We sought to determine the frequency and clinical characteristics of patients with lung cancer harboring NRAS mutations. We used preclinical models to identify targeted therapies likely to be of benefit against NRAS mutant lung cancer cells.
Patients and Methods
We reviewed clinical data from patients whose lung cancers were identified at 6 institutions or reported in the Catalogue of Somatic Mutations in Cancer (COSMIC) to harbor NRAS mutations. 6 NRAS mutant cell lines were screened for sensitivity against inhibitors of multiple kinases (i.e. EGFR, ALK, MET, IGF-1R, BRAF, PI3K and MEK).
Among 4562 patients with lung cancers tested, NRAS mutations were present in 30 (0.7%; 95% confidence interval, 0.45% to 0.94%); 28 of these had no other driver mutations. 83% had adenocarcinoma histology with no significant differences in gender. While 95% of patients were former or current smokers, smoking-related G:C>T:A transversions were significantly less frequent in NRAS mutated lung tumors compared to KRAS-mutant NSCLCs (NRAS: 13% (4/30), KRAS: 66% (1772/2733), p<0.00000001). 5 of 6 NRAS mutant cell lines were sensitive to the MEK inhibitors, selumetinib and trametinib, but not to other inhibitors tested.
NRAS mutations define a distinct subset of lung cancers (~1%) with potential sensitivity to MEK inhibitors. While NRAS mutations are more common in current/former smokers, the types of mutations are not those classically associated with smoking.
NRAS mutation; EGFR mutation; KRAS mutation; lung cancer; non-small cell lung cancer; driver mutation; MEK inhibitor; erlotinib; gefitinib; crizotinib
The discovery of distinct subsets of non-small cell lung cancer (NSCLC) characterized by activation of driver oncogenes has greatly impacted personalized therapy. We hypothesized that the dominant oncogene in NSCLC would be associated with distinct patterns of metastatic spread in NSCLC at the time of diagnosis.
209 consecutive patients with stage IV non-squamous NSCLC with an EGFR mutation (N=39), KRAS mutation (N=49), ALK gene rearrangement (N=41), or wild-type for all three (triple negative, N=80) were included. The percentage of patients with metastatic disease at a given site was compared between each molecular cohort (EGFR, KRAS, or ALK) and the triple negative cohort.
ALK gene rearrangement was significantly associated with pericardial disease (OR=4.61, 95% CI 1.30, 16.37, p=0.02) and pleural disease (OR=4.80, 95% CI 2.10, 10.97, p<0.001). Patients with ALK gene rearrangements (OR=5.50, 95% CI 1.76, 17.18, p= 0.003) and patients with EGFR mutations (OR=5.17, 95% CI 1.63, 16.43, p= 0.006) were predisposed to liver metastasis compared to the triple negative cohort. No molecular cohort had a predisposition to pulmonary nodules, adrenal, bone, or brain metastasis compared to the triple negative cohort. The mean number of metastatic disease sites in patients within the ALK rearranged cohort was significantly greater than the triple negative cohort (mean = 3.6 sites vs. 2.5 sites, p<0.0001).
The results support the hypothesis that the dominant molecular oncogenes in NSCLC are associated with different biological behaviors manifesting as distinct patterns of metastatic spread at the time of diagnosis.
metastasis; Non-Small Cell Lung Cancer; EGFR; ALK tyrosine kinase receptor; KRAS
To evaluate the methylation state of 31 genes in sputum as biomarkers in an expanded nested, case-control study from the Colorado Cohort and to assess the replication of results from the most promising genes in an independent case-control study of asymptomatic Stage I lung cancer patients from New Mexico.
Cases and controls from Colorado and New Mexico were interrogated for methylation of up to 31 genes using nested, methylation specific PCR. Individual genes and methylation indices were used to assess the association between methylation and lung cancer with logistic regression modeling.
Seventeen genes with odds ratios of 1.4 – 3.6 were identified and selected for replication in the New Mexico study. Overall, the direction of effects seen in New Mexico was similar to Colorado with the largest increase in case discrimination (odds ratios, 3.2 – 4.2) seen for the PAX5α, GATA5, and SULF2 genes. ROC curves generated from seven gene panels from Colorado and New Mexico studies showed prediction accuracy of 71% and 77%, respectively. A 22-fold increase in lung cancer risk was seen for a subset of New Mexico cases with five or more genes methylated. Sequence variants associated with lung cancer did not improve the accuracy of this gene methylation panel.
These studies have identified and replicated a panel of methylated genes whose integration with other promising biomarkers could initially identify the highest risk smokers for computed tomography screening for early detection of lung cancer.
gene methylation; sputum; lung cancer; biomarker
Folate receptor alpha (FRα) and reduced folate carrier-1 (RFC1) regulate uptake of folate molecules inside the cell. FRα is a potential biomarker of tumors response to antifolate chemotherapy and a target for therapy using humanized monocloncal antibody. Information on the protein expression of these receptors in non–small cell lung carcinoma (NSCLC) is limited.
