To introduce the advances in surgery of rectal cancer and to discuss some of its critical issues. Preserving the anus, diminishing the damage of urinary and sexual function and reducing recurrence are the three major difficulties in surgery of rectal cancer. The surgical margin, the concept of TME, the indication of local surgery, the necessity of pelvic lymphonodectomy and the reconstruction of the colonic sack are important problems in the surgery of rectal cancer.The surgery for preserving the anal function should not go against the fundamental principle of radical surgery. The distal and circumferential margin must be enough. The impairment of urinary and sexual function can be reduced by protecting the pelvic autonomic nerves. There are many factors contributing to the relapse of rectal cancer. TME can reduce markedly recurrence of rectal cancer. The trend of either over-expanding or over-shrinking the indication of local surgery of rectal cancer should be avoided. The extensive dissection of pelvic lymph nodes should be selective. The reconstruction of the colonic sack is valuable to some extent.[

Proteomics is an emerging branch of bioscience which studies proteome. The main techniques in proteomics include sample preparation in proteomic, two-dimensional gel electrophoresis, two-dimensional difference gel electrophoresis, multidimensional protein identification technology, surface enhanced laser desorption/ionization time-of-flight mass spectrometry. Colorectal cancer is one of the most common cancers worldwide. During the last several years, many advances have been achieved in terms of applications of proteomics in biomarker research for colorectal cancer.

Hereditary nonpolyposis colorectal cancer (HNPCC) is a distinct autosomal dominant syndrome, accounting for 5%-10% of the total colorectal cancer population. To date, we have noticed that patients with HNPCC inherit a germline mutation in one of the genes responsible for repair of DNA mismatch errors. Tumors of HNPCC show a high frequency of microsatellite instability. Identifying individuals afflicted with HNPCC has implications for surgical management, prognosis, follow up, and surveillance of HNPCC patients and family members at risk.

Background and purpose: Colorectal cancer (CRC) is the most frequently occurring primary malignant tumor. Chemotherapy can reduce the risk of local and distant relapse. Therefore, it is very important to ifnd new biomarkers that can predict chemoresistant and help in treatment decisions. Methods:In this study, we examined the expression levels of 1 200 human miRNAs in 6 CRC tissues, using miRNA proifling assay arrays. A validation study was done to corroborate a subset of the results, including expression levels of miR-4299, miR-196b, miR-324-5p, miR-455-3p and miR-939, by analyzing 100 specimens of stageⅣcolorectal adenocarcinoma (not respond and respond to the chemotherapy) to quantitative real-time PCR. We modeled the relationship between the expression levels of these miRNAs and the survival rate of 100 CRC patients by Kaplan-Meier method. Results:Expression proifles in CRCs suggested that 5 miRNAs were candidate markers associated with the chemoresistance of colorectal cancer. We found that miR-4299 and-196b had signiifcant diagnostic value for chemoresistance CRC. miR-4299 yielded an AUC (the areas under the ROC curve) of 0.784 and miR-196b yielded an AUC of 0.647 in discriminating CRC from controls. Combined ROC analysis using these 2 miRNAs revealed an elevated AUC of 0.848 with 67.9%sensitivity and 90.9%speciifcity in discriminating chemoresistance CRC. The low level of miR-4299 expression and the high level of-196b expression are signiifcantly correlated with the good survival of CRC patients. Conclusion:These data suggest that miR-4299 and-196b have strong potential as novel biomarkers for chemoresistant detection of colorectal cancer.

Purpose:To explore the clinicopathologic features of sporadic colorectal cancer patients with microsatellite instability(MSI) and the correlation between the microsatellite instability and the DNA ploidy.Methods:Detecting microsatellite instability with two sites(BAT25 and BAT26),conduct flow cytometry to analyze the DNA ploidy among 71 sporadic colorectal cancer patients and probe into the relationship between the microsatellite instability phenotype and the clinicopathologic characteristics as well as the DNA ploidy.Results:The positive rate of the microsatellite instability among sporadic colorectal cancer patients was 9.86 percent.The microsatellite instability phenotype was correlated with the tumor site and the histopathologic type and the differentiation grade with the P value less than 0.05,while it was independent of the gender,age,lymph node metastasis and Dukes' stage.The proportion of right colon cancers and poorly-differentiated adenocarcinomas of sporadic colorectal cancers showing microsatellite instability was higher than that of microsatellite stable ones.18 and 50 cases showed diploidy and aneuploidy respectively.5 cases of MSI were diploid,There was statistically significant correlation between the microsatellite instability phenotype and the DNA ploidy(P=0.012).Conclusions:Sporadic colorectal cancers with microsatellite instability were prone to occur in the right colon and to be poorly-differentiated adenocarcinomas and inclined to be diploid.

