Preclinical evaluation of thin convex probe endobronchial ultrasound-guided transbronchial needle aspiration for intrapulmonary lesions.

Background: Conventional flexible bronchoscopy has not achieved the high diagnostic yield for intrapulmonary lesions as seen with image-guided transthoracic biopsy. A thin convex probe endobronchial ultrasound bronchoscope (TCP-EBUS) with a 5.9-mm tip was designed to improve peripheral access over conventional EBUS bronchoscopes to facilitate real-time sampling of intrapulmonary lesions under ultrasound guidance. Methods: TCP-EBUS was inserted into the distal airways of ex-vivo human lungs to assess bronchial accessibility relative to clinically available bronchoscopes. The short- (≤1 h) and medium-term (≤10 d) safety of TCP-EBUS insertion and EBUS-guided transbronchial needle aspiration (TBNA) using a 25-gauge needle were evaluated physiologically and radiologically in live pigs. TCP-EBUS-guided TBNA feasibility was assessed in-vivo with pig intrapulmonary pseudo-tumors and ex-vivo with resected human lung cancer specimens. Results: For bronchial accessibility, TCP-EBUS demonstrated greater reach than the 6.6-mm convex probe endobronchial ultrasound (CP-EBUS) in all bronchi, as well as surpassed a 5.5-mm conventional bronchoscope in 63% (131/209) and a 4.8-mm conventional bronchoscope in 27% (57/209) of assessed bronchi. The median bronchial generation and the mean diameter of bronchi TCP-EBUS reached was 4 (range, 3-7) and 3.3±0.7 mm, respectively. No major complications related to TCP-EBUS-guided TBNA in distal airways were observed in the live pigs. Scattered mucosal erythema of the bronchial walls was observed immediately after TCP-EBUS insertion; this self-resolved by day 10. TCP-EBUS could successfully reach and visualize intrapulmonary targets via ultrasound, with no difficulty in needle deployment or sampling. Conclusions: TCP-EBUS has the potential to facilitate safe real-time transbronchial sampling of intrapulmonary lesions in the central and middle lung fields.

Endobronchial ultrasound-guided bipolar radiofrequency ablation for lung cancer: A first-in-human clinical trial.

OBJECTIVE: Percutaneous radiofrequency ablation (RFA) is a therapeutic option for lung tumors. However, percutaneous approaches have limited access to central lung regions and a relatively high complication rate. To overcome these limitations, a needle-type bipolar RFA device compatible with an endobronchial ultrasound (EBUS) bronchoscope was developed. The aim of this pilot study was to evaluate the immediate-term safety and ablation zone of lung tumor EBUS-guided RFA. METHODS: This was an ablate-and-resect study in patients scheduled for surgical resection of clinical stage I or II lung cancer or metastatic lung lesions ≥1 cm that were accessible using an EBUS bronchoscope. The RFA electrodes were placed within the lung nodule using EBUS guidance followed by ablation. Bronchoscopy and contrast-enhanced computed tomography were performed to evaluate for post-RFA complications. The resected lung underwent pathological assessment to characterize the ablation zone. RESULTS: A total of 5 primary lung cancers were ablated in 5 separate patients; no patients with metastatic lesions were recruited. For a total energy of 4 kJ (n = 3), 6 kJ (n = 1), and 8 kJ (n = 1) delivered, the ablation time was a mean of 13.8 (range, 10.3-16.0) minutes, 8.4 minutes, and 15.6 minutes, respectively, and the maximum ablation diameter was a mean of 1.8 (range, 1.3-2.1) cm, 2.7 cm, and 2.6 cm, respectively. No immediate post-RFA complications were observed. CONCLUSIONS: EBUS-guided bipolar RFA can ablate lung tumors using real-time ultrasound guidance. EBUS-guided RFA might ultimately represent a minimally invasive therapy for lung cancer in patients unable to tolerate surgery. Longer-term safety will need to be evaluated.

Development of a minimally invasive pulmonary porcine embolism model via endobronchial ultrasound.

