Clinical and molecular characteristics of non-small-cell lung cancer (NSCLC) harboring EGFR mutation: results of the nationwide French Cooperative Thoracic Intergroup (IFCT) program.

BACKGROUND: EGFR mutations cause inconsistent response to EGFR tyrosine-kinase inhibitors (TKI). To better understand these features, we reviewed all cases of EGFR-mutated non-small-cell lung cancer collected in the Biomarkers France database. PATIENTS AND METHODS: Of 17 664 patients, 1837 (11%) with EGFR-mutated non-small-cell lung cancer were retrospectively analyzed for clinical and molecular characteristics. Results were correlated with survival and treatment response for the 848 stage IV patients. RESULTS: EGFR exon 18, 19, 20 and 21 mutations were found in 102 (5.5%), 931 (51%), 102 (5.5%) and 702 (38%) patients, respectively. Over 50% of exon 18 and 20 mutated patients were smokers. The median follow-up was 51.7 months. EGFR mutation type was prognostic of overall survival (OS) versus wild-type {exon 19: hazard ratio (HR)=0.51 [95% confidence interval (CI): 0.41-0.64], P < 0.0001; exon 21: HR = 0.76 (95% CI: 0.61-0.95), P = 0.002; exon 20: HR = 1.56 (95% CI: 1.02-2.38), P = 0.004}. EGFR mutation type was prognostic of progression-free survival versus wild-type [exon 19: HR = 0.62 (95% CI: 0.49-0.78), P < 0.0001; exon 20: HR = 1.46 (95% CI: 0.96-2.21), P = 0.07]. First-line treatment choice did not influence OS in multivariate analysis. First-line TKI predicted improved progression-free survival versus chemotherapy [HR = 0.67 (95% CI: 0.53-0.85), P = 0.001]. OS was longer for del19 versus L858R, which was associated with better OS compared with other exon 21 mutations, including L861Q. TKI improved survival in patients with exon 18 mutations, while chemotherapy was more beneficial for exon 20-mutated patients. CONCLUSION: EGFR mutation type can inform the most appropriate treatment. Therapeutic schedule had no impact on OS in our study, although TKI should be prescribed in first-line considering the risk of missing the opportunity to use this treatment.

Lung cancer patients with HER2 mutations treated with chemotherapy and HER2-targeted drugs: results from the European EUHER2 cohort.

BACKGROUND: HER2 mutations have been identified as oncogenic drivers in lung cancers and are found in 1-2% of lung adenocarcinomas. There is, to date, no standard of care for these patients. We thus aim to study the therapeutic outcomes of patients harboring HER2 mutations and establish the efficacy of various drug regimens. PATIENTS AND METHODS: This retrospective cohort study in European centers assessed patients with advanced non-small-cell lung cancer (NSCLC), a known HER2 exon-20 insertion, treated with chemotherapy and/or HER2-targeted drugs. RESULTS: We identified 101 eligible patients from 38 centers: median age 61 years (range: 30-87), 62.4% women, 60.4% never-smokers. All tumors were adenocarcinomas. Concomitant EGFR mutations, ALK translocations, and ROS translocations were observed in 5, 1, and 1 patients, respectively. The median number of treatment lines was 3 (range: 1-11). The median overall survival was 24 months. Overall response rate (ORR) and the median progression-free survival (PFS) with conventional chemotherapy (excluding targeted therapies) were 43.5% and 6 months in first-line (n = 93), and 10% and 4.3 months in second-line (n = 52) therapies. Sixty-five patients received HER2-targeted therapies: trastuzumab = 57, neratinib = 14, afatinib = 9, lapatinib = 5, T-DM1 = 1. ORR was 50.9% and PFS was 4.8 months with trastuzumab or T-DM1. CONCLUSION: This series shows the chemosensitivity of HER2-driven NSCLC, and the potential interest of HER2-targeted agents. Our results should help to define the best therapeutic strategy for these patients and to orient future clinical trials.

Rare EGFR exon 18 and exon 20 mutations in non-small-cell lung cancer on 10 117 patients: a multicentre observational study by the French ERMETIC-IFCT network.

BACKGROUND: There is scarce data available about epidermal growth factor receptor (EGFR) mutations other than common exon 19 deletions and exon 21 (L858R) mutations. PATIENTS AND METHODS: EGFR exon 18 and/or exon 20 mutations were collected from 10 117 non-small-cell lung cancer (NSCLC) samples analysed at 15 French National Cancer Institute (INCa)-platforms of the ERMETIC-IFCT network. RESULTS: Between 2008 and 2011, 1047 (10%) samples were EGFR-mutated, 102 (10%) with rare mutations: 41 (4%) in exon 18, 49 (5%) in exon 20, and 12 (1%) with other EGFR mutations. Exon 20 mutations were related to never-smoker status, when compared with exon 18 mutations (P < 0.001). Median overall survival (OS) of metastatic disease was 21 months [95% confidence interval (CI) 12-24], worse in smokers than in non-smoker patients with exon 20 mutations (12 versus 21 months; hazard ratio [HR] for death 0.27, 95% CI 0.08-0.87, P = 0.03). Under EGFR-tyrosine kinase inhibitors (TKIs), median OS was 14 months (95% CI 6-21); disease control rate was better for complex mutations (6 of 7, 86%) than for single mutations (16 of 40, 40%) (P = 0.03). CONCLUSIONS: Rare EGFR-mutated NSCLCs are heterogeneous, with resistance of distal exon 20 insertions and better sensitivity of exon 18 or complex mutations to EGFR-TKIs, probably requiring individual assessment.

