Biological Agents in Non-small Cell Lung Cancer: A Review of Recent Advances and Clinical Results with a Focus on Epidermal Growth Factor Receptor and Vascular Endothelial Growth Factor

Genetic differences between smokers and never-smokers with lung cancer

Smoking is a major risk factor for lung cancer, therefore lung cancer epidemiological trends reflect the past trends of cigarette smoking to a great extent. The geographic patterns in mortality closely follow those in incidence. Although lung cancer is strongly associated with cigarette smoking, only about 15% of smokers get lung cancer, and also some never-smokers develop this malignancy. Although less frequent, lung cancer in never smokers is the seventh leading cause of cancer deaths in both sexes worldwide. Lung cancer in smokers and never-smokers differs in many aspects: in histological types, environmental factors representing a risk, and in genes associated with this disease. In this review, we will focus on the genetic differences between lung cancer in smokers versus never-smokers: gene expression, germ-line polymorphisms, gene mutations, as well as ethnic and gender differences. Finally, treatment options for smokers and never-smokers will be briefly reviewed.

Identification of a 3-mRNA signature as a novel potential prognostic biomarker in patients with ovarian serous cystadenocarcinoma in G2 and G3

The use of mRNAs as biomarkers serves to diagnose, treat, as well as aid the prognosis of cancer. The present study involved an analysis of mRNAs in the cell cycle at the G2 and G3 tumor grades for the prognosis of ovarian serous cystadenocarcinoma (OSC) using 364 clinical samples (G2:G3=42:322). Statistics aided the identification of NPFFR2, XPNPEP2 and CELA3B; the 3-mRNA model that allows for classification of patients into high- and low-risk groups using a median value of 0.9580745. The rates of survival varied (P=0.00149) and the independent detection of stratification of the risk of this disease was validated with success using the 3-mRNA signature, which was demonstrated to be more successful than the weight model. This approach was revealed to provide the prognosis of grade G2 and G3 in patients with OSC compared with factors used traditionally. Compared with traditional factors, this 3-mRNA model was demonstrated to be the only and independent prognostic factor for patients with G2 and G3 stage OSC. A literature survey was also performed in the present study in order to assess the role of the 3 genes and indirectly prove their effectiveness. The establishment of this new genetic model will enhance prospective prognosis and treatment for patients with OSC.

Prognostic Value of KIF2A and HER2-Neu Overexpression in Patients With Epithelial Ovarian Cancer

Kinesin family member 2A (KIF2A) is a member of Kinesin-13 family and involved in cell migration and cell signaling. Human epidermal growth factor receptor 2 (HER2-neu) is implicated in the development of many cancers. Both of these 2 proteins are upstream inducer of PI3K/AKT signaling pathway that plays an important role in the regulation of many cellular events including proliferation, survival, and invasion. We hypothesized that aberrant KIF2A and HER2-neu expression might be associated with aggressive behavior of epithelial ovarian cancer (EOC).To address the prognostic implications of KIF2A and HER2-neu in EOC, we assessed protein levels of KIF2A and HER2-neu in 159 ovarian and fallopian tube tissues (111 carcinomas and 48 normal ovary or fallopian tube tissues) by immunohistochemistry (IHC) analysis on tissue microarray and KIF2A mRNA levels in 35 ovarian and fallopian tube tissues (15 carcinomas and 20 normal ovary or fallopian tube tissues) by real-time PCR.We found that significantly higher KIF2A mRNA expression in EOC tumors than that in normal ovary or fallopian tube tissues. The IHC results showed that protein of KIF2A and HER2-neu was overexpressed in EOC tissues compared with normal ovary or fallopian tube tissues, and KIF2A expression level was significantly associated with lymph nodes, metastasis, ascites cells, and FIGO stage. No correlation between KIF2A and HER2-neu expression was observed. Survival analysis showed that patients with KIF2A and HER2-neu overexpression had a worse overall survival (OS) as compared to patients with low or none expression of the 2 proteins. Multivariate analysis of variance revealed that overexpression of KIF2A was an independent prognostic factor for OS.These findings indicate the important role of KIF2A in predicting EOC prognosis.

