Jeng-Kai Jiang

Transabdominal Anastomosis After Low Anterior Resection: A Prospective, Randomized, Controlled Trial Comparing Long-Term Results Between Side-to-End Anastomosis and Colonic J-Pouch

PURPOSEColonic J-pouch has been constructed to overcome reservoir dysfunction after restorative rectal surgery, whereas no effort has been made for sphincter dysfunction. We conducted a prospective, randomized study comparing surgical and functional outcomes between side-to-end anastomosis and colonic J-pouch after low anterior resection in which the anastomosis was constructed from the abdomen.METHODSFifty-six consecutive patients with middle-to-low rectal cancer undergoing low anterior resection were randomly assigned to side-to-end or colonic J-pouch group preoperatively. Surgical outcomes of all the patients were recorded. Patients underwent functional evaluation, including anorectal manometry and functional assessment, preoperatively and then 3 months, 6 months, 1 year, and 2 years postoperatively.RESULTSTwenty-four patients in each group completed the study. The demographic data and preoperative functional assessment did not differ between the two groups. There was no significant difference in surgical outcomes with regard to anastomotic height (5 cm), blood loss, protective colostomy, operative time, complications, and adjuvant therapy. Anal pressures showed no significant change postoperatively and during the follow-up period; there were no differences between the two groups. Temporal minor fecal incontinence was noted in the early postoperative period in both groups. With regard to bowel function, a significant reduction of volume of urgency and maximal tolerable volume was found postoperatively in both groups; however, a faster recovery was noted in the colonic J-pouch group. Stool frequency increased significantly after surgery in both groups; however, in contrast to rectal volume, a faster recovery was noted in the side-to-end group.CONCLUSIONSAnastomosis after low anterior resection for middle to low rectal cancer could be performed safely from the abdomen. It minimized sphincter injury and showed good continence preservation. On the other hand, the surgical outcomes and long-term functional results of side-to-end anastomosis were comparable with colonic J-pouch. Side-to-end anastomosis provides an easier, alternative way for reconstruction after restorative rectal surgery.

CIP2A is a predictor of poor prognosis in colon cancer.

PurposeThe cancerous inhibitor of protein phosphatase 2A (CIP2A) oncoprotein is overexpressed in colon cancer tissue compared to normal colon mucosa. We investigated the impact of CIP2A on colon cancer.MethodsA tissue microarray consisting of 167 colon cancer specimens was investigated. The association between CIP2A and clinicopathological parameters was analyzed using the χ2 test. Survival was analyzed using the Kaplan–Meier method. The impact of CIP2A on proliferation and drug resistance was evaluated using the 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide test. An anchorage-independent colony formation assay was also performed.ResultsCIP2A was an independent prognostic factor in colon cancer after controlling for other clinical confounding factors, such as stage and lymphovascular invasion, particularly in stages III and IV (hazard ratio = 2.974, P < 0.001). The knockdown of CIP2A reduced the proliferation and anchorage-independent colony formation of colon cancer cells. Knockdown of CIP2A decreased the resistance of the cells to 5-fluorouracil, oxaliplatin, and SN38 (an active metabolite of irinotecan). Treatment with 5-fluorouracil, oxaliplatin, and SN38 decreased CIP2A expression.ConclusionsCIP2A is a prognostic factor in colon cancer. The knockdown of CIP2A reduced proliferation and anchorage-independent colony formation and increased 5-fluorouracil, oxaliplatin, and SN38 efficacy in colon cancer cell lines.

BRAF mutation is a prognostic biomarker for colorectal liver metastasectomy

In metastatic colorectal cancer, v‐Ki‐ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) is a predictive biomarker for anti‐epidermal growth factor receptor (EGFR) treatment and V‐raf murine sarcoma viral oncogene homolog B1 (BRAF) is a prognostic biomarker. We aimed to determine the impact of KRAS and BRAF mutation as determined from liver metastases specimens on overall survival (OS) in patients following colorectal liver metastasectomy.

The Influence of Fecal Diversion and Anastomotic Leakage on Survival after Resection of Rectal Cancer

BackgroundWe analyzed factors associated with the occurrence of anastomotic leakage (AL) and its impact on long-term survival in patients who have undergone resection for rectal cancer. We also investigated the effect of fecal diversion on survival.MethodClinical data of patients who received surgery for rectal cancer were reviewed. The difference in AL incidence among different groups was compared and survival rates were calculated. Cox’s proportional hazards model was used to compare survival in patients who developed AL or received diversion stoma with those who did not.ResultsOf 999 patients who received resection and anastomosis, 53 patients experienced AL. Multivariate analysis revealed advanced age (P = 0.009) and operative method (P = 0.002) were independent risk factors for AL. Anastomotic leakage was an independent risk factor for overall recurrence (HR 2.30; 95% CI 1.12–4.73). Anastomotic leakage and fecal diversion were independent prognostic factors of overall survival (P = 0.002 and P < 0.001, respectively), cancer-specific survival (P = 0.002 and P < 0.001, respectively), and disease-free survival (P < 0.001, respectively).ConclusionsPatients who are older and have anastomosis at the anorectal junction or dentate line have an increased risk of AL. A diversion stoma does not appear to decrease the incidence of anastomotic leakage, but may decrease the need of reoperation when leakage occurred. Anastomotic leakage and fecal diversion are independent prognostic factors of overall, cancer-specific, and disease-free survival.

