Takahiro Mimae

c-MET/phospho-MET protein expression and MET gene copy number in non-small cell lung carcinomas.

Introduction: The hepatocyte growth factor/MET pathway has been shown to cause tumor progression in several types of carcinomas. The aim of this study was to examine the correlations between c-MET/phospho-MET expression as well as MET gene copy number alterations and overall survival (OS) in non-small cell lung carcinomas (NSCLCs). Methods: We analyzed 906 NSCLCs including 704 adenocarcinomas (ADCs), 150 squamous cell carcinomas (SCCs), 43 sarcomatoid carcinomas, and 9 large cell carcinomas. The mutational status of epidermal growth factor receptor and K-ras and anaplastic lymphoma kinase rearrangements were retrospectively examined. We performed immunohistochemistry to detect c-MET/phospho-MET expression and MET gene copy number using bright-field in situ hybridization (BISH). Results: c-MET/phospho-MET expression and MET BISH positivity were observed in 22.2%, 5.6%, and 10.9% of NSCLCs, respectively; they were more prevalent in ADCs (27.3%, 6.9%, and 11.5%, respectively) and sarcomatoid carcinomas (20.9%, 9.3%, and 36.6%, respectively) than in SCCs and large cell carcinomas. Among ADCs, poorly differentiated cases exhibited c-MET expression and MET BISH positivity more commonly than well-differentiated ones. An analysis of all patients revealed that c-MET/phospho-MET expression and MET BISH positivity were not correlated with OS. However, when SCC cases were excluded, both univariate (p=0.019) and multivariate (p=0.020) analyses revealed a significant correlation between MET BISH positivity and OS. Conclusions: c-MET/phospho-MET expression and MET BISH positivity differed according to histological type. Among ADCs, c-MET expression and MET BISH positivity were more common in poorly differentiated cases. MET BISH positivity was an independent prognostic factor in nonsquamous NSCLCs.

The prognostic role of pathologic invasive component size, excluding lepidic growth, in stage I lung adenocarcinoma

OBJECTIVES We performed an investigation of the prognostic significance of the invasive component size, excluding lepidic growth, in lung adenocarcinoma patients. METHODS The data from 603 patients with completely resected pathologic stage I lung adenocarcinomas were analyzed retrospectively to determine the relationship between pathologic tumor size and surgical results. RESULTS The median tumor size of the total growth and the invasive component were 2.2 cm and 1.3 cm, respectively. There were significant differences in recurrence-free survival between patients classified on the basis of invasive component sizes (≤ 0.5 cm vs 0.5-2.0 cm, P < .001; and 0.5-2.0 cm vs > 2.0 cm; P = .026). A multivariate Cox regression analysis showed that invasive component size (P = .002), age, sex, and lymphatic invasion were independent prognostic factors for recurrence-free survival, whereas total tumor size was not (P = .068). There were no significant differences in recurrence-free survival between patients who received adjuvant chemotherapy and those who did not in the group with invasive component size of 0.5 cm or less (P = .29) and in the group with invasive component size of 0.5 to 2.0 cm (P = .50). However, the recurrence-free survival of patients who received adjuvant chemotherapy was significantly better than that of those who did not in the group with invasive component size greater than 2.0 cm (P = .009). CONCLUSIONS Pathologic invasive component size, as opposed to total tumor size, is associated more significantly with malignant behavior and prognosis and specifically should be considered before choosing candidates for adjuvant chemotherapy in pathologic stage I lung adenocarcinoma.

Upregulation of Notch2 and Six1 is associated with Progression of Early-Stage Lung Adenocarcinoma and a More Aggressive Phenotype at Advanced Stages

