Functional and protein­protein interaction network analysis of colorectal cancer induced by ulcerative colitis.

Colorectal cancer (CRC) is a well­recognized complication of ulcerative colitis (UC), and patients with UC have a higher incidence of CRC, compared with the general population. However, the properties of CRC induced by UC have not been clarified using an interaction network to analyze and compare gene sets. In the present study, six microarray datasets of CRC and UC were extracted from the Array Express database, and gene signatures were identified using the genome­wide relative significance (GWRS) method. Functional analysis was performed based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Prediction of the genes and microRNA were performed using a hypergeometric method. A protein­protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/proteins, and clusters were obtained through the Molecular Complex Detection algorithm. Topological centrality and a novel analyzing method, based on the rank value of GWGS, were used to characterize the biological importance of the clusters. A total of 217 differentially expressed (DE) genes of CRC were identified, 341 DE genes were identified in UC, and 62 common genes existed in the two. Several KEGG pathways were the same in CRC and UC. Collagenase, progesterone, heparin, urokinase, nadh and adenosine drugs demonstrated potential for use in treatment of CRC and UC. In the PPI network of CRC, 210 nodes and 752 edges were observed, wheras 314 nodes and 882 edges were identified in UC. Cluster 3 in UC had the highest GWGS, while the topological centrality of Cluster 3 in UC had the lowest degree and betweenness. PPI network analysis provided an effective way to estimate and understand the likelihood of the potential connections between proteins/genes. The results obtained following the use of GWGS to analyze differences between clusters did not agree with the topological degree and betweenness centrality, which indicated that gene fold change based GWGS was controversial with degree here in CRC and UC.

Preservation of the continence function after intersphincteric resection using a prolapsing technique in the patients with low rectal cancer and its clinical prognosis.

BACKGROUND: The technique of intersphincteric resection of tumors combined with coloanal anastomosis has been used to avoid permanent colostomy for patients with a rectal cancer located < 5 cm from the anal verge. This study aimed at assessing the preservation of continence function of the residual rectum and the clinical prognosis of patients with lower rectal cancer after intersphincteric resection using a prolapsing technique. METHODS: This study included patients with the following inclusion criteria: (1) pathological evidence of rectal cancer and the tumors within distal margins located 5 cm or less from the anus by preoperative endoscopic examination; (2) no evidence by MRI of infiltration of either the external sphincter, puborectalis or the levator muscle; (3) the patients are eligible for intersphincteric resection and lower coloanal anastomosis with a preoperative biopsy showing the tumors with well-to-moderate differentiation. From January 2000 to June 2004, 23 patients with low rectal cancer were included in this study. We used the standard abdominoperineal approach to perform radical resection of tumors with excision of the mesorectum and total or part of the internal sphincters. The patients were followed for assessment of the function of the residual rectum and of cancer recurrence after the operations. RESULTS: The median tumor distance from the anal margin was 4.5 (range 3.5 - 5.0) cm and the mean distal surgical margin 1.6 (range 1.0 - 2.0) cm. Cancer was classified into Stage I (30.4%), Stage II (47.8%), and Stage III (21.7%) according to the TNM classification. Two patients developed anastomotic fistula after the surgical resection and 2 patients (8.7%) developed later stages of anastomotic stricture at the site of coloanal anastomosis. The median follow-up period was 31.5 months (range 12 - 54) and 2 patients (8.7%) developed local recurrence. Three deaths were associated with distal organ metastasis. Twenty patients (87.0%) have maintained competence to control solid or liquid stool and the capacity of flatus continence after the surgery. Among these patients, 2 patients were able to control solid stool and occasionally lose continence of liquid stool. And only 1 patient (4.4%) has retained partial rectum function with good continence of solid stool but not liquid after the operations. Average times of defecation per day of 3, 6, 12, 24 and 36 months after the surgery were 13.1, 4.7, 3.1, 2.9, and 3.2 times/day. Anal manometer measurements showed a decrease of pressure during the resting time after intersphincteric resection and this change remained during the period of follow-up. The maximum squeeze pressure was improved after an initial decrease after the surgery. CONCLUSIONS: More residual rectum function after the surgery may be preserved by intersphincteric resection of low rectum cancer. At the same time this technique is safe with few postoperative complication and low tumor recurrence after the surgery.

[Accuracy of preoperative magnetic resonance imaging in prediction of pathological stage and circumferential resection margin in rectal cancer].

OBJECTIVE: To evaluate the accuracy of preoperative magnetic resonance imaging (MRI) in prediction of pathological staging and involvement of circumferential resection margin (CRM) in rectal cancer. METHODS: Fifty-three patients undergoing total mesorectal excision for biopsy-proven rectal cancer were assessed prospectively using high-resolution MRI for tumour (T) and mesorectal nodal (N) staging as well as CRM status using the depth of tumour spread, tumour node metastasis and CRM involvement. Preoperative MRI assessment of these prognostic factors was compared with the histopathological findings in carefully matched whole-mount sections of the specimen. RESULTS: MRI correctly staged the tumor in 41 patients, understaged in 8, and overstaged in 4. The accuracy of T stage was 77.4% (41/53). There was ageneric correlation between pathologic and MRI tumor staging (Kappa = 0.602, P < 0.001). Node status was correctly staged in 37 patients, overstaged in 10, and understaged in 6. The accuracy of node staging was 69.8% (37/53), sensitivity was 75% (18/24), and specificity was 65.5% (19/29). The correlation between pathologic and MRI node staging was poor (Kappa = 0.399, P = 0.003). The CRM status was correctly reported in 51 patients, overstaged in 1, and understaged in 1. The accuracy of CRM status was 96.2% (51/53), sensitivity was 80% (1/5), and specificity was 97.9% (47/48). There was a good correlation between pathologic and MRI CRM involvement (Kappa = 0.779, P < 0.001). CONCLUSION: Preoperative MRI provides poor predictive data as to subsequent pathologic tumor and mesorectal node stage, but does produce reliable prediction of clear CRM.

[Application of single stapler combined with prolapsing technique in anterior resection of ultra-low rectal cancer].

OBJECTIVE: Evaluation of single stapler combined with prolapsing technique for anus-preserving of ultra-low rectal cancer and its indication as well as surgical procedure. METHODS: Forty-three patients with ultra-low low rectal cancer suitable for anterior resection were divided into two groups, single stapler combined with prolapsing technique was applied for experiment group, conventional double stapler technique was applied for control group. To compare the distal margin, local recurrence rate, complications, anal continence function and expenses. RESULTS: The distal margin of experimental group is significantly longer than that of control group (2.2 cm +/- 0.2 cm VS 1.9 cm +/- 0.4 cm, P = 0.006). The distance between dentate line and distal incision line of control group is much longer than experimental group (1.9 cm +/- 0.5 cm VS 1.3 cm +/- 0.3 cm, P < 0.001). There is no recurrence in experimental group but 3 cases recurrence within 1 year in control group. The anastomose fistula rate, instrument expenses of experimental group are less than those of control group. There is no distinct in anal continence between two groups. Occasional minor soiling is present in 1 case of experimental group. CONCLUSION: Single stapler combined with prolapsing technique is superior to double stapler technique for anus-preserving of ultra-low rectal cancer.