The search for non-invasive diagnostic methods of lung cancer has led to new avenues of research, including the exploration of the exhaled breath. Previous studies have shown that lung cancer can in principle be detected through exhaled breath analysis. This study evaluated the potential of exhaled breath analysis for the distinction of benign and malignant pulmonary nodules (PNs).
Breath samples were taken from 72 patients with PNs in a prospective trial. Profiles of volatile organic compounds (VOCs) were determined by (i) gas chromatography/mass spectrometry (GC-MS) combined with solid phase microextraction (SPME) and by (ii) a chemical nanoarray.
53 PNs were malignant and 19 were benign with similar smoking histories and co-morbidities. Nodule size (mean +/− SD) was 2.7±1.7 vs. 1.6±1.3 cm (p=0.004) respectively. Within the malignant group, 47 were NSCLC and 6 were SCLC. Thirty had early stage disease and 23 had advanced disease. GC-MS analysis identified a significantly higher concentration of 1-octene in the breath of lung cancer, and the nanoarray distinguished significantly between benign vs. malignant PNs (p<0.0001; accuracy 88±3%), between adeno- and squamous- cell carcinomas (p<0.0001; 88±3%) and between early stage and advanced disease (p<0.0001; 88±2%).
In this pilot study, breath analysis discriminated benign from malignant PNs in a high-risk cohort based on lung cancer related VOC profiles. Further, it discriminated adeno-and squamous- cell carcinoma and between early vs. advanced disease. Further studies are required to validate this non-invasive approach, using a larger cohort of patients with PNs detected by CT.
Lung cancer; pulmonary nodules; diagnosis; breath; nanoarray
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.
Lung Cancer; Novel ALK Rearrangement; Crizotinib
TRIBUTE was a phase III trial evaluating the addition of erlotinib to carboplatin and paclitaxel as a first-line treatment for advanced non – small cell lung cancer that did not meet its primary end point of improving overall survival. Here, we assess the value of using epidermal growth factor receptor (EGFR) gene copy number in tumor biopsy samples, as determined by fluorescence in situ hybridization (FISH), as a predictor of treatment outcome.
EGFR FISH analysis was done using LSI EGFR SpectrumOrange/CEP7 Spectrum-Green probe.
Of 275 samples, 245 (89.1%) were successfully analyzed by FISH. One hundred (40.8%) of patients were EGFR FISH(+). Median overall survival was not different between FISH(+) and FISH(−) patients in either the chemotherapy+erlotinib arm or the chemotherapy+placebo arm. In FISH(+) patients, median time to progression (TTP) was 6.3 months in the erlotinib arm versus 5.8 months in the placebo arm (hazard ratio, 0.59; 95% confidence interval, 0.35–0.99; P = 0.0430); in FISH(−) patients, median TTP was 4.6 months versus 6.0 months (hazard ratio,1.42; 95%confidence interval, 0.95–2.14; P = 0.0895; treatment interaction test, P = 0.007). After 6 months of treatment, a notable separation of the TTP curves in favor of erlotinib emerged. Objective response rates were11.6% versus 29.8% in FISH(+) patients (chemotherapy+erlotinib arm versus chemotherapy+placebo arm; P = 0.0495) and 21.8% versus 25.4%, respectively, for FISH(−) patients (P = 0.6954).
EGFR gene copy number by FISH did not predict survival benefit. However, among EGFR FISH(+) patients, TTP was longer in patients who received erlotinib and continued to receive it after completing first-line therapy.
The role of cetuximab for the treatment of advanced non-small-cell lung cancer (NSCLC) is currently unclear. The molecular target of cetuximab, epidermal growth factor receptor (EGFR), as measured by fluorescent in situ hybridization (FISH), has shown potential to be a predictive biomarker for cetuximab efficacy in NSCLC. SWOG S0819 is a Phase III trial evaluating both the value of cetuximab in this setting as well as EGFR FISH as a predictive biomarker. This paper describes the decision process for determining the design and interim monitoring plan for S0819. Six possible designs were evaluated in terms of their properties and the hypotheses that can be addressed within the design constraints. A subgroup-focused multiple-hypothesis design was selected for S0819 incorporating co-primary endpoints to assess cetuximab in both the overall study population and among EGFR FISH positive patients with the sample size determined based on evaluation in the EGFR FISH positive group. The interim monitoring plan chosen specifies interim evaluations of both efficacy and futility in the EGFR FISH positive group alone. The futility monitoring plan to determine early stopping in the EGFR FISH non-positive group is based on evaluation within the positive group, the entire study population, and the non-positive group. SWOG S0819 employs a design which addresses both the biomarker-driven and general efficacy objectives of this study.
