Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy in management of peritoneal carcinomatosis: Single center experience in Korea

PURPOSE: Peritoneal carcinomatosis (PC) has been considered a terminal condition and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIEPC) is regarded as an alternative therapeutic option. This study aimed to evaluate the 30-day clinical outcomes of CRS/HIPEC and the feasibility of the surgery by investigating the morbidity and mortality in Inje University Hospital.METHODS: Data were retrospectively collected from 19 patients with PC who underwent CRS/HIPEC at Inje University Hospital in 2018. We evaluated pre-, intra-operative parameters and postoperative clinical outcomes and early complications.RESULTS: The mean operating time was 506.95 minutes and the mean blood loss was 837.11 mL. Six cases (31.58%) had morbidity of grade III or above. A longer operating time (≥560 minutes, P=0.038) and large blood loss (≥700 mL, P=0.060) were positively correlated with grade III or worse postoperative complications.CONCLUSION: Our early experience with CRS/HIPEC resulted in a 31.58% morbidity rate of grade III and above, with risk factors being longer operating time and greater intraoperative blood loss. As the surgical team's skills improve, a shorter operating time with less intraoperative blood loss could result in better short-term outcomes of CRS/HIPEC.

Difference in Tumor Area as a Predictor of a Pathological Complete Response for Patients With Locally Advanced Rectal Cancer

PURPOSE: This study was conducted to discover the clinical factors that can predict pathologically complete remission (pCR) after neoadjuvant chemoradiotherapy (CRT), so that those factors may help in deciding on a treatment program for patients with locally advanced rectal cancer. METHODS: A total of 137 patients with locally advanced rectal cancer were retrospectively enrolled in this study, and data were collected retrospectively. The patients had undergone a total mesorectal excision after neoadjuvant CRT. Histologic response was categorized as pCR vs. non-pCR. The tumor area was defined as (tumor length) × (maximum tumor depth). The difference in tumor area was defined as pre-CRT tumor area – post-CRT tumor area. Univariate and multivariate logistic regression analyses were conducted to find the factors affecting pCR. A P-value < 0.05 was considered significant. RESULTS: Twenty-three patients (16.8%) achieved pCR. On the univariate analysis, endoscopic tumor circumferential rate <50%, low pre-CRT T & N stage, low post-CRT T & N stage, small pretreatment tumor area, and large difference in tumor area before and after neoadjuvant CRT were predictive factors of pCR. A multivariate analysis found that only the difference in tumor area before and after neoadjuvant CRT was an independent predictor of pCR (P < 0.001). CONCLUSION: The difference in tumor area, as determined using radiologic tools, before and after neoadjuvant CRT may be important predictor of pCR. This clinical factor may help surgeons to determine which patients who received neoadjuvant CRT for locally advanced rectal cancer should undergo surgery.

Oncologic safety of self-expanded metal stent insertion as a bridge to elective surgery in malignant colorectal obstruction

PURPOSE: Colorectal obstruction develops most frequently by carcinoma, and 7%–30% of these colorectal carcinomas are acute cases. The oncologic safety of self-expanding metal stent (SEMS) insertion as a bridge to surgery has not yet been established. Thus, we investigated the oncologic safety of SEMS insertion as a bridge to surgery in patients with obstructive colorectal cancer.METHODS: This retrospective had 56 patients enrolled requiring emergency management for obstructive colorectal cancer at stage II or III, who had undergone curative surgery between July 2008 and June 2011. These subjects were divided into two groups: patients who had undergone emergency surgery without SEMS insertion (non-stent group) and those who had undergone elective surgery after preoperative decompression with SEMS insertion (stent group). The two groups were compared for clinicopathologic characteristics, postoperative complications, and survival rate.RESULTS: Enterostomy was performed in 25 patients (100.0%) in the non-stent group and 1 patient (3.2%) in the stent group; laparoscopic surgery was carried out in 7 patients (28.0%) in the non-stent group and 19 patients (61.29%) in the stent group, each showing statistically significant differences. There was no statistically significant difference in postoperative complications and 5-year disease-free survival rate (72% vs. 74.19%, P=0.87, respectively).CONCLUSION: In treatment of malignant colorectal obstruction, elective operation after stent insertion had similar oncologic outcomes compared with emergency operation. Preoperative stent insertion not only lowers the incidence of enterostomy but also makes laparoscopic surgery possible, thereby enhancing patients' quality of life. Therefore, preoperative stent insertion is a useful method that may replace emergency surgery in treatment of malignant colorectal obstruction.

