Cone-beam computed tomography-guided endobronchial ultrasound using an ultrathin bronchoscope for diagnosis of peripheral pulmonary lesions: a prospective pilot study.

Background: Multimodal transbronchial biopsy (TBB) may have improved diagnostic yield for peripheral pulmonary lesions suspected as lung cancer. Radial endobronchial ultrasound (R-EBUS) provides real-time imaging and confirmation of the location of the lesions. Cone-beam computed tomography (CBCT) can confirm that the forceps tip has reached the lesion before biopsy. Methods: Patients with peripheral pulmonary lesions and a positive computed tomography (CT) bronchus sign (based on slice thickness of 1 mm) were prospectively enrolled. An ultrathin bronchoscope (UTB) and R-EBUS probe were advanced to the target bronchus. Thereafter, forceps were advanced, and CBCT was performed. R-EBUS was performed for re-navigation, if possible. The obtained EBUS and CBCT images were classified into "within" (type 1), "adjacent to" (type 2), or "far from" (type 3), based on the probe or forceps tip. Results: For 20 lesions, the diagnostic yield was 85%. The primary EBUS images were of types 1, 2, and 3 in 12, 6, and 2 cases, respectively. The primary CBCT images were of types 1, 2, and 3 in 12, 6, and 2 cases, respectively. Primary EBUS and CBCT image types were equivalent in 14 cases. Of the 12 cases with type 1 primary EBUS image, 9 cases had a type 1 primary CBCT image, while 3 cases exhibited positional misalignment of the forceps tip. Re-navigation was required in 8 cases with types 2 and 3 primary CBCT images. Conclusions: CBCT-guided TBB using an UTB and EBUS may enable real-time positioning guidance and better re-navigation in the diagnosis of peripheral pulmonary lesions.

GHSR methylation-dependent expression of a variant ligand and receptor of the ghrelin system induces thymoma tumorigenesis.

Our previous study reported that the DNA methylation of growth hormone secretagogue receptor (GHSR) was significantly higher in thymoma or thymic carcinoma (TC) than in normal thymic tissue samples. Thymic epithelial tumors (TETs) with higher GHSR DNA methylation were associated with significantly worse prognosis than those with lower levels of DNA methylation. Diversified components of the ghrelin-GHSR axis may exert opposing effects in cancer progression, depending on the cancer type in question. However, the precise function of the axis remains unclear. In the present study, the mRNA expression of five key components of the ghrelin system [native ligand ghrelin, variant ligand In-1 ghrelin, native receptor GHSR1a, variant receptor GHSR1b and acylation enzyme ghrelin O-acyltransferase (GOAT)] were examined in 58 TET samples by reverse transcription-quantitative PCR, and protein expression of GHSR1a and GHSR1b was assessed in 20 TETs using immunohistochemistry. The results revealed that In-1 ghrelin, GHSR1b (variant forms) and GOAT were more strongly expressed in thymoma compared with thymic-adjacent tissue. By contrast, no significant differences were observed in the expression of ghrelin and GHSR1a (native forms) between thymoma and thymic tissue. The mRNA expression of In-1 ghrelin and GHSR1b (variant forms) was positively associated with GHSR methylation in thymoma tissue samples. However, a relationship was not found between ghrelin, GHSR1a or GOAT expression (native forms) and GHSR methylation in thymoma. Immunohistochemical analysis revealed that mRNA expression of GHSR1a and GHSR1b generally correlated with expression of the corresponding protein, and that the expression of GHSR1b was increased in advanced-stage TETs. These results indicate that the DNA methylation of GHSR is associated with a shift from native expression (ghrelin and GHSR1a) to variant expression (In-1 ghrelin and GHSR1b), which induces the tumorigenesis of thymoma, but not TC.

Hypervascularized bronchial arteries as a risk factor for intraoperative bleeding and prolonged surgery.