Background: Current massive pulmonary embolism (PE) animal models use central venous access to deliver blood clots, which have features of random clot distribution and potentially fatal hemodynamic compromise. A clinically relevant preclinical model for generating pulmonary emboli in a more controlled fashion would be of value for a variety of research studies, including initial evaluation of novel therapeutic approaches. Endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) is a newly established approach for peri-tracheal/bronchial targets. The purpose of the present work was to establish a minimally invasive PE model in swine via a transbronchial approach. Methods: In anesthetized Yorkshire pigs, a 21-G EBUS-guided transbronchial needle aspiration (EBUS-TBNA) needle was introduced into the pulmonary artery under EBUS guidance. Autologous blood clots were administered into the right and left lower pulmonary arteries sequentially (PE1 and PE2, respectively). Hemodynamic and biochemical responses were evaluated. Results: Ten pigs were evaluated; all 20 blood clots (6.3±1.9 mL) were successfully injected. After injection, mean pulmonary artery pressure (mPAP; mmHg) increased (baseline: 16.6±5.6 vs. PE1: 24.5±7.6, P<0.0001 vs. PE2: 26.9±6.7, P<0.0001), and a positive correlation was observed between clot volume and change in mPAP (PE1: r=0.69, P=0.025; PE1 + PE2: r=0.60, P=0.063). Mean arterial pressure (MAP; mmHg) (baseline: 57.5±5.1 vs. PE1: 59.0±9.1, P=0.918 vs. PE2: 60.9±9.6, P=0.664) remained stable. No complications were observed. Conclusions: EBUS allows minimally invasive, precise, and reliable generation of pulmonary emboli in pigs. This model may serve as an important tool for new PE-related diagnostic and therapeutic research.

ZMYM3 May Promote Cell Proliferation in Small Cell Lung Carcinoma.

Zinc finger, myeloproliferative, and mental retardation-type containing 3 (ZMYM3) is a highly conserved protein among vertebrates. Although it promotes DNA repair and moderate histone acetylation, the other functions of ZMYM3 remain unclear. We herein examined the physiological functions of ZMYM3 in human lung cancer using a ZMYM3-knockdown small cell lung cancer (SCLC) cell line. ZMYM3-knockdown SCLC cells grew slowly and the Ki-67 labeling index was lower in ZMYM3-knockdown cells than in mock cells. The subcutaneous tumors that formed after xenotransplantation into immunodeficient mice were slightly smaller in the ZMYM3-knockdown group than in the mock group. Furthermore, public RNA-sequencing data analyses showed similar RNA profiles between ZMYM3 and some cell proliferation markers. These results indicate that ZMYM3 promotes cell proliferation in human lung carcinomas, particularly SCLC.

Pilot study using virtual 4-D tracking electromagnetic navigation bronchoscopy in the diagnosis of pulmonary nodules: a single center prospective study.

BACKGROUND: Electromagnetic navigation bronchoscopy (ENB) is a navigation technology intended to improve the diagnostic yield of pulmonary nodules. However, nodule displacement due to respiratory motion may compromise the accuracy of the navigation guidance. The Veran SPiNDrive ENB system employs respiratory-gating (4D-tracking) to compensate for this motion. The aim of the present study was to evaluate the diagnostic performance and safety of the Veran SPiNDrive system for biopsy of pulmonary nodules. METHODS: Adult patients with pulmonary nodules of ≥1 cm were enrolled at a single center. Both conventional bronchoscopy and 4D-tracking ENB were performed in one procedure session under general anesthesia, with the procedure order being randomly assigned. Radial probe endobronchial ultrasound and fluoroscopy were used in both groups. The diagnostic performance, safety, total procedure time, and total fluoroscopy time of the ENB phase were compared to the corresponding conventional bronchoscopy phase. RESULTS: The study was terminated due to poor accrual; a total of eleven patients were enrolled. The mean size of pulmonary nodules was 2.1 cm. The sensitivity for malignancy was 67% (6/9) and 56% (5/9) with conventional bronchoscopy and with 4D-tracking ENB, respectively. Two cases developed minor bleeding after conventional bronchoscopy, while no complications were observed after 4D-tracking ENB. The mean procedure time was 16.1 and 21.7 min (P=0.090), and the mean duration time for fluoroscopy use was 77 and 44 sec (P=0.056) for the conventional bronchoscopy and the 4D-tracking ENB phases, respectively. CONCLUSIONS: The diagnostic performance of the Veran SPiNDrive 4D-tracking ENB did not exceed that of conventional bronchoscopy for pulmonary nodules. No complications were seen during 4D-tracking ENB. A study with a larger number of participants is required for further assessment.