ERCC1 as a Predictive Marker for FOLFOX Chemotherapy in an Adjuvant Setting

PURPOSE: The purpose of this study was to identify the excision repair cross-complementation group 1 (ERCC1) as a predictive marker for FOLFOX adjuvant chemotherapy in stages II and III colon cancer patients. METHODS: A total of 166 high risk stages II and III colon cancer patients were retrospectively enrolled in this study, and data were collected prospectively. They underwent a curative resection followed by FOLFOX4 adjuvant chemotherapy. We analyzed ERCC1 expression in the primary colon tumor by using immunohistochemical staining. The oncological outcomes included the 5-year disease-free survival (DFS) rate. The DFS was analyzed by using the Kaplan-Meier method with the log-rank test. A Cox proportional hazard model was used for the prognostic analysis. RESULTS: ERCC1-positive expression was statistically significant in the older patients (P = 0.032). In the multivariate analysis, the prognostic factors for DFS were female sex (P = 0.016), N stage (P = 0.009), and postoperative carcinoembryonic antigen level (P = 0.001), but ERCC1 expression was not a statistically significant prognostic factor for DFS in the univariate analysis (P = 0.397). The 5-year DFS rate was not significantly associated with the ERCC1 expression in all patients (P = 0.396) or with stage III disease (P = 0.582). CONCLUSION: We found that ERCC1 expression was not significantly correlated with the 5-year DFS as reflected by the oncologic outcomes in patients with high-risk stages II and III colon cancer treated with FOLFOX adjuvant chemotherapy.

A Case of Colonic Perforation after Acute Necrotizing Pancreatitis / 대한내과학회지

Colonic perforation after acute necrotizing pancreatitis is a very rare but critical complication. The mortality rate is greater than 50%. Therefore, a high index of suspicion is needed for early detection of the complication. We present a case of a 50-year-old man diagnosed as colonic perforation after acute necrotizing pancreatitis. During the treatment course, fecal material was drained via a pleural drainage tube. Colonic perforation was confirmed on CT scan. The pathogenesis of colonic perforation in this case involved direct spread of pancreatic enzymes and inflammatory exudate. He was treated successfully with colectomy, ileostomy, debridement of necrotic tissue, and drainage.

Prognostic Significance of the Decreased Rate of Perioperative Serum Carcinoembryonic Antigen Level in the Patients With Colon Cancer After a Curative Resection

PURPOSE: The serum level of carcinoembryonic antigen (CEA) is a clinical prognostic factor in the follow-up evaluation of patients with colon cancer. We aimed to evaluate the prognostic significance of the rate of decrease of the perioperative serum CEA level in patients with colon cancer after a curative resection. METHODS: A total of 605 patients who underwent a curative resection for colon cancer between January 2000 and December 2007 were enrolled retrospectively. The rate of decrease was calculated using the following equation: ([preoperative CEA - postoperative CEA]/[preoperative CEA] x100). RESULTS: In the group with a preoperative serum CEA level of >5 ng/mL, the normalized group with a postoperative serum CEA level of 5 ng/mL, the prognostic factors for the OS and the DFS were the cutoff value (P < 0.0001) and the pN stage (P < 0.0001). CONCLUSION: A rate of decrease of more than 50% in the perioperative serum CEA level, as well as the normalization of the postoperative serum CEA level, may be useful factors for determining a prognosis for colon cancer patients with high preoperative CEA levels.