BACKGROUND: The present study investigated whether highly vascularized bronchial arteries affect the intraoperative blood loss and the operative time of video-assisted thoracic surgery (VATS) lobectomy for patients with non-small cell lung cancer.Methods: We retrospectively collected data on consecutive pathological stage I to IIIA non-small cell lung cancer patients who underwent VATS lobectomy with systematic lymph node dissection between January 2017 and December 2019. Patients were divided into the following two groups according to bronchial artery diameters on preoperative enhanced contrast computed tomography (CT) findings: ≤2 and >2 mm groups. RESULTS: Among the 175 patients enrolled, risk factors for intraoperative blood loss >50 mL were being male (P=0.005), a history of smoking (P=0.01), percent forced expiratory volume in 1 s (FEV1.0%) <70% (P=0.012), squamous cell carcinoma (P=0.049), and a bronchial artery diameter >2.0 mm (P<0.001) in the unadjusted analysis, and a bronchial artery diameter >2.0 mm (P<0.001) in the multivariable analysis. Risk factors for an operative time >200 min were being male (P<0.001), a history of smoking (P=0.007), FEV1.0% <70% (P=0.011), squamous cell carcinoma (P=0.046), a bronchial artery diameter >2.0 mm (P<0.001), and experience of surgeon <10 years (P=0.011) in the unadjusted analysis, and being male (P=0.047), a bronchial artery diameter >2.0 mm (P=0.024), and experience of surgeon <10 years (P=0.047) in the multivariable analysis. CONCLUSIONS: Bronchial artery diameter was the most important risk factor of intraoperative bleeding and prolonged operative time during VATS lobectomy.

Diagnosis of visceral pleural invasion using confocal laser endomicroscopy during lung cancer surgery.

BACKGROUND: Visceral pleural invasion (VPI) in lung cancer is a significant prognostic factor; however, it is difficult to diagnose preoperatively or intraoperatively. In this study, we examined the possibility of intraoperative diagnosis of VPI using confocal laser endomicroscopy (CLE). METHODS: Among patients with primary lung cancer who underwent surgery between April 2018 and August 2019, those in whom the tumor was in contact with the pleura on chest computed tomography and whose pleural changes were intraoperatively confirmed were enrolled in this study. In the 35 patients who underwent lung resection (6 cases with visceral pleural infiltration), the area where pleural change was noted was observed and a short video was recorded using CLE. Based on the video images, three evaluators determined the defect ratio (0%, 25%, 50%, 75%, and 100%) of the autofluorescence-positive structure. The area under the receiver operating characteristic curve was used to evaluate the diagnostic performance for VPI. In 15 cases (3 cases with VPI), a validation study was performed for intraoperative VPI according to the cutoff value of the defect ratio of the autofluorescence-positive structure. RESULTS: The areas under the receiver operating characteristic curve for the defect ratio of the autofluorescence-positive structure were 0.86-0.91 for the three readers. Using defect ratio of autofluorescence-positive structure cutoff of ≥50% as predictor of VPI, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 83.3-100.0%, 57.7-73.1%, 35.3-41.7%, 95.0-100.0%, and 75.0-78.1%, respectively, for the three readers. In the validation study, the sensitivity was 100%, the specificity was 83.3%, and the diagnostic accuracy rate was 86.7%. CONCLUSIONS: The diagnosis of VPI through CLE is simple, non-invasive, and has high diagnostic accuracy rates. This method may be applicable for determining surgical procedures.

Diversity of lymphatic flow in patients with lung cancer revealed by computed tomography lymphography.

OBJECTIVES: This study was conducted to verify the optimal extent of lymph node dissection or sampling during lung cancer surgery based on the sentinel node (SN) map created by computed tomography (CT) lymphography. METHODS: From April 2010 to January 2015, patients with clinical stage I non-small-cell lung cancer, who were candidates for lobectomy or segmentectomy with standard hilar and mediastinal lymph node dissection, and in whom bronchus reached the tumour, were enrolled. An ultrathin bronchoscope was inserted to the target bronchus under the guidance of virtual bronchoscopic navigation images. CT images of the chest were obtained 30 s after 2.5 ml of iopamidol was injected. SNs were identified when the maximum CT attenuation value of the lymph nodes on postcontrast CT images increased by 30 Hounsfield units or more compared with the precontrast images. Patients underwent lobectomy with standard lymph node dissection. RESULTS: SNs were identified in 36 (87.8%) of the 41 patients. The average number of SNs was 1.6 (range, 1-4). There was 1 false negative case; therefore, the accuracy of SN identification was 97.2% (35/36). In 5 (13.9%) of 36 patients, SNs were outside the lobe-specific lymph node station range (#11i from right S1, #7 from right S1, #4R from right S8, #12u from right S8, #7 and #12l from left S1 + 2). CONCLUSIONS: CT lymphography demonstrated the diversity of lymphatic spreading patterns and there were cases in which lymph flows are found outside the lymph node dissection range.

