[Posterior Mediastinal Desmoid Tumor Suspected to be a Neurogenic Tumor Before Surgery:Report of a Case].

A man in his 50s who presented an abnormal shadow on chest X-ray was diagnosed with posterior mediastinal tumor that had grown compared to the previous chest X-ray. Computed tomography showed a 5.7×3.9 cm solid mass with a smooth surface in the posterior mediastinum. A neurogenic tumor was suspected, and the mediastinal tumor was resected through thoracotomy because it was strongly adherent. The postoperative course was good, and he was discharged from the hospital on postoperative day 3. Contrary to preoperative expectations, the tumor was pathologically diagnosed as a desmoid tumor. After 6 months postoperatively without any complications, no recurrence was observed.

[Giant Mature Cystic Teratoma Causing Loss of Consciousness before Surgery].

A 30-year-old woman who presented loss of consciousness was diagnosed as having large anterior mediastinal tumor. Computed tomography (CT) showed a 17.0×13.0×7.3 cm cystic mass with internal calcification in the anterior mediastinum that was markedly compressing the heart, great vessels, trachea and bronchi. A mature cystic teratoma was suspected, and the mediastinal tumor was resected through a median sternotomy. At the induction of anesthesia to prevent the development of the respiratory and circulatory collapse, the patient was consciously intubated under the right lateral decubitus position while preparing for percutaneous cardiopulmonary support by cardiac surgeons, and the surgery was safely performed. The tumor was pathologically diagnosed as a mature cystic teratoma, and symptoms such as loss of consciousness have disappeared.

The Diagnostic Utility of Cell-Free DNA from Ex Vivo Bronchoalveolar Lavage Fluid in Lung Cancer.

Although bronchoscopy is generally performed to diagnose lung cancer, its diagnostic yield remains unsatisfactory. Assuming that lung cancer cells release cell-free DNA into the epithelial lining fluid, we hypothesized that lung cancer could be diagnosed by analyzing gene mutations in cell-free DNA in this fluid. This study included 32 patients with lung cancer who underwent surgery at our hospital. Bronchoalveolar lavage (BAL) was performed on the resected lung samples (ex vivo BAL model) after lobectomy. Each DNA sample (i.e., BAL fluid, primary lesion, and plasma) underwent deep targeted sequencing. Gene mutation analyses in the BAL fluid samples identified mutations identical to those in the primary lesions in 30 (93.8%) of 32 patients. In contrast, the microscopic cytology of the same BAL fluid samples yielded a diagnosis of lung cancer in only one of 32 patients, and the analysis of plasma samples revealed gene mutations identical to those in the primary lesions in only one of 32 patients. In conclusion, cell-free DNA released from lung cancer cells exists more abundantly in the airway than in the blood. The collection and analysis of the BAL fluid containing cell-free DNA derived from lung cancer can thus allow lung cancer diagnosis and the screening of driver mutations.

Sphingomonas and Phenylobacterium as Major Microbiota in Thymic Epithelial Tumors.

The microbiota has been reported to be closely associated with carcinogenesis and cancer progression. However, its involvement in the pathology of thymoma remains unknown. In this study, we aimed to identify thymoma-specific microbiota using resected thymoma samples. Nineteen thymoma tissue samples were analyzed through polymerase chain reaction amplification and 16S rRNA gene sequencing. The subjects were grouped according to histology, driver mutation status in the GTF2I gene, PD-L1 status, and smoking habits. To identify the taxa composition of each sample, the operational taxonomic units (OTUs) were classified on the effective tags with 97% identity. The Shannon Index of the 97% identity OTUs was calculated to evaluate the alpha diversity. The linear discriminant analysis effect size (LEfSe) method was used to compare the relative abundances of all the bacterial taxa. We identified 107 OTUs in the tumor tissues, which were classified into 26 genera. Sphingomonas and Phenylobacterium were identified as abundant genera in almost all the samples. No significant difference was determined in the alpha diversity within these groups; however, type A thymoma tended to exhibit a higher bacterial diversity than type B thymoma. Through the LEfSe analysis, we identified the following differentially abundant taxa: Bacilli, Firmicutes, and Lactobacillales in type A thymoma; Proteobacteria in type B thymoma; Gammaproteobacteria in tumors harboring the GTF2I mutation; and Alphaproteobacteria in tumors without the GTF2I mutation. In conclusion, Sphingomonas and Phenylobacterium were identified as dominant genera in thymic epithelial tumors. These genera appear to comprise the thymoma-specific microbiota.

