Timothy A. Woodward

Minimally invasive endoscopic staging of suspected lung cancer.

CONTEXT In patients with suspected lung cancer, the presence of mediastinal lymph node metastasis is a critical determinant of therapy and prognosis. Invasive staging with pathologic confirmation is recommended. Many methods for staging exist; mediastinoscopy, an invasive procedure requiring general anesthesia, is currently regarded as the diagnostic standard. OBJECTIVE To compare the diagnostic accuracy of 3 methods of minimally invasive endoscopic staging (and their combinations): traditional transbronchial needle aspiration (TBNA), endobronchial ultrasound-guided fine-needle aspiration (EBUS-FNA), and transesophageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). In particular, we aimed to compare EBUS-FNA with TBNA. DESIGN, SETTING, AND PARTICIPANTS Invasive staging of the mediastinum among consecutive patients with suspected lung cancer at a US academic medical center from November 2004 through October 2006. INTERVENTION TBNA, EBUS-FNA, and EUS-FNA performed sequentially as a single combined procedure. MAIN OUTCOME MEASURE Sensitivity for detecting mediastinal lymph node metastases, using pathologic confirmation and 6- to 12-month clinical follow-up as the criterion standard. RESULTS Among 138 patients who met all study criteria, 42 (30%) had malignant lymph nodes. EBUS-FNA was more sensitive than TBNA, detecting 29 (69%) vs 15 (36%) malignant lymph nodes (P = .003). The combination of EUS-FNA and EBUS-FNA (EUS plus EBUS) had higher estimated sensitivity (93% [39/42]; 95% confidence interval, 81%-99%) and negative predictive value (97% [96/99]; 95% confidence interval, 91%-99%) compared with either method alone. EUS plus EBUS also had higher sensitivity and higher negative predictive value for detecting lymph nodes in any mediastinal location and for patients without lymph node enlargement on chest computed tomography. CONCLUSIONS These findings suggest that EBUS-FNA has higher sensitivity than TBNA and that EUS plus EBUS may allow near-complete minimally invasive mediastinal staging in patients with suspected lung cancer. These results require confirmation in other studies but suggest that EUS plus EBUS may be an alternative approach for mediastinal staging in patients with suspected lung cancer.

Prospective, Controlled Tandem Endoscopy Study of Narrow Band Imaging for Dysplasia Detection in Barrett's Esophagus

BACKGROUND & AIMS High-resolution endoscopy with narrow band imaging (NBI) enhances the visualization of mucosal glandular and vascular structures. This study assessed whether narrow band targeted biopsies could detect advanced dysplasia using fewer biopsy samples compared with standard resolution endoscopy. METHODS We conducted a prospective, blinded, tandem endoscopy study in a tertiary care center with 65 patients with Barretts esophagus undergoing evaluation for previously detected dysplasia. Standard resolution endoscopy was used first to detect visible lesions. Narrow band endoscopy was then used by another gastroenterologist to detect and biopsy areas suspicious for dysplasia. The lesions initially detected by standard resolution endoscopy were then disclosed and biopsied, after biopsy of the lesions targeted with NBI. Finally, random 4-quadrant biopsies were taken throughout the segment of Barretts mucosa. RESULTS Higher grades of dysplasia were found by NBI in 12 patients (18%), compared with no cases (0%) in whom standard resolution white light endoscopy with random biopsy detected a higher grade of histology (P < .001). Correspondingly, narrow band directed biopsies detected dysplasia in more patients (n = 37; 57%) compared with biopsies taken using standard resolution endoscopy (n = 28; 43%). In addition, more biopsies were taken using standard resolution endoscopy with random biopsy compared with narrow band targeted biopsies (mean 8.5 versus 4.7; P < .001). CONCLUSIONS In patients evaluated for Barretts esophagus with dysplasia, NBI detected significantly more patients with dysplasia and higher grades of dysplasia with fewer biopsy samples compared with standard resolution endoscopy.

Comparison of Probe-Based Confocal Laser Endomicroscopy With Virtual Chromoendoscopy for Classification of Colon Polyps