Prognostic Significance of the Decreased Rate of Perioperative Serum Carcinoembryonic Antigen Level in the Patients With Colon Cancer After a Curative Resection

PURPOSE: The serum level of carcinoembryonic antigen (CEA) is a clinical prognostic factor in the follow-up evaluation of patients with colon cancer. We aimed to evaluate the prognostic significance of the rate of decrease of the perioperative serum CEA level in patients with colon cancer after a curative resection. METHODS: A total of 605 patients who underwent a curative resection for colon cancer between January 2000 and December 2007 were enrolled retrospectively. The rate of decrease was calculated using the following equation: ([preoperative CEA - postoperative CEA]/[preoperative CEA] x100). RESULTS: In the group with a preoperative serum CEA level of >5 ng/mL, the normalized group with a postoperative serum CEA level of 5 ng/mL, the prognostic factors for the OS and the DFS were the cutoff value (P < 0.0001) and the pN stage (P < 0.0001). CONCLUSION: A rate of decrease of more than 50% in the perioperative serum CEA level, as well as the normalization of the postoperative serum CEA level, may be useful factors for determining a prognosis for colon cancer patients with high preoperative CEA levels.

Association Between a Close Distal Resection Margin and Recurrence After a Sphincter-Saving Resection for T3 Mid- or Low-Rectal Cancer Without Radiotherapy

PURPOSE: To maintain the patient's quality of life, surgeons strive to preserve the sphincter during rectal cancer surgery. This study evaluated the oncologic safety of a sphincter-saving resection with a distal resection margin (DRM) 1 cm), the 5-year cancer-specific survival rates were 81.57% and 80.03% (P = 0.8543), the 5-year local recurrence rates were 6.69% and 9.52% (P = 0.3981), and the 5-year systemic recurrence rates were 19.46% and 23.11% (P = 0.5750), respectively. CONCLUSION: This study showed that the close DRM itself should not be a contraindication for a sphincter-saving resection for T3 mid- or low-rectal cancer without radiotherapy. However, a prospective randomized controlled trial including the effect of adjuvant therapy will be needed.

Adipose-tissue-derived Stem Cells Enhance the Healing of Ischemic Colonic Anastomoses: An Experimental Study in Rats

PURPOSE: This experimental study verified the effect of adipose-tissue-derived stem cells (ASCs) on the healing of ischemic colonic anastomoses in rats. METHODS: ASCs were isolated from the subcutaneous fat tissue of rats and identified as mesenchymal stem cells by identification of different potentials. An animal model of colonic ischemic anastomosis was induced by modifying Nagahata's method. Sixty male Sprague-Dawley rats (10-week-old, 370 +/- 50 g) were divided into two groups (n = 30 each): a control group in which the anastomosis was sutured in a single layer with 6-0 polypropylene without any treatment and an ASCtreated group (ASC group) in which the anastomosis was sutured as in the control group, but then ASCs were locally transplanted into the bowel wall around the anastomosis. The rats were sacrificed on postoperative day 7. Healing of the anastomoses was assessed by measuring loss of body weight, wound infection, anastomotic leakage, mortality, adhesion formation, ileus, anastomotic stricture, anastomotic bursting pressure, histopathological features, and microvascular density. RESULTS: No differences in wound infection, anastomotic leakage, or mortality between the two groups were observed. The ASC group had significantly more favorable anastomotic healing, including less body weight lost, less ileus, and fewer ulcers and strictures, than the control group. ASCs augmented bursting pressure and collagen deposition. The histopathological features were significantly more favorable in the ASC group, and microvascular density was significantly higher than it was in the control group. CONCLUSION: Locally-transplanted ASCs enhanced healing of ischemic colonic anastomoses by increasing angiogenesis. ASCs could be a novel strategy for accelerating healing of colonic ischemic risk anastomoses.