Calcification in thymomas can predict invasiveness to surrounding organs.

BACKGROUND: Thymomas are the most common type of anterior mediastinal tumors. Calcification is sometimes observed in thymomas using computed tomography (CT), and it is more frequent in invasive thymomas than in noninvasive thymomas. However, the significance of calcification in thymomas remains unknown. This study aimed to evaluate the significance of calcification in thymomas on invasiveness to surrounding organs and investigate the characteristics of thymoma cases with calcification at our institution. METHODS: We included thymoma patients treated at our institution between 2000 and 2016, and evaluated their characteristics, including demographics, calcification on CT, histology, Masaoka stage, and myasthenia gravis status. The patients were categorized into calcification (C) and noncalcification (NC) groups. RESULTS: Among 51 included patients, 11 (21.6%) had calcification. A higher proportion of group C patients had World Health Organization histological type B2 and B3 tumors (high-risk) than type A, AB, and B1 tumors (low-risk; p = 0.0477). The number of patients with Masaoka stages III and IV were significantly higher in the C group than in the NC group (p < 0.0001). The C group patients had significantly higher rates of invasion to the mediastinal pleura, pericardium, lung, phrenic nerve, and chest wall and pleural dissemination than the NC group patients. CONCLUSIONS: Calcification reflects invasiveness of tumors to surrounding organs and tissues, and may thus predict thymoma stage and histologically high-risk thymomas. Calcification in thymomas may also predict the pathological stage and help decide therapeutic methods and surgical approaches to treat thymomas based on the calcification status according to CT findings.

GAD1 expression and its methylation as indicators of malignant behavior in thymic epithelial tumors.

Thymic epithelial tumors (TETs) comprise thymomas and thymic carcinoma (TC). TC has more aggressive features and a poorer prognosis than thymomas. Genetic and epigenetic alterations in thymomas and TC have been investigated in an attempt to identify novel target molecules for TC. In the present study, genome-wide screening was performed on aberrantly methylated CpG islands in thymomas and TC, and the glutamate decarboxylase 1 gene (GAD1) was identified as the 4th significantly hypermethylated CpG island in TC compared with thymomas. GAD1 catalyzes the production of γ-aminobutyric acid from L-glutamic acid. GAD1 expression is abundant in the brain but rare in other tissues, including the thymus. A total of 73 thymomas and 17 TC tissues were obtained from 90 patients who underwent surgery or biopsy at Tokushima University Hospital between 1990 and 2017. DNA methylation was examined by bisulfite pyrosequencing, and the mRNA and protein expression levels of GAD1 were analyzed using reverse transcription-quantitative PCR and immunohistochemistry, respectively. The DNA methylation levels of GAD1 were significantly higher in TC tissues than in the normal thymus and thymoma tissues, and GAD1 methylation exhibited high sensitivity and specificity for discriminating between TC and thymoma. The mRNA and protein expression levels of GAD1 were significantly higher in TC tissues than in thymomas. Patients with TET with high GAD1 DNA hypermethylation and high mRNA and protein expression levels had significantly shorter relapse-free survival rates than those with low levels. In conclusion, significantly more epigenetic alterations were observed in TC tissues compared with in thymomas, which may contribute to the clinical features and prognosis of patients.

Cone-beam computed tomography versus computed tomography-guided ultrathin bronchoscopic diagnosis for peripheral pulmonary lesions: A propensity score-matched analysis.