Thrombolysis of Pulmonary Emboli via Endobronchial Ultrasound-Guided Transbronchial Needle Injection.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) is a novel technique for treating peribronchial targets. The aim of this study was to evaluate preliminary feasibility of thrombolysis of pulmonary emboli via EBUS-TBNI. METHODS: Yorkshire pigs (30-48 kg) were anesthetized and mechanically ventilated. Pre-formed autologous clots were injected sequentially into bilateral lower pulmonary arteries in bilateral models (PE1 and PE2, respectively) or into 1 side in unilateral models using a 21-gauge EBUS-TBNA needle under EBUS guidance. In the bilateral model, 2 hours after clot injection either 25 mL of tissue-plasminogen activator (t-PA; 1mg/mL) or distilled water were administered into each embolus via 25-gauge EBUS-TBNA needle. In the unilateral model, 25 mg t-PA was administered intravenously. Hemodynamic parameters were monitored continuously, and clot dissolved volume was evaluated by EBUS 30 minutes post-treatment administration. RESULTS: All clots (6.1 ± 1.7 mL) were successfully injected as documented by EBUS Doppler imaging. Clot injection in the bilateral model (n = 6) increased pulmonary arterial pressure (mm Hg: Baseline 19.2 ± 5.9 vs PE1: 26.7 ± 9.1, P = .005 vs PE2 29.9 ± 7.1, P = .0007). After t-PA TBNI in the bilateral model (n = 6), pulmonary arterial pressure at 30 minutes post-injection showed improvement (mm Hg: PE2 29.9 ± 7.1 vs post-t-PA 24.4 ± 3.9, P = .0283). Treatment with t-PA TBNI demonstrated superior clot dissolution at 30 minutes post-treatment (dissolved mm3: t-PA TBNI 625.4 ± 156.6 vs t-PA intravenously: 181.6 ± 94.3, P = .0003 vs distilled water TBNI 42.5 ± 33.0, P < .0001). There were no complications. CONCLUSIONS: EBUS-guided transbronchial thrombolysis may be a feasible approach for treating central pulmonary emboli.

Specific techniques for right sleeve lower lobectomy: four case reports.

BACKGROUND: Right sleeve lower lobectomy is rarely performed because pulmonary function of the middle lobe is not spared to the extent of the other lobes and achieving a proper bronchial anastomosis is technically more difficult than other sleeve lobectomies. CASE PRESENTATION: We performed four right sleeve lower lobectomies and had good clinical outcomes using specific technical options, such as telescope anastomosing, pericardiotomy, interlobar dissection between the upper and middle lobes, and angioplasty of the lower pulmonary artery, if needed. CONCLUSIONS: The cases presented herein demonstrated that a right sleeve lower lobectomy is one option by which to preserve the middle lobe using specific techniques and is thus recommended in select patients.

A preclinical research platform to evaluate photosensitizers for transbronchial localization and phototherapy of lung cancer using an orthotopic mouse model.