Oncologic Outcomes and Risk Factors for Recurrence after Tumor-specific Mesorectal Excision of Rectal Cancer: 782 Cases

PURPOSE: The aim of this study was to analyze the oncologic outcomes and the risk factors for recurrence after a tumor-specific mesorectal excision (TSME) of resectable rectal cancer in a single institution. METHODS: A total of 782 patients who underwent a TSME for resectable rectal cancer between February 1995 and December 2005 were enrolled retrospectively. Oncologic outcomes included 5-year cancer-specific survival and its affecting factors, as well as risk factors for local and systemic recurrence. RESULTS: The 5-year cancer-specific survival rate was 77.53% with a mean follow-up period of 61 +/- 31 months. The overall local and systemic recurrence rates were 9.2% and 21.1%, respectively. The risk factors for local recurrence were pN stage (P = 0.015), positive distal resection margin, and positive circumferential resection margin (P < 0.001). The risk factors for systemic recurrence were pN stage (P < 0.001) and preoperative carcinoembryonic antigen level (P = 0.005). The prognostic factors for cancer-specific survival were pT stage (P < 0.001), pN stage (P < 0.001), positive distal resection margin (P = 0.005), and positive circumferential resection margin (P = 0.016). CONCLUSION: The oncologic outcomes in our institution after a TSME for patients with resectable rectal cancer were similar to those reported in other recent studies, and we established the risk factors that could be crucial for the planning of treatment and follow-up.

Prognostic Significance of Lymph Node Ratio in Stage III Rectal Cancer

PURPOSE: Although nodal metastasis is the most powerful prognostic factor in rectal cancer, marked heterogeneity exists within stage III rectal cancer. Recent studies of rectal cancer have shown a prognostic superiority of the lymph node ratio (LNR) compared with N stage. The purpose of this study was to investigate the prognostic value of the LNR in the era of the 7th edition of the TNM classification. METHODS: We included 190 patients who underwent a curative resection for rectal cancer with nodal metastasis. The patients were divided into four groups on the basis of statistically calculated cut-off values as 0.21, 0.32, and 0.61. RESULTS: The LNR was an independent risk factor for overall survival (OS; P = 0.008) and for systemic recurrence-free survival (SRFS; P = 0.002). However, the LNR was not a predictive factor for local recurrence. When the N stage of the sixth TNM staging system was separately analyzed as a covariate, the LNR was also found to be a predictive factor for both OS and SRFS (P = 0.012 and P = 0.004, respectively). A LNR value of 0.21 offered the best cut off to separate patients into two prognostic groups. CONCLUSION: The defined cut-off values of the LNR were an independent risk factor for OS and distant metastasis-free survival in patients with rectal cancer, irrespective of the sixth or the seventh version of the TNM classification, and the LNR should be considered as a prognostic variable in any future staging system.

Prognostic Analysis According to N Stage and Circumferential Resection Margin in Patients with Locally Advanced Rectal Cancer

