Harry J.M. Groen

Frequent and Focal FGFR1 Amplification Associates with Therapeutically Tractable FGFR1 Dependency in Squamous Cell Lung Cancer

FGFR1 amplification provides a therapeutic target for squamous cell lung cancer, which is resistant to other targeted lung cancer drugs. A Smoking Gun for Lung Cancer Detectives and scientists alike need strong evidence to take their cases to the judge, who for scientists is often a patient with a deadly disease. Yet, new culprits are sometimes found that can break a case wide open. Lung cancer, which accounts for more than 10% of the global cancer burden, has a poor prognosis and inadequately responds to chemotherapy and radiotherapy. New targeted treatments for lung adenocarcinomas inhibit the oncogenic versions of signaling protein kinases that arise from mutations typically found in lung cancer patients who have never smoked. However, smokers frequently suffer from a different deviant, squamous cell lung cancers, for which there are no known molecular genetic targets for therapy. Now, Weiss et al. have fingered a new suspect in smoking-related lung cancer: amplification of the FGFR1 gene, which encodes the fibroblast growth factor receptor 1 tyrosine kinase (FGFR1). To identify therapeutically viable genetic alterations that may influence squamous cell lung cancer, Weiss et al. performed genomic profiles on a large set of lung cancer specimens. Squamous cell lung cancer samples showed FGFR1 amplification, which was not found in other lung cancer subtypes. The authors then determined that a molecule that broadly inhibits FGF receptor function could block tumor growth and cause cell death in the cancers that expressed high amounts of the FGFR1 gene product in a manner that was dependent on FGFR1 expression. Moreover, FGFR1 inhibition resulted in a considerable decrease in tumor size in a mouse model of FGFR1-amplified lung cancer. This culmination of evidence implies that inhibition of this receptor tyrosine kinase should be explored as a candidate therapy for corralling squamous cell lung cancer in smokers. Lung cancer remains one of the leading causes of cancer-related death in developed countries. Although lung adenocarcinomas with EGFR mutations or EML4-ALK fusions respond to treatment by epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) inhibition, respectively, squamous cell lung cancer currently lacks therapeutically exploitable genetic alterations. We conducted a systematic search in a set of 232 lung cancer specimens for genetic alterations that were therapeutically amenable and then performed high-resolution gene copy number analyses. We identified frequent and focal fibroblast growth factor receptor 1 (FGFR1) amplification in squamous cell lung cancer (n = 155), but not in other lung cancer subtypes, and, by fluorescence in situ hybridization, confirmed the presence of FGFR1 amplifications in an independent cohort of squamous cell lung cancer samples (22% of cases). Using cell-based screening with the FGFR inhibitor PD173074 in a large (n = 83) panel of lung cancer cell lines, we demonstrated that this compound inhibited growth and induced apoptosis specifically in those lung cancer cells carrying amplified FGFR1. We validated the FGFR1 dependence of FGFR1-amplified cell lines by FGFR1 knockdown and by ectopic expression of an FGFR1-resistant allele (FGFR1V561M), which rescued FGFR1-amplified cells from PD173074-mediated cytotoxicity. Finally, we showed that inhibition of FGFR1 with a small molecule led to significant tumor shrinkage in vivo. Thus, focal FGFR1 amplification is common in squamous cell lung cancer and associated with tumor growth and survival, suggesting that FGFR inhibitors may be a viable therapeutic option in this cohort of patients.

Integrative genome analyses identify key somatic driver mutations of small-cell lung cancer

Small-cell lung cancer (SCLC) is an aggressive lung tumor subtype with poor prognosis. We sequenced 29 SCLC exomes, 2 genomes and 15 transcriptomes and found an extremely high mutation rate of 7.4 ± 1 protein-changing mutations per million base pairs. Therefore, we conducted integrated analyses of the various data sets to identify pathogenetically relevant mutated genes. In all cases, we found evidence for inactivation of TP53 and RB1 and identified recurrent mutations in the CREBBP, EP300 and MLL genes that encode histone modifiers. Furthermore, we observed mutations in PTEN, SLIT2 and EPHA7, as well as focal amplifications of the FGFR1 tyrosine kinase gene. Finally, we detected many of the alterations found in humans in SCLC tumors from Tp53 and Rb1 double knockout mice. Our study implicates histone modification as a major feature of SCLC, reveals potentially therapeutically tractable genomic alterations and provides a generalizable framework for the identification of biologically relevant genes in the context of high mutational background.

