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Background: KRAS mutations (KRASmut) drive tumorigenesis through various signaling pathways that are associated with worse survival in colorectal cancer patients (CRC). Immune evasion is a hallmark of KRAS-driven cancer, but the role of KRASmut in the regulation of the immune response is unclear, particularly in the tumor microenvironment (TME), which often assists cancer cells to thrive and successfully escape immune surveillance. Here, we explore the immunobiological impacts of KRASmut in CRC patients. Methods: A total of 97 fresh frozen tumor samples were collected from each CRC patient with stage I-IV who underwent surgical treatment at the Department of Surgery, Faculty of Medicine Siriraj Hospital between October 2010 and March 2011. First, all patients were identified KRAS mutational status and compared overall survival (OS) with wild-type KRAS (KRASwt). Next, we analyzed the gene expression profiling of KRASmut which was performed using the Nanostring platform. Finally, we performed the biological network analysis focusing on immunological pathways associated with KRASmut using the Ingenuity Pathway Analysis (IPA). Results: We observed KRASmut in 41.24% (n=40) of the total cases. Mutations occurred primarily in exon 2 (total n=36; codon 12, n=28; codon 13, n=8) and rarely in exon 3 (n=4). Patients with KRASmut CRC in exon 2 and exon 3, showed significantly worse OS compared to KRASwt (HR 1.77, 95% CI 1.07-2.93; P Conclusions: Our results suggested that KRASmut activated TGFβ and interrupted pro-inflammatory cytokine to suppress tumor immune microenvironment in CRC. Future studies and clinical trials in patients with CRC with KRASmut should take these transcriptional profiles into account. Citation Format: Pariyada Tanjak, Amphun Chaiboonchoe, Tharathorn Suwatthanarak, Onchira Acharayothin, Kullanist Thanormjit, Jantappapa Chanthercrob, Thanawat Suwatthanarak, Bundit Wannasuphaphol, Kemmapon Chumchuen, Bhoom Suktitipat, Somponnat Sampattavanich, Krittiya Korphaisarn, Ananya Pongpaibul, Naravat Poungvarin, Harald Grove, Woramin Riansuwan, Atthaphorn Trakarnsanga, Asada Methasate, Manop Pithukpakorn, Vitoon Chinswangwatanakul. KRAS mutations suppress the tumor immune microenvironment in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2242.

Background and objectives Laparoscopic cholecystectomy with common bile duct exploration (LC with LCBDE) remains the preferred technique for difficult common bile duct stone (CBDS) removal. The chopstick method uses commonly available instruments and may be cost-saving compared to other techniques. We studied the outcome of LCBDE using the chopstick technique to determine if it could be considered a first-choice method. Methods Data from all patients that underwent LCBDE from January 1, 2012 to April 30, 2019 were retrospectively analyzed. A standard 4-port incision and CBDS permitted extraction with two laparoscopic instruments by chopstick technique via vertical choledochotomy. Demographic data, stone clearance rate, surgical outcomes, complications, and other associated factors were evaluated. Results Thirty-two patients underwent LCBDE. The mean number of preoperative endoscopic retrograde cholangiopancreatography (ERCP) sessions was 2.4. In 65.5% of cases, the CBDS was completely removed by the chopstick technique, while 96.9% of stones were removed after using additional tools. The need for additional instruments was associated with increased age, increased numbers of stones, longer period from the latest ERCP session, and previous upper abdominal surgery. The conversion rate to open surgery was 28.1% and was significantly associated with a history of upper abdominal surgery. Conclusion The chopstick technique is a good alternative and could be considered as a first-line technique in LCBDE to remove the CBDS in cases with 1 to 2 large suprapancreatic CBDS due to instrument availability, cost-effectiveness, and comparable surgical outcomes.