Analysis of an EGFR mutation by PNA clamping method in lung carcinoid tumors

Background Pulmonary carcinoid tumors consisting of typical carcinoid tumors (TC) and atypical carcinoid tumors (AC) are rare, accounting for 2–5% of all lung tumors. TC is considered a low-grade tumor with a rate of distant metastasis up to 12%. In contrast, ACs are more aggressive tumors, displaying a metastatic rate up to 70%. Surgery is the treatment of choice; however, the current treatment outcomes of metastatic lung carcinoids are discouraging. This study aimed to investigate the EGFR mutation using the PNA-mediated clamping method and to provide basic data for using EGFR-TK1 and its clinical implications. Materials and Methods A total of 14 cases that underwent surgery were diagnosed as carcinoid tumors and pathologically classified as TC and AC. The paraffin-embedded tissues were analyzed for EGFR mutations using the PNA-mediated PCR clamping technique. The mutant type was noted in the cases with a△Ct greater than 2.0. Result Of 14 cases, eight were AC and six cases were TC. No known EGFR mutation was detected with a△Ct less than 2.0. Conclusion The EGFR genotype determined using the PNA-mediated PCR clamping method was wild-type in all pulmonary carcinoid tumors. Therefore, the application of EGFR-TK1 is limited in pulmonary carcinoid tumors.

P. D, M. V. N. L. C. Isolation of methyl gamma linolenate from Spirulina platensis using flash chromatography and its apoptosis inducing effect

Background

Isolation of methyl gamma linolenate from Spirulina platensis using flash chromatography and its apoptosis inducing effect against human lung carcinoma A- 549 cell lines.

Methods

Gamma linolenic acid is an important omega-6 polyunsaturated fatty acid (PUFA) of medicinal interest was isolated from microalgae Spirulina platensis using flash chromatography system (Isolera system) as its methyl ester. The isolated methyl gamma linolenate was characterized by IR, ¹H NMR, ¹³C NMR and mass spectral analysis and the data were consistent with the structure.

Results

The percentage yield of isolated methyl gamma linolenate is found to be 71 % w/w, which is a very good yield in comparison to other conventional methods. It was subjected to in-vitro cytotoxic screening on A-549 lung cancer cell lines using SRB assay and result was compared with standard rutin.

Conclusion

It may be concluded that the Flash chromatography system plays a major role in improving the yield for theisolation of methyl gamma linoleate from Spirulina platensis and the isolated molecule is a potent cytotoxicagent towards human lung carcinoma cell lines, however it may be further taken up for an extensive study.

Overexpression of MAGE-A9 Is Predictive of Poor Prognosis in Epithelial Ovarian Cancer

The cancer testis antigen, melanoma-associated antigen A9 (MAGE-A9), is expressed in many kinds of different human cancers, and is an important target for immunotherapy. However, the clinicopathologic significance of MAGE-A9 in epithelial ovarian cancer (EOC) is unknown. In this study, real-time PCR (12 carcinomas of high FIGO stage, 12 carcinomas of low FIGO stage, and 20 normal ovary or fallopian tube tissues) and immunohistochemistry by tissue microarrays (128 carcinomas and 112 normal ovary or fallopian tube tissues, benign or borderline ovarian tumor tissues) were performed to characterize expression of MAGE-A9 in EOC. We found that significantly higher MAGE-A9 mRNA expression in EOC tumors than that in normal ovary or fallopian tube tissues (all P < 0.05). Protein expression of MAGE-A9 was significantly associated with FIGO stage, high histological grade, level of CA-125 and metastasis. Consistent with the associated poor clinicopathologic features, patients with MAGE-A9^{H (high-expressing)} tumors had a worse overall survival as compared to patients with MAGE-A9^{L (low or none-expressing)} tumors. Further studies revealed that MAGE-A9 overexpression was an independent prognostic factor for overall survival (OS). Multivariate analysis showed that patients with MAGE-A9 overexpressing tumors had extremely poor OS. These findings indicate that MAGE-A9 expression may be helpful in predicting EOC prognosis.

