Keisei Tachibana

Hepatocyte Growth Factor Expression in EGFR Mutant Lung Cancer with Intrinsic and Acquired Resistance to Tyrosine Kinase Inhibitors in a Japanese Cohort

Introduction: This study was performed to determine the incidence rates of resistance factors, i.e., high-level hepatocyte growth factor (HGF) expression, epidermal growth factor receptor (EGFR) T790M secondary mutation, and MET amplification, in tumors with intrinsic and acquired EGFR tyrosine kinase inhibitor (TKI) resistance in EGFR mutant lung cancer. Methods: Ninety-seven specimens from 93 EGFR mutant lung cancer patients (23 tumors with acquired resistance from 20 patients, 45 tumors with intrinsic resistance from 44 patients [nonresponders], 29 sensitive tumors from 29 patients) from 11 institutes in Japan were analyzed. HGF expression, EGFR T790M secondary mutation, and MET amplification were determined by immunohistochemistry, cycleave real-time polymerase chain reaction, and fluorescence in situ hybridization, respectively. Results: High-level HGF expression, EGFR T790M secondary mutation, and MET amplification were detected in 61, 52, and 9% of tumors with acquired resistance, respectively. High-level HGF expression was detected in 29% of tumors with intrinsic resistance (nonresponders), whereas EGFR T790M secondary mutation and MET amplification were detected in 0 and 4%, respectively. HGF expression was significantly higher in tumors with acquired resistance than in sensitive tumors (p < 0.001, Students t test). Fifty percent of tumors with acquired resistance showed simultaneous HGF expression with EGFR T790M secondary mutation and MET amplification. Conclusions: High-level HGF expression was detected more frequently than EGFR T790M secondary mutation or MET amplification in tumors with intrinsic and acquired EGFR-TKI resistance in EGFR mutant lung cancer in Japanese patients. These observations provide a rationale for targeting HGF in EGFR-TKI resistance in EGFR mutant lung cancer.

Reaction of plasma hepatocyte growth factor levels in non-small cell lung cancer patients treated with EGFR-TKIs

Hepatocyte growth factor induces resistance to epidermal growth factor receptor tyrosine kinase inhibitors. It has been hypothesized that epidermal growth factor receptor tyrosine kinase inhibitors administration may influence the levels of plasma hepatocyte growth factor. Patients with advanced non‐small cell lung cancer and relapsed after chemotherapies were eligible. Plasma hepatocyte growth factor levels were analyzed on pretreatment and post‐treatment day 15 and 30. We also investigated the correlation between plasma hepatocyte growth factor levels and sensitivity to epidermal growth factor receptor tyrosine kinase inhibitors, tissue immunoreactivity for hepatocyte growth factor and MET gene status. Thirty‐one patients were enrolled. Plasma hepatocyte growth factor levels on post‐treatment day 15 (630.1 ± 366.9 pg/ml) were significantly higher (p = 0.029) than the pretreatment plasma hepatocyte growth factor levels (485.9 ± 230.2 pg/ml). Plasma hepatocyte growth factor levels on the post‐treatment day 30 (581.5 ± 298.1 pg/ml) tend to be higher than those before treatment (p = 0.057). Pretreatment plasma hepatocyte growth factor levels in patients with progressive disease (724.1 ± 216.4 pg/ml) were significantly higher than those in patients with stable disease (396.5 ± 148.3 pg/ml; p = 0.0008) and partial response (381.7 ± 179.0 pg/ml; p = 0.0039). The optimal pretreatment plasma hepatocyte growth factor cut‐off value for diagnosis of responder was 553.5 pg/ml, and its sensitivity and specificity were 90% and 65%, respectively. Pretreatment plasma hepatocyte growth factor levels had no correlation with tissue immunoreactivities for hepatocyte growth factor, MET gene status and active EGFR mutations. Administration of epidermal growth factor receptor tyrosine kinase inhibitors significantly increased plasma hepatocyte growth factor levels. High levels of pretreatment plasma hepatocyte growth factor indicated intrinsic resistance to epidermal growth factor receptor tyrosine kinase inhibitors. Plasma hepatocyte growth factor can serve as a useful biomarker for the early diagnosis of tumor relapse treated with epidermal growth factor receptor tyrosine kinase inhibitors.

