Comparative Evaluation of Super High-Resolution CT Scan and Virtual Bronchoscopy for the Detection of Tracheobronchial Malignancies

Novel imaging modalities are currently available for the noninvasive evaluation of the tracheobronchial tree. This study was undertaken to compare the diagnostic potentials of conventional CT scanning, super high-resolution CT (SHR-CT) scanning, and virtual bronchoscopy (VB) directly with fiberoptic bronchoscopy (FB) for the detection of tracheobronchial neoplasms. Prospective observer study, in which 44 consecutive patients with thoracic malignancies were evaluated using several diagnostic imaging modalities. Images of the thorax were interpreted by individuals blind to the results of FB for the detection of endoluminal, obstructive, or mucosal lesions. Image acquisition and simulation of the tracheobronchial anatomy were created successfully in all patients. Thirty-two patients who underwent both SHR-CT scanning and VB had correlative FBs within 1 month. In all nine patients who had a normal anatomy, SHR-CT scanning and VB accurately correlated with the FB findings. However, CT scanning demonstrated two false-positive obstructive lesions in one patient. Twenty-three patients had a total of 35 abnormal FB findings. The sensitivities of SHR-CT scanning and VB for the detection of endoluminal, obstructive, and mucosal lesions were 90%, 100%, and 16%, respectively. The overall sensitivities and specificities of SHR-CT scanning and VB were 83% and 100%, respectively. In contrast, CT scanning had sensitivities of 50%, 72%, and 0% for the detection of endoluminal, obstructive, and mucosal lesions with an overall sensitivity and specificity of 59%, and 85%, respectively. There was no case in which conventional CT scanning was better at detecting lesions than either SHR-CT scanning or VB. SHR-CT scanning and VB are accurate, noninvasive methods for identifying obstructions and endoluminal lesions within the respiratory tract. Thus, these novel imaging techniques are valuable as complementary modalities to FB, providing information that is useful for the detection and management of airway malignancies

Metabolomic and BH3 profiling of esophageal cancers: novel assessment methods for precision therapy

Abstract Background Esophageal cancers accounted for nearly 16,000 deaths in 2016. The number of patients with esophageal cancers increases every year. Neoadjuvant chemoradiotherapy (nCRT) prior to esophagectomy is a standard treatment for esophageal cancers. The patients who have no residual tumor (pathological complete response (pCR)) at surgery are the most likely to experience long term survival. Accurately determining which patients will have a pCR will improve prognostic information for patients and families, confirm lack of response to nCRT, or avoid surgery if no residual tumor is present. Imaging, endoscopy, and liquid biomarkers have all failed to detect pCR without performing an esophagectomy. Methods In this study, we are enrolling patients with esophageal adenocarcinoma and squamous cell carcinoma. Patients will undergo standard evaluation including CT scans, laboratory tests, endoscopy with biopsies, and evaluation by a thoracic surgeon. Tissue biopsy is required for enrollment that will be sent for BH3 profiling and metabolomics. Patients will be treated with standard nCRT followed by surgery. Patients with metastatic disease are not eligible. Surgery at the National Cancer Institute will be minimally-invasive robotic surgery. Patients will remain on study indefinitely with regular clinic visits and imaging tests. Discussion The mitochondria are critically involved in the intrinsic pathway apoptosis. Bcl-2 homology domain 3 (BH3) profiling is a technique to measure a cell’s susceptibility to apoptosis. BH3 profiling measures the relative interactions of proteins that induce or block apoptosis. The collective balance of these proteins determines whether a cell is near the threshold to undergo apoptosis. If the cell is near this threshold, then the tumor may be more likely to die when treated with nCRT. The mitochondria secrete metabolites that may be detectable as biomarkers. Metabolomics is a global assessment of all metabolite changes that has been performed for detection, monitoring, prognosis, and treatment response in cancers. Stratification of patients based on whether pCR occurs or not may elucidate metabolomic signatures that may be associated with response. We are asking whether BH3 profiling or a metabolomic signature will correlate with tumor death after nCRT for esophageal cancer. Trial registration NCT03223662; Clinicaltrials.gov. July 21, 2017

Telomerase Variant A279T Induces Telomere Dysfunction and Inhibits Non-Canonical Telomerase Activity in Esophageal Carcinomas