Erythropoietin receptor expression is a potential prognostic factor in human lung adenocarcinoma

Recombinant human erythropoietins (rHuEPOs) are used to treat cancer-related anemia. Recent preclinical studies and clinical trials, however, have raised concerns about the potential tumor-promoting effects of these drugs. Because the clinical significance of erythropoietin receptor (EPOR) signaling in human non-small cell lung cancer (NSCLC) also remains controversial, our aim was to study whether EPO treatment modifies tumor growth and if EPOR expression has an impact on the clinical behavior of this malignancy. A total of 43 patients with stage III–IV adenocarcinoma (ADC) and complete clinicopathological data were included. EPOR expression in human ADC samples and cell lines was measured by quantitative real-time polymerase chain reaction. Effects of exogenous rHuEPOα were studied on human lung ADC cell lines in vitro. In vivo growth of human ADC xenografts treated with rHuEPOα with or without chemotherapy was also assessed. In vivo tumor and endothelial cell (EC) proliferation was determined by 5-bromo-2’-deoxy-uridine (BrdU) incorporation and immunofluorescent labeling. Although EPOR mRNA was expressed in all of the three investigated ADC cell lines, rHuEPOα treatment (either alone or in combination with gemcitabine) did not alter ADC cell proliferation in vitro. However, rHuEPOα significantly decreased tumor cell proliferation and growth of human H1975 lung ADC xenografts. At the same time, rHuEPOα treatment of H1975 tumors resulted in accelerated tumor endothelial cell proliferation. Moreover, in patients with advanced stage lung ADC, high intratumoral EPOR mRNA levels were associated with significantly increased overall survival. This study reveals high EPOR level as a potential novel positive prognostic marker in human lung ADC.

Genetic polymorphism of XRCC1 Arg399Gln is associated with survival in non-small-cell lung cancer patients treated with gemcitabine/platinum

INTRODUCTION

Elevated DNA-repair capacity has been related to chemoresistance of platinum doublet chemotherapy in non-small-cell lung cancer (NSCLC). We evaluated whether single nucleotide polymorphisms of DN- repair genes excision repair cross-complementing group 1 (ERCC1), ERCC2, x-ray repair cross-complementing group 1 (XRCC1), XRCC3, and RRM1 associate with treatment outcome in NSCLC patients receiving gemcitabine plus platinum as their first-line chemotherapy.

METHODS

Genotyping for eight polymorphisms in five DNA-repair genes was performed with the GenomeLab nucleotide polymorphismstream Genotyping System in 62 advanced NSCLC patients in a training set and 45 patients in a validation set treated with gemcitabine/platinum.

RESULTS

In the training set, the wild-type genotype of XRCC1 Arg399Gln (G/G) was associated with decreased median overall survival (OS) (22 months, 95% confidence interval [CI], 10-34 months versus not reached, log-rank test, p = 0.005) than those carrying variant genotypes (G/A+A/A). In addition, there was a statistically significant longer median OS in patients carrying wild-type ERCC2 Asp312Asn genotype (G/G) (51 months, 95% CI, 19-82 months versus 10 months, log-rank test, p < 0.001) than those carrying heterozygous variant genotypes (G/A). In the multivariate Cox model, we found a significant effect of XRCC1 Arg399Gln (G/A+A/A versus G/G, hazard ratio [HR] 0.290; 95%CI, 0.12-0.705, p = 0.006) and ERCC2 Asp312Asn (G/A versus G/G, HR 14.04; 95% CI, 2.253-87.513, p = 0.005) polymorphisms on patients' OS. In the validation set, only XRCC1 399

CONCLUSIONS

Genetic polymorphism of XRCC1 Arg399Gln may be a candidate for contributing interindividual difference in the OS of gemcitabine/platinum-treated advanced NSCLC patients.

