Tumor microbiome analysis provides prognostic value for patients with stage III colorectal cancer.

Introduction: Although patients with colorectal cancer (CRC) can receive optimal treatment, the risk of recurrence remains. This study aimed to evaluate whether the tumor microbiome can be a predictor of recurrence in patients with stage III CRC. Methods: Using 16S rRNA gene sequencing, we analyzed the microbiomes of tumor and adjacent tissues acquired during surgery in 65 patients with stage III CRC and evaluated the correlation of the tissue microbiome with CRC recurrence. Additionally, the tumor tissue microbiome data of 71 patients with stage III CRC from another center were used as a validation set. Results: The microbial diversity and abundance significantly differed between tumor and adjacent tissues. In particular, Streptococcus and Gemella were more abundant in tumor tissue samples than in adjacent tissue samples. The microbial diversity and abundance in tumor and adjacent tissues did not differ according to the presence of recurrence, except for one genus in the validation set. Logistic regression analysis revealed that a recurrence prediction model including tumor tissue microbiome data had a better prediction performance than clinical factors (area under the curve [AUC] 0.846 vs. 0.679, p = 0.009), regardless of sex (male patients: AUC 0.943 vs. 0.818, p = 0.043; female patients: AUC 0.885 vs. 0.590, p = 0.017). When this prediction model was applied to the validation set, it had a higher AUC value than clinical factors in female patients. Conclusion: Our results suggest that the tumor microbiome of patients with CRC be a potential predictor of postoperative disease recurrence.

Is it Possible to Successfully Treat Locally Advanced Colon Cancer Using Pre-Operative Chemoradiotherapy?

Pre-operative chemoradiotherapy (CRT) is a preferable treatment option for patients with locally advanced rectal cancer. However, few data are available regarding pre-operative CRT for locally advanced colon cancer. Here, we describe two cases of successful treatment with pre-operative CRT and establish evidence supporting this treatment option in patients with locally advanced colon cancer. In the first case, a 65-year-old woman was diagnosed with ascending colon cancer with duodenal invasion. In the second case, a 63-year-old man was diagnosed with a colonic-duodenal fistula due to transverse colon cancer invasion. These case reports will help to establish a treatment consensus for pre-operative CRT in patients with locally advanced colon cancer.

Clinical significance of carcinoembryonic antigen in peritoneal fluid detected during operation in stage I-III colorectal cancer patients.

BACKGROUND/AIMS: Early diagnosis of peritoneal metastases in patients with colorectal cancer (CRC) can influence patient prognosis. The aim of this study was to identify the clinical significance of carcinoembryonic antigen (CEA) in peritoneal fluid detected during operation in stage I-III CRC patients. METHODS: Between April 2009 and April 2015, we reviewed medical records from a total of 60 stage I-III CRC patients who had peritoneal fluid collected during operation. Patients who had positive cytology in the assessment of peritoneal fluid were excluded. We evaluated the values of CEA in peritoneal fluid (pCEA) to predict the long-term outcomes of these patients using Kaplan-Meier curves and Cox regression models. RESULTS: The median follow-up duration was 37 months (interquartile range, 21-50 months). On receiver operating characteristic analysis, pCEA had the largest area under the curve (0.793; 95% confidence interval, 0.635-0.950; P=0.001) with an optimal cutoff value of 26.84 (sensitivity, 80.0%; specificity, 76.6%) for predicting recurrence. The recurrence rate was 8.1% in patients with low pCEA (<26.84 ng/mL, n=37), and 52.2% in patients with high pCEA (≥26.84 ng/mL, n=23). In multivariate Cox regression analysis, high pCEA (≥26.84 ng/mL) was a risk factor for poor cancer-free survival (CFS) in stage I-III patients. CONCLUSIONS: In this study, we determined that high pCEA (≥26.84 ng/mL) detected during operation was helpful for the prediction of poor CFS in patients with stage I-III CRC.

Hematochezia due to Angiodysplasia of the Appendix.

Common causes of lower gastrointestinal bleeding include diverticular disease, vascular disease, inflammatory bowel disease, neoplasms, and hemorrhoids. Lower gastrointestinal bleeding of appendiceal origin is extremely rare. We report a case of lower gastrointestinal bleeding due to angiodysplasia of the appendix. A 72-year-old man presented with hematochezia. Colonoscopy showed active bleeding from the orifice of the appendix. We performed a laparoscopic appendectomy. Microscopically, dilated veins were found at the submucosal layer of the appendix. The patient was discharged uneventfully. Although lower gastrointestinal bleeding of appendiceal origin is very rare, clinicians should consider it during differential diagnosis.

Clinical Practice in the Use of Adjuvant Chemotherapy for Patients with Colon Cancer in South Korea: a Multi-Center, Prospective, Observational Study.