BACKGROUND AND OBJECTIVE: CBCT-guided TBB using a UTB under VBN is a useful method for the diagnosis of peripheral small pulmonary lesions. CBCT-guided TBB using UTB under VBN has been used as an alternative to CT-guided TBB. However, the advantage of CBCT-guided TBB using UTB under VBN over CT-guided TBB is still unknown. This study aimed to compare the diagnostic yield of CT-guided TBB and CBCT-guided TBB using a propensity score-matched analysis. METHODS: Patients with peripheral pulmonary lesions ≤30 mm were included. Lesions whose bronchus could not be determined by CT were excluded. A UTB and biopsy forceps were advanced to the target bronchus under VBN, 2D-fluoroscopy and CT or CBCT. The CT-guided and CBCT-guided groups were matched for their propensity scores based on patient characteristics. RESULTS: We retrospectively reviewed 93 patients in the CT-guided group and 79 patients in the CBCT-guided group for this study. Furthermore, 48 distinct examination pairs were generated by propensity score matching. In the overall diagnostic yield, the CBCT-guided group showed better results (72.9%) than did the CT-guided group (47.9%) (P = 0.012). The median examination time lasted for 43 (IQR: 37-51) min in the CBCT-guided group and 50 (IQR: 43-62) min in the CT-guided group. The examination time in the CBCT-guided group was significantly shorter than that of the CT-guided group (P = 0.001). CONCLUSION: CBCT-guided TBB had a better diagnostic yield and shorter examination time than did CT-guided TBB.

Can computed tomography differentiate adenocarcinoma in situ from minimally invasive adenocarcinoma?

BACKGROUND: Given the subtle pathological signs of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA), effective differentiation between the two entities is crucial. However, it is difficult to predict these conditions using preoperative computed tomography (CT) imaging. In this study, we investigated whether histological diagnosis of AIS and MIA using quantitative three-dimensional CT imaging analysis could be predicted. METHODS: We retrospectively analyzed the images and histopathological findings of patients with lung cancer who were diagnosed with AIS or MIA between January 2017 and June 2018. We used Synapse Vincent (v. 4.3) (Fujifilm) software to analyze the CT attenuation values and performed a histogram analysis. RESULTS: There were 22 patients with AIS and 22 with MIA. The ground-glass nodule (GGN) rate was significantly higher in patients with AIS (p < 0.001), whereas the solid volume (p < 0.001) and solid rate (p = 0.001) were significantly higher in those with MIA. The mean (p = 0.002) and maximum (p = 0.025) CT values were significantly higher in patients with MIA. The 25th, 50th, 75th, and 97.5th percentiles (all p < 0.05) for the CT values were significantly higher in patients with MIA. CONCLUSIONS: We demonstrated that quantitative analysis of 3D-CT imaging data using software can help distinguish AIS from MIA. These analyses are useful for guiding decision-making in the surgical management of early lung cancer, as well as subsequent follow-up.

Long-term outcomes of sentinel node identification using indocyanine green in patients with lung cancer.

BACKGROUND: Sentinel node (SN) biopsy is used in the management of numerous cancers to avoid unnecessary lymphadenectomy. This was a clinical exploration/feasibility study of a novel identification technique for SN biopsy using indocyanine green (ICG) fluorescence imaging during lung cancer surgery. METHODS: SN biopsy using ICG was performed on 22 patients who had cT1 or T2N0M0 lung cancer. ICG was injected just around the primary tumor. The fluorescence imaging system enabled visualization of the lymphatic vessels draining from the primary tumor toward the lymph nodes. Fluorescently labeled nodes were dissected, and patients were followed-up for prognosis and recurrence to confirm the pattern of lymph node metastasis after surgery. RESULTS: SNs were successfully identified in 16 (72.7%) of 22 patients. A total of 13 of 16 patients had pathological N0 and three had SN metastasis. The median follow-up time was 92.7 months. Only one patient had no SN metastasis at the postoperative pathological examination and lymph node metastasis during the follow-up period. The accuracy rate was 93.8% (15/16) and the false-negative rate was 7.7% (1/13). CONCLUSIONS: SNs were identified by ICG fluorescence imaging, and this technique during lung cancer surgery had good identification and accuracy rates throughout the follow-up period. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: We attempted to identify sentinel lymph nodes by indocyanine green in lung cancer surgery. The identification rate was 72.7%. The accuracy rate was 100% immediately after surgery, and 93.8% after follow-up. WHAT THIS STUDY ADDS: Sentinel node biopsy by indocyanine green may be useful for lymph node dissection during lung cancer surgery to avoid unnecessary lymphadenectomy.

