Nicolas Guibert

Specificities of Lung Adenocarcinoma in Women Who Have Never Smoked

Introduction: No clear data are available on the high rate of tobacco-independent lung cancer in women. We hypothesize that genetic events or hormonal factors may be partly involved. Methods: We aimed to compare clinical, pathological, and biological characteristics of lung cancer in two cohorts of women: smokers and never-smokers. A total of 140 women (63 never-smokers and 77 former/current smokers) with adenocarcinoma, were included in this study. Results: The never-smokers were characterized by a higher age (67 versus 58.7 years; p < 0.0001) and a higher frequency of lepidic features (60.3% versus 37.7%; p = 0.008) compared with smokers. We observed differential genetic alteration repartition in women according to their tobacco status: 50.8% of never-smokers displayed an epidermal growth factor receptor (EGFR) mutation versus 10.4% of smokers (p < 0.001). In contrast, K-Ras was more frequently mutated in smokers (33.8%) than in never-smokers (9.5%; p = 0.001). We also observed a higher percentage of estrogen receptors (ER) &agr; expression (p = 0.03; and p = 0.008 with two different antibodies) in patients who never smoked when compared with smokers. There was no significant difference in ER&bgr; and progesterone receptors between the groups. Finally, ER&agr; expression was correlated with the presence of an EGFR mutation. Conclusions: This study suggests that when lung cancer occurs in women who have never smoked, it is more frequently associated with an EGFR mutation and ER&agr; expression, with a correlation between both markers. These findings underline the possibility of treating women who have never smoked by targeting both hormonal factors and genetic abnormalities.

Monitoring KRAS mutations in circulating DNA and tumor cells using digital droplet PCR during treatment of KRAS-mutated lung adenocarcinoma

Liquid biopsies are a new non-invasive strategy to detect and monitor the biology of non-small-cell lung cancer (NSCLC) in the era of personalized medicine. KRAS is an oncogenic driver that is mutated in 30% of NSCLCs and is associated with a poor prognosis. 62 samples from 32 patients, treated for metastatic KRAS-mutated lung adenocarcinoma, had DNA extracted from plasma and circulating tumor cells (CTCs) prospectively tested for the presence of KRAS mutations using droplet digital PCR. A KRAS mutation was detected in 82% of patients. Sensitivity was 78% for circulating free DNA (cfDNA) and 34% for CTCs. The presence of a KRAS mutation in cfDNA was correlated with a poor response to chemotherapy or targeted therapy. When a KRAS-mutated-DNA was detected and then monitored in cfDNA, its variation during targeted or conventional therapy was correlated with response, according to RECIST criteria, in 87.5% of cases (n=14/16), whereas this correlation was observed in 37.5% of cases for CTCs (n=3/8). We report the usefulness of using digital droplet PCR on liquid biopsies to predict and monitor responses to treatment of KRAS-mutated lung adenocarcinoma. ctDNA was much more sensitive than CTCs in this context.

Integration of interventional bronchoscopy in the management of lung cancer

Tracheal or bronchial proximal stenoses occur as complications in 20–30% of lung cancers, resulting in a dramatic alteration in quality of life and poor prognosis. Bronchoscopic management of these obstructions is based on what are known as “thermal” techniques for intraluminal stenosis and/or placement of tracheal or bronchial prostheses for extrinsic compressions, leading to rapid symptom palliation in the vast majority of patients. This invasive treatment should only be used in cases of symptomatic obstructions and in the presence of viable bronchial tree and downstream parenchyma. This review aims to clarify 1) the available methods for assessing the characteristics of stenoses before treatment, 2) the various techniques available including their preferred indications, outcomes and complications, and 3) the integration of interventional bronchoscopy in the multidisciplinary management of proximal bronchial cancers and its synergistic effects with the other specific treatments (surgery, radiotherapy or chemotherapy). Central airway obstruction is a severe complication of lung cancer that can be managed by interventional bronchoscopy http://ow.ly/OdAhF

Characteristics and Outcomes of Patients with Lung Cancer Harboring Multiple Molecular Alterations: Results from the IFCT Study Biomarkers France