<div><p>Background</p><p>Although implicated in the pathogenesis of several chronic inflammatory disorders and hematologic malignancies, telomerase mutations have not been thoroughly characterized in human cancers. The present study was performed to examine the frequency and potential clinical relevance of telomerase mutations in esophageal carcinomas.</p><p>Methods</p><p>Sequencing techniques were used to evaluate mutational status of <i>telomerase reverse transcriptase (TERT)</i> and <i>telomerase RNA component (TERC)</i> in neoplastic and adjacent normal mucosa from 143 esophageal cancer (EsC) patients. MTS, flow cytometry, time lapse microscopy, and murine xenograft techniques were used to assess proliferation, apoptosis, chemotaxis, and tumorigenicity of EsC cells expressing either wtTERT or TERT variants. Immunoprecipitation, immunoblot, immunofluorescence, promoter-reporter and qRT-PCR techniques were used to evaluate interactions of TERT and several TERT variants with BRG-1 and β-catenin, and to assess expression of cytoskeletal proteins, and cell signaling. Fluorescence in-situ hybridization and spectral karyotyping techniques were used to examine telomere length and chromosomal stability.</p><p>Results</p><p>Sequencing analysis revealed one deletion involving <i>TERC (TERC del 341-360)</i>, and two non-synonymous <i>TERT</i> variants [A279T (2 homozygous, 9 heterozygous); A1062T (4 heterozygous)]. The minor allele frequency of the A279T variant was five-fold higher in EsC patients compared to healthy blood donors (p<0.01). Relative to wtTERT, A279T decreased telomere length, destabilized TERT-BRG-1-β-catenin complex, markedly depleted β-catenin, and down-regulated canonical Wnt signaling in cancer cells; these phenomena coincided with decreased proliferation, depletion of additional cytoskeletal proteins, impaired chemotaxis, increased chemosensitivity, and significantly decreased tumorigenicity of EsC cells. A279T expression significantly increased chromosomal aberrations in mouse embryonic fibroblasts (MEFs) following Zeocin™ exposure, as well as Li Fraumeni fibroblasts in the absence of pharmacologically-induced DNA damage.</p><p>Conclusions</p><p>A279T induces telomere dysfunction and inhibits non-canonical telomerase activity in esophageal cancer cells. These findings warrant further analysis of A279T expression in esophageal cancers and premalignant esophageal lesions.</p></div

Gene expression levels of A279T-transduced cells normalized to wtTERT-transduced cells.

<p>*ND: Not detected.</p

Effects of A279T on genomic stability in normal cells.

<p>A. SKY assay demonstrating that A279T-induces genomic instability in Zeocin™-treated MEF-1 cells. Upper panel: translocations, dicentric, and rearranged chromosomes are present in cells expressing A279T compared to wtTERT. Lower left panel: a multi-centric chromosome observed in cells harboring A279T. Lower right panel: a ring chromosome is formed and every chromosome is rearranged in cells transfected with A279T. See text for additional details. B. Upper panel: representative results of SKY analysis Li Fraumeni fibroblasts constitutively expressing wtTERT or A279T-TERT. Lower panel: close-up of chromosomes 1 and 16. C. Summary of results of two independent experiments demonstrating that A279T expression increases genomic instability in Li Fraumeni cells.</p

A279T inhibits proliferation of esophageal cancer cells.

<p>(*p<0.05; **p<0.01). A. MTS assay demonstrating inhibition of EsC1 (left) and EsC2 (right) proliferation by A279T relative to wtTERT. B. Immunofluorescence analysis (left panel) with corresponding summary (right panel) of Ki67 expression in esophageal cancer cells expressing wtTERT or A279T (Red: Ki67; blue: DAPI). EsC1 and EsC2 cells expressing A279T exhibit decreased Ki67 levels relative to respective cells expressing wtTERT. C. Annexin V-FITC assay demonstrating A279T-induces apoptosis in EsC2 but not EsC1 cells. Results are expressing as mean ± SD of triplicate experiments. D. Graphic summarization of immunofluorescence analysis of β-galactosidase expression in EsC1 and EsC2 following constitutive expression of wtTERT or A279T. Red: β-galactosidase; blue: DAPI.</p