PURPOSE: Efforts must be made to clarify the contribution of lymph node metastasis (NM) to adjuvant (chemo) radiotherapy following a curative resection for rectal cancer as the circumferential resection margin (CRM) has increasingly become a more reliable prognosticator for rectal cancer. This study examined the prognostic impact of NM on local recurrence, disease-free survival. and overall survival rates in curatively resected patients with locally advanced rectal cancer. METHODS: Two hundred two patients with locally advanced rectal cancer curatively resected in Pusan Paik Hospital from January 1995 to December 2003 were enrolled. These patients were divided into three groups according to lymph node (N) disease (N0: node negative, n=79; N1: 1-3 nodes positive, n=70; N2: > or =4 nodes positive, n=53). The potential prognostic factors, for example, T and N stage, preoperative carcinoembryonic antigen (CEA), postoperative (chemo) radiotherapy, operative methods, and several pathologic variables, were assessed among the three groups. The potential clinicopathologic factors were analyzed by using the Kaplan-Meier method, and the prognostic factors were compared in a Cox regression model. Also, we compared the oncologic results of 26 patients with a positive CRM (CMI) with those of the N1 and the N2 subgroups. RESULTS: N2 patients had an impaired 5-yr local control rate (19.1%) compared with N0 (6.8%) and N1 (11.6%, P=0.029) patients after a median follow up of 60 months (range, 6 to 156 mo). Differences in disease-free and overall survival were also significantly different statistically among the three groups (84.0% and 85.2% for N0; 54.9% and 65.1% for N1; 37.3% and 49.8% for N2; P<0.001 both). The impact of NM on the local recurrence, disease-free survival and overall survival was confirmed in the regression model for the curatively resected patients. There were no significant differences in the recurrence and the survival rates between CMI and N2 stage. CONCLUSION: NM has an independent prognostic impact on local failure and on disease-free survival and overall survival. Based on these findings, NM should be considered as an indicatior for adjuvant therapy. Although the prognostic impact of CMI is similar to that of N2, a larger prospective study is needed to clarify the prognostic association of CMI and N2.

Laparoscopically Assisted Hartmann's Procedure Followed by Laparoscopic Reversal in a Patient with Peritonitis Induced by Colonic Perforation / 대한내시경복강경외과학회지

Although laparoscopic surgery has been adopted for the treatment of peritonitis since the time laparoscopy was introduced for emergency operations, a laparoscopic Hartmann's procedure has not been described. We report on a Hartmann's procedure and its reversal for the treatment of peritonitis from colonic perforation by laparoscopic surgery. A 43-year-old female was diagnosed with fecal peritonitis due to a colonic perforation in the rectosigmoid colon. Five trocars were used and a Lapdisc(R) (Hakko medical, Japan) was placed at the previous Phannelstiel incision site. One hundred sixty minutes were needed for the laparoscopic Hartmann's procedure following peritoneal lavage. An oral diet was started at the postoperative 6th day and the patient was discharged on the 20th day with complete recovery. Hartmann's reversal was laparoscopically performed 3 months later. A Lapdisc was placed at the colostomy site following colostomy take-down. Four trocars were inserted at the same area as the first operation. The operative time was 180 minutes. There were no postoperative complications.

Oncologic Impact of Extracapsular Invasion of Nodal Metastasis in Patients with Stage III Rectal Cancer

PURPOSE: Extracapsular invasion (ECI) of nodal metastasis is reported to be a prognosticator of colorectal cancer. However, limited knowledge exists about the prognostic value of ECI in stage III rectal cancer. METHODS: From January 1996 to June 2004, 202 stage III rectal cancer patients who underwent surgery were enrolled in this study. The patients were divided into two groups according to ECI (patients with ECI, ECIP, n=122; patients without ECI, ECIN, n=80). The potential prognostic factors were compared in a Cox model. RESULTS: Of 916 positive nodes examined, ECI was seen in 46.7% of the positive nodes. The univariate comparison between the two groups revealed the five-year results after a median follow-up of 48.0 mo. The local control rate of ECIP did not show a significant difference from that of ECIN (77.0% vs. 85.4%, P=0.550). The disease-free survival rate and the overall survival rate differed for the two groups, with rates of 44.1% and 50.0% for ECIP and 70.4% and 63.2% for ECIN (P<0.001, P=0.049, respectively). The impact of ECI on the disease-free survival was confirmed in a Cox model. In a subgroup analysis, no significant differences in the recurrence and the survival rates were seen between the N1 ECIP and the N2 ECIN subgroups. CONCLUSION: Although ECI is not a risk factor for survival and local relapse, ECI is a prognosticator of overall recurrence. Based on these findings, more aggressive adjuvant treatment seems to be needed for decreasing the overall recurrence in stage III rectal cancer with ECI.