Stereotactic ablative radiotherapy versus lobectomy for operable stage I non-small-cell lung cancer: a pooled analysis of two randomised trials

BACKGROUND The standard of care for operable, stage I, non-small-cell lung cancer (NSCLC) is lobectomy with mediastinal lymph node dissection or sampling. Stereotactic ablative radiotherapy (SABR) for inoperable stage I NSCLC has shown promising results, but two independent, randomised, phase 3 trials of SABR in patients with operable stage I NSCLC (STARS and ROSEL) closed early due to slow accrual. We aimed to assess overall survival for SABR versus surgery by pooling data from these trials. METHODS Eligible patients in the STARS and ROSEL studies were those with clinical T1-2a (<4 cm), N0M0, operable NSCLC. Patients were randomly assigned in a 1:1 ratio to SABR or lobectomy with mediastinal lymph node dissection or sampling. We did a pooled analysis in the intention-to-treat population using overall survival as the primary endpoint. Both trials are registered with ClinicalTrials.gov (STARS: NCT00840749; ROSEL: NCT00687986). FINDINGS 58 patients were enrolled and randomly assigned (31 to SABR and 27 to surgery). Median follow-up was 40·2 months (IQR 23·0-47·3) for the SABR group and 35·4 months (18·9-40·7) for the surgery group. Six patients in the surgery group died compared with one patient in the SABR group. Estimated overall survival at 3 years was 95% (95% CI 85-100) in the SABR group compared with 79% (64-97) in the surgery group (hazard ratio [HR] 0·14 [95% CI 0·017-1·190], log-rank p=0·037). Recurrence-free survival at 3 years was 86% (95% CI 74-100) in the SABR group and 80% (65-97) in the surgery group (HR 0·69 [95% CI 0·21-2·29], log-rank p=0·54). In the surgery group, one patient had regional nodal recurrence and two had distant metastases; in the SABR group, one patient had local recurrence, four had regional nodal recurrence, and one had distant metastases. Three (10%) patients in the SABR group had grade 3 treatment-related adverse events (three [10%] chest wall pain, two [6%] dyspnoea or cough, and one [3%] fatigue and rib fracture). No patients given SABR had grade 4 events or treatment-related death. In the surgery group, one (4%) patient died of surgical complications and 12 (44%) patients had grade 3-4 treatment-related adverse events. Grade 3 events occurring in more than one patient in the surgery group were dyspnoea (four [15%] patients), chest pain (four [15%] patients), and lung infections (two [7%]). INTERPRETATION SABR could be an option for treating operable stage I NSCLC. Because of the small patient sample size and short follow-up, additional randomised studies comparing SABR with surgery in operable patients are warranted. FUNDING Accuray Inc, Netherlands Organisation for Health Research and Development, NCI Cancer Center Support, NCI Clinical and Translational Science Award.

Mutations in the DDR2 Kinase Gene Identify a Novel Therapeutic Target in Squamous Cell Lung Cancer

UNLABELLED While genomically targeted therapies have improved outcomes for patients with lung adenocarcinoma, little is known about the genomic alterations which drive squamous cell lung cancer. Sanger sequencing of the tyrosine kinome identified mutations in the DDR2 kinase gene in 3.8% of squamous cell lung cancers and cell lines. Squamous lung cancer cell lines harboring DDR2 mutations were selectively killed by knock-down of DDR2 by RNAi or by treatment with the multi-targeted kinase inhibitor dasatinib. Tumors established from a DDR2 mutant cell line were sensitive to dasatinib in xenograft models. Expression of mutated DDR2 led to cellular transformation which was blocked by dasatinib. A squamous cell lung cancer patient with a response to dasatinib and erlotinib treatment harbored a DDR2 kinase domain mutation. These data suggest that gain-of-function mutations in DDR2 are important oncogenic events and are amenable to therapy with dasatinib. As dasatinib is already approved for use, these findings could be rapidly translated into clinical trials. SIGNIFICANCE DDR2 mutations are present in 4% of lung SCCs, and DDR2 mutations are associated with sensitivity to dasatinib. These findings provide a rationale for designing clinical trials with the FDA-approved drug dasatinib in patients with lung SCCs.

Systematic Review of the Staging Performance of 18F-Fluorodeoxyglucose Positron Emission Tomography in Esophageal Cancer

PURPOSE Despite the increasing number of publications concerning (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) for staging of esophageal cancer and the increasing availability of this novel diagnostic modality, its exact role in preoperative staging of these tumors is still unknown. The aim of this study was to systematically review the literature regarding the diagnostic performance of FDG-PET in preoperative staging of patients with esophageal cancer, and to calculate summary estimates of its sensitivity and specificity. METHODS The databases of PubMed, Embase, and Cochrane were searched for relevant studies. Two reviewers independently assessed the methodological quality of each study. A meta-analysis of the reported sensitivity and specificity of each study was performed. RESULTS Twelve studies met the inclusion criteria. The studies had several design deficiencies. Pooled sensitivity and specificity for the detection of locoregional metastases were 0.51 (95% CI, 0.34 to 0.69) and 0.84 (95% CI, 0.76 to 0.91), respectively. For distant metastases, pooled sensitivity and specificity were 0.67 (95% CI, 0.58 to 0.76) and 0.97 (95% CI, 0.90 to 1.0), respectively. CONCLUSION FDG-PET showed moderate sensitivity and specificity for the detection of locoregional metastases, and reasonable sensitivity and specificity in detection of distant lymphatic and hematogenous metastases.

