A Japanese Prospective, Multicenter Study of Colonic Stenting for Palliation Using a High Axial Force Self-Expandable Metal Stent for Malignant Large Bowel Obstruction in 200 Patients.

Evidence of the efficacy and safety of colorectal stent placement for palliation remains insufficient. This single-arm, prospective, multicenter study with a WallFlex enteral colonic stent included 200 consecutive patients with malignant large bowl obstruction in the palliation cohort. The technical and clinical success, as well as stent patency and complications as short-term (≤7 days) and long-term (>7 days) outcomes, of high axial force self-expandable metal stent (SEMS) placement was evaluated. The technical and clinical success rates were 98.5% and 94.5%, respectively. Non-recurrent colorectal obstruction at 1 year was 63.9%, and 71.2% of the patients remained free of recurrent colorectal obstruction until death or the last follow-up. Fifty-six patients (28.0%) received chemotherapy, and five patients were administered bevacizumab after stent placement. The overall complication rate was 47%, including four (2.0%) early-onset and ten (5.0%) late-onset perforations, mostly due to stent-edge injury. Only the use of a long SEMS was a risk factor for perforation. In conclusion, endoscopic colorectal stenting using high axial force SEMS is an effective and safe procedure for palliation in patients with malignant colorectal obstruction. However, care should be taken to avoid perforation at the stent edge when using a long SEMS.

Long-term outcomes of standardized colonic stenting using WallFlex as a bridge to surgery: Multicenter prospective cohort study.

OBJECTIVES: The oncological outcomes, especially high recurrence rate, of bridge-to-surgery (BTS) self-expandable metallic stent (SEMS) placement remain concerning, emphasizing the necessity of standardized SEMS placement. However, its impact on long-term BTS outcomes is unknown. We investigated the long-term outcomes of BTS colonic stenting using standardized SEMS placement. METHODS: This prospective, multicenter cohort study conducted at 46 hospitals in Japan (March 2012 to October 2013) included consecutive patients with stage II and III obstructive colorectal cancer managed with BTS SEMS placement. The SEMS placement technique was standardized by information dissemination among the participating hospitals. The primary outcome was overall survival (OS) after SEMS placement, and the secondary outcomes were relapse-free survival (RFS), recurrence, and short-term outcomes of SEMS placement and surgery. RESULTS: The 1-, 3-, and 5-year OS rates were 94.1%, 77.4%, and 67.4% (Kaplan-Meier), respectively, with high technical success (99.0%, 206/208) and low perforation (1.9%, 4/208) rates. The 1-, 3-, and 5-year RFS rates were 81.6%, 65.6%, and 57.9% (Kaplan-Meier), respectively, and the overall recurrence rate was 31.0% (62/200). The RFS rate was significantly poorer in patients with perforation (n = 4) than in those without perforation (n = 196) (log-rank P = 0.017); moreover, perforation was identified as an independent factor affecting RFS (hazard ratio 3.31; 95% confidence interval 1.03-10.71, multivariate Cox regression). CONCLUSION: This large, prospective, multicenter study revealed satisfactory long-term outcomes of BTS colonic stenting using a standardized SEMS insertion method, which might be specifically due to the reduced perforation rate. (UMIN000007953).

Determining the difference in the efficacy and safety of self-expandable metallic stents as a bridge to surgery for obstructive colon cancer among patients in the CROSS 0 group and those in the CROSS 1 or 2 group: a pooled analysis of data from two Japanese prospective multicenter trials.