BACKGROUND: Establishing the efficacy of novel photosensitizers (PSs) for phototherapy of lung cancer requires in vivo study prior to clinical evaluation. However, previously described animal models are not ideal for assessing transbronchial approaches with such PSs. METHODS: An ultra-small parallel-type composite optical fiberscope (COF) with a 0.97 mm outer diameter tip. The integration of illumination and laser irradiation fibers inside the COF allows simultaneous white-light and fluorescence imaging, as well as real-time monitoring of tip position during laser phototherapy. An orthotopic lung cancer mouse model was created with three human lung cancer cell lines transbronchially inoculated into athymic nude mice. The COF was inserted transbronchially into a total of 15 mice for tumor observation. For in vivo fluorescence imaging, an organic nanoparticle, porphysome, was used as a PS. Laser excitation through the COF was performed at 50 mW using a 671 nm source. RESULTS: The overall success rate for creating orthotopic lung tumors was 71%. Transbronchial white light images were successfully captured by COF. Access to the left main bronchus was successful in 87% of mice (13/15), the right main bronchus to the cranial lobe bronchus level in 100% (15/15), and to the right basal trifurcation of the middle lobe, caudal lobe and accessory lobe in 93% (14/15). For transbronchial tumor localization of orthotopic lung cancer tumors, PS-laden tumor with the strong signal was clearly contrasted from the normal bronchial wall. CONCLUSIONS: The ultra-small COF enabled reliable transbronchial access to orthotopic human lung cancer xenografts in vivo. This method could serve as a versatile preclinical research platform for PS evaluation in lung cancer, enabling transbronchial approaches in in vivo survival models inoculated with human lung cancer cells.

Photoacoustic imaging to localize indeterminate pulmonary nodules: A preclinical study.

PURPOSE: Diagnosis and resection of indeterminate pulmonary nodules (IPNs) is a growing challenge with increased utilization of chest computed tomography. Photoacoustic (PA) -guided surgical resection with local injection of indocyanine green (ICG) may have utility for IPNs that are suspicious for lung cancer. This preclinical study explores the potential of PA imaging (PAI) to detect ICG-labeled tumors. MATERIALS AND METHODS: ICG uptake by H460 lung cancer cells was evaluated in vitro. A phantom study was performed to analyze PA signal intensity according to ICG concentration and tissue thickness/depth using chicken breast. PA signals were measured up to 48 hours after injection of ICG (mixed with 5% agar) into healthy subcutaneous tissue, subcutaneous H460 tumors and right healthy lung in nude mice. RESULTS: Intracellular ICG fluorescence was detected in H460 cells co-incubated with ICG in vitro. The concentration dependence of the PA signal was logarithmic, and PA signal decline was exponential with increasing tissue depth. The PA signal of 2 mg/mL ICG was still detectable at a depth of 22 mm in chicken breast. The PA signal from ICG mixed with agar was detectable 48 hours post injection into subcutaneous tissue and subcutaneous H460 tumors in nude mice. Similar features of PA signals from ICG-agar in mice lung were obtained. CONCLUSION: The results from this preclinical study suggests that PAI of injected ICG-agar may be beneficial for identifying deeply located tumors. These features may be valuable for IPNs.

Endobronchial Ultrasound-Guided Radiofrequency Ablation of Lung Tumors and Mediastinal Lymph Nodes: A Preclinical Study in Animal Lung Tumor and Mediastinal Adenopathy Models.

Radiofrequency ablation (RFA) can be a therapeutic option in medically inoperable lung cancer patients. In this study, we evaluated a prototype bipolar RFA device applicator that can be deployed from a standard endobronchial ultrasound (EBUS) bronchoscope to determine feasibility and histopathological analysis in animal models. Rabbit lung cancers were created by transbronchial injection of VX2 rabbit cancer cells. Once the tumors were developed, they were ablated transpleurally, under EBUS guidance using the prototype RFA device. The animals were then sacrificed for specimen resection. Pig inflammatory lung pseudo-tumors and lymphadenopathy were created by transbronchial injection of a talc paste and ablated transbronchially under EBUS guidance. Pigs were evaluated at 5 days, 2 weeks, and 4 weeks following ablation by bronchoscopy and cone beam computed tomography before necropsy. Nicotinamide adenine dinucleotide hydrogen diaphorase staining was employed to measure the ablation area. Twenty-four VX2 rabbit tumors were ablated. The total ablated area ranged from 0.6 to 3.0 cm2 (mean: 1.8 cm2), corresponding to a total energy range of 1 to 6 kJ. Six pig lung pseudo-tumors and 5 mediastinal lymph nodes were ablated. Adjacent airway ulceration was observed in 3 ablations of lymph nodes. These airway complications resolved within 4 weeks of RFA without any treatment. There was no hemoptysis, air embolism, respiratory distress, or other serious complication noted. In these 2 animal models, we provide evidence that EBUS-guided bipolar RFA is feasible and histopathology shows that can ablate lung tumors and mediastinal lymph nodes under real-time ultrasound guidance.

