North America. The Kaplan-Meier and Cox analyses were applied to evaluate the relation between EI24 and the outcomes of NSCLC. A gene set enrichment analysis (GSEA) was used to explore EI24 and cancer-related gene signatures.

RESULTS

EI24 was significantly upregulated in mutated TP53 NSCLC samples and significantly downregulated with the increase in the TP53 expression level in NSCLC. GSEA results suggested that EI24 significantly enriched metastasis and poor prognosis gene signatures. Meanwhile, EI24 was significantly upregulated in lung adenocarcinoma compared with normal lungs (p < 0.01). It was also highly expressed in the later TNM stages and the ALK fusion+, higher MYC gene copy and EGFR wild type subgroups (p < 0.05). The Kaplan-Meier analysis demonstrated that the expression of EI24 was significantly associated with poor overall survival and disease-free survival in a dose-dependent manner in GSE31210 dataset. The C-index of Cox model with EI24 is 0.70, that is better than that with MYC (0.51), KRAS (0.51) and EGFR (0.59), which indicates better prognostic performance of EI24. The prognostic significance of EI24 for overall survival of NSCLC was validated by pooled and meta-analysis on 14 datasets. The stratification analysis revealed that EI24 prognosticated poor overall survival (HR = 3.37, 95% CI = 1.39-9.62, p < 0.05) in the TP53 wild type subgroup, but not in the mutated TP53 NSCLC subgroup. Moreover, YY1 might transcriptionally regulate EI24 in a positive manner.

CONCLUSION

EI24 is a potential prognostic biomarker and impacts poor outcome in NSCLC. The prognostic significance of EI24 might rely on TP53 status.

Epidermal Growth Factor Receptor Gene Amplification Predicts Worse Outcome in Patients With Surgically Resected Nonadenocarcinoma Lung Cancer

PURPOSE

The aim of the present study was to examine the prognostic role of amplification and increased expression of the epidermal growth factor receptor (EGFR) gene in surgically resected non-adenocarcinoma of non-small cell lung cancer (NA-NSCLC).

MATERIALS AND METHODS

The present retrospective study included 114 consecutive NA-NSCLC patients with available tumor tissue and survival data. EGFR gene copy number and protein expression were evaluated using fluorescent in situ hybridization (FISH) and immunohistochemistry in tissue microarray sections, respectively.

RESULTS

Among 114 patients, 99 (86.8%) had squamous cell carcinoma histologic features. EGFR gene amplification and high polysomy (EGFR FISH⁺) were observed in 7.9% and 31.6% of cases, respectively. Patients with EGFR FISH⁺ had significantly shorter overall survival (P = .011). A multivariate model confirmed that patients with EGFR FISH⁺ had a significantly greater risk of death than EGFR FISH^- patients after adjusting for pathologic stage, presence of pleural invasion, venous invasion, and surgical margins (hazard ratio, 1.36; 95% CI, 1.040 to 1.782; P = .025). EGFR protein expression by immunohistochemistry was not associated with overall survival in the same group. Neither EGFR gene amplification nor EGFR immunohistochemistry expression was associated with relapse-free survival.

CONCLUSION

An increased EGFR gene copy number in surgically resected NA-NSCLC was associated with worse survival.

Potential Molecular Signatures Predictive of Lung Cancer Brain Metastasis

Brain metastases are the most common tumors of the central nervous system (CNS). Incidence rates vary according to primary tumor origin, whereas the majority of the cerebral metastases arise from primary tumors in the lung (40-50%). Brain metastases from lung cancer can occur concurrently or within months after lung cancer diagnosis. Survival rates after lung cancer brain metastasis diagnosis remain poor, to an utmost of 10 months. Therefore, prevention of brain metastasis is a critical concern in order to improve survival among cancer patients. Although several studies have been made in order to disclose the genetic and molecular mechanisms associated with CNS metastasis, the precise mechanisms that govern the CNS metastasis from lung cancer are yet to be clarified. The ability to forecast, which patients have a higher risk of brain metastasis occurrence, would aid cancer management approaches to diminish or prevent the development of brain metastasis and improve the clinical outcome for such patients. In this work, we revise genetic and molecular targets suitable for prediction of lung cancer CNS disease.

Personalized Radiation Oncology: Epidermal Growth Factor Receptor and Other Receptor Tyrosine Kinase Inhibitors

Molecular biomarkers are currently evaluated in preclinical and clinical studies in order to establish predictors for treatment decisions in radiation oncology. The receptor tyrosine kinases (RTK) are described in the following text. Among them, the most data are available for the epidermal growth factor receptor (EGFR) that plays a major role for prognosis of patients after radiotherapy, but seems also to be involved in mechanisms of radioresistance, specifically in repopulation of tumour cells between radiotherapy fractions. Monoclonal antibodies against the EGFR improve locoregional tumour control and survival when applied during radiotherapy, however, the effects are heterogeneous and biomarkers for patient selection are warranted. Also other RTK´s such as c-Met and IGF-1R seem to play important roles in tumour radioresistance. Beside the potential to select patients for molecular targeting approaches combined with radiotherapy, studies are also needed to evluate radiotherapy adaptation approaches for selected patients, i.e. adaptation of radiation dose, or, more sophisticated, of target volumes.

Clinicopathologic analysis of programmed cell death-1 and programmed cell death-ligand 1 and 2 expressions in pulmonary adenocarcinoma: comparison with histology and driver oncogenic alteration status

Immunotherapies targeting the programmed cell death-1/programmed cell death-ligand 1 pathway have emerged as promising therapeutic strategies for lung cancer. However, the expression pattern and prognostic implications of programmed cell death-ligand 1 and 2 and programmed cell death-1 in comparison with the histology and genetic alterations in pulmonary adenocarcinomas remains unclear and thus were addressed here. Programmed cell death-ligand 1 and 2 expression in tumor cells and the quantities of programmed cell death-1(+) and CD8(+) tumor-infiltrating lymphocytes were immunohistochemically evaluated in 497 resected pulmonary adenocarcinomas and analyzed according to clinicopathological and genetic statuses. Programmed cell death-ligand 1 and 2 expression were observed in 59% and 64% of pulmonary adenocarcinomas, respectively, and showed a strong positive correlation with each other (P < 0.001). Programmed cell death-ligand 1 expression was higher in nodal metastasis cases (P = 0.006), smokers (P = 0.056), poorly differentiated tumors and histologic subtypes of solid and micropapillary patterns (P < 0.001). There was no significant difference in programmed cell death-ligand 1 and 2 expression according to EGFR mutation status. However, programmed cell death-ligand 1 expression was correlated with ALK translocation (P =0.054) and expression of EGFR and MET (P < 0.001). Meanwhile, programmed cell death-ligand 2 expression was correlated with ALK translocation (P = 0.052), and expression of MET (P < 0.001) and ERBB2 (P = 0.013). The numbers of CD8(+) and programmed cell death-1(+) lymphocytes were higher in smokers (P = 0.012 and 0.016) and MET-expressing adenocarcinomas (P < 0.001). Patients expressing programmed cell death-ligand 1 and/or high ratios of programmed cell death-1(+)/CD8(+) lymphocytes showed shorter disease-free survival (P = 0.001). Our study demonstrated that programmed cell death-ligand 1 and 2 expression varied with histology, EGFR, ALK, MET, and ERBB2 statuses, and activation of the programmed cell death-1/programmed cell death-ligand 1 pathway may be a poor prognostic factor in pulmonary adenocarcinomas.

