Mismatch repair status in sporadic colorectal cancer: immunohistochemistry and microsatellite instability analyses.

Background And Aim: The aim of the present study was to evaluate associations between mismatch repair (MMR) status and clinicopathological characteristics and prognosis using immunohistochemistry (IHC) and microsatellite instability (MSI) analyses in a prospective cohort of a large number of accumulated samples.

Methods: Tumor tissue samples obtained during curative surgery (n = 2028) were analyzed using both MLH1/MSH2 IHC and MSI assays. Clinicopathological parameters and survival outcomes were compared according to IHC and MSI results.

Clinical significance of pre- to post-chemoradiotherapy s-CEA reduction ratio in rectal cancer patients treated with preoperative chemoradiotherapy and curative resection.

Purpose: To evaluate the clinical significance of a reduction in serum carcinoembryonic antigen (s-CEA) concentration ratio from before to after preoperative chemoradiotherapy (CRT) in terms of recurrence and prognostic factors in rectal cancer patients.

Methods: We retrospectively evaluated 333 rectal cancer patients who received preoperative CRT followed by surgery with curative intent between January 2000 and December 2006. Patients were divided into three groups: those with pre-CRT s-CEA≤6 ng/mL (group 1), those with pre-CRT s-CEA>6 mg/mL and post-CRT s-CEA≥70% lower than pre-CRT s-CEA (group 2), and those with pre-CRT s-CEA>6 mg/mL and post-CRT s-CEA<70% lower or higher than pre-CRT s-CEA (group 3).

Safety and efficacy of methylnaltrexone in shortening the duration of postoperative ileus following segmental colectomy: results of two randomized, placebo-controlled phase 3 trials.

Purpose: Postoperative ileus contributes to surgical morbidity and is associated with prolonged hospitalization and increased health care costs. The efficacy and safety of the peripherally acting μ-opioid receptor antagonist methylnaltrexone in shortening the duration of postoperative ileus following segmental colectomy was evaluated.

Methods: Two identically designed, multicenter, double-blind, parallel-group, placebo-controlled studies randomly assigned patients undergoing segmental colectomy (study 1, N = 515; study 2, N = 533) to receive 12 or 24 mg of methylnaltrexone intravenously or placebo every 6 hours starting within 90 minutes of surgery completion, continuing for up to 10 days or up to 24 hours after gastrointestinal recovery.

Mucinous rectal cancer: effectiveness of preoperative chemoradiotherapy and prognosis.

Background: This study investigated the effects of preoperative chemoradiotherapy (PCRT) and the prognoses of patients with mucinous rectal cancer compared with those with nonmucinous cancer.

Methods: We retrospectively reviewed the medical records of 368 patients who underwent curative resection after PCRT, between 2000 and 2006, for midrectal to lower-rectal adenocarcinoma. Mucinous cancers were present in 23 patients (6.

Randomized phase 3 trial comparing preoperative and postoperative chemoradiotherapy with capecitabine for locally advanced rectal cancer.

Background: Although many trials have shown the efficacy of preoperative chemoradiotherapy (CRT) or postoperative CRT compared with surgery alone, the optimal sequence of radiotherapy and surgery is unclear. The authors reported the final results of this single institution prospective randomized phase 3 trial comparing preoperative CRT with postoperative CRT using capecitabine in survival, local control, sphincter preservation, and toxicity for the treatment of locally advanced rectal cancer.

Methods: Patients with locally advanced rectal cancer (cT3, potentially resectable cT4 or N+) were randomly assigned to receive preoperative or postoperative CRT.

Symptomatic venous thromboembolism in Asian colorectal cancer surgery patients.

Background: The occurrence of venous thromboembolism (VTE), manifesting as deep vein thrombosis (DVT) or pulmonary embolism (PE), after colorectal cancer surgery in Asian patients remains poorly characterized. The present study was designed to investigate the incidence of symptomatic VTE in Korean colorectal cancer patients following surgery, and to identify the associated risk factors.

Methods: We retrospectively analyzed data from patients who developed symptomatic VTE after colorectal cancer surgery between 2006 and 2008.

Novel classification and pathogenetic analysis of hypoganglionosis and adult-onset Hirschsprung's disease.

Background And Aims: Researchers have not clearly described the clinical and pathogenetic features of hypoganglionosis and adult-onset Hirschsprung's disease, which cause pseudo-obstruction or intractable constipation. We conducted this study to explore these features of hypoganglionosis and adult-onset Hirschsprung's disease in Korean patients.