BACKGROUND Locally advanced rectal cancer is treated using neoadjuvant chemoradiation (nCRT), followed by total mesorectal excision (TME). Tumor regression and pathological post-treatment stage are prognostic for oncological outcomes. There is a significant correlation between markers representing cancer-related inflammation, including high neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte (MLR) and unfavorable oncological outcomes. However, the predictive role of these markers on the effect of chemoradiation is unknown. AIM To evaluate the predictive roles of NLR, MLR, and PLR in patients with locally advanced rectal cancer receiving neoadjuvant chemoradiation. METHODS Patients (n = 111) with locally advanced rectal cancer who underwent nCRT followed by TME at the Minimally Invasive Surgery Unit, Siriraj Hospital between 2012 and 2018 were retrospectively analyzed. The associations between post-treatment pathological stages, neoadjuvant rectal (NAR) score and the pretreatment ratios of markers of inflammation (NLR, MLR, and PLR) were analyzed. RESULTS Clinical stages determined using computed tomography, magnetic resonance imaging, or both were T4 (n = 16), T3 (n = 94), and T2 (n = 1). The NAR scores were categorized as high (score > 16) in 23.4%, intermediate (score 8-16) in 41.4%, and low (score < 8) in 35.2%. The mean values of the NLR, PLR, and MLR correlated with pathological tumor staging (ypT) and the NAR score. The values of NLR, PLR and MLR were higher in patients with advanced pathological stage and high NAR scores, but not statistically significant. CONCLUSION In patients with locally advanced rectal cancer, pretreatment NLR, MLR and PLR are higher in those with advanced pathological stage but the differences are not significantly different.

BackgroundNo consensus has yet been reached regarding the best anesthetic technique for inguinal hernia repair. This study aimed to compare postoperative clinical outcomes and inflammatory markers among patients who were anesthetized using local, spinal, or general anesthesia for inguinal hernia repair.MethodsThis randomized controlled trial included patients scheduled to undergo elective unilateral inguinal hernioplasty at Siriraj Hospital during November 2014 to September 2015 study period. Patients were randomly assigned to the local (LA), spinal (SA), or general (GA) anesthesia groups. Primary outcomes were postoperative pain at rest and on mobilization at 8 and 24 hours after surgery.ResultsFifty-four patients were included, with 18 patients randomly assigned to each group. Patient demographic and clinical characteristics were similar among groups. There were no significant differences among groups for postoperative pain at rest or on mobilization at 8 and 24 hours after surgery. No significant differences were observed for interleukin-1β, interleukin-6, and interleukin-10 at any time points in any groups. Patients with local anesthesia was associated with less time spent in anesthesia (p= 0.010) and surgery (p= 0.009), lower intraoperative cost (p= 0.003) and total cost in hospital (p= 0.036); however, patient satisfaction in the local anesthesia group (94/100) was statistically significantly lower than the spinal and general anesthesia groups (100/100) (p= 0.010).ConclusionsNo statistically significant difference was observed among groups for postoperative pain scores, duration of hospital stays, complications, or change in inflammatory markers. However, time spent in anesthesia and surgery, the intraoperative cost and total cost for hernia repair, and patient satisfaction were significantly lower in the local anesthesia group than in the other two groups.

Background Concurrent chemoradiotherapy (CRT) is the standard treatment for head and neck (HN) cancer patients. Most patients experience malnutrition and weight loss during treatment because of mucositis and difficulty in swallowing. Prevention of malnutrition may allow more patients to complete their treatment. The present study aimed to examine whether prophylactic gastrostomy tube (PGT) could reduce treatment interruption, prevent malnutrition and maintain quality of life, especially in Thai patients who generally do not accept feeding tubes. Methods A prospective study was performed on HN cancer patients undergoing CRT at a tertiary hospital in Thailand (n = 95). Before starting CRT, all patients received nutritional assessment and were counselled about the risks and benefits of PGT. According to patient discretion, they chose to have a PGT (experimental group) or only nutritional counselling with a therapeutic feeding tube if required (control group). During CRT, weight, degree of mucositis, delayed chemotherapy and/or radiotherapy, and nutritional status were recorded. Quality of life (Functional Assessment of Cancer Therapy – Head and Neck Scale; FACT-H&N) was compared between two groups. Results There was no significant difference in the rates of delayed treatment. Mean weight loss was 3.1 and 4.8 kg in the experimental and control groups, respectively (P = 0.04). A higher proportion of patients in the control group experienced ≥10% weight loss (24% versus 4%; P = 0.03). In terms of quality of life, no significant difference in FACT-H&N score was found. Conclusions The results of the present study suggest that PGT provided similar quality of life without a reduction in treatment interruption. However, patients with PGT had significantly less weight loss (P = 0.04) during CRT.