The Efficacy of Combining EGFR Monoclonal Antibody With Chemotherapy for Patients With Advanced Nonsmall Cell Lung Cancer: A Meta-Analysis From 9 Randomized Controlled Trials

Although epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs) have been proved synergistic effect when combined with cytotoxic agents for advanced nonsmall cell lung cancer (NSCLC), the results of relevant clinical trials remain controversial. The purpose of this meta-analysis was to assess the advantage and toxicity profile of chemotherapy plus EGFR-mAbs versus chemotherapy alone for patients with NSCLC.We rigorously searched electronic databases for eligible studies reporting EGFR-mAbs combined with chemotherapy versus chemotherapy alone for patients with advanced NSCLC. The primary outcome was overall survival (OS). Pooled results were calculated using proper statistical methods.Nine phase II/III randomized controlled trials involved a total of 4949 participants were included. In general, compared with chemotherapy alone, the addition of EGFR-mAbs significantly improved OS (hazard ratio [HR] = 0.91, 95% confidence interval [CI]: 0.86-0.97, P = 0.006), progression-free survival (HR = 0.83, 95% CI: 0.87-0.98, P = 0.01), response rate (odd ratio [OR] = 1.28, 95% CI: 1.12-1.47, P = 0.0003), and disease control rate (OR = 1.17, 95% CI: 1.01-1.36, P = 0.04). Subgroup analysis showed that apparent OS benefit present in patients with squamous NSCLC (HR = 0.83, 95% CI: 0.74-0.93, P = 0.001), and those treatment-naive population (HR = 0.88, 95% CI: 0.82-0.95, P = 0.0006). Several manageable adverse events were markedly increased by EGFR-mAbs, such as acne-like rash, infusion reactions, and diarrhea. The risk for some ≥Grade 3 toxicities, such as leukopenia, febrile neutropenia, and thromboembolic events were slightly increased by the addition of EGFR-mAbs. In general, the toxicities of the combination strategy were tolerable and manageable.The addition of EGFR-mAbs to chemotherapy provided superior clinical benefit along with acceptable toxicities to patients with advanced NSCLC, especially those harboring squamous cancer and treatment-naive. Further validation in front-line investigation, proper selection of the potential benefit population by tumor histology, and development of prognostic biomarkers are warranted for future research and clinical application of EGFR-mAbs.

The RET fusion gene and its correlation with demographic and clinicopathological features of non-small cell lung cancer: a meta-analysis

PURPOSE

The RET fusion gene is a novel oncogene observed in a subset of NSCLC in recent years. Nevertheless, the results of epidemiological studies concerning the gene remain unclear. Thus, a meta-analysis was conducted to evaluate the correlation of RET fusion gene with demographic and clinicopathological features of NSCLC.

METHODS

PubMed, Embase, and Web of Science databases were searched to identify eligible studies. The association of RET fusion gene occurrence with gender, age, smoking status, histology type and tumor stage were analyzed in meta-analysis. Subgroup analysis according to patients' location (Asian and non-Asian) was also conducted. Odds ratio (OR) and 95% confidence interval (95% CI) were calculated to assess the correlation.

RESULTS

Nine studies with a total of 6,899 NSCLC patients met the inclusion criteria. A total of 84 patients with RET fusion gene were detected. The RET fusion gene was identified at significantly higher frequencies in female (OR = 0.55, 95%CI = 0.35-0.85) than male patients and in young (<60) patients (OR = 0.43, 95%CI = 0.19-0.99) than old patients (≤60), particularly in patients from Asian. A significant higher frequency was also identified in non-smokers (OR = 0.28, 95% CI = 0.16-0.49), and in patients with lung adenocarcinomas (OR = 3.59, 95%CI = 1.50-8.56). Additionally, no association between RET fusion gene and the TNM stage of tumor was observed.

CONCLUSION

RET fusion gene occurred predominantly in Asian females with younger age, in non-smokers, and in lung adenocarcinomas patients. This subset of NSCLC patients might be good candidates for personalized diagnostic and therapeutic approaches.

Clinicopathological analysis of PD-L1 and PD-L2 expression in pulmonary squamous cell carcinoma: Comparison with tumor-infiltrating T cells and the status of oncogenic drivers

PURPOSE

Programmed cell death-1 (PD-1)/programmed cell death-ligand-1 (PD-L1) pathway-targeted immunotherapy has beneficial therapeutic effects in pulmonary squamous cell carcinoma (SqCC) patients. However, the expression patterns of PD-1 and PD-1 ligands (PD-Ls) in pulmonary SqCC remain unclear. Moreover, the association between the PD-1/PD-Ls pathway and the status of oncogenic drivers in pulmonary SqCC is unknown.

METHODS

PD-L1 and PD-L2 expression in tumor cells and the numbers of PD-1(+) and CD8(+) tumor-infiltrating lymphocytes (TILs) were examined in 331 resected SqCC tumors along with matched lymph node metastases from 77 cases using immunohistochemistry. EGFR and FGFR1 and MET expression and genetic status were also examined.

RESULTS

PD-L1 and PD-L2 expression was detected in 26.9% and 23.9% of the pulmonary SqCC samples, respectively. PD-L1 and PD-L2 expression was maintained or increased in the metastatic lymph node tumors in 81.1% and 93.5% of the 77 cases, respectively. The numbers of PD-1(+) and CD8(+) TILs were significantly positively correlated (P<0.001). Cases displaying high PD-L1 expression exhibited consistently high CD8(+) T cell infiltration (P<0.001), even in subgroup analyses according to age, smoking status, tumor size, lymph node metastasis, stage, and the EGFR, MET and FGFR1 status. Moreover, MET expression in the tumors was significantly correlated with high PD-L2 expression and increased PD-1(+) TILs (P=0.001 for both). Increased numbers of CD8(+) or PD-1(+) TILs were significantly associated with prolonged disease-free survival of these patients, whereas PD-L1 and PD-L2 expression had no significant prognostic implications.