PURPOSE: This study compared the feasibility and safety of endoscopic placement of self-expandable metallic stents (SEMSs) as a bridge to surgery (BTS) between patients with obstructive colorectal cancer (CRC) classified as ColoRectal Obstruction Scoring System (CROSS) 0 and those with CROSS 1 or 2. METHODS: We conducted a post hoc analysis of two prospective, observational, single-arm multicenter clinical trials and performed a pooled analysis of the data. In total, 336 consecutive patients with malignant colorectal obstruction underwent SEMS placement. The primary endpoint was clinical success, defined as resolution of symptoms and radiological findings within 24 h. Secondary endpoints were technical success and adverse events. RESULTS: High clinical (98.0% vs. 98.4%) and technical (96.7% vs. 97.8%) success rates were observed in both groups (CROSS 0 vs. CROSS 1 or 2). The adverse event rate was low. The mean stricture length was lower (3.8 ± 1.2 cm vs. 4.4 ± 1.8 cm) and laparoscopic surgery more common (56.7% vs 52.2%) in the CROSS 0 group than in the CROSS 1 and 2 group. CONCLUSION: This study was the first to compare the degree of stricture in different CROSS groups and demonstrated comparable results with respect to the short-term efficacy and safety of SEMS placement as a BTS for obstructive CRC in CROSS 0, 1, and 2 patients.

Self-expandable metallic stenting as a bridge to surgery for malignant colorectal obstruction: pooled analysis of 426 patients from two prospective multicenter series.

BACKGROUND: Self-expandable metallic stenting (SEMS) for malignant colorectal obstruction (MCO) as a bridge to elective surgery (BTS) is a widely used procedure. The aim of this study was to assess short-term outcomes of SEMS for MCO as BTS. METHODS: This study analyzed pooled data from BTS patients who were enrolled in two multicenter prospective single-arm observational clinical studies that used different stent types. Both studies were conducted by the Japan Colonic Stent Safe Procedure Research Group (JCSSPRG). The first study evaluated the WallFlex™ colonic stent for BTS or palliative treatment (PAL) from May 2012 to October 2013 and the second evaluated the Niti-S™ colonic stent from October 2013 to May 2014. Fifty-three facilities in Japan participated in the studies. Before each study started, the procedure had been shared with the participating institutions by posting details of the standard methods of SEMS placement on the JCSSPRG website. Patients were followed until discharged after surgery. RESULTS: A total of 723 consecutive patients were enrolled in the two studies. After excluding nine patients, the remaining 714 patients were evaluated as a per-protocol cohort. SEMS placement was performed in 426 patients (312 WallFlex and 114 Niti-S) as BTS and in 288 as PAL. In the 426 BTS patients, the technical success rate was 98.1% (418/426). The clinical success rate was 93.8% (392/418). SEMS-related preoperative complications occurred in 8.5% of patients (36/426), perforations in 1.9% (8/426), and stent migration in 1.2% (5/426). Primary anastomosis was possible in 91.8% of patients (391/426), 3.8% of whom (15/393) had anastomosis leakage. The overall stoma creation rate was 10.6% (45/426). The postoperative complication rate was 16.9% (72/426) and mortality rate was 0.5% (2/426). CONCLUSIONS: SEMS placement for MCO as BTS is safe and effective with respect to peri-procedural outcomes. Further investigations are needed to confirm long-term oncological outcomes.

Factors related to difficult self-expandable metallic stent placement for malignant colonic obstruction: A post-hoc analysis of a multicenter study across Japan.