[Targeted agents in the treatment of lung cancer]

Lung cancer is in France, the leading cause of cancer death. Despite the dramatic advances that have allowed in a few years to go, for metastatic cancer, from a median survival without specific treatment of 4.5 months and now almost always more than one year, survival remains disappointing and further improvements are needed. Progress in the accumulated knowledge of the inner workings of normal and tumoral cells have paved the way for the development of targeted therapeutics called biological or simply targeted therapies. Two biological processes are already the target of marketed drugs, this is the way the receptor of epidermal growth factor (EGFR) and the path of neo-angiogenesis. It is almost assumed that, in the very near future, the inhibition of EML4-ALK will also be the subject of new drugs. In the medium term, it is conceivable that the molecular dissection of the tumors actually lead to the prescription of treatments tailored to mutations and other abnormalities that direct the growth of cancers.

A curated database of genetic markers from the angiogenesis/VEGF pathway and their relation to clinical outcome in human cancers

INTRODUCTION

Angiogenesis causes local growth, aggressiveness and metastasis in solid tumors, and thus, is almost always associated with poor prognosis and survival in cancer patients. Because of this clinical importance, several chemotherapeutic agents targeting angiogenesis have also been developed. Genes and genetic variations in angiogenesis/VEGF pathway thus may be correlated with clinical outcome in cancer patients.

MATERIAL AND METHODS

Here, we describe a manually curated public database, dbANGIO, which posts the results of studies testing the possible correlation of genetic variations (polymorphisms and mutations) from the angiogenesis/VEGF pathway with demographic features, clinicopathological features, treatment response and toxicity, and prognosis and survival-related endpoints in human cancers. The scientific findings are retrieved from PUBMED and posted in the dbANGIO website in a summarized form.

RESULTS AND CONCLUSION

As of September 2011, dbANGIO includes 362 entries from 83 research articles encompassing 154 unique genetic variations from 39 genes investigated in several solid and hematological cancers. By curating the literature findings and making them freely available to researchers, dbANGIO will expedite the research on genetic factors from the angiogenesis pathway and will assist in their utility in clinical management of cancer patients. dbANGIO is freely available for non-profit institutions at http://www.med.mun.ca/angio.

Outcome, quality of life and cognitive function of patients with brain metastases from non-small cell lung cancer treated with whole brain radiotherapy combined with gefitinib or temozolomide. A randomised phase II trial of the Swiss Group for Clinical Cancer Research (SAKK 70/03)

PURPOSE

Patients with brain metastases (BM) rarely survive longer than 6months and are commonly excluded from clinical trials. We explored two combined modality regimens with novel agents with single agent activity and radiosensitizing properties.

PATIENTS AND METHODS

In this randomised phase II trial patients with BM from NSCLC were randomly assigned to 30Gy WBRT with either concomitant gefitinib (GFT) 250mg/day continuously or temozolomide (TMZ) 75mg/m(2) for 21/28days. The primary end-point was overall survival, with quality of life and cognitive function as secondary end-points.

RESULTS

We enrolled 59 patients (GFT 16, TMZ 43), and 56 patients have died, mainly (80%) from disease progression. Four patients succumbed complications of the disease or corticosteroids (intestinal perforation (2), CNS haemorrhage and pulmonary emboli). Median overall survival in the gefitinib arm was 6.3months (95% CI 2.1-14.6), and 4.9months (95% CI 2.3-5.6) in TMZ treated patients. Fatigue was the main complaint.

CONCLUSIONS

No relevant toxicity with those therapeutic regimens was observed. Fatal outcome in three patients may have been related to corticosteroids. Cognitive function improved during treatment. However, median overall survival for all patients was only 4.9months (95% CI 2.3-5.7) and 1-year survival 25.4% (95% CI 15.4-37.0%).