Immunohistochemistry to identify EGFR mutations or ALK rearrangements in patients with lung adenocarcinoma.

BACKGROUND: Immunohistochemistry has been proposed as a specific and sensitive method to identify EGFR mutations or ALK rearrangements in lung tumours. PATIENTS AND METHODS: We assessed EGFR and KRAS by direct sequencing in 154 patients with lung adenocarcinoma. ALK rearrangements were assayed by FISH and RT-PCR. Immunohistochemistry was carried out and evaluated closely following published methods using recommended monoclonal rabbit or mouse antibodies. RESULTS: Thirteen of 36 exon 19 EGFR-mutated tumours (36%)-including 12 of 22 with p.Glu746_Ala750del (55%)-were positive with the 6B6 antibody that was raised against p.Glu746_Ala750del. One hundred eleven of 114 EGFR exon 19 wild-type tumours (97%) were negative with 6B6. Four of 21 exon 21 EGFR-mutated tumours (19%)-including 4 of 17 with p.Leu858Arg (24%)-were positive with the 43B2 antibody that was raised against p.Leu858Arg. One hundred twenty-two of 124 (98%) EGFR exon 21 wild-type tumours were negative with 43B2. Two of four ALK rearrangements-including two of three with ELM4-ALK fusion transcripts-were identified with the 5A4 antibody. Eleven of 13 tumours without ALK rearrangement (85%) were negative with 5A4. CONCLUSIONS: Immunohistochemistry is a specific means for identification of EGFR mutations and ALK rearrangements. It suffers, however, from poor sensitivity.

PTEN, ATM, IDH1 mutations and MAPK pathway activation as modulators of PFS and OS in patients treated by first line EGFR TKI, an ancillary study of the French Cooperative Thoracic Intergroup (IFCT) Biomarkers France project.

OBJECTIVES: Tumor mutation screening is standard of care for patients with stage IV NSCLC. Since a couple of years, widespread NGS approaches used in routine diagnostics to detect driver mutations such as EGFR, KRAS, BRAF or MET allows the identification of other alterations that could modulated the intensity or duration of response to targeted therapies. The prevalence of co-occurring alterations that could affect response or prognosis as not been largely analyzed in clinical settings and large cohorts of patients. Thanks to the IFCT program "Biomarkers France", a collection of samples and data at a nation-wide level was available to test the impact of co-mutations on first line EGFR TKI in patients with EGFR mutated cancers. MATERIALS AND METHODS: Targeted NGS was assessed on available (n = 208) samples using the Ion AmpliSeq™ Cancer Hotspot Panel v2 to screen for mutations in 50 different cancer genes. RESULTS: This study showed that PTEN inactivating mutations, ATM alterations, IDH1 mutations and complex EGFR mutations were predictors of short PFS in patients with a stage 4 lung adenocarcinoma receiving first line EGFR TKI and that PTEN, ATM, IDH1 and KRAS mutations as well as alterations in the MAPK pathway were related to shorter OS. CONCLUSION: These findings may lead to new treatment options in patients with unfavorable genotypes to optimize first line responses.

Detection of K-Ras mutations in tumour samples of patients with non-small cell lung cancer using PNA-mediated PCR clamping.

Non-small cell lung cancers (NSCLC), in particular adenocarcinoma, are often mixed with normal cells. Therefore, low sensitivity of direct sequencing used for K-Ras mutation analysis could be inadequate in some cases. Our study focused on the possibility to increase the detection of K-Ras mutations in cases of low tumour cellularity. Besides direct sequencing, we used wild-type hybridisation probes and peptide-nucleic-acid (PNA)-mediated PCR clamping to detect mutations at codons 12 and 13, in 114 routine consecutive NSCLC frozen surgical tumours untreated by targeted drugs. The sensitivity of the analysis without or with PNA was 10 and 1% of tumour DNA, respectively. Direct sequencing revealed K-Ras mutations in 11 out of 114 tumours (10%). Using PNA-mediated PCR clamping, 10 additional cases of K-Ras mutations were detected (21 out of 114, 18%, P<0.005), among which five in samples with low tumour cellularity. In adenocarcinoma, K-Ras mutation frequency increased from 7 out of 55 (13%) by direct sequencing to 15 out of 55 (27%) by clamped-PCR (P<0.005). K-Ras mutations detected by these sensitive techniques lost its prognostic value. In conclusion, a rapid and sensitive PCR-clamping test avoiding macro or micro dissection could be proposed in routine analysis especially for NSCLC samples with low percentage of tumour cells such as bronchial biopsies or after neoadjuvant chemotherapy.