BACKGROUND AND AIM: Colorectal cancer patients often present with large bowel obstruction. Elective placement of a self-expandable metallic stent (SEMS) can relieve obstruction, but can be challenging. Previous studies have compared cases by outcomes only, but the present study investigated successful cases only to identify factors related to prolonged and difficult SEMS placement in patients with malignant colonic obstruction. METHODS: A post-hoc analysis of a multicenter clinical trial conducted between March 2012 and October 2013 at 46 facilities across Japan (UMIN000007953) was carried out; 511 patients who required SEMS placement for acute colorectal obstruction or symptomatic stricture secondary to malignant neoplasm were enrolled. Technical success rates and procedure times were recorded. Clinical and interventional parameters were investigated for their potential effect on procedure time by univariate and multivariate analyses. RESULTS: Technical success rate of SEMS placement was 98%. Median procedure time was 30 (range, 4-170) min. In 27% of patients, procedure time exceeded 45 min, indicating technically difficult placement. Multivariate analyses showed significant associations between technically difficult placement and a ColoRectal Obstruction Scoring System (CROSS) score of 0 before SEMS placement (odds ratio [OR], 1.6; P < 0.05), tumor site in the right colon (OR, 2.5; P < 0.0001), stricture length ≥5 cm (OR, 2.2; P < 0.001), peritoneal carcinomatosis (OR, 1.7; P < 0.05), and multiple SEMS placement (OR, 8.0; P < 0.01). CONCLUSION: Clinicians must anticipate technical challenges in cases with peritoneal carcinomatosis, a CROSS score of 0, or expansive strictures; such cases require experienced clinicians to carry out SEMS placement.

Unusual lymph node metastasis from cancer of the thoracic esophagus.

A 76-year-old male received concurrent chemoradiotherapy, at a dose of 60 Gy with low-dose 5-fluorouracil, for cT1bN0M0 squamous cell carcinoma of the mid-thoracic esophagus. Because his primary tumor relapsed with mediastinal and right supraclavicular node metastasis 4 months after completion of chemoradiotherapy, right transthoracic esophagectomy with mediastinal and right cervical lymphadenectomy was performed. However, metastatic tumors developed deep beneath the anterior border of the trapezius muscle 2 months after esophagectomy. En bloc dissection of the adipose tissue including the tumor and the transverse cervical artery was performed, followed by adjuvant radiotherapy of 50.4 Gy to the area of dissection. The patient died of pneumonia 11 months after metastasectomy, with locally recurrent disease. We have had three cases of this unusual lymph nodes metastasis from cancer of the thoracic esophagus to date and here present the characteristic imaging findings and the possible mechanism of this unusual lymph node metastasis.

Utility of comprehensive genomic sequencing for detecting HER2-positive colorectal cancer.

HER2-targeted therapy is considered effective for KRAS codon 12/13 wild-type, HER2-positive metastatic colorectal cancer (CRC). In general, HER2 status is determined by the use of immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Comprehensive genomic sequencing (CGS) enables the detection of gene mutations and copy number alterations including KRAS mutation and HER2 amplification; however, little is known about the utility of CGS for detecting HER2-positive CRC. To assess its utility, we retrospectively investigated 201 patients with stage I-IV CRC. The HER2 status of the primary site was assessed using IHC and FISH, and HER2 amplification of the primary site was also assessed using CGS, and the findings of these approaches were compared in each patient. CGS successfully detected alterations in 415 genes including KRAS codon 12/13 mutation and HER2 amplification. Fifty-nine (29%) patients had a KRAS codon 12/13 mutation. Ten (5%) patients were diagnosed as HER2 positive because of HER2 IHC 3+, and the same 10 (5%) patients had HER2 amplification evaluated using CGS. The results of HER2 status and HER2 amplification were completely identical in all 201 patients (P < .001). Nine of the 10 HER2-positive patients were KRAS 12/13 wild-type and were considered possible candidates for HER2-targeted therapy. CGS has the same utility as IHC and FISH for detecting HER2-positive patients who are candidates for HER2-targeted therapy, and facilitates precision medicine and tailor-made treatment.

Cardiac tamponade communicating with a posterior mediastinal chylocele after esophagectomy.

A 75-year-old male received neoadjuvant chemotherapy for locally advanced squamous cell carcinoma of the mid-thoracic esophagus, followed by right transthoracic esophagectomy with extended mediastinal lymphadenectomy. Cardiac tamponade developed on postoperative Days 1 and 13, for which emergency ultrasound-guided drainage was required. Pericardial drainage fluid became chylous after administration of polymeric formula. A computed tomography scan demonstrated the presence of a retrocardiac fluid collection, encompassed by the left pulmonary vein and left atrium, descending aorta and vertebral column. Based on these findings, the diagnosis of chylopericardial tamponade communicating with a posterior mediastinal chylocele was made. The ligation of the thoracic duct was successfully performed via the left-sided thoracoscopic approach on postoperative Day 20 and the clinical course after the second operation was uneventful. The possible mechanisms of this exceptionally rare complication after esophagectomy were discussed.

