A biological staging model for operable non-small cell lung cancer

Background Currently the best prognostic index for operable non-small cell lung cancer (NSCLC) is the TNM staging system. Molecular biology holds the promise of predicting outcome for the individual patient and identifying novel therapeutic targets. Angiogenesis, matrix metalloproteinases (MMP)-2 and -9, and the erb/HER type I tyrosine kinase receptors are all implicated in the pathogenesis of NSCLC. Methods A retrospective analysis of 167 patients with resected stage I-IIIa NSCLC and >60 days postoperative survival with a minimum follow up of 2 years was undertaken. Immunohistochemical analysis was performed on paraffin embedded sections for the microvessel marker CD34, MMP-2 and MMP-9, EGFR, and c-erbB-2 to evaluate the relationships between and impact on survival of these molecular markers. Results Tumour cell MMP-9 (HR 1.91 (1.23-2.97)), a high microvessel count (HR 1.97 (1.28-3.03)), and stage (stage II HR 1.44 (0.87-2.40), stage IIIa HR 2.21 (1.31-3.74)) were independent prognostic factors. Patients with a high microvessel count and tumour cell MMP-9 expression had a worse outcome than cases with only one (HR 1.68 (1.04-2.73)) or neither (HR 4.43 (2.29-8.57)) of these markers. EGFR expression correlated with tumour cell MMP-9 expression (p<0.001). Immunoreactivity for both of these factors within the same tumour was associated with a poor prognosis (HR 2.22 (1.45-3.41)). Conclusion Angiogenesis, EGFR, and MMP-9 expression provide prognostic information independent of TNM stage, allowing a more accurate outcome prediction for the individual patient. The development of novel anti-angiogenic agents, EGFR targeted therapies, and MMP inhibitors suggests that target specific adjuvant treatments may become a therapeutic option in patients with resected NSCLC.

Herceptest: HER2 expression and gene amplification in non-small cell lung cancer

HER2 is an erbB/HER type I tyrosine kinase receptor that is frequently over-expressed in malignant epithelial tumours. Herceptin, a humanised mouse monoclonal antibody to HER2, is proven therapeutically in the management of metastatic breast cancer, significantly prolonging survival when combined with cytotoxic chemotherapeutic agents. Immunohistochemical studies suggest that non-small-cell lung cancer (NSCLC) tumours may over-express HER2. Our aim was to evaluate HER2 gene amplification and semi-quantitative immuno-expression in NSCLC. A total of 344 NSCLC cases were immunostained for HER2 expression in 2 centres using the HercepTest. Fluorescence in situ hybridisation (FISH) analysis for HER2 gene amplification was performed on most positive cases and a subset of negative cases. Fifteen cases (4.3%) demonstrated 2+ or 3+ membranous HER2 immuno-expression. There was no correlation between immuno-expression and tumour histology or grade. Tumours from higher-stage disease were more often HercepTest-positive (p < 0.001). All 4 HercepTest 3 + cases demonstrated gene amplification. One of the 5 2+ cases tested for gene amplification showed areas of borderline amplification and areas of polyploidy. None of the 19 HercepTest-negative cases demonstrated gene amplification or polyploidy (p < 0.001). Gene amplification was demonstrated in all HercepTest 3+ scoring NSCLC cases. Unlike breast cancer, gene amplification and HER2 protein over-expression assessed by the HercepTest appeared to be uncommon in NSCLC. Herceptin may therefore target only a small proportion of NSCLC tumours and be of limited clinical value in this disease, particularly in the adjuvant setting. © 2001 Wiley-Liss, Inc.

Prognostic significance of platelet and microvessel counts in operable non-small cell lung cancer

Background: Microvessel density, an indirect measure of angiogenesis, has been shown to be an independent prognostic marker in many solid tumours including non-small cell lung cancer (NSCLC). Platelets transport and release angiogenic growth factors. Platelets are increasingly likely to adhere to tumour microvessels due to raised expression of platelet-binding proteins and stasis in blood-flow. Increased vascular permeability in tumour microvessels facilitates platelet extravasation into the extracellular matrix. Adherence and extravasation both lead to platelet activation and release of growth factors capable of instigating the angiogenic process. Methods: A total of 181 patients were identified who underwent resection of stage I-IIIa NSCLC with a post-operative survival >60 days. Patients were followed-up for a minimum of 24 months. Sections from the tumour periphery were stained for the endothelial marker CD34 (Novocastra NCL-END) using standard ABC immunohistochemistry. Chalkley counting was used to assess microvessel density. Results: A pre-operative platelet count greater than the median and above the normal range (>400) was associated with a poor outcome (P = 0.01 and P = 0.04, respectively). Tumours with an above median and high Chalkley count (upper tertile) had a worse prognosis (P = 0.007 and P = 0.0006, respectively). There was no association between platelet count and Chalkley count. Conclusions: Platelet and microvessel counts are both potential prognostic markers for NSCLC. The role of platelets in the angiogenic process needs to be further investigated. (C) 2000 Elsevier Science Ireland Ltd.