Methods: We enrolled 24 patients pathologically confirmed as having hypoganglionosis and 11 as having adult-onset Hirschsprung's disease.

Randomized trial of postoperative adjuvant therapy in Stage II and III rectal cancer to define the optimal sequence of chemotherapy and radiotherapy: 10-year follow-up.

Purpose: To determine the optimal sequence of postoperative adjuvant chemotherapy and radiotherapy in patients with Stage II or III rectal cancer.

Methods And Materials: A total of 308 patients were randomized to early (n = 155) or late (n = 153) radiotherapy (RT). Treatment included eight cycles of chemotherapy, consisting of fluorouracil 375 mg/m(2)/day and leucovorin 20 mg/m(2)/day, at 4-week intervals, and pelvic radiotherapy of 45 Gy in 25 fractions.

CT colonography for combined colonic and extracolonic surveillance after curative resection of colorectal cancer.

Purpose: To determine the accuracy of contrast material-enhanced computed tomographic (CT) colonography for postoperative surveillance in colorectal cancer patients without clinical or laboratory evidence of disease recurrence.

Materials And Methods: The Institutional Review Board approved this HIPAA-compliant study and waived informed consent. Between January 2006 and December 2007, 742 consecutive patients without clinical or laboratory evidence of recurrence following curative-intent colorectal cancer surgery underwent contrast-enhanced CT colonography.

Clinicopathologic characteristics, surgical treatment and outcomes for splenic flexure colon cancer.

Purpose: This current study examined the clinicopathologic characteristics of patients with splenic flexure (SF) colon cancer and the association with the surgical outcomes to find the optimal procedure to treat this malady.

Materials And Methods: A total of 167 operated patients with SF colon cancer were consecutively recruited between 1993 and 2003. The clinicopathological, operative and survival data was reviewed and analyzed.

Clinical features and long-term prognosis of Crohn's disease in Korea.

Objective: Recent studies have suggested that the clinical characteristics and genetic background of Crohn's disease (CD) patients differ between Asian and Caucasian individuals. However, the clinical features and course of CD in Asian patients remain unclear. Therefore, we investigated the clinical features and long-term prognosis of CD in a Korean population.

Clinicopathologic characteristics of colorectal cancer patients with synchronous and metachronous gastric cancer.

Background: We investigated the characteristics of synchronous and metachronous gastric cancer in patients with colorectal cancer.

Methods: We reviewed 8,680 patients who underwent operations for primary sporadic colorectal cancer from 1989 to 2008. Synchronous gastric cancer was defined as gastric cancer diagnosed within 6 months of a colorectal cancer diagnosis.

Phase I study of preoperative chemoradiation with s-1 and oxaliplatin in patients with locally advanced resectable rectal cancer.

Purpose: To perform a Phase I study of preoperative chemoradiation (CRT) with S-1, a novel oral fluoropyrimidine, plus oxaliplatin in patients with locally advanced rectal cancer, to determine the maximum tolerated dose and the recommended dose.

Methods And Materials: Radiotherapy was delivered to a total of 45 Gy in 25 fractions and followed by a coned-down boost of 5.4 Gy in 3 fractions.

Clinicopathological characteristics of rectal carcinoids.

Purposes: Carcinoids are heterogeneous neuroendocrine tumors with malignant potential. The rectum is the third most common location for gastrointestinal carcinoids. We assessed the clinicopathological characteristics of rectal carcinoids.

Delayed anastomotic leakage following sphincter-preserving surgery for rectal cancer.

Purpose: The aim of the present study was to investigate the characteristics of patients who developed delayed anastomotic leakage (DAL) following sphincter-preserving surgery for rectal cancer. We evaluated the following factors: (1) the incidence of DAL, (2) the clinical features of patients who developed DAL, (3) the risk factors for DAL, and (4) treatment outcomes.

Methods: We reviewed the case histories of 1,838 rectal cancer patients who had undergone curative resection with sphincter preservation and without protective stoma formation between January 2000 and December 2006.

Intra-abdominal fistulas in surgically treated Crohn's disease patients.

Background: Intra-abdominal fistulas occur in one-third of patients with Crohn's disease (CD). Although they are common, these fistulas may pose difficult problems for the surgeon. We assessed the clinical presentation of intra-abdominal fistulas in patients with CD and compared the clinicopathologic characteristics of CD with and without fistulas.