CONCLUSION

PD-L1 and PD-L2 expression in pulmonary SqCC is associated with an increased number of CD8(+) TILs and increased MET expression, which might provide therapeutic insight into targeting the PD-1/PD-Ls pathway in pulmonary SqCC.

Correlation of EGFR expression, gene copy number and clinicopathological status in NSCLC

BACKGROUND

Epidermal Growth Factor Receptor (EGFR) targeting therapies are currently of great relevance for the treatment of lung cancer. For this reason, in addition to mutational analysis immunohistochemistry (IHC) of EGFR in lung cancer has been discussed for the decision making of according therapeutic strategies. The aim of this study was to obtain standardization of EGFR-expression methods for the selection of patients who might benefit of EGFR targeting therapies.

METHODS

As a starting point of a broad investigation, aimed at elucidating the expression of EGFR on different biological levels, four EGFR specific antibodies were analyzed concerning potential differences in expression levels by Immunohistochemistry (IHC) and correlated with fluorescence in situ hybridization (FISH) analysis and clinicopathological data. 206 tumor tissues were analyzed in a tissue microarray format employing immunohistochemistry with four different antibodies including Dako PharmDx kit (clone 2-18C9), clone 31G7, clone 2.1E1 and clone SP84 using three different scoring methods. Protein expression was compared to FISH utilizing two different probes.

RESULTS

EGFR protein expression determined by IHC with Dako PharmDx kit, clone 31G7 and clone 2.1E1 (p ≤ 0.05) correlated significantly with both FISH probes independently of the three scoring methods; best correlation is shown for 31G7 using the scoring method that defined EGFR positivity when ≥ 10% of the tumor cells show membranous staining of moderate and severe intensity (p=0.001).

CONCLUSION

Overall, our data show differences in EGFR expression determined by IHC, due to the applied antibody. Highest concordance with FISH is shown for antibody clone 31G7, evaluated with score B (p=0.001). On this account, this antibody clone might by utilized for standard evaluation of EGFR expression by IHC.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_165.

Synergistic antitumor activity of cetuximab and namitecan in human squamous cell carcinoma models relies on cooperative inhibition of EGFR expression and depends on high EGFR gene copy number

PURPOSE

Despite the frequent overexpression of epidermal growth factor receptor (EGFR) in squamous cell carcinoma (SCC), the efficacy of cetuximab alone is limited. Given the marked activity of namitecan, a hydrophilic camptothecin, against SCC models, the present study was performed to explore the efficacy of the cetuximab-namitecan combination in a panel of SCC models.

EXPERIMENTAL DESIGN

We examined the antiproliferative and antitumor activities of the cetuximab-namitecan combination in four SCC models characterized by a different EGFR gene copy number/EGFR protein level. We also assessed the effects of the combination on EGFR expression at both mRNA and protein levels and investigated the molecular basis of the interaction between the two agents.

RESULTS

Cetuximab and namitecan exhibited synergistic effects, resulting in potentiation of cell growth inhibition and, most importantly, enhanced therapeutic efficacy, with high cure rates in three SCC models characterized by high EGFR gene copy number, without increasing toxicity. The synergistic antitumor effect was also observed with the cetuximab-irinotecan combination. At the molecular level, the two agents produced a cooperative effect resulting in complete downregulation of EGFR. Interestingly, when singly administered, the camptothecin was able to strongly decrease EGFR expression mainly by transcriptional inhibition.

CONCLUSIONS

Our results (i) demonstrate a marked efficacy of the cetuximab-namitecan combination, which reflects a complete abrogation of EGFR expression as a critical determinant of the therapeutic improvement, in SCC preclinical models, and (ii) suggest EGFR gene copy number as a possible marker to be used for patient selection in the clinical setting.

Allelic imbalance in 1p, 7q, 9p, 11p, 12q and 16q regions in non-small cell lung carcinoma and its clinical association: a pilot study

In lung cancer pathogenesis, genetic instability, i.e., loss of heterozygosity (LOH) and microsatellite instability (MSI) is a frequent molecular event, occurring at an early stage of cancerogenesis. The presence of LOH/MSI in non-small cell lung carcinoma (NSCLC) was found in many chromosomal regions, but exclusive of 3p their diagnostic value remains controversial. In this study we focused on other than 3p regions-1p31.2, 7q32.2, 9p21.3, 11p15.5, 12q23.2 and 16q22-the loci of many oncogenes and tumour suppressor genes. To analyze the potential role of LOH/MSI involved in NSCLC pathogenesis we allelotyped a panel of 13 microsatellite markers in a group of 56 cancer specimens. Our data demonstrate the presence of allelic loss for all (13) analyzed markers. Total LOH/MSI frequency in NSCLC was the highest for chromosomal region 11p15.5 (25.84 %), followed by 9p21.3 and 1p31.2 (19.87 and 16.67 % respectively). A statistically significant increase of total LOH/MSI frequency was detected for the 11p15.5 region (p = 0.0301; χ(2) test). The associations of total LOH/MSI frequency: 1) increase in 11p15.5 region (p = 0.047; χ(2) test) and 2) decrease in 7q32.2 region (p = 0.037; χ(2) test) have been statistically significant in AJCC III (American Joint Committee on Cancer Staging). In Fractional Allele Loss (FAL) index analysis, the correlation with cigarette addiction has been statistically significant. The increased amount of cigarettes smoked (pack years) in a lifetime correlates with increasing FAL (p = 0.024; Kruskal-Wallis test). These results demonstrate that LOH/MSI alternation in studied chromosomal regions is strongly influenced by tobacco smoking but do not seem to be pivotal NSCLC diagnostic marker with prognostic impact.

Leser–Trélat syndrome in malignant mesothelioma and pulmonary adenocarcinoma: is the EGFR pathway part of the syndrome?