Highlights • Pneumatosis intestinalis is characterized by the presence of air localizing in the submucosa and subserosa layers of the bowel wall. • Because of its risk of impending perforation, emergency surgery is generally required to be a definite treatment. • Colonic stenting can be used as a safe alternative procedure in the selected patient., Introduction Pneumatosis intestinalis is one of serious conditions following mechanical bowel obstruction. Emergency surgery is generally required to be a definite treatment in these patients of pneumatosis intestinalis, because of its risk of bowel ischemia and perforation. Since the operation in unprepared colon usually resulted in unfavorable outcome, the use of colonic stent is considered one of potential options as a bridge to definitive surgery. Presently, there is no widely published report of using colonic stent in these patients, particularly for stepping to curative surgery. Therefore, we herein report a case of obstructing sigmoid cancer with pneumatosis intestinalis who underwent successfully emergency metallic stent placement to convert from emergency to elective surgery. Presentation of case A 50-year-old woman presented with 3-day history of abdominal pain and obstipation. Abdominal computed tomography demonstrated a short segment of circumferential luminal narrowing at sigmoid colon, the presence of pneumatosis intestinalis at cecum, including ascending colon, and no extraluminal air. We performed colonoscopy and placed the metallic stent. The patient was then improved. After 1 week, the patient underwent elective hand-assisted laparoscopic sigmoidectomy and was discharged 5 days later. Pathological report showed stage IIa sigmoid cancer. The patient had no local recurrence or distant metastasis in 1 year follow up. Conclusion In obstructing colonic patient with pneumatosis intestinalis, nonsurgical treatment by colonic stenting can be used in selected patient as a bridge to definitive surgery. This will result in decreased morbidity and mortality and lower rate of stoma formation.

Siriraj Medical Journal, 69, 2

Perianal Paget's disease (intraepithelial adenocarcinoma) is rare and sometimes difficult to diagnose because symptoms are nonspecific. It is often noninvasive but frequently recurs locally. Invasive disease can metastasize to distant sites.The purpose of this work was to review the diagnosis, management, and outcomes of patients with perianal Paget's disease.Institutional databases were queried for all of the cases of perianal Paget's disease at Memorial Sloan-Kettering Cancer Center between 1950 and 2011. Clinicopathologic factors were investigated for association with recurrence and survival.The study was conducted at a tertiary care center.Sixty-five patients with perianal Paget's disease were included in the study (35 women [54%]; median age at diagnosis, 66 years [range, 60-72 years]; and 41 with invasive disease/24 with noninvasive disease). A total of 56% with invasive disease were men.Measures included median follow-up, disease status, local and distant recurrence, sites of recurrence, disease-specific survival, overall survival, and treatment modality.A total of 95% with invasive disease and 87% with noninvasive disease were symptomatic at presentation. The most common symptoms were pruritus and perianal bleeding. The duration of symptoms was longer in patients with invasive (12.0 months; range, 4.0-18.0 months) versus noninvasive (3.5 months; range, 1.0-10.0 months) disease. Synchronous malignancies unrelated to the primary disease were noted in 5 patients with invasive disease and 3 with noninvasive disease. Noninvasive disease was treated with a wide local excision and invasive disease with a wide local excision (n = 32, 78%) or abdominoperineal resection (n = 9, 22%). Forty-one patients (27 invasive and 14 noninvasive) required multiple operations for tumor clearance. In those with invasive disease, the median time to recurrence was 5 years, and the median tumor-specific survival rate was 10 years.This was a retrospective study, limited by selection bias.Perianal Paget's disease is associated with nonspecific symptoms, frequently delaying diagnosis. Wide local excision is the treatment of choice if negative margins can be obtained. Abdominoperineal resection should be considered for invasive disease. Local recurrence is common; follow-up includes periodic proctoscopy and digital examination. Invasive disease can metastasize to distant sites; follow-up should include the examination of inguinal lymph nodes and the imaging of liver and lungs.