Comparison of the risk of surgical site infection and feasibility of surgery between sennoside versus polyethylene glycol as a mechanical bowel preparation of elective colon cancer surgery: a randomized controlled trial.

PURPOSE: To validate the usefulness of sennoside as a substitute for polyethylene glycol (PEG) as a mechanical bowel preparation (MBP) for elective colon cancer surgery. METHODS: We performed a prospective randomized non-inferiority trial comparing the use of sennoside and PEG in MBP for elective colon cancer surgery, in terms of the risk of surgical site infection (SSI) and the feasibility of surgery. RESULTS: The overall incidence of SSIs was 2.9 % in the sennoside group (n = 68) and 6.3 % in the PEG group (n = 63) with a difference of 3.4 % (95 % confidence interval 6.9-10.6 %). The intraoperative spillage of the stool materials in the sennoside and PEG groups was 4.4 and 3.1 %, respectively, and was not significantly different (p = 0.71), even the upstream stool consistency, was more frequently observed to be non-stool in the PEG group (65.1 vs. 30.9 %, p < 0.01). CONCLUSION: MBP with sennoside could be a substitution for PEG in elective colon cancer surgery.

A prospective multicenter study on self-expandable metallic stents as a bridge to surgery for malignant colorectal obstruction in Japan: efficacy and safety in 312 patients.

BACKGROUND: Endoscopic stenting with a self-expandable metallic stent (SEMS) is a widely accepted procedure for malignant colonic obstruction. The Colonic Stent Safe Procedure Research Group conducted the present prospective feasibility study. METHODS: Our objectives were to estimate the safety and feasibility of SEMS placement as a bridge to surgery (BTS) for malignant colorectal obstruction. We conducted a prospective, observational, single-arm, multicenter clinical trial from March 2012 to October 2013. Each patient was treated with an uncovered WallFlex enteral colonic stent. Patients were followed up until discharge after surgery. RESULTS: A total of 518 consecutive patients were enrolled in this study. The cohort intended for BTS consisted of 312 patients (61 %), and the stent could be released in 305 patients. Technical and clinical success rates were 98 and 92 %, respectively. Elective surgery was performed in 297 patients, and emergency surgery was performed in eight patients for the treatment of complications. The overall preoperative complication rate was 7.2 %. Major complications, including perforation, occurred in 1.6 %, persistent colonic obstruction occurred in 1.0 %, and stent migration occurred in 1.3 % patients. The median time from SEMS to surgery was 16 days. Silent perforations were observed in 1.3 %. Open and laparoscopic surgery was performed in 121 and 184 patients, respectively. The tumor could be resected in 297 patients. The primary anastomosis rate was 92 %. The rate of anastomotic leakage was 4 %, and the overall stoma creation rate was 10 %. The median duration of hospitalization following surgery was 12 days. Overall postoperative morbidity and mortality rates were 16 and 0.7 %, respectively. CONCLUSIONS: This largest, multicenter, prospective study demonstrates the feasibility of SEMS placement as a BTS for malignant colorectal obstruction. SEMS serves as a safe and effective BTS with acceptable stoma creation and complication rates in patients with acute malignant colonic obstruction.

A Japanese prospective multicenter study of self-expandable metal stent placement for malignant colorectal obstruction: short-term safety and efficacy within 7 days of stent procedure in 513 cases.

