Richard Kim

Minimally invasive surgical staging is superior to endoscopic ultrasound in detecting lymph node metastases in esophageal cancer

OBJECTIVE Endoscopic ultrasonography is frequently used to locally stage esophageal cancer, but few studies exist to validate its accuracy for lymph node metastases. Our objective was to compare endoscopic ultrasonography with video-assisted thoracoscopic and laparoscopic staging in evaluating lymph node metastases in esophageal cancer. METHODS Twenty-six patients with potentially resectable esophageal cancer were identified by conventional imaging. Endoscopic ultrasonography was performed followed by laparoscopic and thoracoscopic staging, and locoregional staging was compared. RESULTS In eight patients endoscopic ultrasonography indicated N0 disease, but laparoscopy and thoracoscopy documented N1 disease in six. In five of 26 (19%) obstruction prevented endoscopic ultrasonography; three had N1 by laparoscopy and thoracoscopy. Thirteen patients had N1 disease according to endoscopic ultrasonography, and 12 of 13 (92%) had N1 disease by laparoscopy and thoracoscopy. The sensitivity and specificity of endoscopic ultrasonography for nodal evaluation were 65% and 66%, respectively. Sensitivity decreased to 44% for lymph node metastases less than 1 cm. No instances of T4 disease were found by surgical staging when endoscopic ultrasonography indicated T3 disease. Endoscopic ultrasonography revealed no distant metastases in any patient, but in four of 26 (15%) laparoscopy identified liver metastases. CONCLUSIONS The accuracy of endoscopic ultrasonography in the diagnosis of lymph node metastases in esophageal cancer was 65% and only 44% for lymph node metastases less than 1 cm diameter. Laparoscopy and thoracoscopy improved the accuracy of staging lymph node metastases in esophageal cancer and had the advantage of evaluating the thoracic and abdominal cavities for metastases.

Autonomous proliferation of colon cancer cells that coexpress transforming growth factor α and its receptor: Variable effects of receptor-blocking antibody

Four human colon adenocarcinoma cell lines, SNU-C1, SNU-C4, SNU-C5, and NCI-H716, that are capable of proliferating autonomously in serum-free medium containing no added peptide growth factors were identified. All four cell lines show epidermal growth factor (EGF) receptors (EGFRs), express transforming growth factor alpha (TGF-alpha) messenger RNA, and release anti-TGF-alpha-immunoreactive molecules. The blocking anti-EGFR monoclonal antibody (mAb) 225 blocks autonomous proliferation of SNU-C1 and SNU-C4 cells. In both of these cell lines, the inhibitory effect of mAb 225 is reversible by the addition of EGF, TGF-alpha, or conditioned medium from any of the four cell lines. In contrast, autonomous proliferation of SNU-C5 and NCI-H716 cells is not inhibited by mAb 225 and is not affected by exogenous EGF, TGF-alpha, or conditioned medium. Together, these data confirm the previous finding that anti-EGFR antibodies can inhibit the proliferation of some carcinoma cell lines that coexpress TGF-alpha and EGFR. However, here it is shown that the mechanisms of autonomous proliferation of colon carcinoma cell lines are heterogeneous and not always sensitive to antibody disruption of TGF-alpha/EGFR autocrine interactions.

Quantitative endoscopy: Precise computerized measurement of metaplastic epithelial surface area in Barrett's esophagus

BACKGROUND/AIMS The inability to precisely measure the area of Barretts metaplasia has impaired the study of its natural history and response to therapy. This study used a novel computer program that creates two-dimensional maps of the esophagus allowing for calculation of the area of Barretts metaplasia. METHODS Endoscopic photographs of Barretts models and patients were obtained by independent endoscopists. The program transformed the photographs into maps, and the area of Barretts metaplasia was calculated. RESULTS Using models, calculated areas correlated with actual areas (r = 0.96) with an overall error of 5.2%. Color, size, shape, diameter of the model, or endoscopists experience did not affect the accuracy. Accuracy did improve by decreasing the interval between photographs from 4 cm (10.0% error) to 2 cm (4.8% error). In patients, area calculations from maps created by independent technicians correlated precisely (r = 0.99) at 1-cm (n = 22) and 2-cm (n = 40) intervals. Independent endoscopists correlated precisely in producing photographs for map construction (r = 0.99; n = 20). CONCLUSIONS This novel computer technology produces two-dimensional maps of Barretts metaplasia that can be used to accurately calculate area. Minimal interobserver variability in obtaining photographs is found.

Extent of Barrett's metaplasia: a prospective study of the serial change in area of Barrett's measured by quantitative endoscopic imaging

BACKGROUND An accurate determination of the extent of Barretts metaplasia is critical to the study of its natural history and response to therapy. Our hypothesis is that area calculations offer advantages over length estimates of Barretts. METHODS Changes in both measures and estimates of progression or regression between two endoscopies in 17 patients were compared. Area was calculated using a computer image analysis technique. RESULTS Although there was no significant difference in length correlation versus area correlation between endoscopies (r = 0.90 vs 0.99), the mean change in absolute length (1.4 +/- 0.2 cm) was greater than the change in area (4.5 +/- 1.4 cm2, equivalent to a length of 0.67 +/- 0.2 cm, p = 0.001). The percent change in absolute length (26.9%) was greater than the change in area (16%, p = 0.001). Discordance of estimates of progression or regression between area and length was found in nine patients. The image technique detected no change in the area of squamous islands. CONCLUSIONS Imaging analysis can precisely measure the extent of Barretts including squamous islands. Area showed little change, whereas measures of length were more varied. Computer based image analysis provides a more precise estimate of interval change of Barretts.