Introduction: Little is known about the prevalence, prognosis, and response to treatment of advanced NSCLC harboring multiple genomic alterations. Methods: The French Biomarkers France database, which includes 17,664 patients, was used. The prevalence of multiple alterations, their associations, their impact on prognosis (overall survival [OS]), and their response to targeted or conventional treatments (progression‐free survival [PFS] and objective response rate) were assessed and compared with those of patients harboring single or no mutation. Results: We identified 162 patients (0.9%) with double alterations and three with triple mutations. Multiple molecular alterations preferentially involved KRAS (67.3%), phosphatidylinositol‐4,5‐bisphosphate 3‐kinase catalytic subunit alpha gene (PIK3CA) (53.3%), and EGFR (42.4%). Patients with multiple alterations were more likely to be male (56.4%), be never‐smokers (25.8 versus 34.7%, p < 0.001), and exhibit adenocarcinomas (83.6%). OS did not differ between single and multiple alterations. Patients with EGFR/KRAS and EGFR/PIK3CA mutations experienced worse PFS than did patients with only EGFR mutations (7.1 and 7.1 versus 14.9 months, p = 0.02 and 0.002, respectively). Concomitant mutations in patients harboring anaplastic lymphoma receptor tyrosine kinase gene (ALK) rearrangement bore little impact on OS (17.7 versus 20.3 months, p = 0.57) or PFS (10.3 versus 12.1 months, p = 0.93). Patients harboring KRAS mutations plus another alteration had an OS time (13.4 versus 11.2 months, p = 0.28), PFS time (6.4 versus 7.2 months, p = 0.78), and objective response rate under first‐line chemotherapy (41.7% versus 37.2%) similar to those of patients harboring KRAS mutations only. Conclusions: With almost 1% of patients harboring multiple alterations, the dogma of mutually exclusive mutations should be reconsidered. Although double mutations do not decrease OS, they do alter PFS under first‐line treatment for patients with EGFR mutations. Among limited numbers of patients, therapies targeting the dominant oncogene seem to usually remain active.

Detection and Monitoring of the BRAF Mutation in Circulating Tumor Cells and Circulating Tumor DNA in BRAF-Mutated Lung Adenocarcinoma

Abstract Non-invasive methods, such as liquid biopsies, are needed to avoid iterative biopsies in this era of personalized therapy. BRAF is a rare oncogenic driver that is mutated in 2% of non-small-cell lung cancers (NSCLC) and responds to BRAF inhibitors. Six patients, treated for metastatic BRAF-mutated lung adenocarcinoma, had their DNA prospectively tested and monitored. The presence of BRAF-V600E mutations was assessed using droplet-digital PCR on both circulating tumor DNA (ctDNA) and DNA extracted from circulating tumor cells (CTCs). A BRAF mutation was detected in all patients, and variations in BRAF-mutated ctDNA during targeted therapy were correlated with a response according to RECIST criteria. We report on the feasibility of digital PCR to detect and monitor circulating BRAF-mutated DNA in patients receiving a targeted treatment for BRAF-V600E-mutated lung adenocarcinoma. CtDNA seemed to be much more sensitive than CTCs.

Monitoring of KRAS -mutated ctDNA to discriminate pseudo-progression from true progression during anti-PD-1 treatment of lung adenocarcinoma

Objectives Pseudo-progression is a rare but worrying situation for both clinicians and patients during immunotherapy. Dedicated ir-RECIST criteria have been established to improve this situation. However, this can be sometimes considered inadequate and patients experiencing true progression may then receive inefficient treatments. Additional reliable tools to discriminate pseudo from true progression are thus needed. So far, no biomarker has been identified to distinguish pseudo from true progression. We hypothesize that biomarkers associated with the molecular characteristics of the tumor may be of interest. To avoid a tumor re-biopsy, circulating markers appear to be a less invasive and reproducible procedure. As ctDNA kinetics correlate with the response to treatment in KRAS-mutated adenocarcinoma, we anticipated that this analysis could be of interest. Materials and methods We monitored the level of KRAS-mutated ctDNA by digital droplet PCR in serial plasma samples from two patients who had experienced pseudo-progression and compared the variations with those from of a patient that had true progression. Results ctDNA showed rapid and dramatic decreases in pseudo-progressive patients, whereas it was strongly increased in the progressive patient. Conclusions ddPCR of ctDNA may thus be an additional tool to discriminate pseudo-progression from true progression for tumors that harbor an oncogenic addiction.