Clinical trial design; Molecular targeted therapies; cetuximab; interim monitoring; non-small cell lung cancer
Purpose: Stage III non-small cell lung cancer (NSCLC) patients with poor performance status (PS) or co-morbidities are often not candidates for standard chemoradiotherapy (chemoRT) due to poor tolerance to treatments. A pilot study for poor-risk stage III NSCLC patients was conducted combining cetuximab, a chimeric monoclonal antibody targeting epidermal growth factor receptor (EGFR), with chest radiation (RT).
Methods: Stage III NSCLC patients with Zubrod PS 2, or Zubrod PS 0–1 with poor pulmonary function and co-morbidities prohibiting chemoRT were eligible. A loading dose of cetuximab (400 mg/m2) was delivered week 1, followed by weekly cetuximab (250 mg/m2)/RT to 64.8 Gy in 1.8 Gy daily fractions, and maintenance weekly cetuximab (250 mg/m2) for 2 years or until disease progression. H-score for EGFR protein expression was conducted in available tumors.
Results: Twenty-four patients were enrolled. Twenty-two were assessed for outcome and toxicity. Median survival was 14 months and median progression-free survival was 8 months. The response rate was 47% and disease control rate was 74%. Toxicity assessment revealed 22.7% overall ≥Grade 3 non-hematologic toxicities. Grade 3 esophagitis was observed in one patient (5%). The skin reactions were mostly Grade 1 or 2 except two of 22 (9%) had Grade 3 acne and one of 22 (5%) had Grade 3 radiation skin burn. Grade 3–4 hypomagnesemia was seen in four (18%) patients. One patient (5%) had elevated cardiac troponin and pulmonary emboli. H-score did not reveal prognostic significance. An initially planned second cohort of the study did not commence due to slow accrual, which would have added weekly docetaxel to cetuximab/RT after completion of the first cohort of patients.
Conclusion: Concurrent weekly cetuximab/chest RT followed by maintenance cetuximab for poor-risk stage III NSCLC was well tolerated. Further studies with larger sample sizes will be useful to establish the optimal therapeutic ratio of this regimen.
cetuximab; stage III non-small cell lung cancer; EGFR; performance status; radiosensitization
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.
Epidermal growth factor receptor (EGFR) protein expression in non-small cell lung cancer (NSCLC) is not recommended for predicting response to EGFR tyrosine kinase inhibitors (TKIs) due to conflicting results, all using antibodies detecting EGFR external domain (ED). We tested the predictive value of EGFR protein expression for response to an EGFR TKI using an antibody that detects the intracellular domain (ID) and compared fluorescence-based Automated QUantitative Analysis (AQUA) technology to immunohistochemistry (IHC).
Specimens from 98 gefitinib-treated NSCLC Japanese patients were evaluated by IHC (n=98/98) and AQUA technology (n=70/98). EGFR ID- (5B7) and ED-specific antibodies (3C6 and 31G7) were compared.
EGFR expression evaluated with 5B7 was significantly higher in responders versus non-responders to gefitinib both with IHC and with AQUA. ED-specific antibodies did not significantly predicted response. Using AQUA and ID-specific antibody resulted in the best prediction performance with a positive and negative predictive value (PPV/NPV) for responders of 50% and 87%, respectively. EGFR expression with ID-specific antibody and AQUA also predicted responders in EGFR mutated patients. Increased EGFR expression with the ID antibody associated with increased median PFS (11.7 months vs 5.0, Log-rank p=0.034) and OS (38.6 vs 14.9, p=0.040), from gefitinib therapy.
EGFR protein expression using an ID-specific antibody specifically predicts response to gefitinib in NSCLC patients, including in EGFR mutated patients, and increased PFS/OS from gefitinib. These data suggest that the choice of diagnostic antibody and methodology matters to predict response and outcome to specific therapies. The potential clinical application needs further validation.
EGFR; Biomarker; Lung Cancer; NSCLC; AQUA technology; IHC; EGFR TKI
VEGFR-2 plays a crucial role in mediating angiogenic endothelial cell responses via the VEGF pathway and angiogenesis inhibitors targeting VEGFR-2 are in clinical use. As angiogenesis is a host-driven process, functional heritable variation in KDR, the gene encoding VEGFR-2, may affect VEGFR-2 function, and ultimately, the extent of tumor angiogenesis.
We resequenced KDR using 24 DNAs each from healthy Caucasian, African American and Asian groups. Non-synonymous genetic variants were assessed for function using phosphorylation assays. Luciferase reporter gene assays were used to examine effects of variants on gene expression. KDR mRNA and protein expression, and microvessel density (MVD) were measured in non-small cell lung cancer (NSCLC) tumor samples and matching patient DNA samples were genotyped to test for associations with variants of interest.