First-cycle rash and survival in patients with advanced non-small-cell lung cancer receiving cetuximab in combination with first-line chemotherapy : a subgroup analysis of data from the FLEX phase 3 study

Background: The randomised phase 3 First-Line Erbitux in Lung Cancer (FLEX) study showed that the addition of cetuximab to cisplatin and vinorelbine significantly improved overall survival compared with chemotherapy alone in the first-line treatment of advanced non-small-cell lung cancer (NSCLC). The main cetuximab-related side-effect was acne-like rash. Here, we assessed the association of this acne-like rash with clinical benefit. Methods: We did a subgroup analysis of patients in the FLEX study, which enrolled patients with advanced NSCLC whose tumours expressed epidermal growth factor receptor. Our landmark analysis assessed if the development of acne-like rash in the first 21 days of treatment (first-cycle rash) was associated with clinical outcome, on the basis of patients in the intention-to-treat population alive on day 21. The FLEX study is registered with ClinicalTrials.gov, number NCT00148798. Findings: 518 patients in the chemotherapy plus cetuximab group-290 of whom had first-cycle rash-and 540 patients in the chemotherapy alone group were alive on day 21. Patients in the chemotherapy plus cetuximab group with first-cycle rash had significantly prolonged overall survival compared with patients in the same treatment group without first-cycle rash (median 15·0 months [95% CI 12·8-16·4] vs 8·8 months [7·6-11·1]; hazard ratio [HR] 0·631 [0·515-0·774]; p<0·0001). Corresponding significant associations were also noted for progression-free survival (median 5·4 months [5·2-5·7] vs 4·3 months [4·1-5·3]; HR 0·741 [0·607-0·905]; p=0·0031) and response (rate 44·8% [39·0-50·8] vs 32·0% [26·0-38·5]; odds ratio 1·703 [1·186-2·448]; p=0·0039). Overall survival for patients without first-cycle rash was similar to that of patients that received chemotherapy alone (median 8·8 months [7·6-11·1] vs 10·3 months [9·6-11·3]; HR 1·085 [0·910-1·293]; p=0·36). The significant overall survival benefit for patients with first-cycle rash versus without was seen in all histology subgroups: adenocarcinoma (median 16·9 months, [14·1-20·6] vs 9·3 months [7·7-13·2]; HR 0·614 [0·453-0·832]; p=0·0015), squamous-cell carcinoma (median 13·2 months [10·6-16·0] vs 8·1 months [6·7-12·6]; HR 0·659 [0·472-0·921]; p=0·014), and carcinomas of other histology (median 12·6 months [9·2-16·4] vs 6·9 months [5·2-11·0]; HR 0·616 [0·392-0·966]; p=0·033). Interpretation: First-cycle rash was associated with a better outcome in patients with advanced NSCLC who received cisplatin and vinorelbine plus cetuximab as a first-line treatment. First-cycle rash might be a surrogate clinical marker that could be used to tailor cetuximab treatment for advanced NSCLC to those patients who would be most likely to derive a significant benefit. Funding: Merck KGaA. © 2011 Elsevier Ltd.