Amplicon-based next-generation sequencing of plasma cell-free DNA for detection of driver and resistance mutations in advanced non-small cell lung cancer

Background Genomic analysis of plasma cell-free DNA is transforming lung cancer care; however, available assays are limited by cost, turnaround time, and imperfect accuracy. Here, we study amplicon-based plasma next-generation sequencing (NGS), rather than hybrid-capture-based plasma NGS, hypothesizing this would allow sensitive detection and monitoring of driver and resistance mutations in advanced non-small cell lung cancer (NSCLC). Patients and methods Plasma samples from patients with NSCLC and a known targetable genotype (EGFR, ALK/ROS1, and other rare genotypes) were collected while on therapy and analyzed blinded to tumor genotype. Plasma NGS was carried out using enhanced tagged amplicon sequencing of hotspots and coding regions from 36 genes, as well as intronic coverage for detection of ALK/ROS1 fusions. Diagnostic accuracy was compared with plasma droplet digital PCR (ddPCR) and tumor genotype. Results A total of 168 specimens from 46 patients were studied. Matched plasma NGS and ddPCR across 120 variants from 80 samples revealed high concordance of allelic fraction (R2 = 0.95). Pretreatment, sensitivity of plasma NGS for the detection of EGFR driver mutations was 100% (30/30), compared with 87% for ddPCR (26/30). A full spectrum of rare driver oncogenic mutations could be detected including sensitive detection of ALK/ROS1 fusions (8/9 detected, 89%). Studying 25 patients positive for EGFR T790M that developed resistance to osimertinib, 15 resistance mechanisms could be detected including tertiary EGFR mutations (C797S, Q791P) and mutations or amplifications of non-EGFR genes, some of which could be detected pretreatment or months before progression. Conclusions This blinded analysis demonstrates the ability of amplicon-based plasma NGS to detect a full range of targetable genotypes in NSCLC, including fusion genes, with high accuracy. The ability of plasma NGS to detect a range of preexisting and acquired resistance mechanisms highlights its potential value as an alternative to single mutation digital PCR-based plasma assays for personalizing treatment of TKI resistance in lung cancer.

Techniques of endoscopic airway tumor treatment

Interventional bronchoscopy has a predominant role in the management of both early and advanced-stage airway tumors. Given the very poor prognosis of lung cancer, there is a need for new tools to improve early detection and bronchoscopic treatment of endo-bronchial precancerous lesions. In more advanced stages, interventional bronchoscopy plays an important role, as nearly a third of lung cancers lead to proximal airway obstruction. This will cause great discomfort or even life-threatening symptoms related to local extension, such as dyspnea, post-obstructive pneumonia, and hemoptysis. Surgery for very locally advanced disease is only effective for a limited number of patients and the effects of conventional antitumor therapies, like radiation therapy or chemotherapy, are inconstant and are too delayed in a palliative context. In this review, we aim to provide pulmonologists with an exhaustive technical overview of (I) the bronchoscopic management of benign endobronchial lesions; (II) the bronchoscopic management of malignant tumors, including the curative treatment of localized lesions and palliative management of malignant proximal airway stenosis; and (III) descriptions of the emerging endoscopic techniques used to treat peripheral lung tumors.

The RAS‐related GTPase RHOB confers resistance to EGFR‐tyrosine kinase inhibitors in non‐small‐cell lung cancer via an AKT‐dependent mechanism

Although lung cancer patients harboring EGFR mutations benefit from treatment with EGFR‐tyrosine kinase inhibitors (EGFR‐TKI), most of them rapidly relapse. RHOB GTPase is a critical player in both lung carcinogenesis and the EGFR signaling pathway; therefore, we hypothesized that it could play a role in the response to EGFR‐TKI. In a series of samples from EGFR‐mutated patients, we found that low RHOB expression correlated with a good response to EGFR‐TKI treatment while a poor response correlated with high RHOB expression (15.3 versus 5.6 months of progression‐free survival). Moreover, a better response to EGFR‐TKI was associated with low RHOB levels in a panel of lung tumor cell lines and in a lung‐specific tetracycline‐inducible EGFRL858R transgenic mouse model. High RHOB expression was also found to prevent erlotinib‐induced AKT inhibition in vitro and in vivo. Furthermore, a combination of the new‐generation AKT inhibitor G594 with erlotinib induced tumor cell death in vitro and tumor regression in vivo in RHOB‐positive cells. Our results support a role for RHOB/AKT signaling in the resistance to EGFR‐TKI and propose RHOB as a potential predictor of patient response to EGFR‐TKI treatment.

Mediastinal Teratoma and Trichoptysis

We report the case of a 22-year-old woman suffering from mature mediastinal teratoma, revealed by trichoptysis, which is an exceptional, but pathognomonic symptom of intrathoracic teratomas. Only eight cases of trichoptysis are reported, none of them involved a mediastinal localization. We present the endoscopic and radiologic presentation, its surgical management, and histologic particularities.