The circumferential resection margin (CRM) is highly prognostic for local recurrence in rectal cancer surgery without neoadjuvant treatment. However, its significance in the setting of long-course neoadjuvant chemoradiotherapy (nCRT) is not well defined.Review of a single institution's prospectively maintained database from 1998 to 2007 identified 563 patients with locally advanced rectal cancer (T3/T4 and/or N1) receiving nCRT, followed after 6 weeks by total mesorectal excision (TME). Kaplan-Meier, Cox regression, and competing risk analysis were performed.The authors noted that 75 % of all patients had stage III disease as determined by endorectal ultrasound (ERUS) and/or magnetic resonance imaging (MRI). With median follow-up of 39 months after resection, local and distant relapse were noted in 12 (2.1 %) and 98 (17.4 %) patients, respectively. On competing risk analysis, the optimal cutoff point of CRM was 1 mm for local recurrence and 2 mm for distant metastasis. Factors independently associated with local recurrence included CRM ≤1 mm, and high-grade tumor (p = 0.012 and 0.007, respectively). CRM ≤2 mm, as well as pathological, nodal, and overall tumor stage are also significant independent risk factors for distant metastasis (p = 0.025, 0.010, and0.001, respectively).In this dataset of locally advanced rectal cancer treated with nCRT followed by TME, CRM ≤1 mm is an independent risk factor for local recurrence and is considered a positive margin. CRM ≤2 mm was associated with distant recurrence, independent of pathological tumor and nodal stage.

Background.Traditionally, rectal cancer surgery is recommended 6 to 8 weeks after completing neoadjuvant chemoradiation. Extending the waiting time may increase the tumor response rate. However, the perioperative complication rate may increase. The purpose of this study was to determine the association between extending the waiting time of surgery after neoadjuvant chemoradiation and perioperative outcomes.Methods. Sixty patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiation followed by radical resection at Siriraj hospital between June 2012 and January 2015 were retrospectively analyzed. Demographic data and perioperative outcomes were compared between the two groups.Results. The two groups were comparable in term of demographic parameters. The mean time interval from neoadjuvant chemoradiation to surgery was 6.4 weeks in Group A and 11.7 weeks in Group B. The perioperative outcomes were not significantly different between Groups A and B. Pathologic examination showed a significantly higher rate of circumferential margin positivity in Group A than in Group B (30% versus 9.3%, resp.;P=0.04).Conclusions. Extending the waiting to >8 weeks from neoadjuvant chemoradiation to surgery did not increase perioperative complications, whereas the rate of circumferential margin positivity decreased.

To demonstrate potential benefits of three-port hand-assisted laparoscopic sigmoidectomy (HALS) compared with open sigmoidectomy (OS) in terms of short-term outcomes and cost-benefit.A retrospective review of a database of cases that matched 100 sigmoid cancer patients treated with sigmoidectomy at the Department of Surgery, Siriraj Hospital was performed. Short-term outcomes and costs of treatment were collected and analyzed.There were no differences in age, gender body mass index, American Society of Anesthesiologists' score, Charlson comorbidity index score, and previous surgery between OS and HALS groups. The three-port HALS group had significantly less blood loss (50 (5-400) mL vs. 120 (10-1,000) mL, p0.001), faster time to regular diet (64.6±20.7 hours vs. 97.6±52.5 hours, p0.001), and lower pain score (4.3±1.7 vs. 5.3±1.6, p = 0.008). The hospital-stay related cost was sign icantly lower in HALS group ($114 ($47-$789) vs. $190 ($57-$1,462), pO. 001). The low rate of infection was a major contributory factor (12% vs. 0%, p = 0.03). This was further emphasized in subgroup analysis of surgical site infection (SSI). While there are great benefits, the operative cost is higher in HALS. However there is no significant difference in total costs of OS and HALS (US $2,243 ($1,321-$5,241) vs. $1,942 ($1,427-$11,910), p = 0.054).Simplified three-port HALS can be successfully performed with superior short-term outcomes and preserved oncologic outcomes. Cost-benefit advantage was highlighted especially in the area of high rate of SST.

