To assess the risk factors for clinical anastomotic leakage (AL) in patients undergoing laparoscopic surgery for rectal cancer. Little data are available about risk factors for AL after laparoscopic rectal cancer resection. This was a retrospective analysis of 1609 patients with rectal cancer who had undergone laparoscopic surgery for rectal cancer with sphincter preservation. Clinical data related to AL were collected from 11 institutions. Univariate and multivariate analyses were performed to determine the risk factors for AL. AL was noted in 101 (6.3%) of the patients. The leakage rate ranged from 2.0% to 10.3% for each hospital (P = 0.04). In patients without protective stomas (n = 1187), male sex [hazard ratio (HR), 3.468], advanced tumor stage (HR, 2.520), lower tumor level (HR, 2.418), preoperative chemoradiation (HR, 6.284), perioperative transfusion (HR, 10.705), and multiple firings of the linear stapler (HR, 6.181) were significantly associated with AL. Our theoretical model suggested that the HR for patients with 2 risk factors was significantly higher than that the HR for patients with no or only 1 risk factor. 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.

The aim of this study is to evaluate long-term oncologic outcomes of robotic surgery for rectal cancer compared with laparoscopic surgery at a single institution. Robotic surgery is regarded as a new modality to surpass the technical limitations of conventional surgery. Short-term outcomes of robotic surgery for rectal cancer were acceptable in previous reports. However, evidence of long-term feasibility and oncologic safety is required. Between April 2006 and August 2011, 217 patients who underwent minimally invasive surgery for rectal cancer with stage I-III disease were enrolled prospectively (robot, n = 133; laparoscopy, n = 84). Median follow-up period was 58 months (range, 4-80 months). Perioperative clinicopathologic outcomes, morbidities, 5-year survival rates, prognostic factors, and cost were evaluated. Perioperative clinicopathologic outcomes demonstrated no significant differences except for the conversion rate and length of hospital stay. The 5-year overall survival rate was 92.8% in robotic, and 93.5% in laparoscopic surgical procedures (P = 0.829). The 5-year disease-free survival rate was 81.9% and 78.7%, respectively (P = 0.547). Local recurrence was similar: 2.3% and 1.2% (P = 0.649). According to the univariate analysis, this type of surgical approach was not a prognostic factor for long-term survival. The patient's mean payment for robotic surgery was approximately 2.34 times higher than laparoscopic surgery. No significant differences were found in the 5-year overall, disease-free survival and local recurrence rates between robotic and laparoscopic surgical procedures. We concluded that robotic surgery for rectal cancer failed to offer any oncologic or clinical benefits as compared with laparoscopy despite an increased cost.

Liver metastasis is one of the major causes of death in colorectal cancer (CRC) patients. To understand this process, we investigated whether the gene expression profiling of matched colorectal carcinomas and liver metastases could reveal key molecular events involved in tumor progression and metastasis. We performed experiments using a cDNA microarray containing 17,104 genes with the following tissue samples: paired tissues of 25 normal colorectal mucosa, 27 primary colorectal tumors, 13 normal liver and 27 liver metastasis, and 20 primary colorectal tumors without liver metastasis. To remove the effect of normal cell contamination, we selected 4,583 organ‐specific genes with a false discovery rate (FDR) of 0.0067% by comparing normal colon and liver tissues using significant analysis of microarray, and these genes were excluded from further analysis. We then identified and validated 46 liver metastasis‐specific genes with an accuracy of 83.3% by comparing the expression of paired primary colorectal tumors and liver metastases using prediction analysis of microarray. The 46 selected genes contained several known oncogenes and 2 ESTs. To confirm that the results correlated with the microarray expression patterns, we performed RT‐PCR with WNT5A and carbonic anhydrase II. Additionally, we observed that 21 of the 46 genes were differentially expressed (FDR = 2.27%) in primary tumors with synchronous liver metastasis compared with primary tumors without liver metastasis. We scanned the human genome using a cDNA microarray and identified 46 genes that may play an important role in the progression of liver metastasis in CRC.