Clinical Significance of Serum Carcinoembryonic Antigen (CEA) Level at Diagnosis of Liver Metastases in Patients with Colorectal Cancer

PURPOSE: In numerous clinical trials to stratify prognosis of patients with liver metastases (LM) from colorectal cancer (CRC), the clinical value of serum carcinoembryonic antigen (CEA) levels at diagnosis of LM has not been fully investigated in these group. The aim of this study is to explore the relation of CEA to characteristics of LM and to analyze prognostic value of this widely used tool. METHODS: We retrospectively analyzed clinical data of 143 LM patients who were performed surgical intervention or non-surgical intervention. The cohort was divided into two groups; normal CEA group (NCEAG, or =5 ng/ml, n=102). We examined correlation between serum CEA at diagnosis of LM and other clinicopathologic factors and performed univariate and multivariate analyses to determine the clinical impact of this marker on survival. RESULTS: Compared to ECEAG, the characteristics of LM of NCEAG was associated with unilobar distribution of LM (P=0.003), less metastases (P<0.001), less rate of synchronocity (P=0.008) and more surgical intervention of hepatic deposits (P<0.001). The 5-year survival rate for NCEAG was better than ECEAG (P=0.031). Multivariate analysis revealed that the presence of lymphatic duct invasion, no performance of chemotherapy, bilobar distribution of LM, and treatment of non-surgical intervention had a significant effect on survival. CEA elevation was identified as independently associated with bilobar distribution and non-surgical intervention of LM. CONCLUSIONS: Although CEA level is not a independent prognostic factor in this study, the clinical characteristics identified in this study and correlation to non surgical intervention of LM may help better patient selection in the management of CRC LM patients.

Prognostic Significance of the Circumferential Resection Margin in Invasive T3 Rectal Cancer

PURPOSE: Because depth of invasion by T3 rectal cancer can vary according to the extent of mesorectal invasion, the prognosis for invasive T3 rectal cancer is reported to be very different from that for minimal invasive cancer. Recently, with more emphasis on circumferential resection margin (CRM) status, the T stage, rather than the N stage, seems to be a more valuable prognostic marker in rectal cancer. Therefore, the aim of this study is to determine the prognostic significance of the CRM in invasive T3 rectal cancer. METHODS: Through reviewing 324 consecutive patients with rectal cancer who underwent a curative resection between January 1995 and December 2002 at Busan Paik hospital, 195 patients with invasive T3 rectal cancer, who had not received preoperative neoadjuvant therapy were selected. The patients were classified into a negative CRM group (negative group, n=173) or a positive CRM group (positive group, n=22), and the patients were subgrouped according to the presence of lymph-node (LN) metastasis and CRM status as negative LN and negative CRM (L-/CM-), negative LN and positive CRM (L-/CM+), positive LN and negative CRM (L+/CM-) and positive LN and positive CRM (L+/CM+). All pathological specimens were re-reviewed by a single pathologist, and the distance between the most advanced edge and the outermost aspect of the specimen was re-measured by using a microscope. Local relapse rates, disease free survival, and overall survival were compared using the Kaplan- Meier method. Multivariate analyses to identify independent prognostic factors were performed using the logistic regression model. RESULTS: Local recurrence rates in the positive group and the negative group were 38.6% and 15.3%, respectively (P=0.004, log-rank test). The multiple logistic regression model demonstrated positive CRM (hazard ratio 4.4, P=0.0007) and N2 nodal status (hazard ratio 2.4, P=0.02) as predictors of local recurrence. In the subgroup analysis, the overall recurrence rates and survival rates were, respectively, 12.3% and 86.5% in the L-/CM- subgroup, 53.1% and 50.3% in the L-/CM+ subgroup, 52.7% and 50.0% in the L+/ CM- subgroup, and 58.7 % and 33.8% in the L+/CM+ subgroup (log rank test for trend; P=0.0001 and P=0.0001, respectively). CONCLUSIONS: In the event of predicted CRM involvement in invasive T3 rectal cancer, adjuvant therapy should be performed to improve local control. Also, larger prospective studies are needed to clarify the prognostic role of the CRM in invasive T3 rectal cancer because the number of cases in this study was small, especially in the number of CRM positive cases.