Tumor regression grade (TRG) is a measure of histopathological response of rectal cancer to neoadjuvant chemoradiation and is associated with outcomes. Several TRG systems are used: Mandard (5,3-tier), Dowrak/Rödel (5,3-tier), Memorial Sloan Kettering Cancer Center (MSKCC), and American Joint Committee on Cancer (AJCC) Cancer Staging. A single measure of rectal cancer response would assist in comparing results across institutions, and in designing future rectal cancer studies. In this study, the predictive accuracies of the various published classification schemes are compared.Review of a prospective database identified 563 patients with locally advanced rectal cancer (T3/4 and/or N1) treated between 1998 and 2007 with long-course chemoradiation and total mesorectal excision. TRG was determined by measuring proportion of tumor mass replaced by fibrosis. Patients were classified into TRG schemes, which were compared by analyzing association with recurrence and survival using concordance index. Probabilities of recurrence-free survival were estimated using the Kaplan-Meier method. All statistical tests were two-sided.All TRG systems were predictive of recurrence. Concordance indices of the three-tier Mandard, three-tier Dowrak/Rödel, three-tier MSKCC, and four-tier AJCC systems were: 0.665, 0.653, 0.683, and 0.694, respectively (higher number = better prediction). The AJCC system more accurately predicted recurrence than the three-tier Mandard (P = .002) or Dowrak/Rödel (P = .006) and had a higher concordance index than MSKCC, although this did not reach statistical significance (P = .068).When classifying rectal cancer response to chemoradiation, the AJCC Staging Manual (7(th) edition) system is most accurate and should be adopted as the standard.

Overview: Minimally invasive surgery (MIS) of colorectal cancer has become more popular in the past two decades. Laparoscopic colectomy has been accepted as an alternative standard approach in colon cancer, with comparable oncologic outcomes and several better short-term outcomes compared to open surgery. Unlike the treatment for colon cancer, however, the minimally invasive approach in rectal cancer has not been established. In this article, we summarize the current status of MIS for rectal cancer and explore the various technical options.

Rectal cancers extending through the rectal wall, or involving locoregional lymph nodes (T3/4 or N1/2), have been more difficult to cure. The confines of the bony pelvis and the necessity of preserving the autonomic nerves makes surgical extirpation challenging, which accounts for the high rates of local and distant relapse in this setting. Combined multimodality treatment for rectal cancer stage II and III was recommended from National Institute of Health consensus. Neoadjuvant chemoradiation using fluoropyrimidine-based regimen prior to surgical resection has emerged as the standard of care in the United States. Optimal time of surgery after neoadjuvant treatment remained unclear and prospective randomized controlled trial is ongoing. Traditionally, 6-8 wk waiting period was commonly used. The accuracy of studies attempting to determine tumor complete response remains problematic. Currently, surgery remains the standard of care for rectal cancer patients following neoadjuvant chemoradiation, whereas observational management is still investigational. In this article, we outline trends and controversies associated with optimal pre-treatment staging, neoadjuvant therapies, surgery, and adjuvant therapy.

The effect of lymph node metastasis on local tumor control and distant failure in patients with anorectal melanoma has not been fully studied. Understanding the significance of lymphatic dissemination might assist in stratifying patients for either organ preservation or radical surgery.A retrospective review of all patients with anorectal melanoma who underwent surgery at our institution between 1985 and 2010. Abdominoperineal resection (APR) was performed in 25 patients (39 %), and wide local excision (WLE) in 40 (61%). Extent of primary surgery and locoregional lymphadenectomy (mesorectal vs. inguinal vs. none) and pattern of treatment failure were analyzed. Recurrence-free survival (RFS) and disease-specific survival (DSS) were calculated.In patients undergoing APR, DSS was not associated with presence (29 %) or absence (71 %) of metastatic melanoma in mesorectal lymph nodes. There was a trend toward improved DSS in patients with clinically negative inguinal lymph nodes (n = 17) compared with patients with proven inguinal metastasis (n = 6; P = 0.12). Type of surgery (WLE vs. APR) was not associated with subsequent development of distant disease. Twelve patients (18 %) had synchronous local and distant recurrence. Synchronous recurrence was not associated with surgical strategy used to treat primary tumor (P = 0.28). Perineural invasion (PNI) was significantly correlated with RFS (P = 0.002).Outcome following resection of anorectal melanoma is independent of locoregional lymph node metastasis; lymphadenectomy should be reserved for gross symptomatic disease. PNI is a powerful prognostic marker warranting further exploration in clinical trials.