Peritoneum is one of the common site of colorectal cancer metastasis. Traditionally, peritoneal carcinomatosis is associated with a poor prognosis without effective surgical treatment. Recently, the attitude towards the treatment strategies for colorectal peritoneal metastasis has changed significantly with advances in surgical techniques, hyperthermic intraperitoneal chemotherapy and multi-disciplinary treatment. As to the prognosis, colorectal peritoneal metastasis has an inferior outcome to non-peritoneal metastasis under the palliative systemic treatment. However, the complete peritoneal cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy can achieve a long-term survival in selective patients with colorectal peritoneal metastasas. The prognostic factors include peritoneal carcinomatosis index, completeness of cytoreduction, the presence of extra-peritoneal metastasis (liver etc), peritoneal surface disease severity score and Japanese peritoneal staging. In terms of the treatment, complete peritoneal cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy and systemic treatment (including chemotherapy and targeted therapy) may be the best modality of multi-disciplinary treatment for colorectal peritoneal metastasis.

PURPOSE In order to correct the wrong point of view which considered the colorectal adenoma with malignant change as early stage of carcinoma or as carcinoma with low grade malignancy and to avoid performing simple operation unreasonably. METHODS 148 cases of colorectal adenoma with malignant change which were treated in our department in 1995-1997 were submitted to a retrospective study. RESULTS We find only 27 cases (18. 8%) whose malignant changes were localized in the layers of mucosa.mucosalmuscle and submucosa,72 cases (50. 0 % , whose malignant changes had penetrated to the layer of serosa, and 43 cases (30. 7 % ) had lymph nodes metastases,18 cases (12. 5%) had blood metastases or implantations. We also find 51 cases (35. 5%) that couldn't get a definite diagnoses of malignant changes although 1-3 times of biopsies had been made before operation. and of them in fact 39 cases (74. 3%)had malignant changes that had penetrated to the layers muscle and serosa ,10 cases (19.6%) had metastases of lymph nodes and 7 cases (13. 7%) and blood metastases or implantations. CONCLUSION The adenoma with malignant change can not be considered as the early stage of carcinoma. We can not say the adenoma whose diagnosis was made by 1 - 3 times of biopsies is a real adenoma and certainly has no malignant change. We can not say the tumor whose original diagnosis was adenoma still belongs to the early stage of carcinoma either. So we suggest to treat the adenoma with malignant change correctly,aviod performing simple operation unreasonably.

Objective To summarize the clinical and pathological characteristics of gastrointestinal stromal tumors with hepatic metastasis, and to analyze its survival and explore its principles of diagnosis and treatment. Methods Among 99 patients diagnosed as gastrointestinal stromal tumors who had a completely case history in our hospital, we retrospectively analyzed the clinical data of 26 patients with hepatic metastatic and the factors influencing survival. Results The average age at diagnosis of primary and hepatic metastatic gastrointestinal stromal tumors was 50.8 and 51.8 years old respectively. Five cases were confirmed by pathological examination, 12 cases were diagnosed by the exploration during the operation and 14 patients had an imaging diagnosis only. Synchronous and metachronous hepatic metastasis happened in 8 and 18 patients respectively. The median interval between the primary tumor and the metachronous hepatic metastasis was 12 months. The primary sites of 12 cases were in stomach, 5 in colorectum, 6 in small intestine and 3 in extra-gastrointestinal tract.Four cases of the hepatic metastatic tumors were treated with surgical resections, 2 with injections of anhydrous alcohol, 3 with interven-tional therapies, 7 with systemic chemotherapies, 8 with imatinib and 2 without treatment. The median survival was 21 months after hepatic metastasis. The administration of imatinib was an important factor prolonging the survival after hepatic metastasis. Conclusions The most frequent primary site of hepatic metastatic stromal tumor is the stomach while small intestinal stromal tumors are most inclined to metastasize to the liver. Treatment with imatinib for more than 3 months can prolong the survival.

Objective To investigate the clinicopathologic features of sporadic colorectal cancers with CpG island methylator phenotype. Methods The methylation of the promotors of the five genes including p14, hMLH1, p16, MGMT and MINT1 were detected using methylation specific PCR in 71 patients to determine the clinicopathologic characteristics of sporadic colorectal cancers with CpG island methylator phenotype. Results Fifteen out of 71 (21. 1%) patients were positive for the CpG island methylator phenotype. The proportion of the right-sided colonic cancers(40. 0% vs. 12. 5% , P

Objective To study the clinical characteristics of hereditary nonpolyposis colorectal cancer (HNPCC) in Chinese patients. Methods A series of 101 patients with colorectal cancers (CRC) and HNPCC associated tumors from 22 families fulfilling Amsterdam criteria were analyzed. Results Eighty-four patients were found to have CRC. Mean age at diagnosis of first CRC was 45.7 years. 58.3% and 23.8% of the first CRC were located proximal to the spleen flexure and in rectum respectively. 23.8% of patients had synchronous and metachronous CRC. Twenty patients had extracolonic tumors, among which gastric cancer was the most common tumor type in our series. Conclusions The frequency of HNPCC was 2.6% in this series of patients. It is characterized by early onset with a propensity to involve the proximal colon, and high frequency of multiplicity. Gastric cancer seems more frequent in Chinese patients, which is different from American and European reports. So it is necessary to set up criteria for diagnosis of HNPCC in Chinese.