BACKGROUND: Adjuvant chemotherapy is a crucial part of treatment for patients with locally advanced colon cancer. This study was conducted to investigate the actual practice in the use of adjuvant chemotherapy for patients with high-risk stage II or stage III colon cancer in South Korea. METHODS: This was a 24-month open-label, prospective, observational study conducted at 12 centers across South Korea. Patients with high-risk stage II and stage III colon cancer receiving adjuvant chemotherapy after curative surgery were included, and data were collected at baseline, third, and sixth month. RESULTS: A total of 246 patients were included in the analyses. Of five available regimens (FOLFOX, CAPOX, 5-FU/LV, capecitabine, and UFT/LV), FOLFOX was most commonly used (82.5%). Investigators indicated the "efficacy" as the major cause for selecting FOLFOX or CAPOX. For 5-FU/LV, capecitabine, or UFT/LV, the "safety" or "patient's characteristics (age, comorbidity, and stage)" was one of the most important selecting factors. Patients receiving 5-FU/LV, capecitabine, or UFT/LV had older age, worse PS and lower disease stage (stage II) than patients receiving FOLFOX or CAPOX. Hematologic toxicities were the most common cause of dose adjustment and treatment delay. CONCLUSIONS: In South Korea, FOLFOX was the most commonly used regimen for adjuvant chemotherapy and its efficacy was the main cause for selecting this regimen. Patients receiving 5-FU/LV, capecitabine, or UFT/LV had older age, worse PS and lower disease stage (stage II) than patients receiving FOLFOX or CAPOX.

Long-term Outcomes of Laparoscopic versus Open Surgery for Rectal Cancer: A Single-center Retrospective Analysis.

BACKGROUND/AIMS: Laparoscopic surgery has been proven to be an effective alternative to open surgery in patients with colon cancer. However, data on laparoscopic surgery in patients with rectal cancer are insufficient. The aim of this study was to compare the long-term outcomes of laparoscopic and open surgery in patients with rectal cancer. METHODS: A total of 307 patients with rectal cancer who were treated by open and laparoscopic curative resection at Kosin University Gospel Hospital (Busan, Korea) between January 2002 and December 2011 were reviewed retrospectively. RESULTS: Regarding treatment, 176 patients underwent an open procedure and 131 patients underwent a laparoscopic procedure. The local recurrence rate after laparoscopic resection was 2.3%, compared with 5.7% after open resection (p = 0.088). Distant metastases occurred in 6.9% of the laparoscopic surgery group, compared with 24.4% in the open surgery group (p < 0.001). In univariate analysis, age (≥ 75 years vs. ≤ 60 years), preoperative staging, surgical approach (open vs. laparoscopic), elevated initial CEA level, elevated follow-up CEA level, number of positive lymph nodes, and postoperative chemotherapy affected overall survival and disease free survival. However, in multivariate analysis, the surgical approach apparently did not affect long-term oncologic outcome. CONCLUSIONS: In this study, long-term outcomes after laparoscopic surgery for rectal cancer were not inferior to those after open surgery. Therefore, laparoscopic surgery would be an alternative operative tool to open resection for rectal cancer, although further investigation is needed.

Volvulus of the Sigmoid Colon Associated With Rectal Cancer: A Case Report.

Sigmoid volvulus is one of the three most common causes of acute colonic obstruction. Predisposing factors include chronic constipation, adhesion from a prior abdominal surgery, and megacolon. However, concomitant presentation of volvulus of the sigmoid colon and rectal cancer is extremely rare. We report a case of a 50-year-old woman with coexisting volvulus of the sigmoid colon and rectal cancer. The patient presented with abdominal distension and pain for 2 days. On computed tomography, the whole colon was dilated with gas and feces. A whirl sign with rotation of the inferior mesenteric vessel was identified. The rectum had irregular wall thickening. Colonoscopy showed a circumscribed, ulcerofungating mass approximately 6 cm from the anal verge. The sigmoid colon was obstructed at a point approximately 25 cm from the anal verge. The mucosa was hyperemic and edematous with the pathognomonic spiral pattern. Endoscopic reduction was not successful. On laparotomy, the sigmoid colon was rotated around its mesentery. It was severely distended with edematous, hyperemic serosa. A tumor of the rectum was identified in the mid-rectum. The patient underwent low anterior resection and protective ileostomy. Pathologic findings confirmed adenocarcinoma of the rectum. The postoperative course was complicated by an ileus, which was managed with conservative treatment.

Laparoscopic resection for middle and low rectal cancer.