Overexpression of immunoglobulin (CD79a) binding protein1 (IGBP-1) in small lung adenocarcinomas and its clinicopathological significance

Immunoglobulin binding protein 1 (IGBP‐1) was initially identified as a signal transduction molecule coprecipitating with MB1 (Igα) of the B cell antigen receptor (BCR) complex and was later found to be broadly expressed. Immunoglobulin binding protein 1 has been characterized as an associated and regulatory component of the catalytic subunits of protein phosphatase 2A (PP2A), which is the most abundant phosphatase and plays important roles in cell growth and cell cycle control. The aim of this study was to investigate the expressional characteristics of IGBP‐1 and PP2Ac during pulmonary adenocarcinogenesis. The positivity rate of IGBP‐1 increased during the course of sequential progression from non‐invasive carcinoma (8/30, 26.7%) to invasive adenocarcinoma (37/46, 80.4%) among cases that showed areas of lepidic growth. In contrast, all of the small adenocarcinomas showing a non‐lepidic growth pattern were positive for IGBP‐1 (20/20, 100%). All cancers that proved ultimately fatal were positive for IGBP‐1, and log‐rank analysis showed that IGBP‐1 positivity was significantly correlated with a poor prognosis. In contrast, atypical adenomatous hyperplasias and lung adenocarcinomas were uniformly positive for PP2Ac. Protein phosphatase 2A was not associated with carcinoma progression. Thus we have demonstrated that IGBP‐1 is expressed universally in advanced lung adenocarcinomas, and that its overexpression is significantly related to outcome.

Interobserver Agreement in the Nuclear Grading of Primary Pulmonary Adenocarcinoma

Introduction: Nuclear grading involves an evaluation of the size and shape of nuclei and the percentage of tumor cells that are in the mitotic phase. To estimate the degree of aggressiveness, this approach has been applied to various types of carcinomas, such as breast carcinoma and pulmonary adenocarcinoma (Nakazato et al.). In the present study, we estimated and evaluated the interobserver variability of nuclear grading in primary pulmonary adenocarcinomas. Methods: We selected 122 primary pulmonary adenocarcinomas measuring 2 cm or less in diameter. Eight pathologists independently evaluated the nuclear factors, using the nuclear grading system reported previously by Nakazato et al. The same pathologists also used both the international multidisciplinary classification of pulmonary adenocarcinoma (2011 International Association for the Study of Lung Cancer classification) and Noguchi’s classification, and assessed the extent of the lepidic pattern in the largest cut surface of the tumor. Interobserver agreement was evaluated using the &kgr; statistic. The disease-free survival curves of the patients were obtained using the Kaplan–Meier method and analyzed with the log-rank test. Results: The mean (±SD) &kgr; values for the two histological classifications, the extent of the lepidic pattern, and nuclear grading were 0.46 ± 0.09, 0.48 ± 0.09, 0.45 ± 0.16, and 0.58 ± 0.09, respectively. The cases judged as negative on the basis of nuclear grading showed a significantly better prognosis (5-year disease-free survival rate; 91.8% ± 2.7) than the positive cases did (68.6% ± 3.1). Conclusion: Nuclear grading is practical for prognostic evaluation of pulmonary adenocarcinoma. The interobserver agreement for nuclear grading is significantly higher than for histological classifications and the extent of the lepidic pattern. Nuclear grading is a reliable prognostic indicator for small adenocarcinomas.

