Molecular analysis of peripheral non-squamous non-small cell lung cancer sampled by radial EBUS.

BACKGROUND AND OBJECTIVE: Treatment optimization of non-squamous non-small-cell lung cancers (nonSq-NSCLC) relies on the molecular analysis of the tumour. We aimed to assess the predictive factors of molecular analysis feasibility (MAF) from samples of peripheral nonSq-NSCLC obtained by radial endobronchial ultrasound bronchoscopy (r-EBUS) and 1.5 mm microbiopsy forceps. METHODS: We reviewed data from consecutive peripheral lung nodules sampled with r-EBUS between January 2012 and July 2014 at a single French University Hospital. nonSq-NSCLC were systematically analysed for EGFR, KRAS, ALK, HER2, PI3K and BRAF throughout the study, and c-MET and ROS1 alterations for the last 10 months. RESULTS: Of 111 nonSq-NSCLC diagnosed by r-EBUS (113 procedures, mean nodule diameter 28 ± 15 mm), 88 were analysed for EGFR and ALK, 87 for KRAS, 86 for HER2, PI3K and BRAF and 14 for c-MET. Forty-one mutations were identified (23 KRAS, 10 EGFR, 2 BRAF, 1 HER2 and 5 ALK rearrangements). Four c-MET overexpressions were noted. MAF rose from 67% for the first 57 procedures to 89% for the last 56 procedures (P = 0.02) likely due to a higher number of biopsies performed (2 ± 1 vs 3 ± 2, P = 0.005). Upper or middle lobe location (OR 1.19, 95% CI: 1.02-1.38, P = 0.03), and at least three biopsies (OR 1.20, 95% CI: 1.04-1.40, P = 0.02) were predictive factors of MAF. Percentage of tumour cells, size of lesion and distance to the pleura did not correlate with MAF. CONCLUSION: Multi-gene molecular analysis could be performed in nearly 80% of paraffin-embedded biopsies or smear specimens sampled by r-EBUS assisted bronchoscopy of peripheral tumoral lung nodules.

Safety and performance analysis of acriflavine and methylene blue for in vivo imaging of precancerous lesions using fibered confocal fluorescence microscopy (FCFM): an experimental study.

BACKGROUND: Fibered confocal fluorescence microscopy (FCFM) allows in vivo investigation of pulmonary microstructures. However, the bronchial epithelium can only be imaged using exogenous fluorophores. The objective of this study is to compare methylene blue (MB) and acriflavine genotoxicity and to assess FCFM performance for in vivo imaging of precancerous lesions. METHODS: Genotoxicity was assessed using the comet assay on both cultured human lymphocytes and NCI-H460 cells, which had been exposed to MB or acriflavine before being illuminated at 660 or 488 nm, respectively. FCFM was performed on precancerous lesions in the hamster cheek pouch model, following topical application of the fluorophores. FCFM data were analyzed according to histology. RESULTS: No genotoxicity was found using 0.01% (w/v) MB after illumination at 660 nm for 2 and 15 min (5 mW). Acriflavine exposure (0.025%) led to DNA damages, increasing from 2 to 15 min of light exposure at 448 nm in both lymphocytes (83.4 to 88%, p = 0.021) and NCI H460 cell populations (79.9 to 84.6%, p = 0.045). In total, 11 invasive carcinoma, 24 reserve cell hyperplasia, and 17 dysplasia lesions were imaged using FCFM in vivo. With both fluorophores, the cellular density increased from hyperplasia to high-grade dysplasia (p < 0.05). With MB, the cellular diameter significantly decreased (48.9 to 13.9 µm) from hyperplasia to carcinoma (p < 0.05). In this model, a cut-off diameter of 30 µm enabled the diagnosis of high-grade lesions with a sensitivity of 94.7% and a specificity of 97%. CONCLUSION: Methylene blue can be used safely to image precancerous lesions in vivo. This study does not support the use of acriflavine in humans.

Assessment of Per-Endoscopic Placement of Fiducial Gold Markers for Small Peripheral Lung Nodules < 20 mm Before Stereotactic Radiation Therapy.

BACKGROUND: Stereotactic radiotherapy is used to treat peripheral lung cancer in inoperable patients. Placement of fiducial gold markers (FMs) is crucial for tracking small lesions that are not visible on chest radiographs. Our objective was to assess endoscopic FM placement in small peripheral lung nodules (PLNs) that are not trackable using automated tracking software. METHODS: All patients benefiting from virtual bronchoscopy and radial endobronchial ultrasonography (R-EBUS)-guided placement of FMs for PLNs < 20 mm were included. After confirmation by biopsy sampling, a gold-seed FM was inserted into the nodule using a bronchial brush, without the use of fluoroscopy. The performance and complications of the procedure were recorded. RESULTS: From May 2010 to June 2015, FMs were placed in the PLNs of 54 consecutive patients, 34 of whom presented with a nodule < 20 mm. Seventy-six percent of the procedures were performed using local anesthesia on an outpatient basis. The median long- and short-axis diameters of nodules were 15 mm (9-20 mm) and 11 mm (6-20 mm), respectively, with 31 of 34 nodules exhibiting a short axis of < 15 mm. In 23 cases (79%), histologic samples were obtained during the procedure that allowed FM placement. Migration occurred in six cases, including two in the hours following the procedure. FMs were in place and visible on CT imaging performed 3 months after radiation therapy in 80% of cases. No complications were reported. CONCLUSIONS: Diagnosis of peripheral nodules < 20 mm and FM placement using R-EBUS are efficient and safe in a single procedure.

Photodynamic therapy using methylene blue in lung adenocarcinoma xenograft and hamster cheek pouch induced squamous cell carcinoma.

BACKGROUND: Photodynamic therapy (PDT) is used to treat early proximal bronchial cancer during a flexible bronchoscopy. The technique relies on the excitation of a photosensitizer by an appropriate wavelength, which is delivered into the bronchus in close contact with the tumor. OBJECTIVE: To assess methylene blue (MB) as a PDT agent for the treatment of respiratory tract cancer in animal models. METHODS: MB-induced PDT was performed on 7 subcutaneous NCI-H460 lung adenocarcinoma xenografts in nude mice and 9 induced squamous cell cancer in the hamster cheek pouch model. In mice, PDT was carried out on right-sided tumors after intratumoral injection of methylene blue 1% (w/v) and illumination at 630nm at 200J/cm (Diomed PDT 630), with the left tumor used as control (illumination alone or MB alone). The tumoral volume was assessed before and 15 days after PDT. RESULTS: Fourteen xenografts were treated in mice, including seven treated with MB-PDT, producing a 52% mean tumor volume regression (1568mm(3)vs. 544mm(3)) compared to seven control cases in which tumor volume increased (p=0.007; Mann-Whitney test). Nine cheek pouch induced carcinomas were treated in the hamster group, with a mean volume decrease of 85.8% (from 44.8% to 100%) (initial mean volume=210mm(3)vs. post PDT mean volume=97mm(3)). Histology analysis showed 4/9 complete responses. CONCLUSION: Intratumoral MB appears efficient as PDT agent for cancer treatment in animal models. Further studies are needed to assess the safety and efficacy of MB-associated PDT for the treatment of lung cancer in humans.