Background Single-incision laparoscopic colectomy (SILC) was introduced as a novel minimally invasive technique. The benefits of this technique include reducing number of the incision and cosmetic improvement. Unlike the conventional laparoscopic colectomy, majority of previously reported SILC need to be performed using special curved or articulated instruments. The purpose of this study is to demonstrate our initial experience of SILC, which could be performed using the standard laparoscopic instruments. Material and methods Retrospective review of 14 patients who underwent SILC at Siriraj Hospital from May to December 2010, patient's demographic data, perioperative outcomes, early postoperative complications and pathological data were collected and analyzed. Results The mean age of all patients was 60 years. The most common operation with SILC was sigmoidectomy (n = 9), followed by right hemicolectomy (n = 2), left hemicolectomy (n = 1), anterior resection (n = 1), and total colectomy (n = 1). The trocar insertion techniques were multi-fascial incision using regular port (n = 11) and GelPOINT® (n = 3). The mean operative time was 155 minutes (range 90-280) and the mean estimate blood loss was 32.1 mL (range 10-100). All patients were successfully operated without conversion. The mean length of hospital stay was 9 days (range 5-20). There was no mortality. The pathological results revealed colorectal cancer (n = 12), neoplastic polyp (n = 1) and Familial adenomatous polyposis (FAP) (n = 1). The mean number of lymph nodes retrieval was 16.6 (range 3-34). Conclusion SILC can successfully and safely be performed with standard laparoscopic instruments. This technique might be an alternative procedure to conventional laparoscopic colectomy with better cosmetic result.

Early gastric cancer (EGC) defined as gastric cancer involving up to submucosal layer, regardless of lymph node metastasis, is increasingly found at Siriraj Hospital. Understanding the characteristic of EGC and result of surgical management for EGC can help to choose the optimal treatment. In the present study, the authors reported the first case series in Thailand.The authors analyzed 21 consecutive EGC patients treated with gastrectomy with lymph node dissection between September 2001 and December 2009 at Minimally Invasive Surgery Center, Division of General Surgery, Department of Surgery, Siriraj Hospital, Mahidol University, Thailand.Ratio of EGC to total cases of gastric cancer was increasing yearly, from 1.8% in 2006 to 8.1% in 2009 at Siriraj Hospital. The most common type of EGC was type IIc (66.7%) while type III was found in 19%, and type I in 14.3%. The tumor invaded mucosal layer in 42.9% and submucosal layer in 57.1% of the patients. For N staging, 76.2% of the patients were N0 while N1 was 19% and N2 was 4.8%. Overall, lymph node metastasis was found in 23.8%. For mucosal cancer (m), no lymph node metastasis was seen while for submucosal cancer (sm) five cases (41.7%) had lymph node metastasis, especially in one patient that the metastasis was in N2 group. Lymphatic invasion was seen in 14.3% of cases. All cases with lymphatic invasion were all submucosal cancer. Overall staging was stage 1a in 76.2%, stage 1b in 19%, and stage 2 in 4.8%. Morbidity was seen in 14.3% of the cases. No mortality was seen. The survival was excellent with no recurrence found during the follow-up period of the present study (mean 30.53 months).Surgery for EGC has good results with minimal complications and excellent 5-year survival. Less invasive treatment has become the option for EGC. Understanding the characteristic of EGC and careful selection to assign appropriate treatment is important to improve the result in the treatment of EGC.