Analysis of the seventh edition of American Joint Committee on colon cancer staging

PurposeThe seventh edition of the American Joint Committee on Cancer (AJCC) staging system has new substages for colon cancer. We used survival data from a single medical center to analyze this new AJCC edition.MethodsThe colon cancer database of Taipei Veterans General Hospital provided 1,865 patient records covering from 1999 to 2005. Survival rates were evaluated using the Kaplan–Meier method.ResultsThere were 268, 607, 561, and 421 patients in stages I, II, III, and IV disease with 5-year observed survival rates of 86.3%, 79.2%, 65.4%, and 12.8%, respectively. Survival rates were not significantly different between those with T4a and T4b disease (P = 0.806). The outcome of N1c disease was similar to N1a and N1b but worse than N0 (P = 0.004). Survival rates for M1a and M1b disease became different after reclassifying solely peritoneal seeding as M1a (P < 0.001). No discrepancy of outcomes between stage IIIA and stage IIB/IIC remained in the seventh edition.ConclusionsEvolution from the fifth to seventh edition of the AJCC staging system is successful in separating prognostic groups by substaging. But some issues remain unresolved, including the subdivision of T4, N1, and M1.

Mutations in the RAS and PI3K pathways are associated with metastatic location in colorectal cancers.

Identification of mutations in the downstream epidermal growth factor receptor (EGFR) signaling pathway could provide important insights of EGFR‐targeted therapies in colorectal cancers. We analyzed the mutation spectra of the PI3K/PTEN/AKT and RAS/RAF/MAPK pathways in colorectal cancers and the associations of these mutations with sites of metastases or recurrence.

The prognostic role of microsatellite instability, codon-specific KRAS, and BRAF mutations in colon cancer

This study aimed to establish a correlation between MSI, KRAS mutations, and BRAFV600E in colon cancer and to investigate the prognostic effect.

Clinicopathologic features and prognostic analysis of MSI-high colon cancer

PurposeThe objectives of the study were to estimate the incidence and clarify the clinicopathologic feature of sporadic microsatellite instability (MSI)-high (MSI-H) colon cancer. Furthermore, the role of MSI in colon cancer prognosis was also investigated.MethodsMicrosatellite status was identified by genotyping. The clinicopathologic differences between two groups (MSI-H vs. MSI-L/S) and the prognostic value of MSI were analyzed.ResultsFrom 1993 to 2006, 709 sporadic colon cancer patients were enrolled. MSI-H colon cancers showed significant association with poorly differentiated (28.3% vs. 7.2%, p = 0.001), proximally located (76.7% vs. 34.5%, p = 0.001), more high mucin-containing tumor (10.0% vs. 5.1%, p = 0.001) and female predominance (56.7% vs. 30.2%, p = 0.001). In multivariate analysis, MSI-H is an independent factor for better overall survival (HR, 0.459; 95% CI, 0.241–0.872, p = 0.017).ConclusionsBased on the hospital-based study, MSI-H colon cancers demonstrated distinguished clinicopathologic features from MSI-L/S colon cancers. MSI-H is an independent favorable prognostic factor for overall survival in colon cancer.

Pneumothorax After Bevacizumab-containing Chemotherapy: A Case Report

Bevacizumab added to 5-fluorouracil-based chemotherapy can improve outcomes in patients with metastatic colorectal cancer. Bevacizumab had several notable adverse effects including bowel perforation but pneumothorax had never been reported in the available English literature. We reported a 45-year-old male with lung metastases from colorectal cancer who had spontaneous pneumothorax after the second cycle of bevacizumab-containing chemotherapy. His pneumothorax resolved after tube thoracostomy with a small caliber catheter. The mechanism of pneumothorax developed after bevacizumab therapy was not clear as bowel perforation but tumor necrosis with ruptured parietal pleura might be the cause. In patients who had chest discomfort after bevacizumab-containing therapy, pneumothorax should never be overlooked as one of the differential diagnoses.

Is adjuvant chemotherapy beneficial to high risk stage II colon cancer? Analysis in a single institute.

BackgroundColorectal carcinoma is the most common malignancy of the gastrointestinal tract. It remains controversial for adjuvant chemotherapy in patients with stage II colon cancer. This study was designed to identify the risk factors of tumor recurrence in stage II colon cancer. Furthermore, the benefit of adjuvant chemotherapy for high-risk stage II colorectal cancer will be investigated.Materials and methodsFrom May 1998 until August 2004, 375 patients with stage II (T3N0M0, T4N0M0) colon cancer received curative operation in a single hospital. The clinical data were extracted from the prospectively collected colorectal cancer database. The disease-free survival curves were calculated with Kaplan–Meier’s analysis, and the survival difference was determined by log-rank test. The p value less than 0.05 was considered to be significant.ResultsOf 375 stage II colon cancer, 66 patients received 5-FU-based adjuvant chemotherapy, either oral or intravenous (IV) form. Within the median of 48.5 months of follow-up, recurrence developed in 35 patients (9.3%). T4 lesion (p=0.024), lymphovascular invasion (p=0.022), obstruction at presentation (p=0.008), and mucinous component more than 50% (p=0.032) were associated with significantly decreased disease-free survival. High-risk patients (n=102), but not other patients with stage II colon cancer, benefited from adjuvant therapy (3-year disease-free survival: 96.4% vs. 84.7%, p=0.045; 5-year overall survival: 100% vs. 86.4%, p=0.015).ConclusionAdjuvant therapy for high-risk stage II colon cancer may be beneficial, and we suggest adjuvant therapy should be considered in high-risk stage II colon cancer patients.