The syndrome of Leser–Trélat (LT) is characterized by the sudden appearance of multiple seborrhoeic keratoses (SKs) in association with internal occult malignancy. Usually, the syndrome has been associated with adenocarcinoma, most frequently of the gastrointestinal tract and breast. The pathogenesis is unclear but might be explained by circulating tumor-associated growth factors. We present two thoracic malignancies associated with LT: adenocarcinoma of the lung (ACL) and pleural malignant mesothelioma (MM). Both malignant tumors expressed high levels of epidermal growth factor receptors (EGFR) detected by immunohistochemistry (IHC), with membranous staining on the majority of malignant cells corresponding to maximum IHC scores of 290 and 300, respectively, for the MM and the ACL. SKs revealed a universal membranous staining throughout the entire epithelium with no difference in EGFR expression between the two cases and two controls with no malignant history. By fluorescence in situ hybridization, no amplification of the EGFR gene in malignant tumors as well as in SK lesions was observed. Further investigations are needed to see whether tumor-associated EGFR ligands/EGFR autocrine loops in malignant cells expressing high levels of EGFR protein on the surface might play a role for the development of SKs, as well as for the growth of malignant tumors in LT.

The Role of Gefitinib in Patients with Non-small-cell Lung Cancer in India

Background:

Gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor, represents a new treatment option for patients with advanced non-small-cell lung cancer (NSCLC). We analyzed the data of patients who received Gefitinib for NSCLC in a tertiary care center in South India.

Materials and Methods:

Sixty-three patients with advanced NSCLC who had received Gefitinib either after failure of conventional chemotherapy or were previously not treated as they were unfit or unwilling for conventional treatment were included in the analysis.

Results:

The median follow-up for the cohort was 311 days (range 11-1544 days). Median time to progression was 161 (range 9-883) days. Complete and partial remission was seen in 1 (2%) and 6 (9%) patients, respectively, with overall response rate of 11%. Twenty-four (38%) patients had stable disease. Gefitinib was well tolerated with no significant side effects.

Conclusion:

Gefitinib shows anti-tumor activity in pretreated or previously untreated patients with advanced NSCLC. It has a favorable toxicity profile and is well tolerated. Gefitinib should be considered as a viable therapy in patients with NSCLC.

Correlation of genes associated with drug response to prognosis of large cell lung carcinoma

Platinum-based chemotherapy remains the main treatment of advanced lung cancer. However, platinum resistance has become a major treatment obstacle. Novel therapies, particularly tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR-TKI) and agents that target vascular endothelial growth factor (VEGF), have improved the treatment. Both chemotherapy and targeted therapy have their molecular mechanisms. This study aimed to determine the mutation, amplification, or expression status and interrelationships of the epidermal growth factor receptor (EGFR), K-Ras proto-oncogene, excision repair cross-complementation group 1 (ERCC1), and VEGF genes as well as their correlations to prognosis of large cell lung carcinoma (LCLC) after EGFR-targeted therapy, chemotherapy, and anti-VEGF therapy. EGFR and K-Ras mutations in 60 specimens of LCLC were detected by direct DNA sequencing. EGFR, ERCC1, and VEGF protein expression was detected by immunohistochemistry (IHC). EGFR gene copy number was detected by fluorescence in situ hybridization (FISH). One (1.7%) patient had an EGFR L858M point mutation in exon 21, 3 (5.0%) had K-Ras mutations, and 10 (19.6%) had EGFR amplification (FISH positive). Positive rates of EGFR, ERCC1, and VEGF proteins were 38.3%, 56.7%, and 70.0%, respectively. EGFR amplification was positively correlated to EGFR protein expression (r = 0.390, P = 0.005). The positive rate of VEGF protein was significantly higher in patients with lymph node metastasis than in those without (84.6% vs. 58.8%, P = 0.046). No significant correlations were observed among the EGFR, K-Ras, ERCC1, and VEGF genes. EGFR gene amplification and the low rate of EGFR mutation suggest that patients with LCLC are likely to obtain little benefit from anti-EGFR therapies.

Epidermal growth factor receptor mutation in lung adenocarcinomas: relationship with CT characteristics and histologic subtypes

PURPOSE

To retrospectively identify quantitative computed tomographic (CT) features that correlate with epidermal growth factor receptor (EGFR) mutation in surgically resected lung adenocarcinomas stratified by the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS) classification in an East Asian cohort of patients known to have a high prevalence of EGFR mutations.

MATERIALS AND METHODS

An institutional review board approved this study and waived informed consent. In 153 surgically resected lung adenocarcinomas, EGFR mutation was determined by direct DNA sequencing. Histologic subtype was classified according to IASLC/ATS/ERS classification of lung adenocarcinoma. At preoperative chest CT, the percentage of ground-glass opacity (GGO) volume and total tumor volume of each tumor were measured by using a semiautomated algorithm. Distribution of EGFR mutation according to histologic subtype, percentage of GGO volume, and total tumor volume was evaluated by using the Fisher exact test, the Student t test, trend analysis, and multiple logistic regression analysis.

RESULTS

Exon 21 missense mutation was more frequent in lepidic predominant adenocarcinomas than in other histologic subtypes (odds ratio, 3.44; 95% confidence interval: 1.53, 7.74; P = .003). GGO volume percentage in tumors with exon 21 missense mutation (61.7% ± 31.9 [standard deviation]) was significantly higher than that in EGFR wild-type tumors (30.0% ± 38.5) (P = .0001) and exon 19-mutated tumors (28.9% ± 37.7) (P = .0006). A significant trend of prevalence of exon 21 missense mutation increasing along with increasing GGO volume (P = .0008) was found.

CONCLUSION

GGO volume percentage in tumors with exon 21 missense mutation was significantly higher than that in tumors with other EGFR mutation status. This can be related to the fact that exon 21 missense mutation was significantly more frequent in lepidic predominant adenocarcinomas, including adenocarcinoma in situ, minimally invasive adenocarcinoma, and lepidic predominant invasive adenocarcinoma, according to IASLE/ATS/ERS classification.

Imaging characteristics of stage I non-small cell lung cancer on CT and FDG-PET: relationship with epidermal growth factor receptor protein expression status and survival

OBJECTIVE

To identify CT and FDG-PET features associated with epidermal growth factor receptor (EGFR) protein overexpression, and to evaluate whether imaging features and EGFR-overexpression can help predict clinical outcome.

MATERIALS AND METHODS

In 214 patients (M : F = 129 : 85; mean age, 63.2) who underwent curative resection of stage I non-small cell lung cancer, EGFR protein expression status was determined through immunohistochemical analysis. Imaging characteristics on CT and FDG-PET was assessed in relation to EGFR-overexpression. Imaging features and EGFR-overexpression were also evaluated for clinical outcome by using the Cox proportional hazards model.