BACKGROUND: Endoscopic self-expandable metal stent placement has been used as an alternative to surgery for malignant colorectal obstruction; however, factors affecting its clinical outcome are unclear. OBJECTIVE: To clarify the short-term safety and efficacy of endoscopic self-expandable metal stent placement for malignant colorectal obstruction and to identify factors associated with its clinical and technical failure. DESIGN: Prospective clinical cohort study. SETTING: Fourteen academic centers and 32 community hospitals. PATIENTS: A total of 513 consecutive patients with malignant colorectal obstruction. INTERVENTION: Endoscopic self-expandable metal stent placement, sharing of stent placement methods among participating facilities. MAIN OUTCOME MEASUREMENTS: The primary endpoint was clinical success, defined as symptom and radiological finding resolution within 24 hours. Secondary endpoints were technical success and adverse events. The follow-up period was 7 days. RESULTS: The clinical and technical success rates were 95.5% and 97.9%, respectively. Major adverse events included perforation (2.1%), stent migration (1.0%), and stent occlusion (0.8%). The main causes of perforation were the procedure itself (0.8%) and comorbidities (obstructive colitis and impending perforation) not apparent before stent placement (0.6%). Extrinsic tumor origin was independently associated with the clinical failure after stent placement (odds ratio 4.23; 95% confidence interval, 1.21-14.79; P = .02). Stricture marking trended toward a negative association with technical failure (P = .09). LIMITATIONS: Noncomparative study. CONCLUSION: Strict inclusion criteria and stricture marking may improve the technical and clinical success of stent placement.

[A Case of Carcinoma of the Uterine Body, Right Ovary, and Duodenum in a Patient with Familial Adenomatous Polyposis].

We report a case of 4 carcinomas of the uterine body, right ovary, and duodenum in a patient with familial adenomatous polyposis (FAP). Her mother's family line carries FAP. She underwent proctocolectomy with ileoanal anastomosis for FAP when she was 20 years old. She was diagnosed with carcinoma of the uterine body and right ovary, and underwent abdominal total hysterectomy, bilateral salpingo-oophorectomy, and omentectomy at 48 years of age. The pathological examination revealed endometrioid adenocarcinoma of the uterine body (Stage ⅠB) and endometrioid adenocarcinoma of the right ovary (Stage ⅠA). Her diagnosis was Stage Ⅳ according to the Spigelman classification of duodenal polyposis, and she underwent pancreas-preserving total duodenectomy at 50 years of age. The pathological examination was conclusive for 2 carcinomas in the adenoma, which were 20 mm and 25 mm in diameter, respectively. She has been well without any evidence of cancer recurrence 20 months after the pancreas-preserving total duodenectomy.

[A Case of Metachronous Multiple Thyroid Papillary Carcinoma with FAP].

Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited disorder, the result of a germ line mutation in the adenomatous polyposis coli (APC) gene. FAP can be associated with various extracolonic lesions, including thyroid cancer, which frequently occurs in women. We report the case of a 36-year-old woman diagnosed as having FAP with multiple metachronous thyroid papillary carcinomas. She underwent left thyroidectomy at the age of 19 years without a diagnosis of FAP. Multiple polyps in her stomach were detected by medical examination and more than 100 polyps in the colon were found by colonoscopy. She was referred to our hospital after a diagnosis of non-profuse FAP. Multiple tumors with a maximum diameter of 10mm were detected in the right lobe of the thyroid gland during the preoperative examination. Papillary carcinoma was suspected based on fine-needle aspiration cytology. We performed a right thyroidectomy after prophylactic colectomy. Pathological findings revealed a cribriform-morula variant of papillary thyroid carcinoma. The patient remains well after 2 year 6 months with no recurrence.

[A Case of a Desmoid Tumor the Developed Around Ileostomy in a Patient with FAP].