Activity of gemcitabine in patients with non-small cell lung cancer: A multicentre, extended phase II study

Gemcitabine is a novel nucleoside analogue with activity in solid tumours. This study assessed the objective response rate to gemcitabine given weekly intravenously at a dose of 1250 mg/m2 for 3 weeks followed by 1 week of rest (one cycle) in chemonaive patients with inoperable non-small cell lung cancer (NSCLC). 161 patients with NSCLC were recruited from 10 sites in nine countries. Most patients had stage IIIb (31.3%) or IV (64.6%) disease, and 93.8% had a performance status of 0 or 1 according to the WHO scale. Of 151 evaluable patients, there were 3 complete responses and 30 partial responses lasting at least 4 weeks for an objective response rate of 21.8% (95% CI 15.5-29.3%). All responses were validated by an extramural Oncology Review Board. The mean duration of response was 8.8 months. The mean survival for all patients (16.1% of patients still alive 26 months after last patient started treatment) was 11.5 months. Improvements were also observed in secondary efficacy parameters such as performance status, weight, analgesic requirement, pain, and other disease-related symptoms including cough, dyspnoea, haemoptysis, anorexia, somnolence and hoarseness. Haematological and non-haematological toxicity was mild given the biological activity of gemcitabine. This study confirms gemcitabine as one of the most active agents in NSCLC with the added benefit of a modest toxicity profile and ease of administration on an out-patient basis. Gemcitabine is a suitable candidate for combination chemotherapy in patients with NSCLC.

Trans-eQTLs Reveal That Independent Genetic Variants Associated with a Complex Phenotype Converge on Intermediate Genes, with a Major Role for the HLA

For many complex traits, genetic variants have been found associated. However, it is still mostly unclear through which downstream mechanism these variants cause these phenotypes. Knowledge of these intermediate steps is crucial to understand pathogenesis, while also providing leads for potential pharmacological intervention. Here we relied upon natural human genetic variation to identify effects of these variants on trans-gene expression (expression quantitative trait locus mapping, eQTL) in whole peripheral blood from 1,469 unrelated individuals. We looked at 1,167 published trait- or disease-associated SNPs and observed trans-eQTL effects on 113 different genes, of which we replicated 46 in monocytes of 1,490 different individuals and 18 in a smaller dataset that comprised subcutaneous adipose, visceral adipose, liver tissue, and muscle tissue. HLA single-nucleotide polymorphisms (SNPs) were 10-fold enriched for trans-eQTLs: 48% of the trans-acting SNPs map within the HLA, including ulcerative colitis susceptibility variants that affect plausible candidate genes AOAH and TRBV18 in trans. We identified 18 pairs of unlinked SNPs associated with the same phenotype and affecting expression of the same trans-gene (21 times more than expected, P<10−16). This was particularly pronounced for mean platelet volume (MPV): Two independent SNPs significantly affect the well-known blood coagulation genes GP9 and F13A1 but also C19orf33, SAMD14, VCL, and GNG11. Several of these SNPs have a substantially higher effect on the downstream trans-genes than on the eventual phenotypes, supporting the concept that the effects of these SNPs on expression seems to be much less multifactorial. Therefore, these trans-eQTLs could well represent some of the intermediate genes that connect genetic variants with their eventual complex phenotypic outcomes.

Dual Inhibition of EGFR with Afatinib and Cetuximab in Kinase Inhibitor-Resistant EGFR-Mutant Lung Cancer with and without T790M Mutations

UNLABELLED EGFR-mutant lung cancers responsive to reversible EGFR inhibitors (gefitinib/erlotinib) develop acquired resistance, mediated by second-site EGFR T790M mutation in >50% of cases. Preclinically, afatinib (irreversible ErbB family blocker) plus cetuximab (anti-EGFR monoclonal antibody) overcomes T790M-mediated resistance. This phase Ib study combining afatinib and cetuximab enrolled heavily pretreated patients with advanced EGFR-mutant lung cancer and acquired resistance to erlotinib/gefitinib. Patients provided post-acquired-resistance tumor samples for profiling EGFR mutations. Among 126 patients, objective response rate (overall 29%) was comparable in T790M-positive and T790M-negative tumors (32% vs. 25%; P = 0.341). Median progression-free survival was 4.7 months (95% confidence interval, 4.3-6.4), and the median duration of confirmed objective response was 5.7 months (range, 1.8-24.4). Therapy-related grade 3/4 adverse events occurred in 44%/2% of patients. Afatinib-cetuximab demonstrated robust clinical activity and a manageable safety profile in EGFR-mutant lung cancers with acquired resistance to gefitinib or erlotinib, both with and without T790M mutations, warranting further investigation. SIGNIFICANCE This article reports the results of a trial combining afatinib and cetuximab in patients with acquired resistance and details the first clinical proof-of-concept for the preclinical hypothesis that a significant proportion of tumors in patients with acquired resistance to gefitinib/erlotinib remain dependent on EGFR signaling for survival.