Prognostic value of angiogenesis in operable non-small cell lung cancer

Tumour angiogenesis is an important factor for tumour growth and metastasis. Although some recent reports suggest that microvessel counts in non-small cell lung cancer are related to a poor disease outcome, the results were not conclusive and were not compared with other molecular prognostic markers. In the present study, the vascular grade was assessed in 107 (T1,2-N0,1) operable non-small cell lung carcinomas, using the JC70 monoclonal antibody to CD31. Three vascular grades were defined with appraisal by eye and by Chalkley counting: high (Chalkley score 7-12), medium (5-6), and low (2-4). There was a significant correlation between eye appraisal and Chalkley counting (P < 0.0001). Vascular grade was not related to histology, grade, proliferation index (Ki67), or EGFR or p53 expression. Tumours from younger patients had a higher grade of angiogenesis (P = 0.05). Apart from the vascular grade, none of the other factors examined was statistically related to lymph node metastasis (P < 0.0001). A univariate analysis of survival showed that vascular grade was the most significant prognostic factor (P = 0.0004), followed by N-stage (P = 0.001). In a multivariate analysis, N-stage and vascular grade were not found to be independent prognostic factors, since they were strongly related to each other. Excluding N-stage, vascular grade was the only independent prognostic factor (P = 0.007). Kaplan-Meier survival curves showed a statistically significant worse prognosis for patients with high vascular grade, but no difference was observed between low and medium vascular grade. These data suggest that angiogenesis in operable non-small cell lung cancer is a major prognostic factor for survival and, among the parameters tested, is the only factor related to cancer cell migration to lymph nodes. The integration of vascular grading in clinical trials on adjuvant chemotherapy and/or radiotherapy could substantially contribute in defining groups of operable patients who might benefit from cytotoxic treatment.

Transcriptional regulation of IRS5/DOK4 expression in non-small-cell lung cancer cells

The insulin-receptor substrate family plays important roles in cellular growth, signaling, and survival. Two new members of this family have recently been isolated: IRS5/Dok4 and IRS6/Dok5. This study examines the expression of IRS5/DOK4 in a panel of lung cancer cell lines and tumor specimens. The results demonstrate that expression of IRS5/DOK4 is frequently altered with both elevated and decreased expression in non-small-cell lung cancer (NSCLC) tumor specimens. The altered expression of IRS5/DOK4 observed in tumor samples is not due to aberrant methylation. In vitro cell culture studies demonstrate that treatment of NSCLC cell lines with the histone deacetylase inhibitor trichostatin A (TSA) upregulates IRS5/DOK4. This finding indicates that expression is regulated epigenetically at the level of chromatin remodeling. Chromatin immunoprecipitation experiments confirm that the IRS5/DOK4 promoter has enhanced histone hyperacetylation following treatments with TSA. Finally, hypoxia was demonstrated to downregulate IRS5/DOK4 expression. This expression was restored by TSA. The clinical relevance of altered IRS5/DOK4 expression in NSCLC requires fur ther evaluation.

bcl-2 and c-erbB-2 proteins are involved in the regulation of VEGF and of thymidine phosphorylase angiogenic activity in non-small-cell lung cancer

Tumour angiogenesis has been recently recognised as one of the most important prognostic factors in lung cancer. Although a variety of angiogenic factors have been identified, the angiogenesis process remains poorly understood. Bcl-2, c-erbB-2 and p53 are well-known oncogenes involved in non- small-cell lung cancer pathogenesis. A direct correlation of thymidine phosphorylase (TP) and of vascular endothelial growth factor (VEGF) with intratumoural angiogenesis has been reported. In the present study we investigated the possible regulatory role if bcl-2, c-erB-2 proteins in angiogenesis and in VEGF and TP expression in non-small-cell lung cancer. Two hundred sixteen specimens from T1,2-NO, 1 staged patients treated with surgery alone were immunohistochemically examined. Bcl-2 and c-erbB-2 were significantly inversely related to each other (P = 0.04) and both were inversely associated with microvessel density (P < 0.02). High TP and VEGF reactivity was statistically related to loss of bcl-2 expression (P < 0.01). A significant co-expression of c-erbB-2 with TP was noted (P = 0.01). However, TP expression was related to high angiogenesis only in cases with absence of c-erB-2 expression (P < 0.0001). c-erbB-2 expression in poorly vascularised tumours was linked with poor outcome (P = 0.03). The present study provides strong evidence that the bcl-2 gene has a suppressive function over genes involved in both angiogenesis (VEGF and TP) and cell migration (c- erbB-2) in NSCLC. TP and c-erbB-2 proteins are significantly, and often simultaneously, expressed in bcl-2 negative cases. However, expression of the c-erbB-2 abolishes the TP-related angiogenic activity. Whether this is a result of a direct activity of the c-erbB-2 protein or a consequence of a c- erbB-2-related immune response remains to be further investigated.