Use of a prognostic risk score that aggregates the FDG-PET/CT SUVmax, tumor size, and histologic group for predicting the prognosis of pStage I lung adenocarcinoma.

BACKGROUND: pStage I includes clinicopathologically diverse groups. This study aimed to identify the prognostic factors for pStage I lung adenocarcinoma. METHODS: We retrospectively reviewed 208 patients with pStage I adenocarcinomas who underwent curative resection in our institute between 2006 and 2013. The maximum standardized uptake value (SUVmax) on [F18]-fluoro-deoxy-D-glucose positron emission tomography-computed tomography (PET/CT) was evaluated. Adenocarcinomas were categorized into the following histologic groups: group 0 (minimally invasive adenocarcinoma and lepidic predominant adenocarcinoma), group 1 (papillary predominant adenocarcinoma), and group 2 (acinar predominant adenocarcinoma and all the remaining subtypes). We assessed the relationship between disease-free survival (DFS) and clinicopathological factors. RESULTS: Multivariate analysis of DFS demonstrated that SUVmax > 3.0 (p < 0.001), total tumor size > 20 mm (p = 0.016), and histologic groups (p < 0.05) were independent prognostic factors. The prognostic risk score (PRS) was calculated using the following equation: PRS = SUVmax (≤ 3.0: 0 point, > 3.0: 2 points) + total tumor size (≤ 20 mm: 0 point, > 20 mm: 1 point) + histologic group (group 0: 0 point, group 1: 1 point, group 2: 2 points). Patients were divided into the following three risk groups: low-risk (PRS 0-2 points, n = 136), intermediate-risk (PRS 3-4 points, n = 49), and high-risk groups (PRS 5 points, n = 13). The 5-year DFS rates were 93.2%, 50.6%, and 30.8% for the low-, intermediate-, and high-risk groups, respectively (p < 0.001). CONCLUSIONS: The PRS aggregating the FDG-PET/CT SUVmax, total tumor size, and histologic group predicts the prognosis of pStage I lung adenocarcinoma.

Chromate exposure induces DNA hypermethylation of the mismatch repair gene MLH1 in lung cancer.

Hexavalent chromium is recognized as a human carcinogen. Our previous studies revealed that lung cancer (LC) in chromate-exposed workers (chromate LC) had molecular features of frequent microsatellite instability (MSI), repression of MLH1 level, and aberrant DNA methylation of several tumor-suppressor genes, including MLH1. In the present study, we quantitatively investigated MLH1-promoter methylation status using bisulfite pyrosequencing of paired tumorous/nontumorous tissues from chromate and nonchromate LCs to determine the effect of chromate exposure on MLH1-promoter methylation. The methylation level of MLH1 promoter was significantly higher in chromate LC tumors (P < .001) than nonchromate LC tumors and, among chromate LC, significantly higher in tumorous tissue than nontumorous tissue (P = .004). Moreover, the methylation level of MLH1 promoter in normal lung tissue tended to be higher in chromate LC than nonchromate LC (P = .062). In addition, LC with reduced levels of MLH1 showed significantly higher methylation levels of MLH1 promoter than LC exhibiting normal MLH1 levels (P = .019). Moreover, immunohistochemical analyses determined that levels of SUV39H1, an H3K9me2-related methyltransferase, were higher in chromate LC than nonchromate LC (P = .076). Furthermore, we evaluated three DNA double-strand break-repair genes (MRE11, RAD50, and DNA-PKcs) as possible targets of MSI by fragment-length polymorphism analysis, revealing the mutation frequency of RAD50 as significantly higher in chromate LC than nonchromate LC (P = .047). These results suggest that chromate exposure might induce MLH1 hypermethylation in LC as a mechanism of chromate-induced carcinogenesis.

DNA methylation of GHSR, GNG4, HOXD9 and SALL3 is a common epigenetic alteration in thymic carcinoma.