The role of inflammation in the pathogenesis of non-small cell lung cancer

The link between chronic immune activation and tumorigenesis is well established. Compelling evidence has accumulated that histologic assessment of infiltration patterns of different host immune response components in non-small cell lung cancer specimens helps identify different prognostic patient subgroups. This review provides an overview of recent insights gained in the understanding of the role played by chronic inflammation in lung carcinogenesis. The usefulness of quantification of different populations of lymphocytes, natural killer cells, macrophages, and mast cells within the tumor microenvironment in non-small cell lung cancer is also discussed. In particular, the importance of assessment of inflammatory cell microlocalization within both the tumor islet and surrounding stromal components is emphasized.

Apelin expression in human non-small cell lung cancer: role in angiogenesis and prognosis

INTRODUCTION

The recently discovered bioactive peptide, apelin, has been demonstrated to stimulate angiogenesis in various experimental systems. However, its clinical significance and role in tumor vascularization have not yet been investigated in a human malignancy. Therefore, our aim was to study whether apelin expression is associated with angiogenesis and/or tumor growth/behavior in human non-small cell lung cancer (NSCLC).

METHODS

A total of 94 patients with stage I-IIIA NSCLC and complete follow-up information were included. Apelin expression in human NSCLC samples and cell lines was measured by quantitative reverse-transcriptase polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry. Effects of exogenous apelin and apelin transfection were studied on NSCLC cell lines in vitro. In vivo growth of tumors expressing apelin or control vectors were also assessed. Morphometric variables of human and mouse tumor capillaries were determined by anti-CD31 labeling.

RESULTS

Apelin was expressed in all of the six investigated NSCLC cell lines both at the mRNA and protein levels. Although apelin overexpression or apelin treatments did not increase NSCLC cell proliferation in vitro, increasing apelin levels by gene transfer to NSCLC cells significantly stimulated tumor growth and microvessel densities and perimeters in vivo. Apelin mRNA levels were significantly increased in human NSCLC samples compared with normal lung tissue, and high apelin protein levels were associated with elevated microvessel densities and poor overall survival.

CONCLUSIONS

This study reveals apelin as a novel angiogenic factor in human NSCLC. Moreover, it also provides the first evidence for a direct association of apelin expression with clinical outcome in a human cancer.

Spices, herbal xenobiotics and the stomach: Friends or foes?

Spices and herbal remedies have been used since ancient times to treat a variety of disorders. It has been experimentally demonstrated that spices, herbs, and their extracts possess antimicrobial, anti-inflammatory, antirheumatic, lipid-lowering, hepatoprotective, nephroprotective, antimutagenic and anticancer activities, besides their gastroprotective and anti-ulcer activities. Despite a number of reports on the toxicity of herbs and spices, they are generally accepted as safer alternatives to conventional therapy against gastric ulcers. To this end, it is also believed, that excessive consumption of spices may favor the pathogenesis of gastric and duodenal ulcer and some studies have substantiated this common perception. Based on various in vivo experiments and clinical studies, on the effects of spices and herbs on gastric ulcers, it has indeed been shown that certain spices do possess remarkable anti-ulcer properties mediated by antisecretory, cytoprotective, antioxidant, and anti-Helicobacter pylori effects and mechanisms regulated by nitric oxide, prostaglandins, non-protein sulfhydryl molecules and epidermal growth factor expression. Accordingly, their consumption may attenuate and help prevent peptic ulcer disease. In the present review, the beneficial effects of spices and herbal nutritive components on the gastric mucosa are discussed against the paradigm of their deleterious potential.

