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Background: Laparoscopic colorectal resection is widely used because of its safety and effectiveness compared with conventional surgery; however, surgical assistants find it difficult to perform this surgery in mirror image. This study aimed to evaluate assistants' learning curves in laparoscopic colorectal surgery. Methods: The subjects were three fellows who began their surgical fellowship training at the Center for Colorectal Cancer of the National Cancer Center, Korea, during 2008. We analyzed the data from 145 laparoscopic colorectal surgeries in which these assistants participated. A learning curve was generated for each assistant using the moving average method to assess the execution time and the error rate for grasping tissue. Results: Assistants A, B, and C participated in 50, 45, and 50 laparoscopic colorectal surgeries, respectively. Learning curves indicated that the execution time reached a steady state after 38 cases for Assistant A, 29 cases for Assistant B, and 24 cases for Assistant C. Based on a decline in the error rate, the steady state was reached after approximately 44 cases for Assistant A, 32 cases for Assistant B, and 41 cases for Assistant C. Conclusion: Analysis of the assistants' learning curves suggests that under reverse alignment conditions, assistants require participation in 30-40 cases before gaining surgical competence. These results have implications for training assistants for laparoscopic colorectal surgery. [ABSTRACT FROM AUTHOR]

The influence of obesity on surgical outcomes after laparoscopic colorectal surgery in Asian patients is unclear. The aim of this study was to evaluate the feasibility and safety of laparoscopic surgery in obese Asian patients with colorectal cancer. We retrospectively reviewed the prospectively collected data on 984 consecutive patients who underwent laparoscopic surgery for colorectal cancer between May 2001 and February 2008. Patients were classified according to the categories proposed by the International Obesity Task Force, as Nonobese (body mass index [BMI] < 25.0 kg/m2), Obese I (BMI 25.0–29.9 kg/m2), and Obese II (BMI ≥ 30 kg/m2). Surgical outcomes, including open conversion, operation time, postoperative complications, estimated blood loss, and postoperative hospital stay, were compared in Nonobese, Obese I, and Obese II patients. Of the 984 patients, 645 (65.5%), 312 (31.7%), and 27 (2.7%), were classified as Nonobese, Obese I, and Obese II, respectively. Clinicopathologic characteristics were similar among the three groups. The Obese II group had higher conversion rates (14.8% versus 2.6% and 2.9%, P = 0.001), longer operation time (258 versus 201 and 215 min, P = 0.001), and longer postoperative hospital stay (12.1 versus 9.5 and 9.2 days, P = 0.035) than the Nonobese and Obese I groups. However, the rates of intraoperative events ( P = 0.634) and postoperative complications ( P = 0.603) were similar in nonobese and obese patients. Independent risk factors for conversion were BMI group and operation type. Obese II patients had an 8.36-fold greater risk of conversion than had Nonobese patients ( P = 0.001). With sufficient experience, laparoscopic colorectal surgery in obese Asian patients is feasible and safe, offering all the benefits of a minimally invasive approach. Management of Asian colorectal cancer patients with BMI ≥ 30 kg/m2 requires meticulous perioperative care, and colorectal surgeons must be familiar with obesity-related challenges in such patients. [ABSTRACT FROM AUTHOR]

In rectal cancer patients treated with preoperative chemoradiotherapy (CRT) and curative resection, we evaluated the influence of anemia on tumor response to preoperative CRT. Between August 2001 and July 2007, 490 patients underwent preoperative CRT, followed by curative-intent surgery. Tumor responses were evaluated based on tumor regression grade (TRG), T- and N-level downstaging, and volume reduction rates. The level of pretreatment hemoglobin (Hb) was 12.9 ± 1.7 g/dl (range, 7.2–17.6 g/dl). Tumor response rates were significantly different below and above the Hb level of 9.0 g/dl. Specifically, patients with Hb levels ≥9.0 g/dl achieved better tumor responses than those with Hb levels < 9.0 g/dl (rates of TRG 3 or 4—29.0% vs. 0%, p < 0.001). In addition, there is no differences in tumor response between the nontransfusion and transfusion groups of patients with Hb levels ≥9.0 g/dl (rates of TRG 3 or 4—29.1% vs. 23.1%, p = 0.445). The serum Hb level could be a one of prognostic factors that influences the pathologic tumor response, and pretreatment anemia (below 9.0 g/dl of Hb) is associated with poor response to preoperative CRT. [ABSTRACT FROM AUTHOR]