Purpose: Lung adenocarcinoma often manifests as tumors with mainly lepidic growth. The size of invasive foci determines a diagnosis of in situ, minimally invasive adenocarcinoma, or invasive types and suggests that some adenocarcinomas undergo malignant progression in that order. This study investigates how transcriptional aberrations in adenocarcinoma cells at the early stage define the clinical phenotypes of adenocarcinoma tumors at the advanced stage. Experimental Design: We comprehensively searched for differentially expressed genes between preinvasive and invasive cancer cells in one minimally invasive adenocarcinoma using laser capture microdissection and DNA microarrays. We screened expression of candidate genes in 11 minimally invasive adenocarcinomas by reverse transcriptase PCR and examined their involvement in preinvasive-to-invasive progression by transfection studies. We then immunohistochemically investigated the presence of candidate molecules in 64 samples of advanced adenocarcinoma and statistically analyzed the findings, together with clinicopathologic variables. Results: The transcription factors Notch2 and Six1 were upregulated in invasive cancer cells in all 11 minimally invasive adenocarcinomas. Exogenous Notch2 transactivated Six1 followed by Smad3, Smad4, and vimentin, and enlarged the nuclei of NCI-H441 lung epithelial cells. Immunochemical staining for the transcription factors was double positive in the invasive, but not in the lepidic growth component of a third of advanced Ads, and the disease-free survival rates were lower in such tumors. Conclusions: Paired upregulation of Notch2 and Six1 is a transcriptional aberration that contributes to preinvasive-to-invasive adenocarcinoma progression by inducing epithelial–mesenchymal transition and nuclear atypia. This aberration persisted in a considerable subset of advanced adenocarcinoma and conferred a more malignant phenotype on the subset. Clin Cancer Res; 18(4); 945–55. ©2011 AACR.

Role of lymphatic invasion in the prognosis of patients with clinical node-negative and pathologic node-positive lung adenocarcinoma

OBJECTIVE Some patients with clinical T1 N0 M0 lung adenocarcinoma have pathologic lymph node metastasis. However, neither the precise prognosis nor the factors predictive of the prognosis of such patients have yet been identified. METHODS Our study included 609 patients with clinical T1 N0 M0 lung adenocarcinoma; 568 (93.3%) pathologic node negative [pN(-)] and 41 (6.7%) pathologic node positive [pN(+)] patients, diagnosed after complete surgical resection. The association between prognosis and pathologic findings was analyzed retrospectively. RESULTS pN(+) patients had a significantly lower lepidic growth component ratio (10% vs 50%), a higher lymphatic invasion (LI) rate (68% vs 11%), vessel invasion rate (59% vs 14%), and visceral pleural invasion rate (29% vs 9%), compared with pN(-) patients (all Ps < .001). Surprisingly, 13 of 41 (32%) pN(+) patients showed no LI. In pN(-) patients, a multivariate analysis of recurrence-free survival revealed that lower lepidic growth component ratio, and lymphatic, vessel, and pleural invasion were significantly correlated with a poor prognosis (P = .008, .045, .031, and .024). However, in pN(+) patients, the multivariate analysis of recurrence-free survival showed that only LI was a significant independent prognostic factor (P = .037). The 5-year recurrence-free survival rates were as follows: 91.2% for pN(-)/LI(-) patients, 68.2% for pN(-)/LI(+) patients, 63.5% for pN(+)/LI(-) patients, and 41.9% for pN(+)/LI(+) patients. LI status stratified the prognosis not only in patients with no nodal metastasis but also in those with metastasis. CONCLUSIONS LI, which is not always present in node-positive adenocarcinoma, is an important prognostic variable in patients with node involvement.

Increased ectodomain shedding of lung epithelial cell adhesion molecule 1 as a cause of increased alveolar cell apoptosis in emphysema

Rationale Alveolar epithelial cell apoptosis and protease/antiprotease imbalance based proteolysis play central roles in the pathogenesis of pulmonary emphysema but molecular mechanisms underlying these two events are not yet clearly understood. Cell adhesion molecule 1 (CADM1) is a lung epithelial cell adhesion molecule in the immunoglobulin superfamily. It generates two membrane associated C terminal fragments (CTFs), αCTF and βCTF, through protease mediated ectodomain shedding. Objective To explore the hypothesis that more CADM1-CTFs are generated in emphysematous lungs through enhanced ectodomain shedding, and cause increased apoptosis of alveolar epithelial cells. Methods and results Western blot analyses revealed that CADM1-CTFs increased in human emphysematous lungs in association with increased ectodomain shedding. Increased apoptosis of alveolar epithelial cells in emphysematous lungs was confirmed by terminal nucleotide nick end labelling (TUNEL) assays. NCI-H441 lung epithelial cells expressing mature CADM1 but not CTFs were induced to express αCTF both endogenously (by shedding inducers phorbol ester and trypsin) and exogenously (by transfection). Cell fractionation, immunofluorescence, mitochondrial membrane potentiometric JC-1 dye labelling and TUNEL assays revealed that CADM1-αCTF was localised to mitochondria where it decreased mitochondrial membrane potential and increased cell apoptosis. A mutation in the intracytoplasmic domain abrogated all three abilities of αCTF. Conclusions CADM1 ectodomain shedding appeared to cause alveolar cell apoptosis in emphysematous lungs by producing αCTF that accumulated in mitochondria. These data link proteolysis to apoptosis, which are two landmark events in emphysema.

