Study On The Correlation Between Spiral CT Features, MVD, The Expression Of VEGF And MMP-7 In Esophageal Carcinoma

Background and purpose: Esophageal carcinoma is one of the common malignant tumors in digestive tract. Considered as an effective method in examination of the esophageal carcinoma, Spiral CT (SCT) can provide with more important information of the tumor. Imaging features of all tumors are based on their pathological natures and are determined by their biological behaviors. Recent reports reveal that tumor angiogenesis is necessary for growth of all-solid tumors. Microvessel density (MVD) can mirror the status of tumor angiogenesis and is regarded as the gold standard to assess tumor angiogenesis. Tumor angiogenesis is regulated by many kinds of correlative factors. Vascular endothelial growth factor (VEGF) is considered as a potent angiogenesis-promoting factor that relates to tumor angiogenesis, infiltration, metastasis and prognosis. Matrix metalloproteinases (MMPs) is a main enzyme to degrade extracelluar matrix. Matrix metalloproteinase 7 (MMP-7) is the only MMP that can be expressed specifically by the epithelial tumor cells, playing an important role in the development of digestive tract tumors. The inherent relationship between modern medical imaging and molecular biology can be found by comparing SCT features of tumor with its biological behaviors. Thepurpose of this study is to evaluate the correlation between SCT features, MVD, the expressions of VEGF and MMP-7 in esophageal carcinoma.Materials and methods: Spiral CT contrast-enhanced scans were performed in 46 patients with esophageal carcinoma before operation. About 10 minutes before the scanning, 15 mg 654-2 was injected intramuscularly. Then 800-1200ml lukewarm water was taken. Spiral CT examination was performed with a GE HiSpeed Advantage Rp22 Helical scanner. The field of scanning included lower neck, mediastinum and upper abdomen. 100ml contrast medium (Omnipaque or Ultravist 300mgI/ml) was injected via cubital vein with the speed of 3ml/s, and the scanning began at 40s after the start of injection. Patients were asked to swallow air during scanning and to hold their breathing for 1 time. The tumor location was defined according to the barium meal examination or esophageal endoscope. The collimation of the tumor location was 5mm, and other parts were 10mm, pitch 1:1, reconstruction depth 5mm. After operation, all the specimens were fixed in 10% neutral formalin and embedded in paraffin. Immunohistochemical streptavidin peroxidase conjugate method was used to analyze the MVD as well as the expressions of VEGF and MMP-7 in esophageal carcinoma. Statistical analysis was performed with SPSS 10.0 software, using Mest, Chi-square test, spearman test and Kappa test. Statistically significant level was considered as "alpha equals 0.05".Results: 1. Compared with operation and pathology, the accuracy of Spiral CT contrast-enhanced scan in judging adjacent-infiltration and lymph node metastasis in 46 patients was 89.13%(41 of 46) and 86.96%(40 of 46); The diagnostic outcome of Spiral CT in judging adjacent-infiltration and lymph node metastasis had good coincidence with operation and pathology(Kappa was 0.726 and 0.721, P < 0.001).2. In 46 cases, microvessel densities ranged from 17.33 to 41.67 with a mean of 30.07(standard deviation, 4.63). In the adjacent-infiltration group and the non-adjacent-infiltration group in SCT features, the microvessel densities were 32.92 + 3.47 and 28.82 + 5.54 respectively and the difference was statistically significant(t=2.389, P=0.021). In the group with lymph nodemetastasis and the group without lymph node metastasis in SCT features, the microvessel densities were 32.67 + 3.92 and 28.41 + 5.49 respectively and the difference was statistically significant(r=2.734, P=0.009).3. In 46 cases, VEGF positive-expression was detected in 18 patients. The VEGF positive rate was 39.13%. In the adjacent-infiltration group and the non-adjacent-infiltration group in SCT features, the positive rates of VEGF protein were 75.00% (9 of 12) and 26.47% (9 of 34) respectively, which had statistically significa...