Streptococcus australis and Ralstonia pickettii as Major Microbiota in Mesotheliomas.

The microbiota has been reported to be correlated with carcinogenesis and cancer progression. However, its involvement in the pathology of mesothelioma remains unknown. In this study, we aimed to identify mesothelioma-specific microbiota using resected or biopsied mesothelioma samples. Eight mesothelioma tissue samples were analyzed via polymerase chain reaction (PCR) amplification and 16S rRNA gene sequencing. The operational taxonomic units (OTUs) of the effective tags were analyzed in order to determine the taxon composition of each sample. For the three patients who underwent extra pleural pneumonectomy, normal peripheral lung tissues adjacent to the tumor were also included, and the same analysis was performed. In total, 61 OTUs were identified in the tumor and lung tissues, which were classified into 36 species. Streptococcus australis and Ralstonia pickettii were identified as abundant species in almost all tumor and lung samples. Streptococcus australis and Ralstonia pickettii were found to comprise mesothelioma-specific microbiota involved in tumor progression; thus, they could serve as targets for the prevention of mesothelioma.

Detection of the early stage of spontaneous hemopneumothorax by CT attenuation values.

Spontaneous hemopneumothorax is potentially fatal and can mimic spontaneous pneumothorax when changes in vital signs and bloody discharge from the chest tube are absent. Attenuation values at computed tomography may help detect this condition.

Primary Driver Mutations in GTF2I Specific to the Development of Thymomas.

Thymomas are rare mediastinal tumors that are difficult to treat and pose a major public health concern. Identifying mutations in target genes is vital for the development of novel therapeutic strategies. Type A thymomas possess a missense mutation in GTF2I (chromosome 7 c.74146970T>A) with high frequency. However, the molecular pathways underlying the tumorigenesis of other thymomas remain to be elucidated. We aimed to detect this missense mutation in GTF2I in other thymoma subtypes (types B). This study involved 22 patients who underwent surgery for thymomas between January 2014 and August 2019. We isolated tumor cells from formalin-fixed paraffin-embedded tissues from the primary lesions using laser-capture microdissection. Subsequently, we performed targeted sequencing to detect mutant GTF2I coupled with molecular barcoding. We used PyClone analysis to determine the fraction of tumor cells harboring mutant GTF2I. We detected the missense mutation (chromosome 7 c.74146970T>A) in GTF2I in 14 thymomas among the 22 samples (64%). This mutation was harbored in many type B thymomas as well as type A and AB thymomas. The allele fraction for the tumors containing the mutations was variable, primarily owing to the coexistence of normal lymphocytes in the tumors, especially in type B thymomas. PyClone analysis revealed a high cellular prevalence of mutant GTF2I in tumor cells. Mutant GTF2I was not detected in other carcinomas (lung, gastric, colorectal, or hepatocellular carcinoma) or lymphomas. In conclusion, the majority of thymomas harbor mutations in GTF2I that can be potentially used as a novel therapeutic target in patients with thymomas.

Dual-molecular barcode sequencing detects rare variants in tumor and cell free DNA in plasma.