BACKGROUND & AIMS Probe-based confocal laser endomicroscopy (pCLE) allows in vivo imaging of tissue at micron resolution. Virtual chromoendoscopy systems, such as Fujinon intelligent color enhancement and narrow band imaging, also have potential to differentiate neoplastic colorectal lesions. The accuracy of these systems in clinical practice is, however, unknown. Our primary aim was to compare sensitivity and specificity of pCLE to virtual chromoendoscopy for classification of colorectal polyps using histopathology as a gold standard. A secondary aim was to compare sensitivity and specificity of pCLE to virtual chromoendoscopy using a modified gold standard that assumed that all polyps >/=10 mm had malignant potential and were considered neoplastic or high risk. METHODS Patients underwent colonoscopy using high-resolution colonoscopes. The surface pit pattern was determined with NBI or FICE in all patients. Confocal images were recorded and subsequently analyzed offline, blinded to the endoscopic characteristics and histopathology. Each polyp was diagnosed as benign or neoplastic based on confocal features according to modified Mainz criteria. RESULTS A total of 119 polyps (81 neoplastic, 38 hyperplastic) from 75 patients was assessed. The pCLE had higher sensitivity compared to virtual chromoendoscopy when considering histopathology as gold standard (91% vs 77%; P = .010) and modified gold standard (88% vs 76%; P = .037). There was no statistically significant difference in specificity between pCLE and virtual chromoendoscopy when considering histopathology or modified gold standard. CONCLUSIONS Confocal endomicroscopy demonstrated higher sensitivity with similar specificity in classification of colorectal polyps. These new methods may replace the need for ex vivo histological confirmation of small polyps, but further studies are warranted.

CXC-chemokine/CXCR2 biological axis promotes angiogenesis in vitro and in vivo in pancreatic cancer

Angiogenesis is essential for tumor growth and metastasis. Although ELR+‐CXC‐chemokines and their corresponding receptor, CXC‐receptor 2 (CXCR2), are known mediators of angiogenesis, little is known about their role in pancreatic cancer (PaCa). The aim of our study was to determine the role of ELR+‐CXC‐chemokine/CXCR2 biological axis in promoting PaCa angiogenesis. We prospectively collected secretin‐stimulated exocrine pancreatic secretions (SSEPS) from normal individuals (NP) and PaCa patients. We showed that summed concentrations of ELR+‐CXC‐chemokines in SSEPS from PaCa patients were significantly higher than in those from NP (p = 0.002). We measured ELR+‐CXC‐chemokine levels in supernatants from multiple PaCa cell lines and confirmed that BxPC‐3, Colo‐357 and Panc‐28 had significantly higher expression compared with an immortalized human pancreatic ductal epithelial (HPDE) cell line. After confirming lack of autocrine effects of ELR+‐CXC‐chemokines on PaCa cells (due to absence of CXCR2 expression), we investigated paracrine effects of these chemokines on human umbilical vein endothelial cells (HUVEC). Both recombinant ELR+‐CXC‐chemokines and co‐culturing with BxPC‐3 significantly enhanced proliferation, invasion, and tube formation of HUVEC (p < 0.05). These biological effects were significantly inhibited by treatment with a neutralizing antibody against CXCR2 (anti‐CXCR2 Ab) (p < 0.05). Finally, anti‐CXCR2 Ab significantly reduced tumor volume (p < 0.05), Ki‐67 proliferation index (p = 0.043) and Factor VIII+ microvessel density (p = 0.004) in an orthotopic nude mouse PaCa model. Our results show that ELR+‐CXC‐chemokines promote PaCa tumor‐associated angiogenesis through CXCR2, suggesting that CXCR2 is an anti‐angiogenic target in PaCa.

Photodynamic Therapy for Dysplastic Barrett Esophagus and Early Esophageal Adenocarcinoma

OBJECTIVE To evaluate our results using photodynamic therapy (PDT) for the treatment of dysplasia or superficial cancer (T1 N0 M0) in patients with Barrett esophagus. PATIENTS AND METHODS We retrospectively reviewed our clinical experience with 48 patients (34 patients with high-grade dysplasia and 14 patients with superficial cancer in Barrett esophagus) who had been referred for PDT. Initial evaluation included computed tomography and standard and high-frequency catheter endosonography. Follow-up endoscopy was performed 4 to 6 weeks after PDT with ablation of any residual glandular mucosa, using the argon plasma coagulator. Patients were then followed up indefinitely every 3 to 6 months with computed tomography, endosonography, and endoscopic surveillance. RESULTS The median series follow-up was 18.5 months (range, 1-56 months). Apparent complete photoablation of Barrett mucosa and/or superficial neoplasm was documented in 47 of 48 cases. Complications included symptomatic strictures (11 patients), photosensitivity (7 patients), atrial fibrillation (1 patient) or recurrent congestive heart failure (1 patient), and self-limited esophageal perforation (1 patient). Failure to ablate T1 N0 M0 adenocarcinoma occurred in 1 patient. CONCLUSIONS Porfimer sodium PDT appears to eradicate dysplastic Barrett mucosa and neoplasia. These results are promising; however, long-term studies are needed to document the efficacy of PDT in reducing the morbidity and mortality in such patients.

The learning curve of in vivo probe-based confocal laser endomicroscopy for prediction of colorectal neoplasia.