Loop Colostomy with Not Everted Fashion for Rectal Cancer

PURPOSE: An anastomotic leak after resection of rectal cancer is a omnious complication. The diverting stoma is performed to avoid this serious complication. However, a diverting stoma and a stoma reversal are associated with significant morbidity and a small mortality. As stoma-related complications are associated with a delay of adjuvant therapy for advanced rectal cancer, minimal stoma-related morbidity is mandatory for rectal cancer patients. A safe and simple dissection of the stoma is known to be associated with less morbidity at stoma closure. Since in a loop colostomy of a not everted fashion, it is easy to construct and dissect the peristomal site at colostomy reversal, this study evaluated the usefulness of a protective loop colostomy of a not everted fashion in rectal cancer. METHODS: We reviewed the clinical records of 71 cases of loop colostomy closure for rectal cancer between January 1996 and December 2004. The clinical data, including indications for the stoma, the clinicopathologic features of the patients and their general conditions, the data for patients receiving adjuvant therapy, stoma-related morbidity, stoma-closure-related morbidity, and perioperative data were examined. RESULTS: Indications for stoma creation are the discretion of the surgeon (n=22), poor bowel preparation (n=21), unstable anastomosis (n=16), bowel obstruction (n=6), and anastomotic leakage (n=6). The stoma-related morbidity rate for a non-eversion colostomy was 5.6%. Morbidity events were peristomal erythema (n=2), prolapse (n=1), and parastomal hernia (n=1) requiring surgery. The stoma-closure-related morbidity rates was 9.9%. In the 45 patients undergoing adjuvant therapy, colostomy closure was performed during adjuvant therapy in 39 patients. Major complications, such as anastomotic leakage or abscess following reversal of the non-eversion colostomy, occurred in 1 of the 71 patients (1.4%). The average operating time and the blood loss for clostomy closure were 89.5 minutes and 202.3 ml, respectively. A simple closure of the loop colostomy was performed in 51 patients (71.8%). CONCLUSIONS: Based on our results, a non-eversion colostomy may be considered due to the ease of construction and reversal if a temporary diverting stoma for rectal cancer is indicated.

Clinical Significance of Lateral Resection Margin Involvement for Colon Cancer

PURPOSE: The clinical significance of the lateral resection margin for rectal cancer has been widely investigated. The ascending and the descending colon do not have a peritoneal covering posteriorly. Therefore, colon cancers located on their posterior side can penetrate the entire bowel wall, which is similar to mesorectal invasion in rectal cancer. However, the prognostic significance of the retroperitoneal resection margin involvement is unknown. The aim of this study is to evaluate the prognostic significance of the lateral resection margin in ascending and descending colon cancer. METHODS: A retrospective study was performed and involved 92 patients who had undergone a curative resection for right or left colon cancer with TNM stage II and III. The patients were assigned to either a lateral margin negative group (LMNG, n=73) or a lateral margin positive group (LMPG, n=19) according to the presence of a tumor or a metastatic lymph node within 1 mm of the lateral resection margin. The oncological outcomes of the LMPG were compared with those of the LMNG. RESULTS: The LMPG was younger and had higher incidences of tumors positive vascular or neural invasion and advanced T and N stages. The overall recurrence rate of the LMPG was higher than that of the LMNG (36.8% versus 16.4%) and the cumulative survival rate of the LMPG was significantly lower than that of the LMNG (35.0% versus 76.2%). High preoperative CEA, lymphatic invasion, lateral margin involvement of the tumor, N2 in nodal status were significant factors in the univariate analysis for evaluation of the prognosis, but lateral margin involvement was not a significant factor in the multivariate analysis. In the lymph-node-positive group and the CEA non-elevation group, lateral margin involvement of the tumor was revealed as a prognostic factor. CONCLUSIONS: Lateral margin involvement of ascending and descending colon cancer affects tumor recurrence and overall survival, but it is not a significant prognostic factor.