KDR resequencing led to the discovery of 120 genetic variants, of which 25 had not been previously reported. Q472H had increased VEGFR-2 protein phosphorylation and associated with increased MVD in NSCLC tumor samples. −2854C and −2455A increased luciferase expression and associated with higher KDR mRNA levels in NSCLC samples. −271A reduced luciferase expression and associated with lower VEGFR-2 levels in NSCLC samples. −906C and 23408G, associated with higher KDR mRNA levels in NSCLC samples.
This study has defined KDR genetic variation in three populations and identified common variants that impact on tumoral KDR expression and vascularization. These findings may have important implications for understanding the molecular basis of genetic associations between KDR variation and clinical phenotypes related to VEGFR-2 function.
angiogenesis; KDR; resequencing; gene expression; NSCLC; functional validation
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.
A highly sensitive and fast-response array of sensors based on gold nanoparticles, in combination with pattern recognition methods, can distinguish between the odor prints of non-small-cell lung cancer and negative controls with 100% accuracy, with no need for preconcentration techniques. Additionally, preliminary results indicate that the same array of sensors might serve as a better tool for understanding the biochemical source of volatile organic compounds that might occur in cancer cells and appear in the exhaled breath, as compared to traditional spectrometry techniques. The reported results provide a launching pad to initiate a bedside tool that might be able to screen for early stages of lung cancer and allow higher cure rates. In addition, such a tool might be used for the immediate diagnosis of fresh (frozen) tissues of lung cancer in operating rooms, where a dichotomic diagnosis is crucial to guide surgeons.
breath analysis; lung cancer; nanoparticles; sensors; volatile organic compounds
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.
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
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.
Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) predict better outcome to EGFR tyrosine kinase inhibitors (TKIs). The most common mutations are exon 19 deletions (most frequently E746-A750) and L858R point mutation in exon 21. Here, we evaluated the accuracy of novel EGFR mutation specific antibodies in a Japanese cohort with NSCLC and compared to direct DNA sequencing and clinical outcome.
Materials and methods
Immunohistochemistry (IHC) using antibodies specific for the E746-A750 and L858R mutations in EGFR was performed on tissue microarrays of tumors from 70 gefitinib treated NSCLC patients. Extracted DNA was sequenced for mutational analysis of EGFR exons 18 to 21.
DNA sequencing showed EGFR mutations in 41 patients (58.6%), and exon 19 deletions in 18 patients (25.7%), 61% (11/18) had a deletion in the range of E746-A750) and 12 (17.1%) had exon 21 mutations (L858R). IHC showed, for the E746-A750 and L858R mutations, sensitivity (81.8% and 75%), specificity (100%, 96.6%), PPV (100%, 81.8%) and NPV (96.7%, 94.9%). Analysis for objective response rates (ORR) and survival were not correlated to IHC staining, although the combined staining showed non-significant trends towards better overall survival for patients with EGFR mutations.
The mutation specific IHC antibodies have high sensitivity and specificity for pre-defined EFGR mutations and may be suitable for screening for these pre-defined mutations. However, negative IHC results require further mutation analyses prior to excluding EGFR-targeted therapy.
EGFR; Biomarkers; Lung Cancer; NSCLC; Mutation
Lung cancer continues to be a major public health problem, and more patients die from this disease than any other cancer. The vast majority of patients present with advanced stage disease when therapeutic options are limited and the overall 5 year survival rate remains approximately 15%. Screening with low dose helical computed tomography (CT)has been suggested for early detection, although the effect on mortality is currently under investigation. As part of the National Lung Cancer Screening Trial, a specimen biorepository including blood, sputum, and urine were collected serially for the primary purpose of validating early detection lung cancer biomarkers. In addition tumor samples have been obtained from patients diagnosed with lung cancer to be included in a tissue microarray. This commentary describes the rationale, composition, intent, and availability of specimen in the biorepository.
A plethora of agents are in early stages of development for colorectal cancer, including those that target the insulin-like growth factor receptor (IGF1R) pathway. In the current environment of numerous cancer targets, it is imperative that patient selection strategies be developed with the intent of preliminary testing in the latter stages of phase I trials. The goal of this study was to develop and characterize predictive biomarkers for an IGF1R tyrosine kinase inhibitor, OSI-906, that could be applied in colorectal cancer (CRC)-specific studies of this agent.
Twenty-seven CRC cell lines were exposed to OSI-906 and classified according to IC50 value as sensitive (< 1.5μM), or resistant (>5μM). Cell lines were subjected to immunoblotting and immunohistochemistry for effector proteins, IGFIR copy number by FISH, KRAS/BRAF/PI3K mutation status, and baseline gene array analysis. The most sensitive and resistant cell lines were utilized for gene array and pathway analyses, along with shRNA knockdown of highly ranked genes. The resulting integrated genomic classifier was then tested against 8 human CRC explants in vivo.