Conventional next generation sequencing analysis has provided important insights into cancer genetics. However, the detection of rare (low allele fraction) variants remains difficult because of the error-prone nucleotide changes derived from sequencing/PCR errors. To eliminate the false-positive variants and detect genuine rare variants, sequencing technology combined with molecular barcodes will be useful. Here, we used the newly developed dual-molecular barcode technology (Ion AmpliSeq HD) to analyze somatic mutations in 24 samples (12 tumor tissues and 12 plasma) from 12 patients with biliary-pancreatic and non-small cell lung cancers. We compared the results between next generation sequencing analysis with or without molecular barcode technologies. The variant allele fraction (VAF) between non-molecular barcode and molecular barcode sequencing was correlated in plasma DNA (R2 = 0.956) and tumor (R2 = 0.935). Both methods successfully detected high VAF mutations, however, rare variants were only identified by molecular barcode sequencing and not by non-molecular barcode sequencing. Some of these rare variants in tumors were annotated as pathogenic, and therefore subclonal driver mutations could be observed. Furthermore, the very low VAF down to 0.17% were identified in cell free DNA in plasma. These results demonstrate that the dual molecular barcode sequencing technologies can sensitively detect rare somatic mutations, and will be important in the investigation of the clonal and subclonal architectures of tumor heterogeneity.

Association of Mutation Profiles with Postoperative Survival in Patients with Non-Small Cell Lung Cancer.

Findings on mutations, associated with lung cancer, have led to advancements in mutation-based precision medicine. This study aimed to comprehensively and synthetically analyze mutations in lung cancer, based on the next generation sequencing data of surgically removed lung tumors, and identify the mutation-related factors that can affect clinical outcomes. Targeted sequencing was performed on formalin-fixed paraffin-embedded surgical specimens obtained from 172 patients with lung cancer who underwent surgery in our hospital. The clinical and genomic databases of the hospital were combined to determine correlations between clinical factors and mutation profiles in lung cancer. Multivariate analyses of mutation-related factors that may affect the prognosis were also performed. Based on histology, TP53 was the driver gene in 70.0% of the cases of squamous cell carcinoma. In adenocarcinoma cases, driver mutations were detected in TP53 (26.0%), KRAS (25.0%), and epidermal growth factor receptor (EGFR) (23.1%). According to multivariate analysis, the number of pathogenic mutations (≥3), presence of a TP53 mutation, and TP53 allele fraction >60 were poor prognostic mutational factors. The TP53 allele fraction tended to be high in caudally and dorsally located tumors. Moreover, TP53-mutated lung cancers located in segments 9 and 10 were associated with significantly poorer prognosis than those located in segments 1-8. This study has identified mutation-related factors that affect the postoperative prognosis of lung cancer. To our knowledge, this is the first study to demonstrate that the TP53 mutation profile varies with the site of lung tumor, and that postoperative prognosis varies accordingly.

Identification of Clonality through Genomic Profile Analysis in Multiple Lung Cancers.

In cases of multiple lung cancers, individual tumors may represent either a primary lung cancer or both primary and metastatic lung cancers. In this study, we investigated the differences between clinical/histopathological and genomic diagnoses to determine whether they are primary or metastatic. 37 patients with multiple lung cancers were enrolled in this study. Tumor cells were selected from tissue samples using laser capture microdissection. DNA was extracted from those cells and subjected to targeted deep sequencing. In multicentric primary lung cancers, the driver mutation profile was mutually exclusive among the individual tumors, while it was consistent between metastasized tumors and the primary lesion. In 11 patients (29.7%), discrepancies were observed between genomic and clinical/histopathological diagnoses. For the lymph node metastatic lesions, the mutation profile was consistent with only one of the two primary lesions. In three of five cases with lymph node metastases, the lymph node metastatic route detected by genomic diagnosis differed from the clinical and/or pathological diagnoses. In conclusion, in patients with multiple primary lung cancers, cancer-specific mutations can serve as clonal markers, affording a more accurate understanding of the pathology of multiple lung cancers and their lymphatic metastases and thus improving both the treatment selection and outcome.

Genome analysis of peeling archival cytology samples detects driver mutations in lung cancer.