Intermittent erlotinib in combination with pemetrexed: phase I schedules designed to achieve pharmacodynamic separation

INTRODUCTION

Epidermal growth factor receptor tyrosine kinase inhibitors given concurrently with chemotherapy do not improve patient outcomes compared with chemotherapy alone in advanced non-small cell lung cancer (NSCLC). Pharmacodynamic separation by intermittent delivery of epidermal growth factor receptor tyrosine kinase inhibitors with chemotherapy may increase efficacy by overcoming hypothesized antagonism.

METHODS

Two dose-escalating phase I trials (arm A and arm B) were conducted simultaneously. Pemetrexed was given every 21 days (500 mg/m intravenously). In arm A, erlotinib was given weekly on days 2, 9, and 16 (800-1400 mg). In arm B, erlotinib was given on days 2 to 16 (150-250 mg). Patients continued therapy until disease progression or unacceptable toxicity.

RESULTS

Forty-two patients with advanced solid tumors, including 16 NSCLC, were treated. Patient characteristics included median age of 63 (range, 29-77), 19 males, and Karnofsky performance status >or=90/<90 = 27/15. The median number of cycles was 2. Treatment was well tolerated. Planned dose escalation was completed without reaching a maximum tolerated dose. Dose-limiting toxicities included grade 3 infection/fever (arm A: 500/1200) and grade 3 infection/neutropenia (arm B: 500/150). Rash frequency was 55% in arm A and 90% in arm B. There were six partial responses (four lung, one head and neck, one breast) and 16 stable diseases. Four patients with NSCLC remained on therapy for 9, 16, 16, and 22 cycles.

CONCLUSIONS

We report the first clinical trial to test intermittent erlotinib plus pemetrexed. Pemetrexed 500 mg/m and weekly erlotinib 1400 mg (arm A) or pemetrexed 500 mg/m and erlotinib 250 mg on days 2 to 16 (arm B) are feasible and well tolerated. Arm B efficacy is being examined in a randomized phase II trial for second-line NSCLC.

Systemic disease-induced salivary biomarker profiles in mouse models of melanoma and non-small cell lung cancer

Background

Saliva (oral fluids) is an emerging biofluid poised for detection of clinical diseases. Although the rationale for oral diseases applications (e.g. oral cancer) is intuitive, the rationale and relationship between systemic diseases and saliva biomarkers are unclear.

Methodology/Principal Findings

In this study, we used mouse models of melanoma and non-small cell lung cancer and compared the transcriptome biomarker profiles of tumor-bearing mice to those of control mice. Microarray analysis showed that salivary transcriptomes were significantly altered in tumor-bearing mice vs. controls. Significant overlapping among transcriptomes of mouse tumors, serum, salivary glands and saliva suggests that salivary biomarkers have multiple origins. Furthermore, we identified that the expression of two groups of significantly altered transcription factors (TFs) Runx1, Mlxipl, Trim30 and Egr1, Tbx1, Nr1d1 in salivary gland tissue of melanoma-bearing mice can potentially be responsible for 82.6% of the up-regulated gene expression and 62.5% of the down-regulated gene expression, respectively, in the saliva of melanoma-bearing mice. We also showed that the ectopic production of nerve growth factor (NGF) in the melanoma tumor tissue as a tumor-released mediator can induce expression of the TF Egr-1 in the salivary gland.

Conclusions

Taken together, our data support the conclusion that upon systemic disease development, significant changes can occur in the salivary biomarker profile. Although the origins of the disease-induced salivary biomarkers may be both systemic and local, stimulation of salivary gland by mediators released from remote tumors plays an important role in regulating the salivary surrogate biomarker profiles.

Analysis of ErbB receptors in pulmonary carcinoid tumors

PURPOSE

This study aimed to investigate the expression of the ErbB family of receptor tyrosine kinases in pulmonary typical carcinoid and atypical carcinoid tumors and to understand the role of epidermal growth factor receptor (EGFR) signaling in pulmonary carcinoid tumor proliferation.