BACKGROUND Probe-based confocal laser endomicroscopy (pCLE) is an emerging tool for in vivo imaging of the GI tract that requires the endoscopist to interpret microscopic images. The learning curve for interpretation of pCLE images is unknown. OBJECTIVE To examine the learning curve of correctly identifying benign and neoplastic colorectal lesions by using pCLE and to evaluate the learning curve of obtaining high-quality images. DESIGN Prospective, double-blind review of pCLE images of 76 colorectal lesions by using corresponding polypectomies as the reference standard. A training set of 20 images with known histology was first reviewed to standardize image interpretation, followed by blinded review of 76 unknown images. SETTING Eleven endoscopists from 3 different endoscopy centers evaluated the images obtained by 1 endoscopist using the high-definition confocal probe. PATIENTS Patients undergoing screening and surveillance colonoscopies. INTERVENTION Intravenous fluorescein pCLE imaging of colorectal lesions followed by polypectomies. MAIN OUTCOME MEASUREMENTS Accuracy of image interpretation with constructing learning curve for pCLE image interpretation and acquisition. RESULTS Of the 76 colorectal lesions, 51 (67%) were neoplastic and 25 (33%) were benign, based on histopathology. Accuracy for the overall group was 63% for lesions 1 to 20, 64% for lesions 21 to 40, 79% for lesions 41 to 60, and 86% for lesions 61 to 76. The ability to obtain high-quality images was stable over the 76 cases. LIMITATIONS Small sample size and use of offline video sequences. CONCLUSIONS Accurate interpretation of pCLE images for predicting neoplastic lesions can be learned rapidly by a wide range of GI specialists. Furthermore, the ability to acquire high-quality pCLE images is also quickly learned.

Diagnostic Accuracy of Probe-Based Confocal Laser Endomicroscopy and Narrow Band Imaging for Small Colorectal Polyps: A Feasibility Study

OBJECTIVES:Probe-based confocal laser endomicroscopy (pCLE) allows real-time in-vivo microscopic imaging of tissue. Narrow band imaging (NBI) can also classify colorectal lesions. Both systems may allow accurate optical diagnosis of small (6–9 mm) and diminutive (1–5 mm) polyps without histopathology. This study assesses the accuracy of pCLE and NBI for prediction of histology.METHODS:Participants underwent high-definition colonoscopy. The surface pit pattern of all polyps (1–9 mm) was determined in vivo using NBI. Confocal videos were obtained after administration of IV fluorescein. Recorded videos were subsequently analyzed offline, blinded to endoscopic characteristics, and histopathology. Confocal images were classified as neoplastic and non-neoplastic according to the Miami classification system.RESULTS:A total of 130 polyps (58 neoplastic, 72 non-neoplastic, mean size 4.6 mm) from 65 patients were assessed. Assuming histopathology as gold standard, pCLE had higher sensitivity than NBI (86% vs. 64%, P=0.008), with lower specificity (78% vs. 92%, p=0.027) and similar overall accuracy (82% vs. 79%, P=0.59). When 65 high-confidence cases were analyzed (polyps diagnosed identically with pCLE and NBI and with high-quality confocal videos), sensitivity and specificity were 94 and 97%.CONCLUSIONS:pCLE demonstrated higher sensitivity in predicting histology of small polyps compared with NBI, whereas NBI had higher specificity. When used in combination, the accuracy of pCLE and NBI was extremely high, approaching the accuracy of histopathology. Together, they may reduce the need for histological examination. However, further studies are warranted to evaluate the role of these techniques, especially in the population-based colon cancer screening.

Economic analysis of combined endoscopic and endobronchial ultrasound in the evaluation of patients with suspected non-small cell lung cancer.

Lung cancer remains the most common cause of cancer-related death in the United States. This study evaluated the costs of alternative diagnostic evaluations for patients with suspected non-small cell lung cancer (NSCLC). Researchers used a cost-minimization model to compare various diagnostic approaches in the evaluation of patients with NSCLC. It was less expensive to use an initial endoscopic ultrasound (EUS) with fine needle aspiration (FNA) to detect a mediastinal lymph node metastasis (

Accuracy of endoscopic ultrasonography and magnetic resonance cholangiopancreatography for the diagnosis of chronic pancreatitis : A prospective comparison study

18,603 per patient), compared with combined EUS FNA and endobronchial ultrasound (EBUS) with FNA (

Safety and efficacy of cytology brushings versus standard fine-needle aspiration in evaluating cystic pancreatic lesions: a controlled study.

18,753). The results were sensitive to the prevalence of malignant mediastinal lymph nodes; EUS FNA remained least costly, if the probability of nodal metastases was <32.9%, as would occur in a patient without abnormal lymph nodes on computed tomography (CT). While EUS FNA combined with EBUS FNA was the most economical approach, if the rate of nodal metastases was higher, as would be the case in patients with abnormal lymph nodes on CT. Both of these strategies were less costly than bronchoscopy or mediastinoscopy. The pre-test probability of nodal metastases can determine the most cost-effective testing strategy for evaluation of a patient with NSCLC. Pre-procedure CT may be helpful in assessing probability of mediastinal nodal metastases.