Male sex, low anastomosis, preoperative chemoradiation, advanced tumor stage, perioperative bleeding, and multiple firings of the linear stapler increased the risk of AL after laparoscopic surgery for rectal cancer. A diverting stoma might be mandatory in patients with 2 or more of the risk factors identified in this analysis.

NCT01042743 (http://www.clinicaltrials.gov).

The NOSE approach is feasible with favourable short-term surgical outcomes.

Purpose: Vascular endothelial growth factor (VEGF) or its family may be considered to play an important role in lymphangiogenesis and lymphatic tumor spread, thereby affecting prognosis of colorectal cancer. Accordingly, the present study analyzed VEGF gene polymorphisms and their effect on the prognosis for patients with colorectal cancer. Experimental Design: Four hundred and forty-five consecutive patients with surgically treated colorectal adenocarcinoma were enrolled in the present study. The genomic DNA was extracted from fresh colorectal tissue and three VEGF (−2578C>A, −634G>C, and +936C>T) gene polymorphisms were determined using a PCR/denaturing high-performance liquid chromatography assay. Results: Multivariate survival analysis showed that the survival for the patients with the −634 G/C genotype [overall survival (OS): hazard ratio (HR), 0.158; P < 0.001] or C/C genotype (OS: HR, 0.188; P < 0.001) were better than for the patients with the −634G/G genotype, whereas the +936 C/T genotype (OS: HR, 12.809; P < 0.001) or T/T genotype (OS: HR, 37.260; P < 0.001) was associated with a worse survival compared with the +936 C/C genotype. In haplotype analysis, the −2578A/−634G/+936T haplotype exhibited a significantly worse survival when compared with the wild −2578C/−634G/+936C haplotype (OS: HR, 3.866; P < 0.001). Conclusions: VEGF gene polymorphisms were found to be an independent prognostic marker for patients with colorectal cancer. Accordingly, the analysis of VEGF gene polymorphisms can help identify patient subgroups at high risk of a poor disease outcome.

No abstract

Expression of the homeobox protein CDX1 is lost or reduced in a significant proportion of colorectal carcinomas (CRCs) but the underlying mechanism for this is unclear. We have demonstrated absence of CDX1 mRNA expression in 7 of 37 CRC cell lines and shown that all 7 cell lines have a methylated CDX1 promoter. Twenty-five cell lines showed both CDX1 mRNA expression and an unmethylated CDX1 promoter. The five remaining cell lines had a partially methylated CDX1 promoter and all expressed CDX1 mRNA; when treated with the demethylating agent, 5-aza-2-deoxycytidine, these five cell lines all showed increased CDX1 expression. No mutations were found in the promoter and coding regions of CDX1. One polymorphism was demonstrated in each of the promoter, 5 UTR, and coding region of exon 1 of CDX1, but there were no associations between CDX1 mRNA expression and different polymorphic genotypes. Similarly, there was no association between CDX1 mRNA expression and loss of heterozygosity at the CDX1 locus. In conclusion, absence or reduction of CDX1 expression in CRC seems to be primarily regulated by promoter methylation and is probably selected for because of its impact on the differentiation of colonocytes. C DX1 is a homeobox protein involved in regulating normal development of intestinal epithelium in utero (1). In adulthood, CDX1 expression is maintained in small and large intestinal epithelium (1, 2) although its exact physiological role at this time remains uncertain. That the protein has an oncosuppressor function is supported by in vitro and in vivo evidence of loss of CDX1 expression in colorectal carcinogenesis (3, 4). The mechanism underlying this loss is, however, unclear. Possible roles for genetic and͞or epigenetic controls must therefore be considered. There is an ever growing list of oncosuppressor genes whose expressions are silenced through specific methylation of gene promoter CpG islands (CGIs). These genes all show 5Ј regions that are rich in CGIs (5). In sharing this feature, CDX1 represents a prime candidate for promoter methylation control. Indeed, half way through our study, Suh et al. published preliminary data supporting this hypothesis (6).The most comprehensive way of analyzing a gene for evidence of promoter methylation control is by direct sequencing after bisulfite modification of target DNA (so called ''bisulfite sequencing'') (7). Ideally, this analysis should be accompanied by looking for reexpression of the silenced gene after treatment with the demethylating agent, 5-azacytidine or the less toxic 5-aza-2Ј-deoxycytidine (5aza2). Suh et al. (6) showed CDX1 promoter methylation status to explain CDX1 mRNA expression among eight colorectal carcinoma (CRC) cell lines and also successfully used 5aza2 treatment to induce or increase CDX1 mRNA expression in six of the cell lines. Nonetheless, two important questions regarding control of CDX1 expression in CRC remain unanswered. First, possible contributions of gene mutation and͞or loss of heterozygosity (LOH) have not yet been excluded. Secon...

Objectives: The clinical significance of aquaporin-1 (AQP1), aquaporin-3 (AQP3), and aquaporin-5 (AQP5) expression was analyzed in a large number of patients with colon cancer. Methods: AQP1, AQP3, and AQP5 expression was investigated based on the immunohistochemistry of tissue microarray specimens from 486 colon cancer patients who underwent curative surgery. Scores were given to the staining intensity and percentage of positive cells, and the staining score was defined as the sum of these scores then used to categorize the AQP expression as negative, weakly AQP-positive, or strongly AQP-positive. Results: A total of 298 (61.3%) patients were identified as strongly AQP1-positive (staining score ≥6), while 38 (7.8%) were strongly AQP3-positive and 145 (29.8%) were strongly AQP5-positive. The overexpression of AQP1, AQP3, and AQP5 was significantly correlated with lymph node metastasis in a multivariate logistic analysis (AQP1, p = 0.026; AQP3, p = 0.023; AQP5, p = 0.003). While the multivariate survival analysis, which included age, histology, TNM stage, and CEA level showed that the expression of AQP1, AQP3, and AQP5 had no effect on the overall survival and disease-free survival. Conclusions: The current study found a significant correlation between AQP1, AQP3, and AQP5 expression and lymph node metastasis in patients with surgically resected colon cancer.

Since vascular endothelial growth factor (VEGF) is known to be a potent pro-angiogenic factor, we evaluated the potential association of two VEGF gene polymorphisms (-634G>C and 936C>T) with the susceptibility and the clinicopathologic characteristics of colorectal cancer (CRC). The VEGF genotypes were determined using fresh colorectal tissue from 465 patients who had undergone a surgical resection and peripheral blood lymphocytes from 413 healthy controls by PCR/DHPLC assay. For the -634G>C polymorphism, the -634 GC or CC genotype was associated with a decreased risk of CRC (odds ratio [OR], 0.62; p=0.001) as a dominant model of C allele, whereas the 936 TT genotype correlated with advanced stage/ metastasis, a high serum level of CA19-9, and an higher grade in patients with CRC. In the haplotype analyses, haplotype -634C/936C and -634G/936T were associated with a decreased susceptibility of CRC (OR, 0.53 and 0.56; p<0.001, respectively). These observations imply that the VEGF gene polymorphisms may be associated with the susceptibility or clinicopathologic features of CRC. However, further studies of other VEGF sequence variants and their biological functions are needed to understand the role of the VEGF gene polymorphisms in the development and progression of CRC.