Rabbit VX2 lung tumor models can form early nodal metastases.

BACKGROUND: The rabbit squamous cell cancer line, VX2, has been used to generate various tumor models in rabbits. It is notable for its ability to generate nodal metastases. However, the timing and extent of nodal metastases vary by primary inoculation site and methodology. The development of metastases specifically in lung cancer models has not been well-described. We sought to characterize the generation of nodal metastases in rabbit transbronchial VX2 lung tumor models. METHODS: Rabbit VX2 lung tumor models were created in the right lung via transbronchial injection and serially imaged by computed tomography. Rabbits (n = 15) were sacrificed from between 5 and 24 days post-inoculation for collection of the ipsilateral and contralateral paratracheal lymph nodes. These underwent histopathological evaluation for metastases using hematoxylin and eosin as well as cytokeratin AE1/AE3 immunohistochemical staining. RESULTS: Nodal metastases were detectable as early as 1 week after inoculation but were more prevalent with longer inoculation; all rabbits at > 2 weeks post-inoculation had nodal metastases. Contralateral metastases were in general seen later than ipsilateral metastases. Lymph node volume did not predict the likelihood of nodal metastases (p = 0.4 and p = 0.07 for ipsilateral and contralateral nodal metastases, respectively), but primary tumor volume was significantly associated with the likelihood of nodal metastases (p = 0.001 and p = 0.005 for ipsilateral and contralateral nodal metastases, respectively). Ipsilateral metastases were detectable at a tumor diameter of 1 cm; contralateral metastases were more variable but in general required a tumor diameter of 2 cm. CONCLUSIONS: Rabbit transbronchial VX2 lung tumor models generate nodal metastases relatively early after inoculation. These results suggest such models may be valuable tools in the investigation of novel therapeutic modalities relevant for the treatment of both early-stage and locally advanced lung cancer.

Significance of Tsukushi in lung cancer.

OBJECTIVES: Tsukushi (TSK), a member of the small leucine-rich repeat proteoglycan (SLRP) family, plays multifunctional roles by interacting with signaling molecules during development. However, the role of TSK in cancer remains unknown. The aim of the present study was to investigate the biological significance of TSK in lung cancer. MATERIALS AND METHODS: Immunohistochemistry of lung cancer tissues and reverse transcription polymerase chain reaction (PCR) of lung cancer cell lines were carried out to detect TSK. Then, RNA sequence analysis, Gene Ontology analysis, quantitative real-time PCR, western blotting, cell counting assay, invasion assays, and xenograft studies were done in a human lung adenocarcinoma cell line, H1975 with modification of TSK expression levels, in order to investigate its biological roles, in particular epithelial-mesenchymal transition (EMT) and proliferation. RESULTS: TSK was found to be highly expressed in lung cancer tissues and cell lines. Modification of TSK expression levels in H1975 resulted in changes in molecules related to EMT, including cadherin-1, snail family transcriptional repressor 1, snail family transcriptional repressor 2, and vimentin. The results of cell counting and xenograft assays showed that TSK promotes cell proliferation. CONCLUSIONS: In lung cancer cells, TSK is expressed more highly than the other SLRPs family members, and regulates the EMT and proliferation. Thus, TSK may be a key coordinator of multiple pathways and an important structural element in the lung cancer microenvironment.