RESULTS

EGFR-overexpression was found in 51 patients (23.8%). It was significantly more frequent in tumors with an SUV(max) > 5.0 (p < 0.0001), diameter > 2.43 cm (p < 0.0001), and with ground glass opacity ≤ 50% (p = 0.0073). SUV(max) > 5.0 (OR, 3.113; 95% CI, 1.375-7.049; p = 0.006) and diameter > 2.43 cm (OR, 2.799; 95% CI, 1.285-6.095; p = 0.010) were independent predictors of EGFR overexpression. Multivariate analysis showed that SUV(max) > 4.0 (hazard ratio, 10.660; 95% CI, 1.370-82.966; p = 0.024), and the presence of cavitation within a tumor (hazard ratio, 3.122; 95% CI, 1.143-8.532; p = 0.026) were factors associated with poor prognosis.

CONCLUSION

EGFR-overexpression is associated with high SUV(max), large tumor diameter, and small GGO proportion. CT and FDG-PET findings, which are closely related to EGFR overexpression, can be valuable in the prediction of clinical outcome.

Characteristics of lung cancer in women: importance of hormonal and growth factors

Based on epidemiological, clinical, and preclinical data, lung carcinogenesis can be distinctive in women, suggesting that women should be treated differently depending on the expression of various specific biomarkers. We aimed to describe the hormonal and genetic profile of lung cancer in both men and women to identify gender specificities. Primary lung-tumor tissues from surgically treated patients, (50 men, 50 women) were analyzed and compared for expression of estrogen receptors (ER) α and β, progesterone receptors (PR), epidermal growth-factor receptor (EGFR), and HER2 (for EGFR and K-Ras mutations). These data were combined with clinical and outcome data. Fewer women with lung cancer were smokers (p=0.001) and they smoked fewer cigarettes (p=0.001). We observed a higher rate of EGFR mutations (p=0.02) and ERα expression (p=0.006) in women. ERβ and EGFR were also expressed more frequently in women (p=0.29 and p=0.16). HER2 was overexpressed regardless of gender in three men and two women. K-Ras was mutated in 16% of both men and women. Interestingly, there was a positive link between EGFR expression and expression of ERα (p=0.028) and ERβ (p=0.047) in both men and women. Expression of ERα was associated with improved disease-free survival (p=0.007). Our findings provide further evidence on the specificities of lung cancer in women. The differential expression of specific biomarkers, which could be targeted by therapy, favors the development of gender-based treatment guided by biomarker expression.

EGFR-mutated oncogene-addicted non-small cell lung cancer: current trends and future prospects

Non-small cell lung cancer (NSCLC) tumours with certain mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase have been termed 'oncogene addicted' to reflect their dependence on EGFR-mediated pro-survival signalling and their high susceptibility to apoptosis induced by EGFR tyrosine kinase inhibitors (EGFR-TKIs, e.g. gefitinib and erlotinib). The most common mutations (L858R and exon 19 deletions) predict an improved clinical response to first-line oral EGFR-TKIs compared with standard platinum-based chemotherapy in patients with advanced NSCLC. Moreover, these mutations are also prognostic of a relatively indolent course of disease, regardless of treatment, as compared with classical NSCLC. Treatment strategies for oncogene-addicted NSCLC are therefore distinct from those for non-oncogene addicted NSCLC, and will depend on the specific genetic mutation present.

Molecular classification of nonsmall cell lung cancer using a 4-protein quantitative assay

BACKGROUND

The importance of definitive histological subclassification has increased as drug trials have shown benefit associated with histology in nonsmall-cell lung cancer (NSCLC). The acuity of this problem is further exacerbated by the use of minimally invasive cytology samples. Here we describe the development and validation of a 4-protein classifier that differentiates primary lung adenocarcinomas (AC) from squamous cell carcinomas (SCC).

METHODS

Quantitative immunofluorescence (AQUA) was employed to measure proteins differentially expressed between AC and SCC followed by logistic regression analysis. An objective 4-protein classifier was generated to define likelihood of AC in a training set of 343 patients followed by validation in 2 independent cohorts (n = 197 and n = 235). The assay was then tested on 11 cytology specimens.

RESULTS

Statistical modeling selected thyroid transcription factor 1 (TTF1), CK5, CK13, and epidermal growth factor receptor (EGFR) to generate a weighted classifier and to identify the optimal cutpoint for differentiating AC from SCC. Using the pathologist's final diagnosis as the criterion standard, the molecular test showed a sensitivity of 96% and specificity of 93%. Blinded analysis of the validation sets yielded sensitivity and specificity of 96% and 97%, respectively. Our assay classified the cytology specimens with a specificity of 100% and sensitivity of 87.5%.

CONCLUSIONS

Molecular classification of NSCLC using an objective quantitative test can be highly accurate and could be translated into a diagnostic platform for broad clinical application.

ASCO Provisional Clinical Opinion: Epidermal Growth Factor Receptor Mutation Testing in Practice

ASCO has recently provided guidance on emerging data on EGFR testing for the purpose of selecting first-line therapy for persons with advanced NSCLC through its Provisional Clinical Opinion.

Molecular epidemiology of female lung cancer

Lung cancer is still a leading cause of cancer mortality in the world. The incidence of lung cancer in developed countries started to decrease mainly due to global anti-smoking campaigns. However, the incidence of lung cancer in women has been increasing in recent decades for various reasons. Furthermore, since the screening of lung cancer is not as yet very effective, clinically applicable molecular markers for early diagnosis are much required. Lung cancer in women appears to have differences compared with that in men, in terms of histologic types and susceptibility to environmental risk factors. This suggests that female lung cancer can be derived by carcinogenic mechanisms different from those involved in male lung cancer. Among female lung cancer patients, many are non-smokers, which could be studied to identify alternative carcinogenic mechanisms independent from smoking-related ones. In this paper, we reviewed molecular susceptibility markers and genetic changes in lung cancer tissues observed in female lung cancer patients, which have been validated by various studies and will be helpful to understand the tumorigenesis of lung cancer.

Analysis of ERBB4 mutations and expression in japanese patients with lung cancer

Only the kinase domain of ERBB4 has been analyzed in East Asian populations, but a recent large-scale mutation analysis has indicated a higher incidence of mutations in the extracellular domain. Mutations in the extracellular and kinase domains of ERBB4 were examined by direct sequencing in 72 patients with primary lung cancer and 8 cell lines. In addition, ERBB4 expression was determined in 60 patients by quantitative real-time polymerase chain reaction. We investigated the relationship between ERBB4 expression and clinicopathologic characteristics including prognosis. One patient possessed Q793Q polymorphism in the kinase domain. However, we detected no mutations in extracellular or kinase domains of ERBB4. There was no significant difference in the clinicopathologic characteristics including prognosis of patients with high or low expression of ERBB4. The clinical significance of ERBB4 in lung cancers is negligible.