Transanal endoscopic microsurgery (TEM) is a minimally invasive alternative to transanal excision, enabling complete local excision of selected benign or malignant rectal tumors. This study aimed to determine the surgical and oncologic results for rectal tumors excised by TEM. From November 2001 to October 2007, 45 patients underwent TEM for excision of adenoma (13 patients), carcinoid tumor (6 patients), and carcinoma (26 patients). The patients included 27 men and 18 women with a median age of 52 years (range, 22–72 years). The median tumor distance from the anal verge was 7 cm (range, 3–15 cm), and the median tumor size was 17 mm (range, 2–60 mm). There was no procedure-related morbidity or mortality. However, one patient with rectal carcinoma died of lung cancer during the follow-up period. Of 13 patients with adenomas, 1 patient (7.7%, 1/13) experienced local recurrence 5 months after surgery. No recurrence occurred for six patients with carcinoid tumors. Histologic examination of the carcinomas showed pathologic tumor (pT) stage 0 (ypT0) in 2 patients, pT1 in 17 patients (including ypT1 in 1 patient), pT2 in 6 patients, and pT3 in 1 patient. Immediate salvage surgery was performed for five patients (19%, 5/26). During a median follow-up period of 37 months (range, 5–72 months), one patient (3.8%, 1/26) experienced local recurrence. The overall and disease-free 5-year survival rates for patients with carcinoma were 96.2% and 88.5%, respectively. The TEM procedure is a safe and appropriate surgical treatment option for benign rectal tumors. With strict patient selection, it is oncologically safe for early-stage rectal carcinomas. [ABSTRACT FROM AUTHOR]

Laparoscopic surgery demands mastery of a steep learning curve. Defining a learning curve in laparoscopic surgery is useful for planning training programs or clinical trials. This study aimed to define the learning curves for laparoscopic sigmoidectomy used to manage curable sigmoid colon cancer by evaluating early surgical outcome data from three colorectal surgeons. This study analyzed data from 138 consecutive patients undergoing laparoscopic sigmoidectomy for curable sigmoid colon cancer performed by three colorectal surgeons between May 2001 and November 2006. The learning curve for each surgeon were generated using the moving average method to assess changes in operation time and cumulative sum (CUSUM) analysis to assess changes in failure rates [(failure = conversion to open surgery, major perioperative complication, or failure to harvest an adequate number of lymph nodes (<12 nodes)]. Learning curves generated with the moving average method indicated that the operation time reached a steady state after 42 cases for surgeon A, 35 cases for surgeon B, and 30 cases for surgeon C. The overall open conversion rate was 2.9%. There was only one laparoscopy-related perioperative major complication (0.7%). An inadequate number of lymph nodes was harvested in 10 cases (7.2%): 6 (10.5%) for surgeon A, 1 (2.4%) for surgeon B, and 3 (7.7%) for surgeon C. Learning curves generated using CUSUM analysis based on a 90% success rate showed that adequate learning occurred after 10 cases for surgeon A, 17 cases for surgeon B, and 5 cases for surgeon C. Pertinent learning curves for laparoscopic sigmoidectomy used to manage curable sigmoid colon cancer can be generated using the moving average method and CUSUM analysis. These results are likely to be useful in designing laparoscopic training programs and clinical trials aimed at investigating outcomes of laparoscopic colorectal cancer surgery. [ABSTRACT FROM AUTHOR]

Since the Clinical Outcomes of Surgical Therapy (COST) trial data were reported in May 2004, the laparoscopic technique for primary colorectal cancer has been increasingly used and become the approach of choice at our center. This study aimed to evaluate our laparoscopic experience of 570 consecutive patients between October 2000 and December 2006, and assess the feasibility of this technique as the surgical approach of choice for primary colorectal cancer. The study times were divided into three periods based on the COST trial report and the time when the laparoscopic technique was accepted as the surgical approach of choice at our center (period I: October 2000 to May 2004, II: June 2004 to December 2005, III: January to December 2006). Data regarding clinicopathological, surgical, and perioperative outcomes were collated from registry and compared between periods. The use of laparoscopic surgery increased from 2.4% in period I, to 19.2% in period II, to 66.1% in period III. Over the periods, the proportion of rectal cancer and right colon cancer increased ( p < 0.001), T- and N-stage became more advanced ( p < 0.001, p = 0.011 respectively), and operative time decreased ( p < 0.001). The overall open conversion and morbidity rates were 3.5% and 9.8%, respectively, and these did not differ between periods. It was possible to apply laparoscopic approach in two-thirds of primary colorectal cancer patients. The short-term favorable outcomes support the feasibility of laparoscopic technique as surgical approach of choice for colon cancer. Laparoscopic resection for rectal cancer may require a randomized clinical trial prior to gain similar acceptance. [ABSTRACT FROM AUTHOR]