Insulin-like growth factor-1 receptor protein expression and gene copy number alterations in non–small cell lung carcinomas

Insulin-like growth factor-1 receptor (IGF-1R) is a tyrosine kinase receptor implicated in the pathogenesis of several malignancies and is potentially an attractive target for anticancer treatment. In this study, we included 379 patients who underwent surgical resection (179 diagnosed as having adenocarcinoma [ADC]; 150, squamous cell carcinoma [SCC]; 41, sarcomatoid carcinoma and 9, large cell carcinoma). IGF-1R expression and gene copy number were assessed by immunohistochemistry and bright-field in situ hybridization (BISH), respectively. IGF-1R expression in non-small cell lung carcinoma was observed in 41.4% of samples and was more prevalent in SCC (69.3%) than in ADC (25.1%), large cell carcinoma (33.3%), and sarcomatoid carcinoma (12.2%) (P < .001). Among ADCs, most mucinous ADCs (75%) showed strong membranous staining with the IGF-1R antibody. Compared with protein expression, IGF-1R gene alteration was rare (8.4%). A statistically significant correlation between IGF-1R expression and positive IGF-1R BISH was observed (γ = 0.762, P < .001). IGF-1R-positive tumors were more common in smokers (P = .004), and these tumors were larger (P = .006) than the IGF-1R-negative tumors. IGF-1R BISH positivity was not correlated with any clinicopathologic factor. IGF-1R expression and IGF-1R BISH positivity were not correlated with overall survival. IGF-1R is highly expressed in SCC and mucinous ADC, although copy number alterations in the IGF-1R gene were rare. These findings may have important implications for future anti-IGF-1R therapeutic approaches.

Prediction for prognosis of resected pT1a-1bN0M0 adenocarcinoma based on tumor size and histological status: relationship of TNM and IASLC/ATS/ERS classifications.

OBJECTIVES This study aimed to estimate the relationship between 7th TNM classification and IASLC/ATS/ERS classification with regard to tumor size and pathological status and to determine the utility of these classifications for predicting prognosis in resected node-negative adenocarcinoma with tumor size ≤2.0 cm and >2.0-3.0 cm. MATERIALS AND METHODS We reviewed 321 pN0M0 lung adenocarcinoma cases resected at Hiroshima University Hospital from January 1991 to December 2010. Histological differences between T1a and T1b based on the IASLC/ATS/ERS classification were estimated and followed by evaluation of overall survival (OS) and recurrence-free interval (RFI) based on differences in tumor size and histological features. RESULTS We found 188 cases of pT1a-1bN0M0 (135 T1a, 53 T1b). Pathological T1a tumors included significantly more adenocarcinoma in situ (AIS) cases and minimally invasive adenocarcinoma (MIA) cases than T1b tumors (60.7% vs 18.8%, respectively; p<0.0001), while more invasive adenocarcinoma cases were included in pT1b. By considering the two classifications simultaneously, the 5-year OS rates of T1a AIS/MIA, T1b AIS/MIA, T1a invasive adenocarcinoma, and T1b invasive adenocarcinoma were 97.5%, 87.5%, 95.8%, and 86.8%, respectively. The 5-year RFIs of T1a AIS/MIA, T1b AIS/MIA, T1a invasive adenocarcinoma, and T1b invasive adenocarcinoma were 100%, 100%, 91.3%, and 72.5%, respectively. T1a AIS/MIA and T1b AIS/MIA could be separated as good prognostic cases with a 100% RFI. Multivariate analysis indicated that only T1b invasive adenocarcinoma was an independent factor for predicting recurrence (p=0.001). CONCLUSION Compared to a single classification, combining TNM and IASLC/ATS/ERS classifications could provide more detail information concerning disease recurrence. AIS and MIA should be handled equally, regardless of tumor size, because their non-/less invasive status is more useful for predicting prognosis than their tumor size classification. In contrast, the T descriptors based on TNM classification are important for predicting prognosis in invasive adenocarcinoma.