INTRODUCTIONS: When tumor tissue samples are unavailable to search for actionable driver mutations, archival cytology samples can be useful. We investigate whether archival cytology samples can yield reliable genomic information compared to corresponding formalin-fixed paraffin-embedded (FFPE) tumor samples. PATIENTS AND METHODS: Pretreatment class V archival cytology samples with adequate tumor cells were selected from 172 lung cancer patients. The genomic profiles of the primary lung tumors have been analyzed through whole-exome regions of 53 genes. We compared the genomic profiles based on the oncogenicity and variant allele frequency (VAF) between the archival cytology and the corresponding primary tumors. We also analyzed the genomic profiles of serial cytological samples during the treatment of EGFR-TKI. RESULTS: A total of 43 patients were analyzed with the paired samples for DNA mutations and other three patients were analyzed for their fusion genes. A total of 672 mutations were detected. Of those, 106 mutations (15.8%) were shared with both samples. Sixty of seventy-seven (77.9%) shared mutations were oncogenic or likely oncogenic mutations with VAF ≧10%. As high as 90% (9/10) actionable driver mutations and ALK and ROS1 fusion genes were successfully detected from archival cytology samples. Sequential analysis revealed the dynamic changes in EGFR-TKI-resistant mutation (EGFR p.T790M) during the course of treatment. CONCLUSION: Archival cytology sample with adequate tumor cells can yield genetic information compared to the primary tumors. If tumor tissue samples are unavailable, we can use archival cytology samples to search for actionable driver mutations.

Stereotactic Radiotherapy for Oligometastasis.

Oligometastatic disease is defined as "a condition with a few metastases arising from tumors that have not acquired a potential for widespread metastases." Its behavior suggests a transitional malignant state somewhere between localized and metastatic cancer. Treatment of oligometastatic disease is expected to achieve long-term local control and to improve survival. Historically, patients with oligometastases have often undergone surgical resection since it was anecdotally believed that surgical resection could result in progression-free or overall survival benefits. To date, no prospective randomized trials have demonstrated surgery-related survival benefits. Short courses of highly focused, extremely high-dose radiotherapies (e.g., stereotactic radiosurgery and stereotactic ablative body radiotherapy (SABR)) have frequently been used as alternatives to surgery for treatment of oligometastasis. A randomized study has demonstrated the overall survival benefits of stereotactic radiosurgery for solitary brain metastasis. Following the success of stereotactic radiosurgery, SABR has been widely accepted for treating extracranial metastases, considering its efficacy and minimum invasiveness. In this review, we discuss the history of and rationale for the local treatment of oligometastases and probe into the implementation of SABR for oligometastatic disease.

PD-L1 Expression and Tumor-Infiltrating Lymphocytes in Thymic Epithelial Neoplasms.

Thymic epithelial tumors (TETs) are rare malignant mediastinal tumors that are difficult to diagnose and treat. The programmed death 1 (PD-1) receptor and its ligand (PD-L1) are expressed in various malignant tumors and have emerged as potential immunotherapeutic targets. However, the immunobiology of TETs is poorly understood. We evaluated PD-L1 expression and the presence of tumor-infiltrating lymphocytes (CD8 and CD3 expression) in surgical TET specimens from 39 patients via immunohistochemistry and determined their relation to clinicopathological parameters. Cases with membranous reactivity of the PD-L1 antibody in ≥1% of tumor cells were considered positive. Positive PD-L1 expression was observed in 53.9% of cases. Histologically, PD-L1 expression was positive in 2/6 type A, 2/6 type AB, 3/9 type B1, 4/4 type B2, 5/6 type B3, and 5/8 type C TET cases. Thus, the number of cases with PD-L1 expression and the percent expression of PD-L1 were significantly higher in more aggressive thymomas (type B2 or B3). CD3+ and CD8+ tumor-infiltrating lymphocytes were diffusely and abundantly distributed in all cases. These data suggest that a PD-1/PD-L1 blockade is a promising treatment for TETs, with more beneficial treatment effects for aggressive thymomas such as type B2 or B3.

Clinical Implications of Noncoding Indels in the Surfactant-Encoding Genes in Lung Cancer.