Potential role of bcl-2 as a suppressor of tumour angiogenesis in non- small-cell lung cancer

It has been reported that genes regulating apoptosis may play a role in tumoral angiogenesis. This study examined the relationship between tumour vascularization, a measure of tumour angiogenesis, and bcl-2 and p53 expression in operable non-small-cell lung cancer (NSCLC). The relationship between bcl-2, p53 and tumour vascularization and epidermal-growth-factor- receptor(EGFR) and c-erbB-2 expression was also studied. Tissue sections from resected tumour specimens of 107 NSCLC patients were evaluated immunohistochemically for vascular grade and bcl-2, p53, EGFR and c-erbB-2 expression. bcl-2 expression was found in 20/107 (19%) cases and was associated with squamous-cell histology (p = 0.03). A strong inverse relationship was found between bcl-2 expression and vascular grade (p = 0.005). All c-erbB-2-positive cases were negative for bcl-2 expression (p = 0.01). Overall no association was found between c-erbB-2 expression and vascular grade. However, in bcl-2-negative cases positive c-erbB-2 expression correlated with low angiogenesis (p = 0.05). No relationship was found between p53 and EGFR expression and bcl-2, c-erbB-2 or vascular grade. The improved prognosis reported in bcl-2-positive NSCLC may be related to low tumour vascularization. The results suggest that the anti-apoptotic gene bcl- 2 plays a role in regulating tumour angiogenesis. Since normal lung epithelium expresses bcl-2, a sequence of tumour progression involving loss of bcl-2, then activation of c-erbB-2 or increase in tumour vascularization is proposed.

Phase III trial comparing paclitaxel poliglumex (CT-2103, PPX) in combination with carboplatin versus standard paclitaxel and carboplatin in the treatment of PS 2 patients with chemotherapy-naïve advanced non-small cell lung cancer

INTRODUCTION: Performance status (PS) 2 patients with non-small cell lung cancer (NSCLC) experience more toxicity, lower response rates, and shorter survival times than healthier patients treated with standard chemotherapy. Paclitaxel poliglumex (PPX), a macromolecule drug conjugate of paclitaxel and polyglutamic acid, reduces systemic exposure to peak concentrations of free paclitaxel and may lead to increased concentrations in tumors due to enhanced vascular permeability. METHODS: Chemotherapy-naive PS 2 patients with advanced NSCLC were randomized to receive carboplatin (area under the curve = 6) and either PPX (210 mg/m/10 min without routine steroid premedication) or paclitaxel (225 mg/m/3 h with standard premedication) every 3 weeks. The primary end point was overall survival. RESULTS: A total of 400 patients were enrolled. Alopecia, arthralgias/myalgias, and cardiac events were significantly less frequent with PPX/carboplatin, whereas grade ≥3 neutropenia and grade 3 neuropathy showed a trend of worsening. There was no significant difference in the incidence of hypersensitivity reactions despite the absence of routine premedication in the PPX arm. Overall survival was similar between treatment arms (hazard ratio, 0.97; log rank p = 0.769). Median and 1-year survival rates were 7.9 months and 31%, for PPX versus 8 months and 31% for paclitaxel. Disease control rates were 64% and 69% for PPX and paclitaxel, respectively. Time to progression was similar: 3.9 months for PPX/carboplatin versus 4.6 months for paclitaxel/carboplatin (p = 0.210). CONCLUSION: PPX/carboplatin failed to provide superior survival compared with paclitaxel/carboplatin in the first-line treatment of PS 2 patients with NSCLC, but the results with respect to progression-free survival and overall survival were comparable and the PPX regimen was more convenient. © 2008International Association for the Study of Lung Cancer.

An evaluation of tumor oxygenation and gene expression in patients with early stage non-small cell lung cancers

Background: To directly assess tumor oxygenation in resectable non - small cell lung cancers (NSCLC) and to correlate tumor pO2 and the selected gene and protein expression to treatment outcomes. Methods: Twenty patients with resectable NSCLC were enrolled. Intraoperative measurements of normal lung and tumor pO2 were done with the Eppendorf polarographic electrode. All patients had plasma osteopontin measurements by ELISA. Carbonic anhydrase-IX (CA IX) staining of tumor sections was done in the majority of patients (n = 16), as was gene expression profiling (n = 12) using cDNA microarrays. Tumor pO2 was correlated with CA IX staining, osteopontin levels, and treatment outcomes. Results: The median tumor pO2 ranged from 0.7 to 46 mm Hg (median, 16.6) and was lower than normal lung pO2 in all but one patient. Because both variables were affected by the completeness of lung deflation during measurement, we used the ratio of tumor/normal lung (T/L) pO2 as a reflection of tumor oxygenation. The median T/L pO 2 was 0.13. T/L pO2 correlated significantly with plasma osteopontin levels (r = 0.53, P = 0.02) and CA IX expression (P = 0.006). Gene expression profiling showed that high CD44 expression was a predictor for relapse, which was confirmed by tissue staining of CD44 variant 6 protein. Other variables associated with the risk of relapse were T stage (P = 0.02), T/L pO2 (P = 0.04), and osteopontin levels (P = 0.001). Conclusions: Tumor hypoxia exists in resectable NSCLC and is associated with elevated expression of osteopontin and CA IX. Tumor hypoxia and elevated osteopontin levels and CD44 expression correlated with poor prognosis. A larger study is needed to confirm the prognostic significance of these factors. © 2006 American Association for Cancer Research.