Esophagectomy via left thoracotomy for esophageal cancer with situs inversus totalis: Report of a case

We report a case of successful esophagectomy via a left thoracotomy for esophageal cancer in a 57-year-old Japanese man with situs inversus totalis. An upper gastrointestinal endoscopy, performed to investigate the cause of dysphagia, revealed a 7-cm irregular shaped mass occupying more than half of the circumference of the middle-third of the esophagus. Computed tomography (CT) showed enlarged mediastinal lymph nodes and situs inversus totalis. Histological examination of a biopsy specimen revealed squamous cell carcinoma of the esophagus. Although esophagectomy is usually performed through a right thoracotomy because of the left position of the aortic arch, we performed successful subtotal esophagectomy with radical lymph node dissection through a left thoracotomy. During surgery, we modifi ed the standard surgical technique in a mirrorimage fashion to complete the esophagectomy safely. The patient had an uneventful postoperative course.

Segmentectomy versus lobectomy for clinical stage IA lung adenocarcinoma

BACKGROUND Despite the increasing prevalence of the early discovery of small-sized non-small cell lung cancers (NSCLCs), particularly adenocarcinoma, sublobar resection has not yet gained acceptance for patients who can tolerate lobectomy. METHODS We compared the outcomes of segmentectomy (n=155) and lobectomy (n=479) in 634 consecutive patients with clinical stage IA lung adenocarcinoma and in propensity score-matched pairs. Those who had undergone wedge resection were excluded. RESULTS The 30-day postoperative mortality rate in this population was zero. Patients with large or right-sided tumors, high maximum standardized uptake value (SUVmax), pathologically invasive tumors (with lymphatic, vascular, or pleural invasion), and lymph node metastasis underwent lobectomy significantly more often. Three-year recurrence-free survival (RFS) was significantly higher after segmentectomy compared to lobectomy (92.7% vs. 86.9%, P=0.0394), whereas three-year overall survival (OS) did not significantly differ (95.7% vs. 94.1%, P=0.162). Multivariate analyses of RFS and OS revealed age and SUVmax as significant independent prognostic factors, whereas gender, tumor size and procedure (segmentectomy vs. lobectomy) were not. In 100 propensity score-matched pairs with variables adjusted for age, gender, tumor size, SUVmax, tumor location, the three-year RFS (90.2% vs. 91.5%) and OS (94.8% vs. 93.3%) after segmentectomy and lobectomy respectively were comparable. CONCLUSIONS Segmentectomy with reference to SUVmax should be considered as an alternative for clinical stage IA adenocarcinoma, even for low-risk patients.

Prognostic value of the new IASLC/ATS/ERS classification of clinical stage IA lung adenocarcinoma

OBJECTIVES We analyzed and validated the prognostic utility of the new International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) for clinical stage IA lung adenocarcinoma (ADC) classification of adenocarcinoma (ADC). METHODS We retrospectively reviewed 347 patients with clinical stage IA nonmucinous ADC, who had undergone complete resection. The histological subtype was classified according to the predominant subtype, as proposed by the new IASLC/ATS/ERS ADC classification. RESULTS The histopathological subtypes, defined according to the new IASLC/ATS/ERS ADC classification, were ADC in situ (AIS) in 56 patients (16.1%), minimally invasive ADC (MIA) in 15 (4.3%), lepidic-predominant ADC in 109 (31.4%), papillary-predominant ADC in 70 (20.2%), acinar-predominant ADC in 61 (17.6%), solid-predominant ADC in 30 (8.6%), and micropapillary-predominant ADC in 6 (1.7%). The 5-year disease-free survival (DFS) rate was 100% for both AIS and MIA. All cases of recurrence involved invasive ADC. The 5-year DFS for lepidic-predominant ADC was 99.0%; acinar-predominant ADC, 82.4%; papillary-predominant ADC, 80.8%; solid-predominant ADC, 73.6%; and micropapillary-predominant ADC, 33.3%. The predominant subtype of ADC was significantly correlated with DFS (P<0.0001). Multivariate analysis indicated that the pathological stage was an independent predictor of DFS (P=0.031). Other independent predictors of increased risk of recurrence were the presence of vascular or lymphatic invasion (HR=4.96, P=0.001), and a pathological stage more advanced than IB (HR=2.87, P=0.010). The coincidence between the clinical stage and pathological stage was 79.8%. The stage migration was found in 53.3% of solid-predominat ADC and in 83.3% of micropapillary-predominant ADC. CONCLUSION The new IASLC/ATS/ERS ADC classification has prognostic value in predicting the recurrence and survival of patients with clinical stage IA ADC. The frequency of stage migration was found in more than half of solid and micropapillary predominant ADCs.