Material and Methods
Expressions of FRα and RFC1 were examined by IHC in 320 surgically resected NSCLC (202 adenocarcinomas and 118 squamous cell carcinomas) tissue specimens and correlated with patients’ clinicopathologic characteristics. FOLR1 mRNA expression was examined using publicly available microarray datasets. FRα expression was correlated with thymidylate synthase (TS) and p53 expression in NSCLCs, and with EGFR and KRAS mutations in adenocarcinomas.
NSCLC overexpressed FRα and RFC1. In a multivariate analysis, lung adenocarcinomas were more likely to express FRα in the cytoplasm (odds ratio [OR] = 4.39; P<0.0001) and membrane (OR = 5.34; P<0.0001) of malignant cells than squamous cell carcinomas. Tumors from never-smokers were more likely to express cytoplasmic (OR = 3.35; P<0.03) and membrane (OR = 3.60; P=0.0005) FRα than those from smokers. In adenocarcinoma, EGFR mutations correlated with higher expression of membrane FRα and FOLR1 gene expressions. High levels of FRα expression was detected in 42 NSCLC advanced metastatic tumor tissues.
FRα and RFC1 proteins are overexpressed in NSCLC tumor tissues. The high levels of FRα in lung adenocarcinomas may be associated to these tumors’ better responses to antifolate chemotherapy and represents a potential novel target for this tumor type.
non–small cell lung carcinoma; EGFR; membrane transporter; FRα; FRC1
Lung adenocarcinoma (AdC) and lung squamous cell carcinoma (SCC) are the most common non-small cell lung cancer (NSCLC) subtypes. This study was designed to determine whether reduced expression of transforming growth factor β type II receptor (TGFβRII) promotes lung AdC and SCC carcinogenesis.
We examined TGFβRII expression at the protein and mRNA levels in human NSCLC samples and assessed the relationship between TGFβRII expression and clinico-pathologic parameters. To determine if sporadic TGFβRII deletion in airway epithelial cells induces NSCLC formation, we targeted TGFβRII deletion alone and in combination with oncogenic KrasG12D to murine airways using a keratin 5 (K5) promoter and inducible Cre recombinase.
Reduced TGFβRII expression in human NSCLC is associated with male gender, smoking, SCC histology, reduced differentiation, increased tumor stage, increased nodal metastasis, and reduced survival. Homozygous or heterozygous TGFβRII deletion in mouse airway epithelia increases the size and number of KrasG12D-initiated AdC and SCC. TGFβRII deletion increases proliferation, local inflammation, and TGFβ ligand elaboration; TGFβRII knockdown in airway epithelial cells increases migration and invasion.
Reduced TGFβRII expression in human NSCLC is associated with more aggressive tumor behavior and inflammation that is at least partially mediated by increased TGFβ1 expression. TGFβRII deletion in mouse airway epithelial cells promotes AdC and SCC formation, indicating that TGFβRII loss plays a causal role in lung carcinogenesis. That TGFβRII demonstrates haploid insufficiency, suggests that a 50% TGFβRII protein reduction would negatively impact lung cancer prognosis.
lung adenocarcinoma; lung squamous cell carcinoma; TGFβ; tumor progression; mouse model
To explore whether the progression-free survival (PFS) with pemetrexed differs between anaplastic lymphoma kinase (ALK)-positive and other major molecular subtypes of non-small cell lung cancer.
In an ALK-enriched population, patients with metastatic non-small cell lung cancer were screened by ALK fluorescence in situ hybridization and for epidermal growth factor receptor (EGFR) and KRAS mutations. Triple-tested, pemetrexed-treated patients (monotherapy or combination therapy) were identified and PFS with pemetrexed captured retrospectively.
Eighty-nine eligible cases were identified (19 ALK fluorescence in situ hybridization positive, 12 EGFR mutant, 21 KRAS mutant, and 37 triple negatives). Eighty-three cases (93%) were adenocarcinomas, two were adenosquamous, one squamous, and three had large cell histology. None of the ALK-positive patients had received crizotinib before pemetrexed. Pemetrexed was first-line therapy in 48% (72% as platinum-based combinations). Median PFS (95% confidence interval) data were EGFR mutant (5.5 months; 1–9), KRAS mutant (7 months; 1.5–10), ALK positive (9 months; 3–12), and triple negative (4 months; 3–5). In a multivariate analysis adjusting for line of therapy, mono- versus platinum and nonplatinum combination therapy, age, sex, histology, and smoking status, the only variable associated with prolonged PFS on pemetrexed was ALK+ (hazard ratio = 0.36 [95% confidence interval: 0.17– 0.73], p = 0.0051).
In this exploratory analysis, ALK-positive patients have a significantly longer PFS on pemetrexed compared with triple-negative patients, whereas EGFR or KRAS mutant patients do not. This information should be considered when sizing randomized studies in ALK-positive patients that involve pemetrexed. Pemetrexed should also be prioritized as a cytotoxic to explore further in patients with known ALK-positive disease.
Anaplastic lymphoma kinase; Non-small cell lung cancer; Epidermal growth factor receptor; KRAS; Pemetrexed
Patients with anaplastic lymphoma kinase (ALK) gene rearrangements often manifest dramatic responses to crizotinib, a small molecule ALK inhibitor. Unfortunately, not every patient responds and acquired drug resistance inevitably develops in those that do respond. This study aimed to define molecular mechanisms of resistance to crizotinib in ALK+ non-small cell lung cancer (NSCLC) patients.