Prognostic significance of lymphovascular invasion in sporadic colorectal cancer.

Purpose: It remains unclear whether lymphovascular invasion marks a poor prognosis for patients with sporadic colorectal cancers. Here, we analyzed the association between lymphovascular invasion and the clinicopathological features and prognosis of sporadic colorectal cancer patients.

Methods: The clinicopathological features and prognosis of 2417 patients with sporadic primary colorectal cancer who underwent an operation at the Asan Medical Center between January 1998 and December 2002 were examined.

CT colonography after metallic stent placement for acute malignant colonic obstruction.

Purpose: To evaluate the feasibility of using computed tomographic (CT) colonography for preoperative examination of the proximal colon after metallic stent placement in patients with acute colon obstruction caused by colorectal cancer.

Materials And Methods: Institutional review board approval was obtained, and patient informed consent was waived. Fifty patients (mean age +/- standard deviation, 58.

Complications after sphincter-saving resection in rectal cancer patients according to whether chemoradiotherapy is performed before or after surgery.

Purpose: The aim of the present study was to compare the influence of preoperative chemoradiotherapy (CRT) with postoperative CRT on the incidence and types of postoperative complications in rectal cancer patients who underwent sphincter-saving resection.

Patients And Methods: We reviewed 285 patients who received preoperative CRT and 418 patients who received postoperative CRT between January 2000 and December 2006.

Results: There was no between-group difference in age, gender, or cancer stage.

Extensive lymphadenectomy in colorectal cancer with isolated para-aortic lymph node metastasis below the level of renal vessels.

Background And Objectives: The effects of isolated metastatic node dissection in the para-aortic region have not been established in colorectal cancer (CRC). The authors undertook to evaluate the role of para-aortic lymph node (PALN) dissection in CRC with isolated PALN metastasis.

Methods: Between January 1993 and March 2006, 24 patients underwent PALN dissection for isolated PALN metastasis from CRC.

Dual-design expandable colorectal stent for malignant colorectal obstruction: comparison of flared ends and bent ends.

Objective: The purpose of this study was to compare, focusing on colonic perforation and stent migration, the clinical safety and efficacy of dual-design expandable colorectal stents with flared ends with those of stents with bent ends in the treatment of patients with malignant colorectal obstruction.

Subjects And Methods: A total of 122 patients with malignant colorectal obstruction underwent implantation of dual-design stents with flared (n = 69) or bent (n = 53) ends.

Results: Stent placement was technically successful in 116 of 122 patients (95.

lymph node ratio as a prognostic factor in patients with stage III rectal cancer treated with total mesorectal excision followed by chemoradiotherapy.

Purpose: To investigate the prognostic impact of lymph node ratio (LNR) on survival in the patients with Stage III rectal cancer.

Methods And Materials: We retrospectively reviewed the data of 421 consecutive patients who underwent total mesorectal excision followed by chemoradiotherapy for rectal cancer from 1996 to 2006. The 232 patients with positive lymph nodes (LNs) were divided into four groups according to LNR quartiles: LNR View Article and Find Full Text PDF

Malignant rectal obstruction within 5 cm of the anal verge: is there a role for expandable metallic stent placement?

Background: Placement of expandable metallic stents (EMS) has been considered contraindicated for patients with malignant rectal obstruction within 5 cm of the anal verge because of the potential problems of anal pain.

Objective: Our purpose was to investigate the technical feasibility, clinical effectiveness, and safety of EMS placement in patients with malignant rectal obstruction within 5 cm of the anal verge.

Design: Retrospective study.

Risk factors for lymph node metastasis in submucosal invasive colorectal cancer.

Background: Recent studies have shown a 7-15% lymph node (LN) metastasis rate in submucosal invasive colorectal cancer (SICC). Identifying risk factors for LN metastasis is crucial in selecting therapeutic modalities for SICC. We assessed the possibility of and the risk factors for LN metastasis in SICC.

Extramammary Paget's disease in Korea: its association with gastrointestinal neoplasms.

Background: Extramammary Paget's disease (EMPD) most commonly occurs in the perineal and genital areas of elderly people. The current treatment of choice is adequate surgical excision.

Materials And Methods: Between 1990 and 2007, 28 patients (27 men and one woman) with EMPD were treated at Asan Medical Center, Seoul, Korea, by wide local excision (WLE) with a 2- to 3-cm normal skin margin.