Preoperative chemotherapy in patients with resectable non-small cell lung cancer: results of the MRC LU22/NVALT 2/EORTC 08012 multicentre randomised trial and update of systematic review

BACKGROUND Although surgery offers the best chance of cure for patients with non-small cell lung cancer (NSCLC), the overall 5-year survival rate is modest, and improvements are urgently needed. In the 1990s, much interest was generated from two small trials that reported striking results with neo-adjuvant chemotherapy, and therefore our intergroup randomised trial was designed to investigate whether, in patients with operable non-small cell lung cancer of any stage, outcomes could be improved by giving platinum-based chemotherapy before surgery. METHODS Patients were randomised to receive either surgery alone (S), or three cycles of platinum-based chemotherapy followed by surgery (CT-S). Before randomisation, clinicians chose the chemotherapy that would be given from a list of six standard regimens. The primary outcome measure was overall survival, which was analysed on an intention-to-treat basis. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN25582437. RESULTS 519 patients were randomised (S: 261, CT-S: 258) from 70 centres in the UK, Netherlands, Germany, and Belgium. Most (61%) were clinical stage I, with 31% stage II, and 7% stage III. Neo-adjuvant chemotherapy was feasible (75% of patients received all three cycles of chemotherapy), resulted in a good response rate (49% [95% CI 43%-55%]) and down-staging in 31% (25%-37%) of patients, and did not alter the type or completeness of the surgery (lobectomy: S: 56%, CT-S: 60%, complete resection: S: 80%, CT-S: 82%). Post-operative complications were not increased in the CT-S group, and no impairment of quality of life was observed. However, there was no evidence of a benefit in terms of overall survival (hazard ratio [HR] 1.02, 95% CI 0.80-1.31, p=0.86). Updating the systematic review by addition of the present result suggests a 12% relative survival benefit with the addition of neoadjuvant chemotherapy (1507 patients, HR 0.88, 95% CI 0.76-1.01, p=0.07), equivalent to an absolute improvement in survival of 5% at 5 years INTERPRETATION Although there was no evidence of a difference in overall survival with neo-adjuvant chemotherapy, the result is statistically consistent with previous trials, and therefore adds considerable weight to the current evidence.

Randomized Phase III Trial of Maintenance Bevacizumab With or Without Pemetrexed After First-Line Induction With Bevacizumab, Cisplatin, and Pemetrexed in Advanced Nonsquamous Non–Small-Cell Lung Cancer: AVAPERL (MO22089)

PURPOSE Maintenance therapy is associated with improved survival in patients with non-small-cell lung cancer (NSCLC), but few studies have compared active agents in this setting. AVAPERL evaluated the safety and efficacy of bevacizumab with or without pemetrexed as continuation maintenance treatment. PATIENTS AND METHODS Patients with advanced nonsquamous NSCLC received first-line bevacizumab 7.5 mg/kg, cisplatin 75 mg/m(2), and pemetrexed 500 mg/m(2) once every 3 weeks for four cycles. Those achieving response or stable disease were randomly assigned at a ratio of 1:1 to maintenance bevacizumab 7.5 mg/kg or bevacizumab 7.5 mg/kg plus pemetrexed 500 mg/m(2) once every 3 weeks until disease progression or unacceptable toxicity. The primary end point was progression-free survival (PFS) after random assignment. RESULTS In total, 376 patients received induction treatment, 71.9% achieved disease control, and 67.3% were randomly assigned to maintenance therapy, with 125 and 128 receiving single-agent bevacizumab and bevacizumab plus pemetrexed treatment, respectively. At a median follow-up of 8.1 months, PFS from random assignment was significantly improved in the bevacizumab plus pemetrexed arm (median, 3.7 v 7.4 months; hazard ratio, 0.48; 95% CI, 0.35 to 0.66; P < .001) per a stratified model. The PFS benefit extended across age, performance status, smoking history, and induction response (stable disease v partial response) subgroups. Any grade, grade ≥ 3, and serious adverse events occurred more often with bevacizumab plus pemetrexed maintenance. No new safety signals were observed. CONCLUSION In an unselected population of patients with nonsquamous NSCLC who had achieved disease control with platinum-based chemotherapy plus bevacizumab, bevacizumab plus pemetrexed maintenance was associated with a significant PFS benefit compared with bevacizumab alone. The combination was well tolerated.