Abnormality of the hepatocyte growth factor/MET pathway in pulmonary adenocarcinogenesis

BACKGROUND Signaling mediated by hepatocyte growth factor (HGF)/MET promotes multiple biological activities, including cell proliferation, motility, invasion, angiogenesis, and morphogenesis. Overexpression of HGF and MET and an increase of the MET gene copy number have recently been found in various cancers that had a poor outcome. Here we investigated the copy number of the MET gene and expression of MET and HGF in small pulmonary adenocarcinomas. METHODS Tumor tissues were obtained from 106 pulmonary small adenocarcinomas 2 cm or less in diameter. MET gene copy number, and the expression of MET and HGF, were analyzed using fluorescence in situ hybridization (FISH) and immunohistochemistry, respectively. RESULTS MET FISH-positive signals were observed in 11 (10.4%) of 106 cases. One case (0.9%) showed gene amplification and 10 (9.4%) exhibited high polysomy. High immunoreactivity for MET and HGF in tumor cells was found in 30 (28.3%) and 19 cases (17.9%), respectively. HGF was also expressed in stromal cells in 32 cases (30.2%). No cases of non-invasive adenocarcinoma (adenocarcinoma in situ, localized bronchioloalveolar carcinoma) showed MET FISH-positive signals or high expression of HGF in the tumor cells. Expression of both MET and stromal HGF was stronger in invasive than in non-invasive adenocarcinoma. MET FISH-positive signals and high immunoreactivity for MET and HGF in tumor cells were associated with factors indicative of poor prognosis such as pleural invasion, vascular invasion, lymphatic permeation, lymph node metastasis, and nuclear grading. Univariate and multivariate analyses that included these factors showed that all statuses except for MET and HGF immunoreactivity were significantly associated with an increased risk of death. However, multivariate analysis revealed no independent factors related to poor prognosis. CONCLUSION Our results suggest that abnormality of the HGF/MET pathway occurs during the course of progression from non-invasive to invasive pulmonary adenocarcinoma. An increased MET gene copy number is indicative of a poor outcome in patients with small pulmonary adenocarcinomas.

Diffusion-weighted imaging and positron emission tomography in various cytological subtypes of primary lung adenocarcinoma

The purpose of the study was to retrospectively characterize diffusion-weighted magnetic resonance imaging (DWI) and positron emission tomography for differentiating among the various cytological subtypes of primary lung adenocarcinomas. The maximum diffusion signal intensities and the maximum standardized uptake value (SUV max) of 31 lesions were analyzed after delineation of regions of interest on the images. Diffusion intensities were 0.934 for Clara type, 0.938 for type II type, 1.473 for nongoblet type, and 1.617 for poorly differentiated adenocarcinoma type based on Shimosatos cytological classification (P=.020). The SUV max values were 4.926, 5.491, 5.709, and 12.132, respectively (P=.044). DWI might reflect some of the cytological characteristics of the tumor cells for differentiating the subtypes of lung adenocarcinomas.

Immediate cytology improves accuracy and decreases complication rate in real-time computed tomography-guided needle lung biopsy

Computed tomography‐guided percutaneous transthoracic needle biopsy (CTNB) of the lung is a well‐established diagnostic technique for the evaluation of thoracic lesions. At our institution, we have performed real‐time CTNB using automated biopsy needles since 1998 and we introduced immediate cytology in 2004. We evaluate immediate cytology in CTNB to increase the diagnostic accuracy and to reduce the number of inadequate specimens.

Expression of developing neural transcription factors in lung carcinoid tumors

In lung tumors, the association between carcinoids and high‐grade neuroendocrine tumors (HGNETs) is controversial. To understand the phenotypic similarities/differences between lung carcinoids and HGNETs, we comparatively investigated the expression of three kinds of developing neural transcription factors (DNTFs: BRN2, TTF1 and ASCL1) and multiple endocrine neoplasia type 1 (MEN1) as well as RB1 and P53 using 18 carcinoids and 16 HGNETs. The DNTFs were expressed in 10 of the 18 carcinoids and in all the HGNETs, while normal neuroendocrine cells, which are considered the major cell origin of lung carcinoids and small cell carcinomas, did not express DNTFs. Both the DNTF‐ and DNTF+ carcinoids contained typical and atypical carcinoids. All the DNTF‐ carcinoids examined were formed in the bronchial wall. All the MEN1‐ carcinoids examined were classified into the DNTF‐ carcinoids, while all the HGNETs expressed MEN1. This finding suggests that DNTF‐ MEN1‐ carcinoids are unlikely to be precursors of HGNETs. Although the status of RB1 and P53 between carcinoids and HGNETs were apparently different, the DNTF+ carcinoids of two male patients and one female patient revealed morphologies resembling HGNET cells and relatively high Ki67 indices. Further investigation of DNTF expression in carcinoids might provide important clues to understand the association between carcinoids and HGNETs.