Endoscopically, rectal carcinoids have a variety of sizes and features which may assist in determining treatment plans. The present study was performed to assess the relationship between endoscopic features and metastasis in rectal carcinoids. A total of 115 rectal carcinoids of 112 patients with rectal carcinoids were enrolled, and the medical records were retrospectively reviewed. All tumors were classified according to size (longest diameter), and then according to endoscopic features such as shape, color, and surface changes including depressions, erosion, and ulceration. The relationship between endoscopic features and metastasis was evaluated. 11 cases (9.6%) of the 115 rectal carcinoids presented with metastatic disease. Tumor size was associated with metastasis ( p < 0.001). Endoscopic features associated with metastasis were tumor shape, surface change, and color ( p < 0.001). Atypical endoscopic features occurred more frequently as the size of the tumor increased ( p < 0.001). For tumors 10–19 mm in diameter, atypical surface change was associated with metastasis ( p = 0.007). Endoscopic features were found to be associated with metastasis in rectal carcinoids. In particular, atypical surface change may be useful in determining treatment plans for tumors 10–19 mm in diameter. [ABSTRACT FROM AUTHOR]

Most investigations on MutY human homolog ( MYH)-associated polyposis (MAP) have been conducted in Western countries. Limited data on MAP in Asia are currently available. The present study investigated germline mutations of the MYH gene among patients with 10 to 99 adenomatous colorectal polyps and familial adenomatous polyposis (FAP) without adenomatous polyposis coli ( APC) germline mutations in Korea. The study population included 46 patients with 10 to 99 adenomatous polyps in the colorectum and 16 FAP patients with no identified APC germline mutations. Subjects were screened for MYH germline mutations, and we additionally screened for MYH mutations in 96 normal control individuals. Two of 46 (4.3%) patients with multiple polyps displayed heterozygous biallelic germline mutations of the MYH gene. A 39-year-old male patient with biallelic MYH mutations (p.G272E and p.A359V) received total proctocolectomy for rectal cancer and 36 colorectal polyps. A 58-year-old female patient with biallelic MYH mutations (p.Q253X and p.Q440P) received right hemicolectomy for ascending colon cancer and 16 colonic polyps. The frequency of biallelic MYH mutation in 14 of 46 multiple-polyp patients, who had 15 to 99 polyps, was 14.3% (2 of 14). No biallelic MYH mutations were detected in the 32 patients with 10 to 14 colorectal polyps, 16 FAP patients, or 96 normal controls. We identified biallelic MYH germline mutations in 2 of 14 (14.3%) Korean patients with 15 to 99 colorectal polyps. In this study, there was no Y165C or G382D hot-spot mutation, which had been reported most frequently in previous studies. [ABSTRACT FROM AUTHOR]

Background and aims: Colorectal cancers exhibiting microsatellite instability (MSI) appear to have unique biological behavior. The influence of MSI on the prognosis of sporadic colorectal cancers is controversial and requires further investigation. The aim of this study was to analyze the association between MSI status and clinicopathological features and prognosis in sporadic colorectal cancer patients. Patients and methods: Of the 322 consecutive colorectal cancer patients operated upon at the Seoul National University Hospital between January and December 1998, we examined the clinicopathological features and prognosis of 248 patients with sporadic primary colorectal cancer. The MSI status of these 248 patients has been reported in a previous study. Of the 248 patients, 23 (9.3%) had MSI+ tumors. The patients' clinicopathological parameters were obtained from their medical records, and follow-up and survival data were obtained from medical records and phone calls. Results: MSI+ sporadic colorectal cancers were found predominantly in the proximal colon (p<0.001) and were associated with poor differentiation (p=0.030), a lower preoperative serum carcinoembryonic antigen (CEA) level (p=0.012), and less frequent systemic metastasis (p=0.034) than MSI- tumors. Low tumor grade (p=0.022), low tumor T-stage (p=0.002), no lymph node metastasis (p<0.001), no systemic metastasis (p<0.001), adjuvant chemotherapy (p<0.001) and MSI+ status (p=0.038) were independent favorable prognostic factors for survival in sporadic colorectal cancer patients. Conclusion: MSI status was an independent favorable prognostic factor for survival in sporadic primary colorectal cancer patients. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in relation to the use of colonoscopy in situs inversus totalis (SIT) patients.

A letter to the editor entitled "Synchronous penile metastasis from a rectal carcinoma" published within the issue is presented.

A letter to the editor is presented in response to an article about Ewing's sarcoma/primitive neuroectodermal tumor of the small bowel in the May 9, 2006 issue.