A 21-year-old woman who underwent laparoscopic total colectomy for familial adenomatous polyposis (FAP) 1 year 3 months previously presented with a mass larger than 10 cm around the ileostomy. Multiple tumors in the mesentery around the ileostomy and anterior to the sacrum, accompanied by bilateral hydronephrosis, were detected by computed tomography. The patient was diagnosed with intraabdominal desmoid tumors, stage Ⅳ according to the Church's classification. The desmoid tumor (15×9 cm) around the ileostomy was completely resected surgically, whereas another desmoid tumor (5×4 cm) was incompletely resected. We found a desmoid tumor of more than 10 cm in size and many fibromatous plaques in the mesentery. We then performed 4 courses of systemic chemotherapy with dacarbazine and doxorubicin in for the residual desmoid tumors after surgery. There was no growth of the residual desmoid tumors for 12 months after chemotherapy. Genetic tests detected a pathogenic germline mutation of the APC gene in the high-risk region of the desmoid tumor. We also confirmed somatic mutations in the resected specimens.

[Two Cases of Digestive Organ Cancer in Patients with Situs Inversus Treated with Laparoscopic Surgery].

Case 1: A 53-year-old woman had a positive fecal occult blood test during an examination performed in June 2014, and she visited our department in August. Colonoscopic examination showed a type 2 rectal cancer 4 cm from the anal verge. CT showed situs inversus totalis. We performed laparoscopic abdominoperineal resection (D2) for a diagnosis of cT1b, N0, M0, Stage Ⅰrectal cancer. Case 2: A 60-year-old man had a positive fecal occult blood test. Colonoscopic examination showed a type 2 cancer of the ascending colon. Chest radiography showed dextrocardia, but the arrangement of the organs in the abdomen was normal. We performed laparoscopic ileocecal resection (D3) for a diagnosis of cT2, N0, M0, StageⅠ colon cancer. Laparoscopic surgery can be performed safely in patients with situs inversus totalis.

[A Case of FAP Who Underwent Mucosectomy for Intramucosal Cancer That Repeatedly Developed in the Residual Rectal Mucosa after Stapled Ileal-Pouch Anal Anastomosis].

When we perform stapled ileal pouch anal anastomosis (IPAA) for familial adenomatous polyposis (FAP), some rectal mucosa persists. There is no consensus on surgical treatment when cancer develops at the residual mucosa. We report the case of a 43-year-old woman who repeatedly underwent endoscopic resection for intramucosal cancer that developed in the residual rectal mucosa 6 years after stapled IPAA, which she received at age 33. She was referred to our department for surgical treatment. We performed mucosectomy for the residual rectum mucosa, including a 0-Ⅱa lesion at the anterior wall. Two months later, stenosis was observed at the anastomotic site. We repeatedly conducted balloon expansion of the stenotic lesion. Six months later, the resected lesion was covered with white epithelium, and columnar epithelium was confirmed by step biopsy of the epithelium from the dentate line to the ileoanal pouch anastomotic site. This finding indicated that the regenerating epithelium was derived from the epithelium from the anal side. The patient remains well after 2 year 4 months with no complaints.

[A Family Affected by Lynch Syndrome Caused by MSH6 Germline Mutation].

The clinical features of Lynch syndrome caused by MSH6 are not fully understood since very few cases have been described in Japan. We report 2 cases of Lynch syndrome with germline mutation of MSH6 in a family. Case 1: A 47-year-old man was referred to our department due to positive fecal occult blood test. He had family history of endometrial cancer and gastric cancer (mother), and bladder cancer (father). We performed sigmoidectomy for sigmoid cancer. The pathological findings revealed mucosal cancer (pTis, pN0, H0, P0, pStage 0). Since the patient met the revised Bethesda guidelines, we performed microsatellite instability (MSI) testing and immunohistochemistry for mismatch repair genes (MLH1, MSH2, MSH6, and PMS2) as screening for Lynch syndrome. MSI-high and loss of MSH6 were found. Based on these results, genetic testing of MSH6 revealed a frame-shift mutation in codon 604 (c. 1806-1809delAAG/p. Glu604LeufsX5). Case 2: The patient was a younger brother of case 1. The same mutation was detected in the MSH6 gene.