EGFR gene copy number gain is related to high tumor SUV and frequent relapse after adjuvant chemotherapy in resected lung adenocarcinoma

OBJECTIVE

The purpose of our study was to define the prognostic impact of increased copies of epidermal growth factor receptor (EGFR) gene in lung adenocarcinoma patients receiving adjuvant chemotherapy after surgery.

METHODS

The study included 95 adenocarcinoma patients who received curative resection for non-small cell lung cancer. Patients received adjuvant chemotherapy composed of paclitaxel and carboplatin. We performed fluorescent in situ hybridization on tissue microarray in duplicate to detect EGFR copy number change.

RESULTS

The EGFR fluorescent in situ hybridization result was available in 93 patients with a positive rate of 32.6%. EGFR copy number change did not correlate with age, gender or smoking history. However, EGFR copy number gain was related to high tumor standardized uptake value at diagnosis (P = 0.042). An increase in EGFR copy number was a negative prognostic factor in terms of disease-free survival (median disease-free survival not reached versus 23.6 months, P = 0.037) and overall survival (median overall survival 74.6 versus 43.5 months, P = 0.032). An increase in EGFR copy number was independently related to short disease-free survival in multivariate analysis (hazard ratio 2.039, P = 0.025).

CONCLUSIONS

EGFR copy number gain is associated with aggressive tumor biology and is a poor prognostic factor for tumor relapse in resected lung adenocarcinoma patients receiving adjuvant chemotherapy of paclitaxel and carboplatin.

An unusual loss of EGFR gene copy in glioblastoma multiforme in a child: a case report and analysis of a successfully derived HGG-02 cell line

PURPOSE

The aim of this study was to perform a detailed cytogenetic and molecular genetic analysis of a tumor taken from a 14.5-year-old boy with glioblastoma multiforme who showed an atypical clinical course.

METHODS

Formalin-fixed, paraffin embedded tumor tissue and the corresponding HGG-02 cell line derived from this tumor were analyzed using fluorescence in situ hybridization (FISH), G-banding, multiplex ligation-dependent probe amplification (MLPA), functional analysis of separated alleles in yeast (FASAY), immunohistochemistry (IHC), and immunocytochemistry (ICC).

RESULTS

Mutation of the p53 gene and hypermethylation of the MLH1 gene were detected by FASAY and MLPA, respectively. Cytogenetic analysis showed a polyploid karyotype with extensive heterogeneity in chromosome number. Using FISH, we identified a very unusual genetic change - a loss of EGFR gene copy in both the tumor tissue and the HGG-02 cell line. In accordance with the cytogenetic findings, IHC and ICC did not demonstrate overexpression of EGFR in the tumor tissue or HGG-02 cells.

CONCLUSIONS

Despite his very poor prognosis, the patient experienced 34 months of event-free survival after surgery and adjuvant radiotherapy and chemotherapy. The detected loss of the EGFR gene copy may contribute to the unusual biological features of this tumor, but the forthcoming detailed expression analysis of cancer regulatory pathways is necessary to better understand this tumor phenotype.

High MET gene copy number leads to shorter survival in patients with non-small cell lung cancer

INTRODUCTION

Activation of MET, either by increased gene copy number (GCN) or mutation, has been detected in various cancers. We investigate the clinicopathologic features of MET gene copy in nonsmall cell lung cancer (NSCLC).

METHODS

Tumor tissues were obtained from 180 resected NSCLCs, including 97 squamous cell carcinomas (SCCs) and 72 adenocarcinomas. No patient received epidermal growth factor receptor (EGFR)-targeted therapy. EGFR and MET GCNs were studied using fluorescence in situ hybridization (FISH) and were estimated according to the University of Colorado Cancer Center (UCCC) criteria. For MET, we also assessed GCNs using the Cappuzzo system.

RESULTS

FISH-positive MET was observed in 16.7% using the UCCC criteria; specifically, amplification was seen in 3.9% and high polysomy in 12.8%. FISH-positive MET status was significantly correlated with FISH-positive EGFR (p = 0.003). In the Cappuzzo system, high MET GCN (mean, >/=5 copies/cell) was found in 6.7% and also associated with FISH-positive EGFR (p = 0.031). MET gene copy status was not associated with gender, smoking history, histology, or stage. However, true MET amplification was more frequent in patients with SCC than in those with adenocarcinoma. FISH-positive MET status predicted worse survival in patients with NSCLC at advanced stages (p = 0.034) and in patients with SCC (p = 0.028). In multivariate analyses, increased MET GCN was significantly associated with shorter survival in patients with SCC, as analyzed using both the UCCC and Cappuzzo criteria (p = 0.019 and 0.008).

CONCLUSIONS

Our results suggest that increased MET GCN would be an independent poor prognostic factor in SCC of the lung.

The clinicopathologic values of the molecules associated with the main pathogenesis of the glioblastoma

Glioblastoma (GBM) is a malignant CNS neoplasm. The prognosis of GBM may be influenced by the molecules of p53/MDM2/p14ARF, RB/p16INK4a, and the EGFR/PTEN/protein kinase B (PKB)/phosphoinositide 3-kinase (PI3K) pathways. We studied the expression status of specific molecular markers in GBMs by immunohistochemistry (IHC) and FISH in correlation with the clinical outcomes. The positivity of EGFR FISH and those of EGFR IHC by pharmDx and Zymed antibodies were 64.9%, 73.5%, and 43.4%, respectively. EGFR pharmDx antibody was more sensitive but less specific than EGFR Zymed antibody. p53 overexpression, MDM2 expression, p16 loss, PTEN loss, PKB and PI3K expression were found in 48.2%, 26.5%, 56.6%, 21.4%, 15.7% and 6.0%, respectively. EGFR IHC and FISH significantly, although not completely, correlated and EGFR and p53 immunoexpression also showed positive correlation. On multivariate survival studies, old age (> or =40 yrs) and bilaterality were independent unfavorable prognosis factors (p<0.05). Stratified by age, resectability and tumor size <5 cm were favorable survival factors in young (40<yrs) and old age groups (> or =40 yrs), respectively. Furthermore, the patients with supratentorial tumor lived longer than the patients with infratentorial tumor (p<0.05). Longer survival (survival length, > or =3 years) was statistically less frequent in the patients in the EGFR FISH-positive group (p=0.031).