The beneficial effects of specialist thoracic surgery on the resection rate for non-small-cell lung cancer

We aimed to evaluate the effect of the appointment of a dedicated specialist thoracic surgeon on surgical practice for lung cancer previously served by cardio-thoracic surgeons. Outcomes were compared for the 240 patients undergoing surgical resection for lung cancer in two distinct 3-year periods: Group A: 65 patients, 1994-1996 (pre-specialist); Group B: 175 patients, 1997-1999 (post-specialist). The changes implemented resulted in a significant increase in resection rate (from 12.2 to 23.4%, P<0.001), operations in the elderly (over 75 years) and extended resections. There were no significant differences in stage distribution, in-hospital mortality or stage-specific survival after surgery. Lung cancer surgery provided by specialists within a multidisciplinary team resulted in increased surgical resection rates without compromising outcome. Our results strengthen the case for disease-specific specialists in the treatment of lung cancer. © 2004 Published by Elsevier Ireland Ltd.

SRL 172 (killed Mycobacterium vaccae) in addition to standard chemotherapy improves quality of life without affecting survival, in patients with advanced non-small-cell lung cancer : phase III results

Background: This open-label, randomised phase III study was designed to further investigate the clinical activity and safety of SRL172 (killed Mycobacterium vaccae suspension) with chemotherapy in the treatment of non-small-cell lung cancer (NSCLC). Patients and methods: Patients were randomised to receive platinum-based chemotherapy, consisting of up to six cycles of MVP (mitomycin, vinblastine and cisplatin or carboplatin) with (210 patients) or without (209 patients) monthly SRL172. Results: There was no statistical difference between the two groups in overall survival (primary efficacy end point) over the course of the study (median overall survival of 223 days versus 225 days; P = 0.65). However, a higher proportion of patients were alive at the end of the 15-week treatment phase in the chemotherapy plus SRL172 group (90%), than in the chemotherapy alone group (83%) (P = 0.061). At the end of the treatment phase, the response rate was 37% in the combined group and 33% in the chemotherapy alone group. Patients in the chemotherapy alone group had greater deterioration in their Global Health Status score (-14.3) than patients in the chemotherapy plus SRL172 group (-6.6) (P = 0.02). Conclusion: In this non-placebo controlled trial, SRL172 when added to standard cancer chemotherapy significantly improved patient quality of life without affecting overall survival times. © 2004 European Society for Medical Oncology.

Epigenetic regulation of glucose transporters in non-small cell lung cancer

Due to their inherently hypoxic environment, cancer cells often resort to glycolysis, or the anaerobic breakdown of glucose to form ATP to provide for their energy needs, known as the Warburg effect. At the same time, overexpression of the insulin receptor in non-small cell lung cancer (NSCLC) is associated with an increased risk of metastasis and decreased survival. The uptake of glucose into cells is carried out via glucose transporters or GLUTs. Of these, GLUT-4 is essential for insulin-stimulated glucose uptake. Following treatment with the epigenetic targeting agents histone deacetylase inhibitors (HDACi), GLUT-3 and GLUT-4 expression were found to be induced in NSCLC cell lines, with minimal responses in transformed normal human bronchial epithelial cells (HBECs). Similar results for GLUT-4 were observed in cells derived from liver, muscle, kidney and pre-adipocytes. Bioinformatic analysis of the promoter for GLUT-4 indicates that it may also be regulated by several chromatin binding factors or complexes including CTCF, SP1 and SMYD3. Chromatin immunoprecipitation studies demonstrate that the promoter for GLUT-4 is dynamically remodeled in response to HDACi. Overall, these results may have value within the clinical setting as (a) it may be possible to use this to enhance fluorodeoxyglucose (18F) positron emission tomography (FDG-PET) imaging sensitivity; (b) it may be possible to target NSCLC through the use of HDACi and insulin mediated uptake of the metabolic targeting drugs such as 2-deoxyglucose (2-DG); or (c) enhance or sensitize NSCLC to chemotherapy. © 2011 by the authors; licensee MDPI, Basel, Switzerland.