Baseline gene array data from cell lines and xenografts was used to develop a k-Top Scoring Pair (k-TSP) classifier, which in combination with IGFIR FISH and KRAS mutational status, was able to predict with 100% accuracy a test set of patient-derived CRC xenografts.
These results indicate that an integrated approach to the development of individualized therapy is feasible and should be applied early in the development of novel agents, ideally in conjunction with late-stage phase I trials.
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.
The purpose of this study was to characterize insulin-like growth factor-1 receptor (IGF1R) protein expression, mRNA expression, and gene copy number in surgically resected non–small-cell lung cancers (NSCLC) in relation to epidermal growth factor receptor (EGFR) protein expression, patient characteristics, and prognosis.
Patients and Methods
One hundred eighty-nine patients with NSCLC who underwent curative pulmonary resection were studied (median follow-up, 5.3 years). IGF1R protein expression was evaluated by immunohistochemistry (IHC) with two anti-IGF1R antibodies (n = 179). EGFR protein expression was assessed with PharmDx kit. IGF1R gene expression was evaluated using quantitative reverse transcription polymerase chain reaction (qRT-PCR) from 114 corresponding fresh-frozen samples. IGF1R gene copy number was assessed by fluorescent in situ hybridization using customized probes (n = 181).
IGF1R IHC score was higher in squamous cell carcinomas versus other histologies (P < .001) and associated with stage (P = .03) but not survival (P = .46). IGF1R and EGFR protein expression showed significant correlation (r = 0.30; P < .001). IGF1R gene expression by qRT-PCR was higher in squamous cell versus other histologies (P = .006) and did not associate with other clinical features nor survival (P = .73). Employing criteria previously established for EGFR copy number, patients with IGF1R amplification/high polysomy (n = 48; 27%) had 3-year survival of 58%, patients with low polysomy (n = 87; 48%) had 3-year survival of 47% and patients with trisomy/disomy (n = 46; 25%) had 3-year survival of 35%, respectively (P = .024). Prognostic value of high IGF1R gene copy number was confirmed in multivariate analysis.
IGF1R protein expression is higher in squamous cell versus other histologies and correlates with EGFR expression. IGF1R protein and gene expression does not associate with survival, whereas high IGF1R gene copy number harbors positive prognostic value.
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
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.
The majority of lung cancers are caused by long term exposure to the several classes of carcinogens present in tobacco smoke. While a significant fraction of lung cancers in never smokers may also be attributable to tobacco, many such cancers arise in the absence of detectable tobacco exposure, and may follow a very different cellular and molecular pathway of malignant transformation. Recent studies summarized here suggest that lung cancers arising in never smokers have a distinct natural history, profile of oncogenic mutations, and response to targeted therapy. The majority of molecular analyses of lung cancer have focused on genetic profiling of pathways responsible for metabolism of primary tobacco carcinogens. Limited research has been conducted evaluating familial aggregation and genetic linkage of lung cancer, particularly among never smokers in whom such associations might be expected to be strongest. Data emerging over the past several years demonstrates that lung cancers in never smokers are much more likely to carry activating mutations of the Epidermal Growth Factor Receptor (EGFR), a key oncogenic factor and direct therapeutic target of several newer anti-cancer drugs. EGFR mutant lung cancers may represent a distinct class of lung cancers, enriched in the never smoking population, and less clearly linked to direct tobacco carcinogenesis. These insights followed initial testing and demonstration of efficacy of EGFR-targeted drugs. Focused analysis of molecular carcinogenesis in lung cancers in never smokers is needed, and may provide additional biologic insight with therapeutic implications for lung cancers in both ever smokers and never smokers.
Epidermal growth factor receptor (EGFR) related therapies – mainly tyrosine kinase inhibitors (TKIs) such as erlotinib and gefitinib, but also monoclonal antibodies targeting EGFR, for example, cetuximab – have been investigated in numerous settings in non-small cell lung cancer (NSCLC) and in different combinations. The overall clinical benefit of EGFR TKI therapy is roughly 10–30%, with higher benefit in nonsmoker Asiatic women with EGFR-mutated adenocarcinoma. Currently, there are several biomarkers that are able to direct and predict the yield of EGFR-related therapies in NSCLC. These include EGFR mutation status, EGFR protein expression, EGFR gene copy number and a serum proteomic marker (Veristrat®, Biodesix; CO). The usage of such biomarkers is important from many aspects. First, it helps clinicians to make the right treatment decisions and second, it leads to a wiser usage of financial resources. This review will focus on EGFR-related biomarkers for their prognostic power and their ability to predict clinical benefit from EGFR-related therapy.
non-small cell lung cancer; epidermal growth factor receptor; biomarkers