Targeted Therapies in Lung Cancer

An ongoing research and multiple clinical trials involve new targeted therapies and less aggressive treatment regimens that improve survival in patients with lung cancer. Targeted therapeutic agents are based on the concept of discovering genetic alterations and the signaling pathways altered in cancer and have added significantly to our armamentarium in order to prolong patient survival and minimizing drug toxicity. Among 34 molecularly targeted drugs approved by U.S. Food and Drug Administration (FDA) for treatment of various cancers since 1998 three targeted therapies have been approved for treatment of lung cancer (gefitinib in 2002, erlotinib in 2003, and bevacizumab in 2006).This review focuses on the targeted therapies in lung cancer, the molecular biomarkers that help identify patients that will benefit for these targeted therapies, describes the basic molecular biology principles and selected molecular diagnostic techniques and the pathological features correlated with molecular abnormalities in lung cancer. Lastly, new molecular abnormalities described in lung cancer that are predictive to novel promising targeted agents in various phases of clinical trials are discussed.

Amplification of epidermal growth factor receptor gene in renal cell carcinoma

Expression of epidermal growth factor receptor (EGFR) may be of prognostic value in renal cell cancer (RCC). Gene amplification of EGFR was investigated in a cohort of 315 patients with advanced RCC from a previously reported randomised study. Using fluorescent in situ hybridisation, only 2 patients (0.6%) had gene amplification; therefore gene amplification is of no prognostic value in RCC.

Differential expression of biomarkers in men and women

Lung cancer is one of the most common cancers in the world. While historically, more men than women have died from lung cancer as a result of higher numbers of male smokers, the sex mortality ratio is now showing signs of narrowing. Tumors in women with lung cancer may be slightly different to those in men with lung cancer. This review focuses on biomarkers differentially expressed between female and male patients with lung cancer. There is variation in gene expression between men and women in some genes that encode carcinogen-metabolizing enzymes (CYP1A1, GSTM). Gastrin-releasing peptide (GRP), a bombesin-like peptide, is present in two actively transcribed alleles in women compared with men. Higher prevalence of infection with oncogenic variants human papilloma viruses (HPVs) HPV16 and HPV18 has been suggested in women. A higher frequency of G to T transversion was found in the p53 gene in lung tumors of women. KRAS mutation was found to be more frequent in women with resected non-small cell lung cancer (NSCLC) than in men with resected NSCLC. Epidermal growth factor receptor (EGFR) mutation is more frequently found in lung tumors from women, but the confounding effect of tobacco exposure may explain this difference. Lower levels of ERCC1 and BRCA1 have been reported in women with NSCLC. Lung tumors from women are more likely to express estrogen receptors than those from men. An in silico analysis of transcriptome datasets from lung cancer patients demonstrated that only seven genes (in at least two studies) had significantly different expression patterns in male versus female patients. All of these genes are localized on the sex chromosomes: one on chromosome X and six on chromosome Y. Many areas remain under debate and there are still significant gaps in our understanding, particularly how sex-linked factors relate to lung cancer risk, and to biological and clinical behaviors. Future research into lung cancer needs to address these gender differences more specifically.

DNA/RNA markers for colorectal cancer risk in preserved stool specimens: a pilot study

AIMS AND BACKGROUND

Exfoliated cells in human stool offer excellent opportunities to non-invasively detect molecular markers associated with colorectal tumorigenesis, and to evaluate the effects of exposures to exogenous and endogenous carcinogenic or chemopreventive substances. This pilot study investigated the feasibility of determining DNA methylation and RNA expression simultaneously in stool specimens treated with a single type of nucleic acid preservatives.

METHODS

Stool specimens from 56 volunteers that were preserved up to a week with RNA later were used in this study. Bisulfite sequencing was used to determine methylation at 27 CpG loci on the estrogen receptor 1 (ESR1) promoter. Taqman assay was used for quantitative reverse transcription polymerase chain reactions to measure cyclooxygenase 2 (COX2) and epidermal growth factor receptor (EGFR) mRNA expression. Subjects' basic demographic and other selected risk factors for colorectal cancer were captured through questionnaires and correlated with the levels of these markers.

RESULTS

Less than 10% of the samples failed in individual assays. Overall, 24.0% of the CpG loci on the ESR1 promoter were methylated. COX2 expression and alcohol use were positively correlated; an inverse association was present between EGFR expression and cigarette smoking; and subjects using anti-diabetic medication had higher ESR1 methylation. In addition, higher EGFR expression levels were marginally associated with history of polyps and family history of colorectal cancer.

CONCLUSIONS

The present study demonstrates that simultaneous analyses for DNA and RNA markers are feasible in stool samples treated with a single type of nucleotide preservatives. Among several associations observed, the association between EGFR expression and polyps deserves further investigation as a potential target for colorectal cancer screening. Larger studies are warranted to confirm some of our observations.

Evaluation of PTEN and Mcl-1 expressions in NSCLC expressing wild-type or mutated EGFR

Signaling pathways activated by epidermal growth factor receptors (EGFRs) are important in lung carcinogenesis. New treatment strategies with EGFR-targeting drugs provided improvements in management of lung cancer. However, molecular mechanisms underlying resistance to these drugs need to be evaluated. Surgically resected samples were obtained from 50 patients with non-small-cell-lung cancer. PTEN, Mcl-1 and EGFR protein expression levels were evaluated by Western-blot. Direct sequencing was performed to investigate EGFR tyrosine kinase domain mutations. We detected c.2235-2249 (pGlu746-Ala750del) mutation in exon 19 in two patients with adenocarcinoma histology. Elevated expression levels of both Mcl-1 isoforms (Mcl-1S and Mcl-1XL) and EGFR proteins were found in 15 (30%) and 23 (46%) of the cases, respectively. Reduced PTEN protein expression levels were observed in 17 (34%) of the cases. PTEN expression level was reduced in 26% of cases that showed increased EGFR expression. Also, increased expression of Mcl-1 protein was observed in 26% of cases with EGFR overexpression. One of the cases harboring pGlu746-Ala750del mutation had increased levels of Mcl-1 and decreased PTEN expression levels. Our results indicate that, in addition to lack of PTEN expression, elevated levels of the Mcl-1 protein might be one of the important intrinsic mechanisms protecting non-small-cell-lung cancer cells from apoptosis induced by several compounds. Therefore, EGFR mutations in conjunction with evaluation of Mcl-1 and PTEN expression levels in large cohorts might provide important clues for improvements of new treatment strategies in non-small-cell-lung cancer management.