Lung cancer arises from the accumulation of genetic mutations, usually in exons. A recent study identified indel mutations in the noncoding region of surfactant-encoding genes in lung adenocarcinoma cases. In this study, we recruited 94 patients with 113 lung cancers (88 adenocarcinomas, 16 squamous cell carcinomas, and nine other histologies) who had undergone surgery in our department. A cancer panel was designed in-house for analyzing the noncoding regions, and targeted sequencing was performed. Indels in the noncoding region of surfactant-encoding genes were identified in 29/113 (25.7%) cases and represent the precise cell of origin for the lung cancer, irrespective of histological type and/or disease stage. In clinical practice, these indels may be used as clonal markers in patients with multiple cancers and to determine the origin of cancer of unknown primary site.

Genomic Characteristics of Invasive Mucinous Adenocarcinomas of the Lung and Potential Therapeutic Targets of B7-H3.

Pulmonary invasive mucinous adenocarcinoma (IMA) is considered a variant of lung adenocarcinomas based on the current World Health Organization classification of lung tumors. However, the molecular mechanism driving IMA development and progression is not well understood. Thus, we surveyed the genomic characteristics of IMA in association with immune-checkpoint expression to investigate new potential therapeutic strategies. Tumor cells were collected from surgical specimens of primary IMA, and sequenced to survey 53 genes associated with lung cancer. The mutational profiles thus obtained were compared in silico to conventional adenocarcinomas and other histologic carcinomas, thereby establishing the genomic clustering of lung cancers. Immunostaining was also performed to compare expression of programmed death ligand 1 (PD-L1) and B7-H3 in IMA and conventional adenocarcinomas. Mutations in Kirsten rat sarcoma viral oncogene homolog (KRAS) were detected in 75% of IMAs, but in only 11.6% of conventional adenocarcinomas. On the other hand, the frequency of mutations in epidermal growth factor receptor (EGFR) and tumor protein p53 (TP53) genes was 5% and 10%, respectively, in the former, but 48.8% and 34.9%, respectively, in the latter. Clustering of all 78 lung cancers indicated that IMA is distinct from conventional adenocarcinoma or squamous cell carcinoma. Strikingly, expression of PD-L1 in ≥1% of cells was observed in only 6.1% of IMAs, but in 59.7% of conventional adenocarcinomas. Finally, 42.4% and 19.4% of IMAs and conventional adenocarcinomas, respectively, tested positive for B7-H3. Although currently classified as a variant of lung adenocarcinoma, it is also reasonable to consider IMA as fundamentally distinct, based on mutation profiles and genetic clustering as well as immune-checkpoint status. The immunohistochemistry data suggest that B7-H3 may be a new and promising therapeutic target for immune checkpoint therapy.

Impact of comorbidity index on morbidity and survival in non-small cell lung cancer.

BACKGROUND: The number of surgeries in older patients with comorbidities is constantly growing. The present study examined the impact of comorbidity on postoperative complications and long-term survival in patients with completely resected non-small cell cancer. METHODS: Between 2004 and 2008, 423 patients with non-small cell lung cancer underwent complete resection. A retrospective comparison of perioperative mortality, morbidity, Charlson comorbidity index (CCI), and postoperative length of hospital stay was performed. RESULTS: The number of patients with CCI 0, 1-2, and ≥ 3 was 226, 170 and 27, respectively. The 5-year overall survival was 88% among patients with CCI 0, and 84% in those with CCI ≥ 1 (p = 0.05) in all pathological stages. The CCI 0 group had significantly better overall survival than CCI 0 group and 30 (15%) in the CCI ≥ 1 group (p = 0.024). Length of stay was shorter in the CCI 0 group (11 ± 5 days) than in the CCI ≥ 1 group (15 ± 19 days, p = 0.015). CONCLUSIONS: A high CCI correlated with higher postoperative morbidity and longer length of stay. We identified better a prognosis in patients with CCI 0 compared to those with CCI 1-2.