We analyzed tissue obtained from 14 ALK+ NSCLC patients demonstrating evidence of radiologic progression while on crizotinib in order to define mechanisms of intrinsic and acquired resistance to crizotinib.
Eleven patients had material evaluable for molecular analysis. Four patients (36%) developed secondary mutations in the tyrosine kinase domain of ALK. A novel mutation in the ALK kinase domain, encoding a G1269A amino acid substitution that confers resistance to crizotinib in vitro, was identified in two of these cases. Two patients, one with a resistance mutation, exhibited new onset ALK copy number gain (CNG). One patient demonstrated outgrowth of EGFR mutant NSCLC without evidence of a persistent ALK gene rearrangement. Two patients exhibited a KRAS mutation, one of which occurred without evidence of a persisting ALK gene rearrangement. One patient demonstrated the emergence of an ALK gene fusion negative tumor compared to the baseline sample, but with no identifiable alternate driver. Two patients retained ALK positivity with no identifiable resistance mechanism.
Crizotinib resistance in ALK+ NSCLC occurs through somatic kinase domain mutations, ALK gene fusion CNG, and emergence of separate oncogenic drivers.
oncogene fusion; anaplastic lymphoma kinase; protein kinase inhibitors; drug resistance; non-small cell lung cancer
This phase II study (S0341) evaluated the efficacy and tolerability of single-agent erlotinib in unselected chemotherapy-naïve patients with advanced non-small cell lung cancer (NSCLC) and a performance status (PS) of 2. Exploratory analyses of a number of biomarkers relating to EGFR pathway activation were also performed.
Patients and Methods
Patients with stage IIIB (pleural effusion) or stage IV NSCLC with a PS of 2 and no prior chemotherapy or biologic treatment for NSCLC received erlotinib 150 mg daily.
A total of 81 patients entered the study; 76 were assessable. One complete and 5 partial responses were noted for an overall response rate of 8% (95% CI 3%–16%).Stable disease (SD) was seen in 26 patients (34 %) resulting in a disease control rate (DCR=CR/PR/SD) of 42%. Progression free and median survival were 2.1 months (95% CI 1.5–3.1) and 5 months (95% CI 3.6–7.2) respectively. One-year survival was 24% (95% CI 15%–34%). Although treatment was generally well tolerated, grade 3–4 toxicity was reported in 30 patients (40%), including fatigue (16%), rash (9%), diarrhea (7%) and anorexia (7%). There was one possible treatment related death (pneumonitis).
In chemotherapy-naïve patients with advanced NSCLC and a PS of 2, single agent erlotinib resulted in an acceptable but significant level of treatment-related side effects. With an overall DCR of 42% and median survival of 5 months, results are comparable to those achieved with chemotherapy in this population. Development of an EGFR-directed biomarker selection strategy may optimize use of erlotinib in PS 2 patients.
Erlotinib prolongs survival in patients with advanced non–small-cell lung cancer (NSCLC). We report the results of a randomized, phase II study of erlotinib alone or intercalated with chemotherapy (CT + erlotinib) in chemotherapy-naïve patients with advanced NSCLC who were positive for epidermal growth factor receptor (EGFR) protein expression and/or with high EGFR gene copy number.
Patients and Methods
A total of 143 patients were randomly assigned to either erlotinib 150 mg daily orally until disease progression (PD) occurred or to chemotherapy with paclitaxel 200 mg/m2 intravenously (IV) and carboplatin dosed by creatinine clearance (AUC 6) IV on day 1 intercalated with erlotinib 150 mg orally on days 2 through 15 every 3 weeks for four cycles followed by erlotinib 150 mg orally until PD occurred (CT + erlotinib). The primary end point was 6-month progression-free survival (PFS); secondary end points included response rate, PFS, and survival. EGFR, KRAS mutation, EGFR fluorescent in situ hybridization and immunohistochemistry, and E-cadherin and vimentin protein levels were also assessed.
Six-month PFS rates were 26% and 31% for the two arms (CT + erlotinib and erlotinib alone, respectively). Both were less than the historical control of 45% (P = .001 and P = .011, respectively). Median PFS times were 4.57 and 2.69 months, respectively. Patients with tumors harboring EGFR activating mutations fared better on erlotinib alone (median PFS, 18.2 months v 4.9 months for CT + erlotinib).
The feasibility of a multicenter biomarker-driven study was demonstrated, but neither treatment arms exceeded historical controls. This study does not support combined chemotherapy and erlotinib in first-line treatment of EGFR-selected advanced NSCLC, and the patients with tumors harboring EGFR mutations had a better outcome on erlotinib alone.
Anaplastic lymphoma kinase (ALK) rearrangements, associated with sensitivity to an experimental ALK/MET inhibitor, occur in 3% to 5% of non-small cell lung cancers. Intratumoral fluorescence in situ hybridization (FISH) heterogeneity has been reported. We explored the heterogeneity basis, the requirements for accurately determining ALK FISH positivity, and the effect of enriching the tested population using clinical and molecular factors.
Lung cancer patients were screened by ALK and MET FISH and for EGFR and KRAS mutations.