A Novel Laser Fiberscope for Simultaneous Imaging and Phototherapy of Peripheral Lung Cancer.

BACKGROUND: Phototherapy is an alternative treatment for patients with localized non-small cell lung cancer who are unable to undergo surgical resection. However, phototherapy is currently limited to treatment of centrally located lung cancer, with the much larger proportion of peripheral lesions remaining inaccessible. There are also concerns over the accuracy of targeted laser treatment because of the need to exchange visualization and irradiation fibers during therapy, preventing the operator from confirming the final location of the irradiation fiber. METHODS: A newly developed parallel-type ultrasmall composite optical fiberscope (Laser-eYe Ultrathin fiberscope [LYU]), which enables simultaneous white-light imaging and phototherapy, was evaluated in preclinical lung cancer models. Three models were used: human lung cancer xenografts (A549) in mice, orthotopic VX2 lung tumors in rabbits, and ex vivo pig lungs into which A549 tumor tissue was transplanted. A multifunctional porphyrin-phospholipid nanoparticle (porphysome) was used as a photosensitizer to evaluate fluorescence-guided photothermal therapy. RESULTS: The LYU's 0.97 mm diameter and hydrophilic coating allowed easy passage through the working channel of all types of bronchoscopes and controlled guidance of the LYU tip in any desired direction. The LYU could visualize the peripheral bronchus and porphysome-laden peripheral tumors. The LYU could also perform photothermal therapy with simultaneous imaging. CONCLUSIONS: The LYU enables simultaneous imaging and phototherapy that allows accurate irradiation of peripheral lung cancers. This new laser device may enable ultraminimally invasive transbronchial treatment of peripheral lung cancer.

Evaluation of Novel Imaging Devices for Nanoparticle-Mediated Fluorescence-Guided Lung Tumor Therapy.

BACKGROUND: Nonsurgical and minimally invasive approaches for early-stage peripheral lung cancer are needed to avoid the known morbidity of surgical resection, particularly in high-risk patients. We previously demonstrated the utility of multifunctional porphyrin-phospholipid nanoparticles (porphysomes) for fluorescence imaging and phototherapy after preferential accumulation into tumors. The objective of this study was to demonstrate the feasibility of porphysome-mediated imaging and photothermal therapy using a newly developed fiberscope and thoracoscope. METHODS: To prepare this technology for clinical translation, we developed a porphysome-specific fiberscope (scanning fiber endoscope and porphysome-specific thoracoscope), both capable of detecting porphysome fluorescence, for image-guided transbronchial and transpleural photothermal therapy to treat endobronchial/peribronchial and subpleural tumors, respectively. These were tested in three animal models: human lung cancer xenografts (A549) in mice, orthotopic VX2 lung tumors in rabbits, and ex vivo pig lung into which A549 tumor tissue was transplanted. RESULTS: The scanning fiber endoscope, with a 1.2-mm diameter, is small enough to pass through the working channel of a conventional bronchoscope and could visualize porphysome-laden tumors located inside or close to the peripheral bronchial wall. The porphysome-specific thoracoscope system had high sensitivity for porphysome fluorescence and enabled image-guided thoracoscopic resection of porphysome-accumulating tumors close to the pleura. Porphysomes also enhanced the efficacy of scanning fiber endoscope-guided transbronchial photothermal therapy and porphysome-specific thoracoscope-guided transpleural photothermal therapy, resulting in selective and efficient tumor tissue ablation in the rabbit and pig models. CONCLUSIONS: These results support the potential for clinical translation of this novel platform to affect nonsurgical and minimally invasive treatment options for early-stage peripheral lung cancer.

First Evaluation of the Next-Generation Endobronchial Ultrasound System in Preclinical Models.

