Masayuki Sugano

Significance of epidermal growth factor receptor gene mutations in squamous cell lung carcinoma

Epidermal growth factor receptor (EGFR) gene mutations have been reported to be clinically significant in non-small cell lung cancer (NSCLC). However, because most previous studies focused only on adenocarcinomas, EGFR mutations in other histotypes are poorly investigated. We evaluated the frequency of EGFR gene mutations in squamous cell carcinoma (SCC) and its clinicopathological features. In total, 89 frozen tumor specimens that had been first diagnosed as SCCs, were examined for EGFR mutations in exons 19 and 21 using direct sequencing, PNA-enriched sequencing and SmartAmp2. Additionally, pathological investigation, including immunostaining for p63 and TTF-1, alcian blue staining and EGFR mutation-specific immunohistochemistry in mutation-positive samples was also performed. The frequency of EGFR mutations was 5.6% (5/89); all mutations were deletions in EGFR exon 19. Immunohistological investigation of these samples revealed that two of five were positive for p63 and TTF-1 staining, and showed production of mucin, as evidenced by alcian blue staining. Consequently, three of the samples were considered to be true SCC at final pathological diagnosis, while the remaining two samples were revised to adenosquamous carcinoma and adenocarcinoma. The final frequency of the EGFR mutations in true SCC was 3.4% (3/87). In conclusion, EGFR mutations were found in a small, but significant, number of SCC tumor samples and thus EGFR mutational analysis was useful in the accurate diagnosis of SCC. Our data demonstrate that EGFR mutational analysis should be performed not only in adenocarcinoma, but also in SCC to allow accurate diagnosis and treatment.

Clinicopathological features of lung adenocarcinoma with KRAS mutations.

KRAS and epidermal growth factor receptor (EGFR) mutations are thought to play an important role in the carcinogenesis of lung adenocarcinoma. However, clinicopathological findings of KRAS mutated adenocarcinoma cases have not yet been fully clarified. The authors analyzed the relationship between the KRAS mutation and corresponding clinicopathological findings, focusing on nonmucinous and mucinous bronchioloalveolar elements.

Mutation detection of epidermal growth factor receptor and KRAS genes using the smart amplification process version 2 from formalin-fixed, paraffin-embedded lung cancer tissue.

Recent evidence indicates that the presence of epidermal growth factor receptor (EGFR) or KRAS mutations in non-small cell lung cancer (NSCLC) can predict the response of the tumor to gefinitib. However, it is difficult to detect these mutations using formalin-fixed, paraffin-embedded (FFPE) tissues because the fixation process and aging can damage the DNA. In this study, we describe our work in adapting the Smart Amplification Process version 2 (SmartAmp2) to detect EGFR or KRAS mutations in DNA extracted from FFPE tissues. We were able to detect these mutations in 37 (97%) of 38 FFPE lung cancer tissue samples within 60 minutes with the SmartAmp2 assay and to confirm the correlation between EGFR mutations in FFPE tissues and gefitinib responsiveness. All mutations had previously been confirmed in the 38 samples using DNA extracted from frozen tissues. Electrophoresis results indicated that PCR analysis was not reliable for DNA extracted from FFPE tissue when primers with a long amplicon (>300 bp) were used. This study confirms that the SmartAmp2 assay is suitable for use with DNA extracted from FFPE as well as frozen tissues.

Establishment of a human lung cancer cell line with high metastatic potential to multiple organs: gene expression associated with metastatic potential in human lung cancer

Convenient and reliable multiple organ metastasis model systems might contribute to understanding the mechanism(s) of metastasis of lung cancer, which may lead to overcoming metastasis and improvement in the treatment outcome of lung cancer. We isolated a highly metastatic subline, PC14HM, from the human pulmonary adenocarcinoma cell line, PC14, using an in vivo selection method. The expression of 34,580 genes was compared between PC14HM and parental PC14 by cDNA microarray analysis. Among the differentially expressed genes, expression of four genes in human lung cancer tissues and adjacent normal lung tissues were compared using real-time reverse transcription polymerase chain reaction. Although BALB/c nude mice inoculated with parental PC14 cells had few metastases, almost all mice inoculated with PC14HM cells developed metastases in multiple organs, including the lung, bone and adrenal gland, the same progression seen in human lung cancer. cDNA microarray analysis revealed that 981 genes were differentially (more than 3-fold) expressed between the two cell lines. Functional classification revealed that many of those genes were associated with cell growth, cell communication, development and transcription. Expression of three upregulated genes (HRB-2, HS3ST3A1 and RAB7) was higher in human cancer tissue compared to normal lung tissue, while expression of EDG1, which was downregulated, was lower in the cancer tissue compared to the normal lung. These results suggest that the newly established PC14HM cell line may provide a mouse model of widespread metastasis of lung cancer. This model system may provide insights into the key genetic determinants of widespread metastasis of lung cancer.