Tumor Necrosis Factor-alpha-308G/A Promoter Polymorphism is Associated with the Severity of Gastric Carcinomas

PURPOSE: The pro-inflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), is a central mediator of the immune response involved in a wide range of immuno-inflammatory and infectious diseases. There is increasing evidence that TNF-alpha may promote the development and spread of the cancer. Polymorphisms in the TNF-alpha promoter have been related to TNF-alpha production. Therefore, we investigated the potential association of TNF-alpha genotypes with gastric cancer in the Korean population. METHODS: The study included 66 patients with gastric adenoma, 75 patients with gastric carcinoma, and 551 healthy controls. The -308 and -238 polymorphisms in the TNF-alpha promoter were analyzed by PCR- restriction fragment length polymorphism (RFLP). Distributions of TNF-alpha promoter polymorphisms were compared between groups by chi2 test. P values smaller than 0.05 were considered to be significant. RESULTS: The proportion of individuals carrying the TNF-alpha -308A allele was higher in the carcinoma group compared to controls and adenomas, but the differences were not significant (P=0.124). However, the TNF-alpha -308A allele was significantly associated with advanced gastric carcinoma (P=0.026), serosa invasion (P=0.004), neural invasion (P= 0.021), and lymph node metastasis (P=0.005). On the other hand, the TNF-alpha -238G/A polymorphism was not associated with the development of gastric adenoma and carcinoma and the severity of gastric carcinoma. CONCLUSION: These results suggest that the TNF-alpha -308A allele is associated with the severity of gastric carcinoma in terms of invasion and metastasis in the Korean population. Therefore, TNF-alpha promoter polymorphism could be used as a predictive marker of the severity of gastric carcinoma.

Regional Distribution of Peptide YY Concentrations in Human Lower Gastrointestinal Mucosa

PURPOSE: Peptide YY is composed of 36 amino acids, and its functions are suppression of gastric acid secretion, delay of gastric emptying, increase of intestinal motility, inhibition of pancreatic exocrine secretion, and enhanced postprandial colonic absorption of water and electrolyte. PYY is released from PYY cells, which are mainly distributed in the ileum and colon, in response to the presence of intraluminal lipids. This study was designed to determine the regional distribution of PYY in the normal human ileum, colon, rectum, and anal canal by studying mucosal concentrations. METHODS: Fresh tissues were obtained from specimens of segmental resections of the small bowel, colectomies, ileostomies, and abdominoperineal resections for the management of colonic or rectal carcinomas or benign diseases of the bowel. Only specimens devoid of advanced luminal obstruction were included. Mucosa was separately recruited by microdissection of frozen sections. Radioimmunoassays were performed using the methods of Adrian et al. RESULTS: The concentration of PYY was highest at 25 cm proximal to the ileocecal valve in the ileum (307.6 pmol/ g) and in the upper rectum at the colon (653.1 pmol/g). The concentration of PYY was 27.3 pmol/g in the anal canal distal to the dentate line. A clear differential distribution of PYY was shown in the ileum and colon. CONCLUSIONS: This study showed PYY was present in large amounts in the mucosa of the ileum and colon, with high concentrations in locations 25 cm proximal to ileocecal valve and in the upper rectum, respectively. The trend of regional differences in PYY in the colonic mucosa probably reflects local differences in functions, such as absorption and storage. Also, the peak concentration in the ileum at 25 cm proximal to ileocecel valve suggests that this region is the most abundant production site of PYY in the ileum.