Thymic epithelial tumors comprise thymoma, thymic carcinoma and neuroendocrine tumors of the thymus. Recent studies have revealed that the incidence of somatic non­synonymous mutations is significantly higher in thymic carcinoma than in thymoma. However, limited information is currently available on epigenetic alterations in these types of cancer. In this study, we thus performed genome­wide screening of aberrantly methylated CpG islands in thymoma and thymic carcinoma using Illumina HumanMethylation450 K BeadChip. We identified 92 CpG islands significantly hypermethylated in thymic carcinoma in relation to thymoma and selected G protein subunit gamma 4 (GNG4), growth hormone secretagogue receptor (GHSR), homeobox D9 (HOXD9) and spalt like transcription factor 3 (SALL3), which are related to cancer. We examined the promoter methylation of 4 genes in 46 thymic epithelial tumors and 20 paired thymus tissues using bisulfite pyrosequencing. Promoter methylation was significantly higher in thymic carcinoma than in thymoma and revealed a high discrimination between thymic carcinoma and thymoma in all 4 genes. Promoter methylation was higher in thymic carcinoma than in the thymus. No significant differences were observed in the promoter methylation of GNG4, HOXD9, or SALL3 between thymoma and the thymus. The promoter methylation of the 4 genes was not significantly higher in advanced­stage tumors than in early­stage tumors in all thymic epithelial tumors. Among the 4 genes, relapse­free survival was significantly worse in tumors with a higher DNA methylation than in those with a lower DNA methylation in all thymic epithelial tumors. Moreover, relapse­free survival was significantly worse in thymomas with a higher DNA methylation of HOXD9 and SALL3 than in those with a lower DNA methylation. On the whole, the findings of this study indicated that the promoter methylation of cancer­related genes was significantly higher in thymic carcinoma than in thymoma and the thymus. This is a common epigenetic alteration of high diagnostic value in thymic carcinoma and may be involved in the carcinogenesis of thymic carcinoma. However, epigenetic alterations in the 3 genes, apart from GHSR, are not involved in the tumorigenesis of thymoma.

Transbronchial Biopsy Using an Ultrathin Bronchoscope Guided by Cone-Beam Computed Tomography and Virtual Bronchoscopic Navigation in the Diagnosis of Pulmonary Nodules.

BACKGROUND: Transbronchial biopsy is a safe diagnostic approach for patients with peripheral pulmonary lesions; however, the diagnostic yield is low. OBJECTIVES: This study was conducted to evaluate the feasibility and diagnostic yield of transbronchial biopsy using the combination of an ultrathin bronchoscope, virtual bronchoscopic navigation (VBN), and cone-beam computed tomography (CBCT). METHODS: Patients with peripheral pulmonary lesions, no >30 mm, with the responsible bronchus, were prospectively included. An ultrathin bronchoscope and biopsy forceps were advanced to the target bronchus under VBN, 2D-fluoroscopy, and CBCT. We categorized the CBCT findings before biopsy into 3 types according to positions of the target lesion and forceps (CBCT target-forceps sign). In type A, the forceps reached the inside of the target lesion. In type C, the forceps could not reach the lesion. When the CBCT findings could not be categorized into either type A or C, the sign was categorized as type B. RESULTS: Although the target lesions were invisible by conventional C-arm fluoroscopy in 29 patients, CBCT visualized all 40 lesions. The overall diagnostic yield was 90.0%, and diagnostic yields for malignant and benign lesions were 92.0 and 86.7%, respectively. Diagnostic yields for CBCT target-forceps sign types A, B, and C were 100, 75.0, and 0%, respectively. Four undiagnosed patients proceeded to other diagnostic procedures based on the CBCT target-forceps sign (type B: n = 2, type C: n = 2) and were correctly diagnosed without delay. CONCLUSIONS: Transbronchial biopsy using an ultrathin bronchoscope guided by CBCT and VBN showed a very high yield in the diagnosis of pulmonary nodules.

Indocyanine green fluorescence imaging for resection of pulmonary metastasis of hepatocellular carcinoma.