BACKGROUND: The next-generation convex probe endobronchial ultrasound (CP-EBUS) was developed to improve the ease of operation and the acquisition of EBUS skills for new trainees. The aim of this study was to evaluate the changes in the prototype next-generation CP-EBUS compared with the current CP-EBUS. METHODS: The prototype next-generation CP-EBUS, with a decreased forward oblique view, more flexible angulation range, smaller ultrasound probe, and sharper needle angle, was compared with the current CP-EBUS. The operability, which was evaluated by using a 5-level Likert-type scale, and safety were evaluated in 2 live pigs, a cadaveric lung, and 10 ex vivo human lungs by 9 bronchoscopists. The time required to access the upper lobe bronchus and the time required to detect prespecified lymph node stations by 7 novice bronchoscopists with both CP-EBUS were compared with assess the operability difference for new trainees. RESULTS: In all evaluated models, operability (eg, maneuverability, endoscopic visibility, bronchial trees selectivity, insertability to the upper airway) was scored 5 (significantly improved). All trainee bronchoscopists were able to access the upper lobe bronchi and detect each lymph node except 4R significantly faster than with the current CP-EBUS without any airway damage. CONCLUSIONS: The next-generation CP-EBUS has improved operability, which resulted in better access to each lobar bronchus and more prompt detection of mediastinal or hilar lymph nodes. These improvements may allow more precise lymph node staging and diagnosis, as well as improve EBUS procedural skill acquisition, once introduced to clinical practice.

Interstitial fluid pressure of thymic epithelial tumours.

Tumours show an increased interstitial fluid pressure, which correlates with various pathophysiological features. Moreover, interstitial fluid pressure is a prognostic factor for cervical and lung cancer. However, there have been no reports on the usefulness of measuring interstitial fluid pressure in thymic epithelial tumours. Therefore, this study aimed to examine the relationship between interstitial fluid pressure and the clinicopathological characteristics of thymic epithelial tumours. Interstitial fluid pressure was prospectively measured at the centre of the tumour using a 1-Fr Mikro-Tip sensor catheter in 44 patients with thymic epithelial tumours, 40 with thymomas and 4 with thymic carcinomas. Data from these 44 patients were analysed for correlations between interstitial fluid pressure and clinicopathological and demographic factors including sex, age, tumour size, World Health Organization histological subtypes, myasthenia gravis, capsular invasion, mediastinal pleura invasion, lung invasion, pericardium invasion, dissemination, Masaoka-Koga stage, maximal standardized uptake value and recurrence-free survival (RFS). The mean interstitial fluid pressure was 11.3 mmHg; interstitial fluid pressure was significantly correlated with maximal standardized uptake value, lung invasion, dissemination and Masaoka-Koga stage. Low interstitial fluid pressure (≤14 mmHg) showed a tendency for better RFS compared with high interstitial pressure (P = 0.053). Lung invasion, dissemination and Masaoka-Koga stage were correlated with RFS in univariable analysis; lung invasion was selected as an independent prognostic factor in multivariable analysis. On the basis of these results, interstitial fluid pressure of thymic epithelial tumours has been shown to correlate with their clinicopathological features.

Pathobiology of Notch2 in lung cancer.

Notch signalling has been reported to be involved in initiation, progression, and suppression in various types of cancer. The pathological significance of Notch1 has been well studied in lung cancer, but that of Notch2 remains unclear. An immunohistochemical study was performed to clarify the expression of NOTCH2 in non-neoplastic lung tissues and lung cancers in comparison with Clara (Club) cell 10 kDa protein (CC10), and western blotting analysis was performed to detect NOTCH2 in human cancer cell lines. A Notch2 gene knockdown experiment was carried out to reveal the function of Notch2. Transient transfection of the intracellular domain of the Notch2 (N2ICD) gene was used. In addition, the relationship of the expressions of Notch1, 2, and 3 was studied. Immunohistochemical study of lung tissues revealed that NOTCH2 was detected in bronchiolar epithelial cells and was often colocalised with CC10, and that adenocarcinoma tissues were more positively stained than those of squamous cell carcinoma and small cell carcinoma. In human lung cancer cell lines, expression of NOTCH2 was similar to that of NOTCH1, and preferentially detected in non-small cell lung carcinoma (NSCLC) cell lines. Knockdown of the Notch2 gene in NSCLC cell lines showed no remarkable changes in expression of molecules associated with cell differentiation, proliferation, apoptosis, and motility, and the seemingly unvalued effects of Notch2 gene knockdown could be masked by concomitant Notch1 activation, as indicated by an increase in the intracellular domain of NOTCH1. Additionally, transient transfection of the N2ICD gene induced CC10 expression in an adenocarcinoma cell line. The present study revealed that Notch2 is important in Club cell differentiation in normal lungs and adenocarcinoma. Notch2 is regulated mutually with Notch1, and the balance of the expression of Notch receptors could determine the biological behaviours of lung cancer cells.