Pulmonary arterial enlargement predicts cardiopulmonary complications after pulmonary resection for lung cancer: a retrospective cohort study.

BACKGROUND: The finding of pulmonary arterial enlargement on computed tomography has been reported to be associated with pulmonary hypertension. On the other hand, pulmonary hypertension is a known risk factor for thoracic surgery. We investigated whether pulmonary arterial enlargement predicts cardiopulmonary complications following pulmonary resection for lung cancer. METHODS: We reviewed 237 consecutive patients who underwent pulmonary resection for lung cancer. Preoperative patient characteristics (sex, age, Brinkman index, cardiopulmonary comorbidities, cardiothoracic ratio, pulmonary function, and pulmonary arterial enlargement) and surgical data (surgical procedure, pathological stage, postoperative complications, mortality, and length of postoperative hospital stay) were analyzed. In order to evaluate preoperative pulmonary arterial enlargement, we measured the diameter of the main pulmonary artery at its bifurcation and that of the ascending aorta at its widest point using chest computed tomography and calculated the ratio of the former diameter to the latter. RESULTS: In all, 16 patients developed postoperative cardiopulmonary complications and 221 did not. One patient died from postoperative pneumonia. The mean age of patients who developed postoperative cardiopulmonary complications was significantly higher than that of those who did not (78 ± 5 years vs 69 ± 9 years, P=0.0001). The pulmonary artery-to-ascending-aorta ratio was significantly higher in patients who developed postoperative complications than in those who did not (0.94 ± 0.15 vs. 0.81 ± 0.11, P=0.03). Other preoperative patient characteristics and surgical data did not differ significantly between the groups. On multivariate analysis, pulmonary artery-to-ascending-aorta ratio (0.1-point increase; odds ratio 2.3, 95 % confidence interval 1.5-3.5; P=0.0002) and age (1-year increase; odds ratio 1.2, 95 % confidence interval 1.1-1.3; P=0.03) were found to be independent predictors of postoperative cardiopulmonary complications. CONCLUSIONS: A finding of pulmonary arterial enlargement on computed tomography is a potential predictor of postoperative cardiopulmonary complications after lung cancer surgery.

Prognostic impact of preoperative tumor marker levels and lymphovascular invasion in pathological stage I adenocarcinoma and squamous cell carcinoma of the lung.

INTRODUCTION: Some unfavorable prognostic factors for stage I non-small-cell lung cancers have been reported; however, they are not reflected in the current Tumor-Node-Metastasis classification. METHODS: We retrospectively reviewed 629 patients who underwent complete resection of pathological stage I adenocarcinomas (ADs) or squamous cell carcinomas (SQs) at two institutes between 1996 and 2011. The correlation between clinicopathological characteristics and survival rates was analyzed to identify prognostic factors. RESULTS: Multivariate analysis indicated that among ADs, high serum carcinoembryonic antigen levels (p = 0.04 for overall survival [OS]; p < 0.01 for recurrence-free survival [RFS]; p = 0.02 for disease-specific survival [DSS]), lymphatic permeation (p < 0.01 for RFS and DSS), and vascular invasion (p < 0.01 for OS and RFS; p = 0.03 for DSS) were independent prognostic factors. Among SQs, high squamous cell carcinoma antigen (SCC) (p < 0.05 for OS), and vascular invasion (p < 0.05 for RFS and DSS) were independently prognostic. We suggest that among completely resected tumors less than or equal to 5 cm without lymph node metastasis, the current stages IA and IB AD with high serum carcinoembryonic antigen levels, lymphatic permeation, or vascular invasion should be upgraded to stage IB and IIA, respectively. The current stage IA SQ with high SCC antigen levels or vascular invasion should be upgraded to stage IB. These reclassifications accurately reflect survival status (p < 0.04 in all comparisons). CONCLUSIONS: Some important differences in prognostic factors were observed between AD and SQ. High preoperative serum tumor marker levels and lymphovascular invasion should be included as additional criteria in the forthcoming Tumor-Node-Metastasis staging.