EXPERIMENTAL DESIGN

Surgically resected typical carcinoid (n = 24) and atypical carcinoid (n = 7) tumor tissues were analyzed by immunohistochemical staining for EGFR, ErbB2, ErbB3, and ErbB4. Sequencing of tumor DNA of exons 18 to 21 of the EGFR gene and the KRAS gene was carried out. Biochemical analysis of lung carcinoid cell lines was used to investigate EGFR signal transduction and response to erlotinib inhibition.

RESULTS

The analysis showed that 45.8% of typical carcinoid and 28.6% of atypical carcinoid tumors express EGFR, 100% of the tumors lack expression of ErbB2, and 100% have moderate to intense staining for ErbB3 and ErbB4. Sequencing of tumor DNA of exons 18 to 21 of the EGFR gene revealed the absence of tyrosine kinase domain mutations in these tumors. Instead, 80.6% tumors harbored a synonymous single nucleotide polymorphism in exon 20. Because EGFR and KRAS mutations tend not to be present at the same time, we sequenced the KRAS gene from pulmonary carcinoid tumor DNA and found that 100% were wild-type. Using a lung carcinoid cell line that expresses EGFR, we found that erlotinib reduced proliferation by inhibiting EGFR signal transduction.

CONCLUSIONS

Our findings suggest clinical potential for the use of EGFR inhibitors in the treatment of patients with pulmonary carcinoid tumors, particularly for patients with EGFR-positive pulmonary carcinoid tumors not amenable to surgical resection.

Recent advances of novel targeted therapy in non-small cell lung cancer

Lung cancer is the leading cause of cancer deaths world-wide. Recent advances in cancer biology have led to the identification of new targets in neoplastic cells and the development of novel targeted therapies. At this time, two targeted agents are approved by the FDA in advanced non-small cell lung cancer (NSCLC): the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) erlotinib, and the anitangiogenic bevacizumab. A third agent, cetuximab, which was recently shown to enhance survival when used with cisplatin and vinorelbine as first line therapy for advanced NSCLC, will likely be approved by regulatory agencies. With more than 500 molecularly targeted agents under development, the prospects of identifying novel therapies that benefit individual patients with lung cancer are bright.

Correlation of F-18 fluorodeoxyglucose-positron emission tomography maximal standardized uptake value and EGFR mutations in advanced lung adenocarcinoma

OBJECTIVE

Epidermal growth factor receptor (EGFR) mutations in lung adenocarcinoma are involved in the tumorigenesis and regulation of cell metabolism via Akt signaling. F-18 fluorodeoxyglucose-positron emission tomography ([(18)F]FDG PET), a functional imaging modality, can be used to measure tumor cell metabolism. Thus, in this study, we hypothesize that there exist correlations between EGFR mutation status and [(18)F]FDG uptake of advanced lung adenocarcinoma.

METHODS

From May 2004 to April 2008, patients with stage IIIB or IV lung adenocarcinoma who underwent [(18)F]FDG PET and EGFR mutation analysis before receiving any treatment were eligible to participate in this study. The association of EGFR mutation status with patient characteristics and the SUV(MAX) from the [(18)F]FDG PET was evaluated. Multivariate logistic regression analysis was used to analyze predictors of EGFR mutations.

RESULTS

Seventy-seven lung adenocarcinoma patients were included in this study. EGFR mutations were identified in 49 (64%) of the patients. The [(18)F]FDG uptake was significantly higher in EGFR-mutant (mean SUV(MAX) = 10.5 +/- 4.7) than wild-type (8.0 +/- 3.3) lung adenocarcinoma patients (P = 0.008). The median SUV(MAX) was 9.5, and patients with an SUV(MAX) >or= 9.5 were more likely to harbor EGFR mutations (P = 0.009). In the multivariate analysis, an SUV(MAX) >or= 9.5 remained a statistically significant predictor of EGFR mutations (P = 0.005).

CONCLUSIONS

Among Asian patients with advanced lung adenocarcinoma, those with higher SUV(MAX) on the [(18)F]FDG PET are more likely to carry EGFR mutations.