[Chronic Progressive Pulmonary Aspergillosis after Surgery for Lung Cancer].

Case 1:A 62-year-old man underwent right S9+10 segmentectomy for non-small cell lung cancer. Three years later, pleural thickening appeared in the apex, and gradually developed cystic change. Case 2:A 64-year-old man underwent left upper lobectomy for non-small cell lung cancer. One year after surgery, chest computed tomography (CT) showed cysts in the apex of the lower lobe. The cysts expanded slowly with consolidation. Both cases were diagnosed as chronic progressive pulmonary aspergillosis. Although anti-fungal drugs were administered in both cases, case 1 died of the disease. Chronic progressive pulmonary aspergillosis is a rare late postoperative complication;when CT shows progressive cysts with consolidation in the apex area of the residual lung, frequent check-ups are needed.

Synchronous Multiple Lung Adenocarcinomas: Estrogen Concentration in Peripheral Lung.

BACKGROUND: The detection rate of synchronous multiple lung adenocarcinomas (SMLA), which display multiple ground glass opacity nodules in the peripheral lung, is increasing due to advances in high resolution computed tomography. The backgrounds of multicentric development of adenocarcinoma are unknown. In this study, we quantitated estrogen concentration in the peripheral lungs of postmenopausal female patients with SMLA. METHODS: The tissue concentration of estrogens (estrone [E1] and estdadiol [E2]) in the noncancerous peripheral lung were measured with liquid chromatography/electrospray tandem mass spectrometry in postmenopausal female patients with lung adenocarcinoma. The expression levels of CYP19A1 in the normal lung were also quantitated with real-time PCR. Thirty patients with SMLA and 79 cases of control patients with single lung adenocarcinoma were analyzed. RESULTS: The concentrations of E1 and E2 in the noncancerous tissue were significantly higher in SMLA cases than control cases (P = 0.004 and P = 0.02, respectively). The minor allele (A) of single nucleotide polymorphism rs3764221 were significantly associated with higher concentration of E1 and E2 (P = 0.002 and P = 0.01, respectively) and higher CYP19A1 mRNA expression (P = 0.03). CONCLUSION: The tissue estrogen concentration of peripheral lung was significantly higher in SMLA than control cases. The high concentration of estrogen may be one of the causes of multicentric development of peripheral lung adenocarcinomas.

Pulmonary hepatoid adenocarcinoma: report of a case.

Hepatoid adenocarcinoma (HAC) is a rare neoplasm with aberrant hepatocellular differentiation. HAC occurs in extrahepatic organs such as the gastrointestinal tract, testes, ovaries, and lungs and frequently produces alpha-fetoprotein. A 69-year-old patient was diagnosed clinically with T2aN0M0, stage IB, non-small cell lung carcinoma. Because the tumor showed tight adhesion to the chest wall, we performed left upper lobectomy, combined resection of the 3rd and 4th ribs, and lymph node dissection. Pathological examination confirmed the diagnosis of HAC of the lung (pathological T2aN0M0, stage IB), and four courses of cisplatin and gemcitabine were administered as adjuvant chemotherapy. Genetic analysis of the epidermal growth factor receptor showed wild type. Preoperative serum alpha-fetoprotein level, a useful marker of disease progression, was elevated to 4497 ng/ml, decreasing within the normal range by about 3 months postoperatively. The patient remains alive without recurrence as of 51 months after surgery.