Radical esophagectomy was reported to have prolonged survival in patients with esophageal cancer However, it is associated with high morbidity and mortality. Controversy still exists regarding value of radical esophagectomyThe authors analyzed the results, including complications and survival in 68 consecutive patients with esophageal cancer who were treated with transthoracic radical esophagectomy at the Department of Surgery, Siriraj hospital, Mahidol University between June 2002 and June 2008.There were 57 males and eight females with a mean age of 59.28 +/- 11.25 years. Regarding T staging, 81.5% of the patients were in T3 stage while 1.5% of the patients had Ti stage, 15.4% had T2 stage, and 1.5% had T4 stage. Lymph node metastasis (NI) was found in 63.1% of the patients and NO was in 36.9%. Most of the patients were in advanced stages with 53.8% in stage III, 44.6% in stage II, and 1.5% in stage I. The 5-year survival rate of the patients with node positive was significantly lower than the patients with node negative (p = 0.018). The survival was significantly better in stage Ilcompared to stage III (p = 0.012). Overall 5-year survival rate was 28. 5%. Most common complications were from pulmonary causes (22.1%), anastomotic leakage (8.8%), and wound infection (8.8%). Mortality rate was 4.41%.Radical esophagectomy was associated with relatively low mortality and acceptable survival. It should be considered in surgical treatment of patients with esophageal cancer

Extent of lymph node dissection still remains one of the most controversial issues regarding radical gastrectomy. Knowledge of the pattern and incidence of lymph node metastasis may help to define the optimal extent of lymph node dissection.The authors analyzed lymph node metastasis and survival rate in 130 consecutive gastric cancer patients who underwent radical gastrectomy with D2 dissection between June 2001 and October 2008 at the Department of Surgery, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand.For N staging, 28.5% of the patients were N0 while N1 was 40% and N2 was 31.5%. 44% of the patients with lymph node positive had metastasis up to group 2 lymph nodes. The patients with node positive had 5 year survival of 39% while the patients with node negative had survival of 73% (p = 0.003). Tumor at the middle part of the stomach had the most widespread lymph node metastasis compared to other regions. Lymph node group 7, 8 and 9 had a high incidence of lymph node metastasis especially for distal cancer while lymph node group 10, 11, 12 had lower incidence of metastasis. No mortality was seen in the present study.N staging, number of metastatic node5 and angiolymphatic invasion were the lymph node related factors contributing to survival. For radical gastrectomy, D2 dissection is required for adequate clearance of metastatic lymph nodes, which can be done without mortality.

3583 Background: Tumor regression grade (TRG) is a measure of histopathologic response of rectal cancer to preoperative chemoradiation (CRT) and correlates with outcomes. Several TRG systems have been reported including Mandard (5, 3 tier), Dowrak/Rodel (5, 3 tier), Memorial Sloan Kettering Cancer Center (MSKCC), and American Joint Committee of Cancer (AJCC). The purpose of this study is to compare the different TRG systems and determine which one(s) best predict recurrence and survival. Methods: Review of prospective maintained database from 1998 to 2007 identified 563 patients with locally advanced rectal cancer (T3/4 and/or N1) and treated with long-course CRT followed by total mesorectal excision. TRG was determined by measuring proportion of tumor mass replaced by fibrosis. Patients were then classified into the various TRG schemes which were compared by analyzing association with recurrence and survival using concordance index (CI) and reclassification index. CI is a measure that summarizes the predictive strength of a marker. Computing and contrasting CI across several markers is a way of selecting the best prognostic marker. Results: 75% of patients were noted to have clinical stage III disease by endorectal ultrasound or rectal MRI. Following resection with median follow-up of 39.3 months, 2% developed local recurrence and 17% developed distant metastasis. The median interval time between completion of CRT and surgery is 48 days. 20% demonstarted complete pathological response. CI of the 3 tier Mandard, 3 tier Dowrak/Rodel, MSKCC and AJCC are 0.665, 0.653, 0.683, and 0.694, respectively (higher number indicates better prediction). The AJCC was significantly more accurate in predicting recurrence than the 3- tier Mandard (p=0.002), and Dowrak/Rodel (p=0.006). AJCC had a higher CI than MSKCC although it did not reach significance (p=0.068). Comparing the 3 tier systems, MSKCC was most accurate and correctly reclassified 17 % and 23 % of the patients Mandard and Dowrak/Rodel systems, respectively. Conclusions: TRG predicts recurrence and survival following combined modality therapy for rectal cancer. The TRG system that recently was proposed in the 7thAJCC staging is currently the most accurate predictor.