[Efficacy of Postoperative Chemotherapy in Stage â £ Colorectal Cancer with Perforation].

The clinical outcome and efficacy of postoperative chemotherapy in patients with Stage Ⅳ colorectal cancer with perforation were investigated. We compared the clinical outcomes between 11 patients with Stage Ⅳ colorectal cancer (perforation group), who underwent emergency surgery for colonic perforation between September 2005 and March 2012, and 22 matched patients (matching group) who underwent elective colorectal surgery during the same period. The colostomy rate in the perforation group was significantly higher than that of the matching group: patients with perforation received stoma construction surgery more frequently (p<0.01). Seven patients (64%) in the perforation group received postoperative chemotherapy, while 20 patients (91%) in the matching group received chemotherapy (p=0.15). Oxaliplatin-based chemotherapy was administered to all patients in both groups. There was no difference in the median relative dose intensity of oxaliplatin between these groups (p=0.37). No significant difference was observed between the cumulative 3-year overall survival rate in the perforation group and that of the matching group (35% and 54%, respectively; p=0.35). Moreover, the 3-year overall survival rates of patients who received oxaliplatin-based chemotherapy were 51%in the perforation group and 57% in the matching group (p=0.74). Our results suggest that postoperative oxaliplatin-based chemotherapy may improve the prognosis of patients with Stage Ⅳ colorectal cancer with perforation.

[Problems in the Treatment of Stage â ¢ Colorectal Cancer with Perforation].

We retrospectively investigated clinical outcome and treatment strategies in Stage Ⅲcolorectal cancer patients who underwent emergency surgery because of tumor-related perforation. We compared the clinical outcome of 6 patients (perforation group) who underwent emergency surgery for colonic perforation due to Stage Ⅲ colorectal cancer with 12 matched patients (matching group) who underwent elective colorectal surgery, between April 1998 and March 2012. Patients in the perforation group underwent colostomy procedures more frequently (p=0.02), had longer operative times (p=0.02), and more bleeding (p=0.04) than those in the matching group. There was no significant difference between the groups in terms of the introduction rate of chemotherapy, recurrence rate, or recurrence pattern. The 3-year disease-free survival rate was 44% in the perforation group and 81% in the matching group, resulting in no significant differences between these groups (p=0.28). The 3-year disease-free survival rates in the perforation and the matching groups were 44% and 81%, respectively (p=0.07). The 3-year overall survival rates in the perforation and the matching groups were 17% and 81%, respectively (p<0.01). The 3-year overall survival rate of patients who received adjuvant chemotherapy was 50% in the perforation group and 88%in the matching group (p=0.03). We concluded that patients with perforated Stage Ⅲ colorectal cancer had a significantly poorer prognosis compared with patients with non-perforated Stage Ⅲ colorectal cancer.

[A Case of Pelvic Schwannoma, Mimicking Metastasis of Rectal Carcinoma].

INTRODUCTION: Schwannoma in the lateral lymph node region is extremely rare; however, this tumor has been reported to have relatively high SUV on PET-CT, suggestive of malignancy. CASE: A 67-year-old man with advanced lower rectal cancer had a small nodule with FDG accumulation (SUVmax 2.6) near the left internal iliac artery. His preoperative diagnosis was rectal cancer with lateral lymph node metastasis. He underwent super-low anterior resection with lateral lymph node dissection. Histopathological examination was conclusive for pT3 (A), with an Rt263D lymph node metastasis. Interestingly, a schwannoma was detected among the harvested lymph nodes. CONCLUSION: Although rectal cancer is known to involve pelvic lymph nodes, the role of preoperative diagnosis with FDG-PET is unclear. We should consider that schwannoma is associated with slight elevation of SUVmax and it may mimic lymph node metastasis.