Reliability of chromogenic in situ hybridization for epidermal growth factor receptor gene copy number detection in non-small-cell lung carcinomas: a comparison with fluorescence in situ hybridization study

Fluorescence in situ hybridization (FISH) has been known to be the most representative and standardized test for assessing gene amplification. However, FISH requires a fluorescence microscope, the signals are labile and rapidly fade over time. Recently, chromogenic in situ hybridization (CISH) has emerged as a potential alternative to FISH. The aim of this study is to test the reliability of CISH technique for the detection of epidermal growth factor receptor (EGFR) gene amplification in non-small-cell lung carcinomas (NSCLC), to compare CISH results with FISH. A total of 277 formalin-fixed and paraffin embedded NSCLC tissue samples were retrieved from the surgical pathology archives at Seoul National University Bundang Hospital. CISH and FISH examinations were performed to test EGFR gene amplification status. There was high concordance in the assessment of EGFR gene copy number between CISH and FISH tests (Kappa coefficient=0.83). Excellent concordance was shown between two observers on the interpretation of the CISH results (Kappa coefficient=0.90). In conclusion, CISH result is highly reproducible, accurate and practical method to determine EGFR gene amplification in NSCLC. In addition, CISH allows a concurrent analysis of histological features of the tumors and gene copy numbers.

SRC promotes survival and invasion of lung cancers with epidermal growth factor receptor abnormalities and is a potential candidate for molecular-targeted therapy

Molecular-targeted therapy using tyrosine kinase inhibitors against epidermal growth factor receptor (EGFR) is an effective therapy for non-small cell lung cancer that harbor EGFR mutations. This study aimed to investigate the role of Src, a close EGFR associator, as a drug target in NSCLC cells with different EGFR genomic statuses. Src inhibition was achieved using 4-(4'-Phenoxyanilino)-6,7-dimethoxyquinazolinee (SKI-1) and the specificity of action was verified by RNA interference. The results showed that SKI-1 induced significant apoptosis in a dose-dependent manner in cancer cells with high basal Src activation. Activation of FAK and p130Cas was involved in Src-mediated invasion in SKI-1-sensitive cells. SKI-1 inhibited phosphorylation of EGFR as well as EGFR downstream effectors, such as signal transducers and activators of transcription 3/5, extracellular signal-regulated kinase 1/2 and AKT in the mutant cells but not the wild-type cells. This inhibition profile of EGFR implicates that induction of apoptosis and sensitivity of mutant cells to SKI treatment is mediated by EGFR and EGFR downstream pathways. Cotreatment with SKI-1 and gefitinib enhanced apoptosis in cancer cells that contained EGFR mutation and/or amplification. SKI-1 treatment alone induced significant apoptosis in H1975 cells known to be resistant to gefitinib. Src phosphorylation was shown by immunohistochemistry in around 30% of primary lung carcinomas. In 152 adenocarcinomas studied, p-Src was associated with EGFR mutations (P = 0.029). Overall, the findings indicated that Src could be a useful target for treatment of non-small cell lung cancer. Besides EGFR genomic mutations, other forms of EGFR and related family member abnormalities such as EGFR amplification might enhance SKI sensitivity.

Brain metastasis development and poor survival associated with carcinoembryonic antigen (CEA) level in advanced non-small cell lung cancer: a prospective analysis

Background

Central nervous system is a common site of metastasis in NSCLC and confers worse prognosis and quality of life. The aim of this prospective study was to evaluate the prognostic significance of clinical-pathological factors (CPF), serum CEA levels, and EGFR and HER2 tissue-expression in brain metastasis (BM) and overall survival (OS) in patients with advanced NSCLC.

Methods

In a prospective manner, we studied 293 patients with NSCLC in IIIB-IV clinical stage. They received standard chemotherapy. CEA was measured prior to treatment; EGFR and HER2 were evaluated by immunohistochemistry. BM development was confirmed by MRI in symptomatic patients.

Results

BM developed in 27, and 32% of patients at 1 and 2 years of diagnosis with adenocarcinoma (RR 5.2; 95% CI, 1.002–29; p = 0.05) and CEA ≥ 40 ng/mL (RR 11.4; 95% CI, 1.7–74; p < 0.01) as independent associated factors. EGFR and HER2 were not statistically significant. Masculine gender (RR 1.4; 95% CI, 1.002–1.9; p = 0.048), poor performance status (RR 1.8; 95% CI, 1.5–2.3; p = 0.002), advanced clinical stage (RR 1.44; 95% CI, 1.02–2; p = 0.04), CEA ≥ 40 ng/mL (RR 1.5; 95% CI, 1.09–2.2; p = 0.014) and EGFR expression (RR 1.6; 95% CI, 1.4–1.9; p = 0.012) were independent associated factors to worse OS.

Conclusion

High CEA serum level is a risk factor for BM development and is associated with poor prognosis in patients with advanced NSCLC. Surface expression of CEA in tumor cells could be the physiopathological mechanism for invasion to CNS.

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.

Expression pattern and functional relevance of epidermal growth factor receptor and cyclooxygenase-2: novel chemotherapeutic targets in pancreatic endocrine tumors?

OBJECTIVES

Pancreatic endocrine tumors represent morphologically and biologically heterogeneous neoplasms. Well-differentiated endocrine tumors (benign or of uncertain behavior) can be distinguished from well-differentiated and poorly differentiated endocrine carcinomas. Although many well-differentiated endocrine carcinomas show rather low rates of tumor growth, more than two-thirds of pancreatic endocrine carcinomas display distant metastases at the time of diagnosis. As the currently applied therapies beyond surgery only achieve partial or complete response rates of approximately 15%, additional chemotherapeutic targets are needed, especially in the therapy of inoperable and progressive pancreatic endocrine carcinomas.

METHODS

The expression of epidermal growth factor receptor (EGFR) and cyclooxygenase (COX)-2 were investigated in 110 clinically and pathomorphologically well-characterized pancreatic endocrine tumors, using immunohistochemistry and immunoblot analyses. Functional tests were performed using the human pancreas carcinoid cell line BON and the mouse insulinoma cell line beta-TC-3.

RESULTS

The expression of EGFR correlated significantly with the grade of malignancy, increasing from low rates of expression in benign tumors and tumors of uncertain behavior to high rates of expression in well- and poorly differentiated endocrine carcinomas. The expression of COX-2 was independent of the malignant potential, but was more frequently expressed in primary tumors than in metastases. The treatment of the human pancreas carcinoid cell line BON and the mouse insulinoma cell line beta-TC-3 with EGFR and COX-2 inhibitors (monotherapy and combined therapy) resulted in a significant, dose-dependent reduction of cell viability coupled with increased apoptosis.

CONCLUSIONS

Our results suggest that EGFR and COX-2 may represent useful additional chemotherapeutic targets in pancreatic endocrine tumors.