Thirteen ALK-positive cases were identified from 73 screened patients. Gene copy number increases occurred together with classic rearrangements. All positive cases were adenocarcinomas, 12 were EGFR/KRAS wild-type, and 1 had a coexistent EGFR exon 20 mutation. No association with MET amplification occurred. ALK positivity was associated with <10-pack-year smoking status (P = 0.0004). Among adenocarcinomas, without KRAS or EGFR mutations, with <10-pack-year history, 44.8% of cases were ALK positive. ALK FISH positivity was heterogeneous, but mean values in tumor areas from ALK-positive patients (54% of cells; range, 22-87%) were significantly higher than in adjacent normal tissue or tumor/ normal areas from ALK-negative patients (mean, 5-7%). Contiguous sliding field analyses showed diffuse heterogeneity without evidence of focal ALK rearrangements. One hundred percent sensitivity and specificity occurred when four or more fields (~60 cells) were counted.
Intratumoral ALK FISH heterogeneity reflects technique, not biology. The clinical activity of ALK/MET inhibitors in ALK-positive patients probably reflects ALK, but not MET, activity. Prescreening by histology, EGFR/KRAS mutations, and smoking status dramatically increases the ALK-positive hit rate compared with unselected series.
Sensitivity to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and frequency of activation mutations in EGFR is lower in Caucasian than Asian non small-cell lung cancer (NSCLC) patients. Increased EGFR gene copy numbers evaluated by fluorescence in situ hybridization (FISH) has been reported as predictor of clinical benefit from EGFR-TKIs in Caucasian NSCLC patients. This study was carried out to verify whether EGFR FISH had similar performance in Japanese patients.
A cohort of 44 Japanese patients with recurrent NSCLC after surgery was treated with gefitinib 250 mg daily. The cohort included 48% females and 52% never-smokers; 73% had prior chemotherapy and 57% had stage III-IV at the time of surgery. Adenocarcinoma was the most common histology (86%). FISH was performed using the EGFR/Chromosome Enumeration Probe 7 and PathVysion DNA probes (Abbott Molecular). Specimens were classified as FISH positive when showing gene amplification or high polysomy (≥4 copies of the gene in ≥40% of tumor cells). Tumor response to gefitinib was assessed by RECIST for 33 patients with measurable diseases.
Twenty-nine tumors (66%) were EGFR FISH+ and 23 (53%) were HER2 FISH+. Overall response rate was 52%, representing 65% of EGFR FISH+ patients and 29% of EGFR FISH+ patients (p = 0.0777). Survival was not impacted by the EGFR FISH (p = 0.9395) or the HER2 FISH (p = 0.0671) status. EGFR FISH= was significantly associated with HER2 FISH+ (p = 0.015) and presence of EGFR mutation (p = 0.0060). EGFR mutation significantly correlated with response (p < 0.0001) and survival after gefitinib (p = 0.0204). EGFR and HER2 FISH status were not associated with KRAS mutation.
Frequency of EGFR FISH+ status was higher and its predictive power for TKI sensitivity was lower in this Japanese cohort than in Western NSCLC cohorts. These findings support differences in the mechanisms of EGFR pathway activation in NSCLC between Asian and Caucasian populations. Confirmation of these results in larger cohorts is warranted.
FISH; EGFR; HER2; KRAS; Biomarkers; NSCLC; Tyrosine inhibitors
Epidermal growth factor receptor (EGFR) gene copy number detected by fluorescent in situ hybridization (FISH) has proven to be useful for selection of non–small-cell lung cancer (NSCLC) patients for treatment with EGFR tyrosine kinase inhibitors. Here, we evaluate EGFR FISH as a predictive marker in NSCLC patients receiving the EGFR monoclonal antibody inhibitor cetuximab plus chemotherapy.
Patients and Methods
Two hundred twenty-nine chemotherapy-naive patients with advanced-stage NSCLC were enrolled onto a phase II selection trial evaluating sequential or concurrent chemotherapy (paclitaxel plus carboplatin) with cetuximab.
EGFR FISH was assessable in 76 patients with available tumor tissue and classified as positive (four or more gene copies per cell in ≥ 40% of the cells or gene amplification) in 59.2%. Response (complete response/partial response) was numerically higher in FISH-positive (45%) versus FISH-negative (26%) patients (P = .14), whereas disease control rate (complete response/partial response plus stable disease) was statistically superior (81% v 55%, respectively; P = .02). Patients with FISH-positive tumors had a median progression-free survival time of 6 months compared with 3 months for FISH-negative patients (P = .0008). Median survival time was 15 months for the FISH-positive group compared with 7 months for patients who were FISH negative. (P = .04). Furthermore, survival favored FISH-positive patients receiving concurrent therapy.
These results are the first to suggest that EGFR FISH is a predictive factor for selection of NSCLC patients for cetuximab plus chemotherapy. Prospective validation of these findings is warranted.