Correlation between computed tomography findings and epidermal growth factor receptor and KRAS gene mutations in patients with pulmonary adenocarcinoma.

We examined the correlation between computed tomography (CT) findings and the incidence of epidermal growth factor receptor (EGFR) and KRAS mutations in lung adenocarcinoma. We analyzed the tumors of 136 patients with surgically resected primary lung adenocarcinoma. CT scans were evaluated for the presence of ground grass opacity (GGO), spiculation and the maximum diameter of the tumor was measured. SMart Amplification Process (ver. 2) was used to detect the presence of EGFR and KRAS mutations. EGFR and KRAS mutations were found in 56 (41.1%) and 25 (18.4%) of the 136 cases, respectively. Although no significant association was found between GGO and EGFR mutations (p=0.07), the EGFR mutation occurred more frequently in male patients with GGO than in those without GGO (p=0.04). The KRAS mutation occurred more frequently in patients whose tumor diameter was ≥ 31 mm than in those whose tumor diameter was <30 mm (p=0.003). Evaluation of CT findings may be helpful for determining the presence of EGFR and KRAS mutations, particularly when it is not possible to obtain a tumor specimen.

Immunohistopathological re-evaluation of adenocarcinoma of the lung with mixed subtypes using a tissue microarray technique and hierarchical clustering analysis.

To re‐evaluate adenocarcinoma, mixed subtypes (ADMIX) of the lung, a total of 201 cases were classified into three main subgroups according to the most differentiated histological growth pattern; namely bronchioloalveolar carcinoma (BAC)‐mixed, which was the most predominant (73.1%), papillary (PAP)‐mixed (21.9%), and acinar‐mixed (5%). The PAP‐mixed was significantly male predominant and had more progressed clinicopathological features. A significant cytological difference was observed among the three subgroups. A tissue microarray was constructed and immunohistochemistry was undertaken using 15 biomarkers. Hierarchical clustering analysis was separately applied to the immunohistochemical results of ADMIX and ADMIX subgroups, and it was found that most acinar‐mixed cases were placed in a separate cluster, while the BAC‐mixed and PAP‐mixed failed to form significant independent clusters. The antibody clustering profile for the acinar‐mixed was clearly different from that for the BAC‐mixed or PAP‐mixed, but the PAP‐mixed shared a dendrogram profile with the other two subgroups. Statistically, approximately half of the 15 biomarkers were significant for differentiating between ADMIX subgroups and between different histological growth patterns. In conclusion, ADMIX can be classified into three histopathological subgroups according to the most differentiated growth pattern, of which a PAP growth pattern might indicate more aggressive behavior than that of a BAC growth pattern.

Prognostic Model of Stage II Non-Small Cell Lung Cancer by a Discriminant Analysis of the Immunohistochemical Protein Expression

PurposeWe aimed to identify the key proteins that influence the prognosis of non-small cell lung cancer (NSCLC) using protein expression profiles of previously known prognostic markers.MethodsThirty-one cases of Stage II NSCLC with 5-year follow-up data were selected. Tissue microarrays (TMA) and immunohistochemistry were used to make protein expression profiles of 18 previously reported immunohistochemical prognostic markers and their value in NSCLC was statistically re-evaluated by a discriminant analysis.ResultsFor the discriminant analysis using marker protein expression profiles, we selected three significant markers, TTF-1, RCAS1 and c-MET, to evaluate each patients 5-year survival. The requested discriminant function was V = −1.08754 × (RCAS1 score) − 0.83174 × (TTF1 score) + 0.55204 × (cMET score) + 5.46972, and V = 0 served as a cut-off point. The correctness for evaluating a patients 5-year survival by a discriminant analysis was 87.1%.ConclusionsA discriminant analysis is thus considered to be a useful statistical method for analyzing the protein expression profiles obtained by combined TMA and immunohistochemical techniques using archival NSCLC tissues. However, the sample size and selection of the marker protein depending on the histology greatly influence the results of a NSCLC study.