EGFR-TKI and lung adenocarcinoma with CNS relapse: interest of molecular follow-up.

The epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) erlotinib improves survival of lung cancer as second- or third-line therapy. However, after an initial response, most patients will recur, particularly within the central nervous system. The present study reports the case of a 27-yr-old nonsmoking male presenting with a metastatic lung adenocarcinoma with EGFR exon 19 deletion, associated with sensitivity to EGFR-TKI. Gefitinib, followed by chemotherapy and finally erlotinib resulted in prolonged disease control, until multiple liver metastases were detected. After stopping EGFR-TKI, brain metastases with carcinomatous meningitis were diagnosed. A secondary T790M mutation, associated with resistance to EGFR-TKI, was found on the liver biopsy but not in the cerebrospinal fluid. Erlotinib was reintroduced and allowed a quick neurological improvement, even though the extra-cranial disease remained resistant to erlotinib. The present report underscores the interest of molecular monitoring in lung cancer. Persistent cerebral tyrosine kinase inhibitor sensitivity should be considered in patients presenting with an early central nervous system relapse after stopping epidermal growth factor receptor tyrosine kinase inhibitor, even with a T790M-resistant mutation in noncerebral metastases. Questions remain concerning the selection of sub-clones during epidermal growth factor receptor tyrosine kinase inhibitor therapy, which could differ according to metastatic sites, especially in the central nervous system.

Allelic imbalance at loci containing FGFR, FGF, c-Met and HGF candidate genes in non-small cell lung cancer sub-types, implication for progression.

Fibroblast growth factors (FGF), hepatocyte growth factor (HGF) and their receptors, FGFR and c-Met, are essential components of the regulatory networks between the epithelium and mesenchyme in embryonic lung, but their respective roles in tumour growth are not clear. We performed allelotyping at loci containing the candidate genes FGFR-1-2-3-4, FGF-1-2-7-10, c-Met and HGF in 36 non-small cell lung cancer (NSCLC) (20 squamous-cell carcinomas (SQC) and 16 adenocarcinomas (ADC)), by surrounding each locus with two microsatellites (MS), as close as possible to the genes of interest. Unexpectedly, SQC and ADC were frequently altered at all of these loci, and SQC showed more simultaneously altered loci. In ADC, alterations at the 15q13-22 locus (FGF7 candidate gene) were significantly more frequent. Thus, these loci showed different patterns of molecular alterations between SQC and ADC. Finally, alterations at loci containing FGFR and HGF candidate genes were inversely correlated to the lymph node status in SQC and ADC, respectively.

[Targeted therapies in thoracic oncology]. / Les thérapeutiques ciblées en oncologie thoracique.

INTRODUCTION: Better understanding of the alterations of cellular physiology during carcinogenesis has resulted in the development of new anticancer agents called biological targeted therapies. These therapies will probably complement the traditional treatments (surgery, radiotherapy and chemotherapy). STATE OF THE ART: In thoracic oncology, targeted therapies may interfere with signal transduction by interaction with growth factors receptors. This is the case with monoclonal antibodies directed against the extracellular part of the receptors and with small molecules inhibiting the intracellular part of the receptors (for example, EGF-R). PERSPECTIVES: Other strategies include the use of farnesyl transferase inhibitors or of antisense oligonucleotides; the new therapies may also inhibit angiogenesis by targeting either the VEGF receptor or the matrix metalloproteases. Inhibitors of metalloproteases were the first targeted agents tested. However, all published studies on metalloproteases inhibitors have been negative so far. CONCLUSIONS: Currently, the agents most advanced in clinical development are the EGFR inhibitors (either monoclonal antibodies or small molecules inhibiting tyrosine-kinases) which, in those that have clinical activity, may produce a sustained response at a cost of a degree of toxicity.

[A simple view on lung cancer biology: the MET pathway]. / Un regard simple sur la biologie du cancer bronchique : MET.

MET is a cell membrane tyrosine kinase receptor for its ligand the hepatocyte growth factor (HGF), also called scatter factor (SF). MET conveys mitogenic, motogenic and proangiogenic signals, important during embryonic development and during the development of cancer. Activation of the HGF-MET pathway seems to be associated with a poor prognosis in lung cancer. Activation in lung cancer may be related to several molecular anomalies: ligand overexpression, receptor overexpression, genomic amplification or MET mutation. In MET amplified or mutated lung cancer, MET may be an important oncogene, as the tumor appears "MET addicted". In other lung cancers, MET may be implicated in tumour progression by tissue invasion and formation of metastases. MET amplification is also a mechanism known to be implicated in 20% of secondary resistance to EGFR inhibitors in patients presenting EGFR mutated lung cancer. Different strategies of MET inhibition in lung cancer are being studied, particularly in EGFR mutated lung cancer. In this review we discuss the structure of the MET receptor, the activated pathways, the main genomic anomalies in lung cancer and the development of MET inhibitors.