There are no established chemopreventive agents for lung cancer, the leading cause of cancer death in the United States. Prostacyclin levels are low in lung cancer and supplementation prevents lung cancer in preclinical models. We carried out a multicenter double-blind, randomized, phase II placebo-controlled trial of oral iloprost in current or former smokers with sputum cytologic atypia or endobronchial dysplasia. Bronchoscopy was performed at study entry and after completion of six months of therapy. Within each subject, the results were calculated by using the average score of all biopsies (Avg), the worst biopsy score (Max), and the dysplasia index (DI). Change in Avg was the primary end point, evaluated in all subjects, as well as in current and former smokers. The accrual goal of 152 subjects was reached and 125 completed both bronchoscopies (60/75 iloprost, 65/77 placebo). Treatment groups were well matched for age, tobacco exposure, and baseline histology. Baseline histology was significantly worse for current smokers (Avg 3.0) than former smokers (Avg 2.1). When compared with placebo, former smokers receiving oral iloprost exhibited a significantly greater improvement in Avg (0.41 units better, P = 0.010), in Max (1.10 units better, P = 0.002), and in DI (12.45%, P = 0.006). No histologic improvement occurred in current smokers. Oral iloprost significantly improves endobronchial histology in former smokers and deserves further study to determine if it can prevent the development of lung cancer.
This phase I/II study evaluated the safety and anti-tumor effect of the combination of erlotinib with cixutumumab, a recombinant fully humanized anti-insulin-like growth factor-1 receptor IgG1 monoclonal antibody, in advanced non-small cell lung cancer (NSCLC).
Patients with advanced NSCLC were treated in an initial safety-lead and drop-down cohorts using erlotinib 150 mg/d with cixutumumab 6 or 5 mg/kg on days 1, 8, 15, and 22 in 28-day cycles (cohorts 1 and 2). Emerging pharmacokinetic data led to an additional cohort (3 + 3 design) with cixutumumab at 15 mg/kg on day 1 in 21-day cycles (cohort 3).
Eighteen patients entered the study (6 at 6 mg/kg, 8 at 5 mg/kg, and 4 at 15 mg/kg), with median age of 65 years. Four of six patients at 6 mg/kg experienced dose-limiting toxicities (DLTs), whereas at 5 mg/kg, one of eight patients experienced DLT but three of eight patients still required a dose delay during cycle 1. At 15 mg/kg every 21 days, two of four patients experienced DLTs. In all cohorts, DLTs were either G3 rash or fatigue. Five patients had stable disease as best response and 14 patients had progressive disease. The median progression-free survival was 39 days (range 21–432+ days). Biomarkers analyses showed a trend toward better progression-free survival seen with higher free baseline insulin-like growth factor-1 levels as seen with other insulin-like growth factor-1R inhibitors.
The combinations of cixutumumab at 6 mg/kg every 7 days and 15 mg/kg every 21 days and full-dose erlotinib are not tolerable in unselected patients with NSCLC, as measured by DLT. Cixutumumab at 5 mg/kg every 7 days was tolerable per DLT, but dose delays were common. Efficacy in unselected patients with NSCLC seems to be low.
Non-small cell lung cancer; IGF1R monoclonal antibody; EGFR; Metastatic disease
The ISEL (Iressa Survival Evaluation in Lung Cancer) clinical trial evaluated the efficacy of gefitinib versus placebo in pretreated nonsmall-cell lung cancer patients. Two different antibodies, scoring systems, and cutoff points of epidermal growth factor receptor (EGFR) protein expression were compared to predict response and survival of enrolled patients.
EGFR expression was assessed in tumor samples by immunohistochemistry using the Dako EGFR pharmDx kit (scoring percent of tumor cells with positive staining) and Zymed monoclonal antibody clone 31G7 (scoring staining index derived from proportion of positive cells times staining intensity).
Data for EGFR expression were available for 379 patients for Dako and 357 patients for Zymed antibody (22% and 21%, respectively, of trial population). Objective response rates in gefitinib-treated EGFR-positive patients defined with various cutpoints with Dako antibody varied between 8% and 12%, and with Zymed antibody between 10% and 13%. Lower cutoff points with Dako antibody provided the best discrimination between EGFR-positive and EGFR-negative patients for survival hazard ratios comparing gefitinib to placebo, with a significant treatment/cutoff point interaction for 10% cutoff point (P = .049). A similar but less apparent trend was noted for Zymed antibody, although the discrimination between hazard ratios was not significant for any cutoff point analyzed.
Assessment with the Dako PharmDx kit and percentage of cells with positive staining may provide more accurate prediction of differential effect on survival with gefitinib than assessment with Zymed antibody and staining index. Using higher cutpoints to define positivity does not improve test discrimination.
nonsmall-cell lung cancer; epidermal growth factor receptor; immunohistochemistry; phase 3 trial; cutoff point
Early detection may help improve survival from lung cancer. In this study our goal was to derive and validate a signature from the proteomic analysis of bronchial lesions that could predict the diagnosis of lung cancer. Using previously published studies of bronchial tissues we selected a signature of 9 matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) mass to charge ratio features to build a prediction model diagnostic of lung cancer. The model was based on MALDI MS signal intensity (MALDI score) from bronchial tissue specimens from our 2005 published cohort of 51 patients. The performance of the prediction model in identifying lung cancer was tested in an independent cohort of bronchial specimens from 60 patients. The probability of having lung cancer based on the proteomic analysis of the bronchial specimens was characterized by an area under the receiver operating characteristic curve of 0.77 (95% CI 0.66 to 0.88) in this validation cohort. Eight of the 9 features were identified and validated by Western blotting and immunohistochemistry. These results demonstrate that proteomic analysis of endobronchial lesions may facilitate the diagnosis of lung cancer and the monitoring of high risk individuals for lung cancer in surveillance and chemoprevention trials.