Impact of the Bim Deletion Polymorphism on Survival Among Patients With Completely Resected Non–Small-Cell Lung Carcinoma

Purpose A deletion polymorphism of the Bim gene has been reported to be a prognostic factor for patients with non–small-cell lung cancer (NSCLC) treated with epidermal growth factor receptor-tyrosine kinase inhibitors in the Asian population. We investigated the impact of the Bim deletion polymorphism on survival among patients with completely resected NSCLC. Patients and Methods The Bim polymorphism was detected by polymerase chain reaction analysis. We measured overall survival (OS) and recurrence-free survival rates in 411 patients and postrecurrence survival (PRS) in 94 patients who experienced recurrence and received additional anticancer therapy. Results The Bim deletion polymorphism was detected in 61 patients (14.8%). OS rates were significantly lower for patients with the Bim deletion polymorphism than for those with the wild-type sequence. On multivariable analysis, the Bim deletion polymorphism was identified as an independent prognostic factor for OS (hazard ratio, 1.98; 95% CI, 1.17 to 3.36; P = .011). Among the 94 patients who experienced recurrence and were treated with anticancer therapy, patients with the Bim deletion polymorphism showed significantly poorer PRS than those with the wild-type sequence (median, 9.8 months v 26.9 months, respectively; P < .001). Multivariable analysis revealed that the Bim deletion polymorphism was an independent predictor of PRS (hazard ratio, 3.36; 95% CI, 1.75 to 6.47; P < .001). This trend remained apparent in subgroup analyses stratified by EGFR status, histology, and therapeutic modality. Conclusion The Bim deletion polymorphism is a novel indicator of shortened PRS among patients with recurrent NSCLC treated with anticancer therapy in the Asian population.

Pulmonary Large Cell Carcinoma Mimicking an Infected Thoracoabdominal Aortic Aneurysm

Tetsuhiro Nakano, MD, PhD, Kimihiro Shimizu, MD, PhD, Toru Takahashi, MD, PhD,Jun Mohara, MD, PhD, Norimasa Koike, MD, PhD, Osamu Kawashima, MD, PhD,Mitsuhiro Kamiyoshihara, MD, PhD, Masayuki Sugano, MD, Takashi Ibe, MD, PhD,Seiichi Kakegawa, MD, Toshiteru Nagashima, MD, Jun Atsumi, MD, and Izumi Takeyoshi, MD, PhD

Expression of amino acid transporter (LAT1 and 4F2hc) in pulmonary pleomorphic carcinoma

Amino acid transporters are necessary for tumor growth, metastasis, and survival of various neoplasms; however, the clinicopathological significance of L-type amino acid transporter 1 (LAT1) and 4F2 cell surface antigen (4F2hc) in patients with pulmonary pleomorphic carcinoma (PPC) remainsunknown. The aim of this study is to clarify the prognostic impact of these amino acid transporters in PPC. One hundred five patients with surgically resected PPC were assessed by immunohistochemistry. The expression of LAT1 and 4F2hc, and Ki-67 labeling index were investigated using specimens of the resected tumors. LAT1 and 4F2hc were highly expressed in 35% and 53% of all patients (n = 105, P < .01), 25% and 48% of patients with an adenocarcinoma component (n = 48, P = .02), and 44% and 58% of patients with a nonadenocarcinoma component (n = 57, P = .18), respectively. A high LAT1 expression was significantly related to advanced disease, lymphatic permeation, tumor cell proliferation, and 4F2hc expression. By multivariate analysis, LAT1 and 4F2hc were identified as significant independent markers for predicting a worse prognosis. LAT1 is highly expressed in PPC, and high LAT1 expression can serve as a significant predictor linked to a worse prognosis in patients with PPC.