BACKGROUND: Indocyanine green (ICG) accumulates in hepatocellular carcinoma (HCC), and tumor fluorescence can be observed under irradiation with near infrared light (NIR). This study investigated the clinical utility of ICG fluorescence imaging during resection of pulmonary metastases of HCC. METHODS: From April 2010 to June 2018, six patients with suspected pulmonary metastasis of HCC were enrolled prospectively. Prior to surgery, all patients underwent the ICG hepatic function test following intravenous administration of ICG (0.5 mg/kg body weight). During surgery, metastatic HCC was identified by observation of ICG fluorescence, allowing assessment of the surgical margin. Tumor fluorescence was also evaluated on cut sections. RESULTS: A total of 11 metastatic HCCs were resected in six patients at nine operations. Eight lesions were removed by wedge resection and 3 lesions were managed by lobectomy. During surgery, tumor fluorescence could be confirmed through the visceral pleura in 6 out of 7 lesions treated by wedge resection, while NIR irradiation was difficult for 1 lesion. For these 6 lesions, the median distance from the tumor to the visceral pleura and the median surgical margin were 0 mm (range, 0-2 mm) and 14 mm (range, 11-17 mm), respectively. When cut sections were examined, all tumors emitted fluorescence. All lesions were histologically confirmed to be metastatic HCC. CONCLUSIONS: In patients with pulmonary metastasis of HCC, ICG fluorescence imaging is useful for identifying the tumor and securing its margin when the lesion is peripheral and wedge resection is planned.

A feasibility study of postoperative adjuvant chemotherapy with fluoropyrimidine S-1 in patients with stage II-IIIA non-small cell lung cancer.

BACKGROUND: Adjuvant chemotherapy with uracil tegafur (UFT) improved survival among patients with completely resected stage I lung adenocarcinoma. S-1, an oral dihydropyrimidine dehydrogenase (DPD)-inhibitory 5-fluorouracil, is a more potent DPD inhibitor than UFT;therefore, we hypothesized that postoperative adjuvant chemotherapy with S-1 would be effective for advanced non-small cell lung cancer (NSCLC). We conducted a feasibility study of S-1 as postoperative adjuvant chemotherapy in patients with curatively resected pathological stage bold I back 10 bold I and bold I back 10 bold I back 20 bold I A NSCLC. METHODS: Adjuvant chemotherapy consisted of 9 courses (4-week administration, 2-week withdrawal) of S-1 at 80-120 mg/body per day. Twenty-four patients with completely resected NSCLC were enrolled in this study from November 2007 through December 2010. The primary endpoint was the rate of completion of the scheduled adjuvant chemotherapy. The secondary endpoints were safety, overall survival, and relapse-free survival. RESULTS: Five patients were censored because of disease recurrence. The planned 9 courses of S-1 were administered to completion in 8 patients. Twelve patients completed more than 70% of the planned courses. Grade 3 adverse reactions, such as elevated total bilirubin (4.2%) and pneumonitis (4.2%), were observed, but there were no Grade 4 adverse reactions. Patients who completed more than 70% of the 9 courses demonstrated better overall survival than those who completed less than 70%. CONCLUSION: Postoperative administration of S-1 may be possible with few severe adverse events as adjuvant chemotherapy for patients with curatively resected pathological stage bold I back 10 bold I -bold I back 10 bold I back 20 bold I A NSCLC. J. Med. Invest. 65:90-95, February, 2018.

Autofluorescence for the diagnosis of visceral pleural invasion in non-small-cell lung cancer.

OBJECTIVES: This study was conducted to evaluate the accuracy of autofluorescence as a mode of diagnosis for visceral pleural invasion of non-small-cell lung cancer compared with white-light by means of clinical questions to several thoracic surgeons. METHODS: Eight independent thoracic surgeons evaluated visceral pleural invasion in 25 cases of non-small-cell lung cancer attached to the visceral pleura on lung windows of preoperative computed tomography images. At the first study meeting to evaluate the accuracy of visceral pleural invasion diagnosis using conventional white-light images, the surgeons diagnosed visceral pleural invasion based on information in preoperative computed tomography images, histological types and videos recorded with white-light mode using a thoracoscope. At the second study meeting to evaluate the accuracy of visceral pleural invasion diagnosis using autofluorescence, the same surgeons diagnosed visceral pleural invasion based on information in 2 videos recorded in white-light mode and in autofluorescence mode using the thoracoscope. RESULTS: The overall average sensitivity, specificity and accuracy of visceral pleural invasion diagnosis by white-light versus autofluorescence mode were 64.6% vs 83.3%, 53.9% vs 73.7% and 56.5% vs 76.0%, respectively. CONCLUSIONS: The sensitivity, specificity and accuracy of visceral pleural invasion diagnosis was improved through the additional use of the autofluorescence mode compared with the white-light mode alone.