Lung cancer; Proteomic signature; Early detection; Biomarkers; Tumorigenesis
Oncogenic activation of KRAS occurs commonly in non-small cell lung cancer (NSCLC), but strategies to therapeutically target this pathway have been challenging to develop. Information about downstream effectors of KRAS remains incomplete and tractable targets are yet to be defined. In this study we investigated the role of Protein Kinase C delta (PKCδ) in KRAS dependent lung tumorigenesis using a mouse carcinogen model and human NSCLC cells. The incidence of urethane-induced lung tumors was decreased by 69% in PKCδ deficient (δKO) mice compared to wild type (δWT) mice. δKO tumors are smaller and showed reduced proliferation. DNA sequencing indicated that all δWT tumors had activating mutations in KRAS, whereas only 69% of δKO tumors did, suggesting that PKCδ acts as a tumor promoter downstream of oncogenic KRAS, while acting as a tumor suppressor in other oncogenic contexts. Similar results were obtained in a panel of NSCLC cell lines with oncogenic KRAS, but which differ in their dependence on KRAS for survival. RNAi-mediated attenuation of PKCδ inhibited anchorage-independent growth, invasion, migration and tumorigenesis in KRAS-dependent cells. These effects were associated with suppression of MAPK pathway activation. In contrast, PKCδ attenuation enhanced anchorage-independent growth, invasion and migration in NSCLC cells that were either KRAS-independent or that had wild-type KRAS. Unexpectedly, our studies indicate that the function of PKCδ in tumor cells depends on a specific oncogenic context, as loss of PKCδ in NSCLC cells suppressed transformed growth only in cells dependent upon oncogenic KRAS for proliferation and survival.
PKC delta; K-Ras; lung cancer; transformation
Genome-wide association studies (GWAS) have identified three genomic regions, at 15q24-25.1, 5p15.33 and 6p21.33, which associate with risk of lung cancer. Large meta-analyses of GWA data have failed to find additional associations of genome-wide significance. In this study, we sought to confirm 7 variants with suggestive association to lung cancer (P<10−5) in a recently published meta-analysis. In a GWA dataset of 1,447 lung cancer cases and 36,256 controls in Iceland, three correlated variants on 15q15.2 (rs504417, rs11853991 and rs748404) showed a significant association with lung cancer whereas rs4254535 on 2p14, rs1530057 on 3p24.1, rs6438347 on 3q13.31 and rs1926203 on 10q23.31 did not. The most significant variant, rs748404, was genotyped in additional 1,299 lung cancer cases and 4,102 controls from the Netherlands, Spain and the USA and the results combined with published GWAS data. In this analysis, the T allele of rs748404 reached genome-wide significance (OR=1.15, P=1.1×10−9). Another variant at the same locus, rs12050604, showed association with lung cancer (OR=1.09, 3.6×10−6) and remained significant after adjustment for rs748404 and vice versa. rs748404 is located 140 kb centromeric of the TP53BP1 gene that has been implicated in lung cancer risk. Two fully correlated, non-synonymous coding variants in TP53BP1, rs2602141 (Q1136K) and rs560191 (E353D), showed association with lung cancer in our sample set; however, this association did not remain significant after adjustment for rs748404. Our data show that one or more lung cancer risk variants of genome-wide significance and distinct from the coding variants in TP53BP1 are located at 15q15.2.
Lung cancer; genome-wide association studies; GWAS; 15q15.2; TP53BP1
Randomized clinical trials failed to show a survival benefit for epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors plus concurrent chemotherapy in patients with metastatic non–small-cell lung cancer (NSCLC), with preclinical data suggesting potential negative interactions. In contrast, pilot trials of the EGFR-targeted antibody, cetuximab, plus chemotherapy suggested enhanced antitumor activity. This randomized phase II trial was designed to select a cetuximab plus chemotherapy regimen for phase III evaluation.
Patients and Methods
Treatment-naive patients with advanced-stage NSCLC were randomly assigned to receive paclitaxel (225 mg/m2) and carboplatin (area under the curve, 6) every 3 weeks plus concurrent cetuximab (400 mg/m2 loading dose followed by 250 mg/m2 weekly) for four cycles followed by maintenance cetuximab or sequential paclitaxel-carboplatin for four cycles followed by cetuximab.
Of 242 patients enrolled, 224 were eligible and assessable for response (106 and 118 patients in the concurrent and sequential arms, respectively). With a median follow-up time of 32 months, the median overall survival was 10.9 months (95% CI, 9.2 to 13.0 months) for patients receiving concurrent therapy and 10.7 months (95% CI, 8.5 to 12.8 months) for patients receiving sequential therapy (P = .57); 1-year survival rates were 45% (95% CI, 36% to 54%) and 44% (95% CI, 35% to 53%), respectively. Response rates and progression-free survival times were similar in both arms, as was grade 3 rash, whereas sensory neuropathy was higher in the concurrent arm (15% v 5% in the sequential arm; P = .036).