Introduction Circumferential margin (CRM) is highly prognostic for rectal cancer recurrence; however, its significance in the setting after long-course neoadjuvant chemoradiation (nCR) is undefined. Methods Review of a prospectively maintained database from 1998 to 2005 identified 463 patients with locally advanced rectal cancer (T3/T4 and/or N1) receiving nCR followed in 6 weeks by total mesorectal excision. CRM was analyzed for association with recurrence and survival using the maximal chi-square method. Results 70% of patients were noted to have clinical Stage III disease by endorectal ultrasound or rectal MRI. Following resection with a median follow-up of 35 months, local and distant relapse was noted 10 (2.2%) and 80 (17.3%) patients, respectively. 39 patients had pathologic CRM ≤ 2 mm and 4 developed local recurrence and 13 developed distant recurrence. Factors associated with overall recurrence included tumor response to nCR (% tumor destruction), pathologic tumor stage and nodal status, tumor grade, and CRM ≤ 2 mm. Disease free survival and overall survival were 40.9 and 66.5 months with CRM ≤ 2 mm and 78.6 and 89.5 months with CRM > 2 mm (p Conclusions In this dataset of locally advanced rectal cancer treated with nCR both positive CRM and local recurrence were rare events and not clearly related. A CRM ≤ 2mm was associated with higher overall recurrence, independent of nodal status and response to nCR.

Endoscopic tattooing is one of the most useful tools for the localization of small colorectal lesions especially in the laparoscopic setting. This is a minimally invasive endoscopic procedure without risk of major complications. However, many studies have revealed complications resulting from this procedure. In this article, several topics are reviewed including the accuracy, substance preparation, injected techniques and complications related to this procedure.

For Choledochal cyst type I, complete excision of cyst with Roux-en-Y hepaticojejunostomy anastomosis is the treatment of choice. It has been performed laparoscopically with the advancement of laparoscopic skill. Recently, a telemanipulative robotic surgical system was introduced, providing laparoscopic instruments with wrist-arm technology and 3-dimensional visualization of the operative field. We present a case of robot-assisted total excision of a choledochal cyst type I and biliary reconstruction in a 14-year-old girl. No intraoperative complications or technical problems were encountered. An intraabdominal collection occurred and was successfully treated with continuous percutaneous drainage. At one-year follow-up, she is doing well without evidence of recurrent cholangitis.

AIM: To characterize clinical features, surgery, outcome, and survival of malignant melanoma (MM) of the gastrointestinal (GI) tract in a surgical training center in Bangkok, Thailand. METHODS: A retrospective review was performed for all patients with MM of the GI tract treated at our institution between 1997 and 2007. RESULTS: Fourteen patients had GI involvement either in a metastatic form or as a primary melanoma. Thirteen patients with sufficient data were reviewed. The median age of the patients was 66 years (range: 32-87 years). Ten patients were female and three were male. Seven patients had primary melanomas of the anal canal, stomach and the sigmoid colon (5, 1 and 1 cases, respectively). Seven patients underwent curative resections: three abdominoperineal resections, two wide local excisions, one total gastrectomy and one sigmoidectomy. Six patients had distant metastatic lesions at the time of diagnosis, which made curative resection an inappropriate choice. Patients who underwent curative resection exhibited a longer mean survival time (29.7 mo, range: 10-96 mo) than did patients in the palliative group (4.8 mo, P = 0.0006). CONCLUSION: GI MM had an unfavorable prognosis, except in patients who underwent curative resection (53.8% of cases), who had a mean survival of 29.7 mo.