Frequent silencing of RASSF1A by DNA methylation in thymic neuroendocrine tumours.

OBJECTIVES: Aberrant methylation of promoter CpG islands (CGIs) of tumour suppressor genes is a common epigenetic mechanism underlying cancer pathogenesis. The methylation patterns of thymic tumours have not been studied in detail since such tumours are rare. Herein, we sought to identify genes that could serve as epigenetic targets for thymic neuroendocrine tumour (NET) therapy. MATERIALS AND METHODS: Genome-wide screening for aberrantly methylated CGIs was performed in three NET samples, seven thymic carcinoma (TC) samples, and eight type-B3 thymoma samples. The methylation status of thymic epithelial tumours (TETs) samples was validated by pyrosequencing in a larger cohort. The expression status was analysed by quantitative polymerase chain reaction (PCR) and immunohistochemistry. RESULTS: We identified a CGI on a novel gene, RASSF1A, which was strongly hypermethylated in NET, but not in thymic carcinoma or B3 thymoma. RASSF1A was identified as a candidate gene statistically and bibliographically, as it showed frequent CGI hypermethylation in NET by genome-wide screening. Pyrosequencing confirmed significant hypermethylation of a RASSF1A CGI in NET. Low-grade NET tissue was more strongly methylated than high-grade NET. Quantitative PCR and immunohistochemical staining revealed that RASSF1A mRNA and protein expression levels were negatively regulated by DNA methylation. CONCLUSIONS: RASSF1A is a tumour suppressor gene epigenetically dysregulated in NET. Aberrant methylation of RASSF1A has been reported in various tumours, but this is the first report of RASSF1A hypermethylation in TETs. RASSF1A may represent an epigenetic therapeutic target in thymic NET.

[Malignant Pleural Mesothelioma Presenting Refractory Pneumothorax Successfully Treated by Intrapleural Administration of Diluted Fibrin Glue;Report of a Case].

Malignant pleural mesothelioma sometimes accompanies intractable neumothorax due to the visceral pleural invasion of the tumor. A 68-years-old man was found to have massive pleural effusion and pleural mass combined with pneumothorax by computed tomography(CT). CT guided biopsy revealed the mass to be malignant pleural mesothelioma. Since continuous air leakage was observed by chest drainage, pleurodesis by OK-432 twice and bronchial occlusion by Endobronchial Watanabe Spigot (EWS)were performed. But air leakage continued, and the surgery was performed, however the treatment failed to stop the air leakage. Finally, the intrapleural administration of diluted fibrin glue was challenged and the air leakage stopped immediately after the treatment.

Lung regeneration by fetal lung tissue implantation in a mouse pulmonary emphysema model.

The mortality and morbidity of chronic obstructive pulmonary disease are high. However, no radical therapy has been developed to date. The purpose of this study was to evaluate whether fetal mouse lung tissue can grow and differentiate in the emphysematous lung. Fetal lung tissue from green fluorescent protein C57BL/6 mice at 16 days' gestation was used as donor material. Twelve-month-old pallid mice were used as recipients. Donor lungs were cut into small pieces and implanted into the recipient left lung by performing thoracotomy under anesthesia. The recipient mice were sacrificed at day 7, 14, and 28 after implantation and used for histological examination. Well-developed spontaneous pulmonary emphysema was seen in 12-month-old pallid mice. Smooth and continuous connection between implanted fetal lung tissue and recipient lung was recognized. Air space expansion and donor tissue differentiation were observed over time. We could clearly distinguish the border zones between injected tissue and native tissue by the green fluorescence of grafts. Fetal mouse lung fragments survived and differentiated in the emphysematous lung of pallid mice. Implantation of fetal lung tissue in pallid mice might lead to further lung regeneration research from the perspective of respiratory and exercise function. J. Med. Invest. 63: 182-186, August, 2016.