Although both regimens met the efficacy criterion for continued evaluation, the concurrent regimen of paclitaxel/carboplatin plus cetuximab was chosen.
No chemoprevention strategies have been proven effective for lung cancer.
We evaluated the effect of 13-cis retinoic acid (13-cis RA), with or without α tocopherol, as a lung cancer chemoprevention agent in a phase II randomized controlled clinical trial of adult subjects at high risk for lung cancer as defined by the presence of sputum atypia, history of smoking, and airflow obstruction, or a prior surgically cured nonsmall cell lung cancer (disease free, >3 years). Subjects were randomly assigned to receive either 13-cis RA, 13-cis RA plus α tocopherol (13-cis RA/α toco) or observation for 12 months.
Outcome measures are derived from histologic evaluation of bronchial biopsy specimens obtained by bronchoscopy at baseline and follow-up. The primary outcome measure is treatment “failure” defined as histologic progression (any increase in the maximum histologic score) or failure to return for follow-up bronchoscopy.
Seventy-five subjects were randomized (27/22/26 to obervations/13-cis RA/13-cis RA/α toco); 59 completed the trial; 55 had both baseline and follow-up bronchoscopy. The risk of treatment failure was 55.6% (15 of 27) and 50% (24 of 48) in the observation and combined (13 cis RA plus 13 cis RA/α toco) treatment arms, respectively (odds ratio adjusted for baseline histology, 0.97; 95% confidence interval, 0.36–2.66; P = 0.95). Among subjects with complete histology data, maximum histology score in the observation arm increased by 0.37 units and by 0.03 units in the treated arms (difference adjusted for baseline, −0.18; 95% confidence interval, −1.16 to 0.81; P = 0.72). Similar (nonsignificant) results were observed for treatment effects on endobronchial proliferation as assessed by Ki-67 immunolabeling.
Twelve-month treatment with 13-cis RA produced nonsignificant changes in bronchial histology, consistent with results in other trials. Agents advancing to phase III randomized trials should produce greater histologic changes. The addition of α tocopherol did not affect toxicity.
Patients with early-stage non–small-cell lung cancer (NSCLC) have a poor prognosis even after complete resection. Earlier studies of preoperative (induction) chemotherapy in resectable NSCLC demonstrated feasibility and encouraging survival data. This randomized phase III trial compared overall survival (OS) for preoperative paclitaxel and carboplatin followed by surgery with surgery alone in patients with early-stage NSCLC.
Patients and Methods
Patients with clinical stage IB-IIIA NSCLC (excluding superior sulcus tumors and N2 disease) were eligible. Patients were randomly assigned to surgery alone or to three cycles of paclitaxel (225 mg/m2) and carboplatin (area under curve, 6) followed by surgical resection. The primary end point was OS; secondary end points were progression-free survival (PFS), chemotherapy response, and toxicity.
The trial closed early with 354 patients after reports of a survival benefit for postoperative chemotherapy in other studies. The median OS was 41 months in the surgery-only arm and 62 months in the preoperative chemotherapy arm (hazard ratio, 0.79; 95% CI, 0.60 to 1.06; P = .11.) The median PFS was 20 months for surgery alone and 33 months for preoperative chemotherapy (hazard ratio, 0.80; 95% CI, 0.61 to 1.04; P = .10.) Major response to chemotherapy was seen in 41% of patients; no unexpected toxicity was observed.
This trial closed prematurely after compelling evidence supporting postoperative chemotherapy emerged. Although OS and PFS were higher with preoperative chemotherapy, the differences did not reach statistical significance. At present, stronger evidence exists for postoperative chemotherapy in early-stage NSCLC.
Lung cancer is usually disseminated at diagnosis making prognosis poor. Smokers are at high risk for lung cancer and are targets for prevention and early detection strategies. Sputum is a potential source for lung cancer biomarkers, but no test is currently available with sufficient sensitivity and specificity for clinical screening utility. Chromosomal aneusomy (CA) was measured in sputum samples collected prospectively from 100 incident lung cancer cases and 96 controls matched on age, gender, and date of collection. The CA-FISH assay was performed using a four-target DNA FISH probe including EGFR, MYC, 5p15 and CEP6. Sensitivity for a positive CA-FISH assay (abnormal for ≥ 2 of the 4 markers) was substantially higher for samples collected within 18 months (76%) than >18 months before lung cancer diagnosis (31%). Specificity for a positive FISH by this same definition was 85%. Among subjects providing sputum sample within 18 months before diagnosis, sensitivity was higher for squamous cell cancers (94%) than for other histologic types (69%). The adjusted odds ratios for specimens collected within 18 months of cancer diagnosis were higher using the CA-FISH assay (OR=27.2, 95% CI 7.8 to 94.1) than previous studies assessing cytologic atypia (OR=2.3, CI 0.8 to 6.4) or gene promoter methylation (OR=6.5; CI 1.2 to 35.5). In conclusion, chromosomal aneusomy in sputum is a promising biomarker for prediction of lung cancer risk. Evaluation of the 4-DNA targets was more effective than any single marker and had highest sensitivity for samples collected ≤ 18 months to lung cancer diagnosis and patients diagnosed with squamous cell carcinoma.
