| Background and purpose: Colorectal carcinoma is a common tumor in gastrointestinal tract. In recent years, its incidence is gradually increasing. The diagnosis and the stage of colorectal carcinoma, especially the latter, determined the choice of therapy. Many reports revealed that post-contrast spiral CT (SCT) scan with hypotonic water enema could clearly demonstrate the invasion of adjacent tissues and distant metastasis of colorectal carcinoma, and increase the accuracy of preoperative stage. It is a practical and credible examination for the stage of colorectal carcinoma. Characteristics of SCT appearances of tumor had their specifical basement of pathology. Recent research revealed that matrix metalloproteinase-7 (MMP-7) and matrix metalloproteinase-9 (MMP-9) could degrade the components of the extracellular matrix (ECM), so they played an important role in the invasion and metastasis of colorectal carcinoma. Tissue inhibitor of metalloproteinase-1 (TIMP-1) is inhibitor of MMPs, which operated a negative adjustment in the degrading of ECM, thereby inhibited tumor invasion and metastasis. SCT signs were compared with the expressions of MMP-7, MMP-9 and TIMP-1 to investigate the relationship betweenpathology, molecular biology and SCT appearances of colorectal carcinoma, and to study biologic characteristics of invasion and metastasis of colorectal carcinoma.Materials and methods: Pre- and post-contrast hypotonic water enema SCT scans were performed in 45 patients with colorectal carcinoma before operation. Laxation was given to patients the day before yesterday before examination. About 15 minutes before the scanning, 20mg 654-2 was injected intramuscularly, 1500 -2000ml lukewarm water was administered via a Foley tube. SCT examination was performed with a GE Hispeed Advantage Rp22 helical scanner. The plain scan was taken firstly, scanning parameters of SCT were 120KV, 260mAs, collimation 10mm, pitch=l. A total of 100ml nonionic contrast medium was administered with a power injector at the rate of 3ml/s. Arterial phase (AP) and venous phase (VP) were obtained at 45s, 65-70s after the beginning of the injection, respectively. In post-contrast SCT scan, the parameters were 120KV, 260mAs. On AP scan, only the region of the primary tumor was covered, 5-mm thin slice was adopted. The whole abdomen and pelvis were examined in the VP. All the patients were performed coloproctectomy within one week after SCT scan. Post-operative specimens were fixed in neutral formalin and embedded in paraffin. The expressions of MMP-7, MMP-9 and TIMP-1 were detected immuohistochemically with streptavidin peroxides (SP) assay in 45 carcinomatous tissues, 11 adjacent tissues and 10 normal tissues, respectively. Statistical analysis was executed by SPSS 10.0 software, all binary data were compared using chi-square test or Fisher's exact test of probabilities, and rank data were compared using Spearman's rank correlation, significant difference was defined as/><0.05.Results: (1) The accuracy of post-contrast SCT scan was 86.67%(39/45) in T stage, 82.22%(37/45) in N stage and 100%(45/45) in M stage of colorectal carcinoma. The accuracy of SCT for TNM and Dukes stage of colorectal carcinoma were 82.22%(37/45) and 88.89%(40/45), respectively.(2) The MMP-7 positive rates were 75.56% ( 34/45 ) ,54.55 % ( 6/11 ) and 10.00%(1/10) in carcinomatous tissues, adjacent tissues and normal tissues, respectively.There were remarkable differences between these groups(P=0.000); The MMP-9positive rates in the above three tissues were 66.67% (30/45) ,54.55% (6/11) and 20.00% (2/10) , respectively. There were significant differences between these groups( P<0.05); The TIMP-1 positive rates in the above three tissues were 37.78% (17/28) ,45.45% (5/11) and 90.00% (9/10), respectively. There were also significant differences between these groups (P<0.05).(3) In the serosa infiltration group and the non-serosa infiltration group on SCT features of colorectal carcinoma, the positive rates of MMP-7 protein were 88.00%( 22/25 ) and 60.00 %... |
PDF Full Text Request