Combination therapy with gefitinib and rofecoxib in patients with platinum-pretreated relapsed non-small-cell lung cancer

Purpose: In non-small-cell lung cancer (NSCLC), the epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) play major roles in tumorigenesis. This phase I/II study evaluated combined therapy with the EGFR tyrosine kinase inhibitor (TKI) gefitinib and the COX-2 inhibitor rofecoxib in platinum-pretreated, relapsed, metastatic NSCLC (n = 45). Patients and Methods: Gefitinib 250 mg/d was combined with rofecoxib (dose escalated from 12.5 to 25 to 50 mg/d through three cohorts, each n = 6). Because the rofecoxib maximum-tolerated dose was not reached, the 50 mg/d cohort was expanded for efficacy evaluation (n = 33). Results: Among the 42 assessable patients, there was one complete response (CR) and two partial responses (PRs) and 12 patients with stable disease (SD); disease control rate was 35.7% (95% CI, 21.6% to 52.0%). Median time to tumor progression was 55 days (95% CI, 47 to 70 days), and median survival was 144 days (95% CI, 103 to 190 days). In a pilot study, matrix-assisted laser desorption/ionization (MALDI) proteomics analysis of baseline serum samples could distinguish patients with an objective response from those with SD or progressive disease (PD), and those with disease control (CR, PR, and SD) from those with PD. The regimen was generally well tolerated, with predictable toxicities including skin rash and diarrhea. Conclusion: Gefitinib combined with rofecoxib provided disease control equivalent to that expected with single-agent gefitinib and was generally well tolerated. Baseline serum proteomics may help identify those patients most likely to benefit from EGFR TKIs. © 2007 by American Society of Clinical Oncology.

Molecular biomarkers in non-small-cell lung cancer : a retrospective analysis of data from the phase 3 FLEX study

Background: Findings from the phase 3 FLEX study showed that the addition of cetuximab to cisplatin and vinorelbine significantly improved overall survival, compared with cisplatin and vinorelbine alone, in the first-line treatment of EGFR-expressing, advanced non-small-cell lung cancer (NSCLC). We investigated whether candidate biomarkers were predictive for the efficacy of chemotherapy plus cetuximab in this setting. Methods: Genomic DNA extracted from formalin-fixed paraffin-embedded (FFPE) tumour tissue of patients enrolled in the FLEX study was screened for KRAS codon 12 and 13 and EGFR kinase domain mutations with PCR-based assays. In FFPE tissue sections, EGFR copy number was assessed by dual-colour fluorescence in-situ hybridisation and PTEN expression by immunohistochemistry. Treatment outcome was investigated according to biomarker status in all available samples from patients in the intention-to-treat population. The primary endpoint in the FLEX study was overall survival. The FLEX study, which is ongoing but not recruiting participants, is registered with ClinicalTrials.gov, number NCT00148798. Findings: KRAS mutations were detected in 75 of 395 (19%) tumours and activating EGFR mutations in 64 of 436 (15%). EGFR copy number was scored as increased in 102 of 279 (37%) tumours and PTEN expression as negative in 107 of 303 (35%). Comparisons of treatment outcome between the two groups (chemotherapy plus cetuximab vs chemotherapy alone) according to biomarker status provided no indication that these biomarkers were of predictive value. Activating EGFR mutations were identified as indicators of good prognosis, with patients in both treatment groups whose tumours carried such mutations having improved survival compared with those whose tumours did not (chemotherapy plus cetuximab: median 17·5 months [95% CI 11·7-23·4] vs 8·5 months [7·1-10·8], hazard ratio [HR] 0·52 [0·32-0·84], p=0·0063; chemotherapy alone: 23·8 months [15·2-not reached] vs 10·0 months [8·7-11·0], HR 0·35 [0·21-0·59], p<0·0001). Expression of PTEN seemed to be a potential indicator of good prognosis, with patients whose tumours expressed PTEN having improved survival compared with those whose tumours did not, although this finding was not significant (chemotherapy plus cetuximab: median 11·4 months [8·6-13·6] vs 6·8 months [5·9-12·7], HR 0·80 [0·55-1·16], p=0·24; chemotherapy alone: 11·0 months [9·2-12·6] vs 9·3 months [7·6-11·9], HR 0·77 [0·54-1·10], p=0·16). Interpretation: The efficacy of chemotherapy plus cetuximab in the first-line treatment of advanced NSCLC seems to be independent of each of the biomarkers assessed. Funding: Merck KGaA. © 2011 Elsevier Ltd.