Sputum; Lung Cancer; FISH; biomarker; Chromosomal Abnormality
We herein assessed the influence of Epidermal Growth Factor Receptor (EGFR) gene mutations on EGFR expression levels, downstream mediators such as Akt or ERK and overall survival in patients with ovarian cancer.
Twenty-nine EGFR gene mutations were detected in 24 of 102 patinets (23.5%). EGFR mutations were observed in 27.9% (19/68) in serous adenocarcinomas, 15.0% (3/20) in clear cell adenocarcinomas and 66.7% (2/3) in mucinous adenocarcinomas, while no mutations were observed in endometrioid adenocarcinomas (0/11). Protein expression of EGFR, pAkt and pERK were detected in 47 (46.1%), 49 (48%) and 17 (16.7%) of patients, respectively. EGFR gene mutations, EGFR and pERK expression were not associated with a poor prognosis. In a multivariate analysis, a High pAkt expression was found to be a significant predictor for both the progression free survival (p = 0.017) and overall survival (p = 0.025).
EGFR mutation status was analyzed by direct sequencing in 102 Japanese ovarian cancer patients. The EGFR expression, phosphorylated Akt (pAkt) and phosphorylated ERK (pERK) were determined by immunohistochemistry.
EGFR gene mutations were frequently observed in not only non-small-cell lung cancer (NSCLC), but also in ovarian cancer in Japanese patients. The selective EGFR inhibitor Gefitinib might therefore offer some benefit in patients with EGFR mutations in ovarian cancer. Our results indicate that the Akt, but not necessarily EGFR, is one of the most important target in the response of the platinum-based chemotherapy and prognosis for ovarian cancer patients.
ovarian cancer; EGFR mutation; pAkt; pERK; EGFR protein; gefitinib; platinum; immunohistochemistry; prognostic factor
Lung cancer is the leading cause of cancer deaths worldwide. New diagnostics are needed to detect early stage lung cancer because it may be cured with surgery. However, most cases are diagnosed too late for curative surgery. Here we present a comprehensive clinical biomarker study of lung cancer and the first large-scale clinical application of a new aptamer-based proteomic technology to discover blood protein biomarkers in disease.
We conducted a multi-center case-control study in archived serum samples from 1,326 subjects from four independent studies of non-small cell lung cancer (NSCLC) in long-term tobacco-exposed populations. Sera were collected and processed under uniform protocols. Case sera were collected from 291 patients within 8 weeks of the first biopsy-proven lung cancer and prior to tumor removal by surgery. Control sera were collected from 1,035 asymptomatic study participants with ≥10 pack-years of cigarette smoking. We measured 813 proteins in each sample with a new aptamer-based proteomic technology, identified 44 candidate biomarkers, and developed a 12-protein panel (cadherin-1, CD30 ligand, endostatin, HSP90α, LRIG3, MIP-4, pleiotrophin, PRKCI, RGM-C, SCF-sR, sL-selectin, and YES) that discriminates NSCLC from controls with 91% sensitivity and 84% specificity in cross-validated training and 89% sensitivity and 83% specificity in a separate verification set, with similar performance for early and late stage NSCLC.
This study is a significant advance in clinical proteomics in an area of high unmet clinical need. Our analysis exceeds the breadth and dynamic range of proteome interrogated of previously published clinical studies of broad serum proteome profiling platforms including mass spectrometry, antibody arrays, and autoantibody arrays. The sensitivity and specificity of our 12-biomarker panel improves upon published protein and gene expression panels. Separate verification of classifier performance provides evidence against over-fitting and is encouraging for the next development phase, independent validation. This careful study provides a solid foundation to develop tests sorely needed to identify early stage lung cancer.
Previous studies in non–small-cell lung cancer (NSCLC) have demonstrated a wide variation in responsiveness to epidermal growth factor receptor (EGFR) –targeting agents and in genetic aberrancies of the EGFR pathway according to ethnic background, most notably a higher frequency of activating EGFR mutations among East-Asian patients. We investigated the frequency of EGFR pathway aberrancies among African American patients with NSCLC, for whom limited information presently exists.
Patients and Methods
EGFR fluorescent in situ hybridization (FISH) was performed on archived tissues from 53 African American patients. Extracted DNA was sequenced for mutational analysis of EGFR exons 18 to 21 and KRAS exon 2. Results were compared by multivariate analysis to an historical control cohort of 102 white patients with NSCLC.
African Americans were significantly less likely to harbor activating mutations of EGFR than white patients (2% v 17%; P = .022). Only one EGFR mutation was identified, a novel S768N substitution. EGFR FISH assay was more frequently positive for African Americans than for white patients (51% v 32%; P = .018). KRAS mutational frequency did not differ between the groups (23% v 21%; P = .409).
African American patients with NSCLC are significantly less likely than white counterparts to harbor activating mutations of EGFR, which suggests that EGFR tyrosine kinase inhibitors (TKIs) are unlikely to yield major remissions in this population. Our findings add to a growing body of evidence that points to genetic heterogeneity of the EGFR pathway in NSCLC among different ethnic groups and that underscores the need for consideration of these differences in the design of future trials of agents that target the EGFR pathway.