Solitary Pulmonary Capillary Hemangioma of Adult Cases: Clinicopathologic Characteristics as an Unrecognized Entity.

Solitary pulmonary capillary hemangioma (SPCH) is a rare disease, first described about autopsy cases in 2000 and about surgically resected cases in 2006. To date, only 9 surgically resected cases have been published in English. Here, we report 7 original cases with surgery (median age, 54 y; 4 females, 2 never-smokers). All patients were asymptomatic, and all nodules were detected by computed tomography (CT). The median (range) size of nodule was 11 (8 to 16) mm. Six of 7 cases showed the part-solid nodule appearance and 1 showed pure ground-glass nodule appearance in CT findings. The growth speed was very slow. No abnormal uptake of fluorine-18 fluorodeoxyglucose was observed in systemic positron-emission CT in all 3 cases we examined. No patients died from SPCH. Histologically, SPCH manifested as a solitary lesion composed of densely proliferating and dilated capillaries without cytologic atypia within the alveolar septa. In addition, capillaries of SPCH spread into the vascular lumen and involved the walls of bronchioles with protrusion into the lumen. Immunohistochemically, capillaries of SPCH uniformly expressed endothelial markers, such as CD31, CD34, and Factor VIII; and &agr;-smooth muscle actin positive cells were also observed. To be accurately diagnosed, especially in intraoperative frozen sections, SPCH should be conceived as an entity that presents as a solitary nodule in CT. We propose that SPCH is an unrecognized benign capillary proliferative disease.

Thoracoscopic modified pleural tent for spontaneous pneumothorax

OBJECTIVES We developed a modified pleural tent (m-tent) procedure and used it in our hospital in almost 30 consecutive patients with spontaneous pneumothorax. The objective of this study was to clarify the feasibility and effectiveness of a thoracoscopic m-tent for the treatment of spontaneous pneumothorax. METHODS From July 2013 to November 2014, 107 patients with spontaneous pneumothorax were treated in our institution. Eighty-nine of these patients were analysed retrospectively. The inclusion criteria for thoracoscopic m-tent for spontaneous pneumothorax were multiple and widespread bullae, postoperative relapse and secondary spontaneous pneumothorax. The surgical procedures were usually performed through three ports. After bullectomy, an m-tent is made to strip the parietal pleura off the chest wall from about the level of the fourth or fifth rib to the apex, and two or three ligations are then applied to fix the pleural tent and lung parenchyma. Patients in whom an m-tent was not indicated underwent bullectomy plus coverage using absorbable materials. RESULTS Twenty-seven patients underwent bullectomy plus m-tent (m-tent group) and 62 underwent bullectomy plus coverage over a staple line using an absorbable material such as a polyglycolic acid sheet or nitrocellulose sheet (coverage group). No severe postoperative complications were observed in either group. The m-tent and coverage groups showed significant differences in operation time (129 vs 86 min, mean), haemorrhage (12.8 vs 7.2 ml), postoperative hospital stay (3.7 vs 2.9 days) and postoperative painkiller intake (8.6 vs 6.8 days). Recurrence was observed in 1 (3.7%) and 2 patients (3.2%), respectively. CONCLUSIONS The thoracoscopic m-tent procedure requires a longer operation, a longer hospital stay and greater painkiller intake. However, these differences are acceptable, and an m-tent should be considered as an option for pleural reinforcement in spontaneous pneumothorax, especially in patients who are complicated with severe pulmonary emphysema, widespread bullae or recurrent pneumothorax.