AIMS: The purpose of this study was to evaluate the technical feasibility, safety and oncological outcomes of laparoscopic resection for middle and low rectal cancers. MATERIALS AND METHODS: From January 2004 to December 2011, review of prospectively collected database revealed a series of 97 laparoscopic resections for middle and low rectal cancer within 10 cm from the anal verge. Five patients with multiple primary cancers were excluded. Operation time, intra-operative blood loss, surgical complications, duration of hospital stay, retrieved lymph nodes, tumour, node, metastasis (TNM) stage and recurrence were retrospectively analysed. RESULTS: Tumours were located within 5 cm of the anal verge in 28 patients (30.4%) and from 5 cm to 10 cm in 64 patients (69.6%). Abdominoperineal resection was performed in 12 patients (13%), and conversion to open surgery was necessary in four patients (4.3%). The mean operation time was 199.7 min (range 105-450 min) and the mean intra-operative blood loss was 169.9 mL (range 20-800 mL). The mean hospital stay was 11.8 days (range 5-45 days) and a mean of 12.2 lymph nodes were retrieved. The incidence of surgical complications was 11.9%, including anastomosis site leakage in five patients (5.4%). There were no mortalities resulting from laparoscopic surgery. The median follow-up period was 28.4 months (range 7-85 months). Recurrence occurred in eight patients (8.7%). CONCLUSIONS: Laparoscopic resection can be applied for middle and low rectal cancers with acceptable surgical and oncological outcomes.

Primary Isolated Extramedullary Plasmacytoma in the Colon.

Primary isolated extramedullary plasmacytoma is a rare tumor. Although it commonly involves nasopharynx or upper respiratory tract, only 10% of cases involves the gastrointestinal tract. Stomach and small intestine are the most commonly involved sites in the gastrointestinal tract. Primary isolated extramedullary plasmacytoma of colon is extremely rare. We report a case of 45-year-old man who presented with 1-year history of lower abdominal pain. Colonoscopy showed a colonic stricture about 50 cm from the anal verge. Colonoscopic biopsy showed lymphoid hyperplasia. On computed tomography, enhancing circumferential wall thickening and luminal narrowing with pericolic lymph node enlargement in the transverse colon was identified. Patient underwent extended left hemicolectomy. Histopathologic examination of resected colon identified an isolated primary colonic plasmacytoma of 1.7 cm in diameter with regional lymph node involvement (8/50 positive). To administer adequate treatment, further study about clinical features of primary isolated extramedullary plasmacytoma of colon is necessary.

BRAF mutation in multiple primary cancer with colorectal cancer and stomach cancer.

AIMS: Recently, BRAF mutation testing has been introduced as a marker in differentiating Lynch syndrome from sporadic colorectal cancers or in predicting colorectal cancers with worse prognosis. Individuals with hereditary predisposition to cancer development are at an increased risk of developing multiple primary cancers. The purpose of this study is to identify mutation in the BRAF gene in multiple primary cancers with colorectal cancer and stomach cancer. METHODS: BRAF mutation was analysed in 45 patients with colorectal cancer and stomach cancer, synchronously or metachronously. RESULTS: Mean age was 64.07 years (range: 47-83 years). For the colorectal cancer, tumors were located at the sigmoid colon in eight patients (17.8%) and at the rectum in 22 patients (48.9%). Twenty-three patients (51.1%) had synchronous cancer. Four patients (8.9%) had family members with cancer. BRAF mutation was identified in three patients (6.7%). All three of these patients had metachronous cancers. The colorectal cancers were located in the sigmoid colon (1 patient) and the rectum (2 patients). CONCLUSIONS: BRAF mutation rate was low in the multiple primary cancer with colorectal cancer and stomach cancer. With only BRAF gene study, it was not possible to identify any correlation with family history of colorectal cancer. Further study means considering other genes - MSI, MSH2, MLH1, MSH6.

Acute abdomen caused by an infected mesenteric cyst in the ascending colon: a case report.

Mesenteric cysts are rare intra-abdominal tumors. Mesenteric cysts are usually asymptomatic and are incidentally detected during physical or radiological examination. Although uncommon, complications such as infection, bleeding, torsion, rupture and intestinal obstruction cause an acute abdomen. Spontaneous infection is a very rare complication. We present a case of infected mesenteric cysts in the ascending colon, which caused an acute abdomen. A 26-year-old woman was admitted to our hospital with acute abdominal pain. She had a painful mass in the right abdomen on physical examination. Abdominal computed tomography showed a hypodense cystic mass with septation at the mesenteric region of the ascending colon. A laparotomy revealed two cystic tumors at the mesenteric region of the ascending colon. She underwent a right hemicolectomy. The two cysts were filled with a yellowish turbid fluid. The walls of both two cysts were lined with a thin fibrotic membrane without any epithelial cell. They were diagnosed as psuedocysts with E. coli infection. Mesenferic cysts may cause life-threatening complications. Mesenteric cyst, even if it is asymptomatic and was diagnosed incidentally, should be removed completely.

Adenocarcinoma in ileal pouch after proctocolectomy for familial adenomatous polyposis: report of a case.

Restorative proctocolectomy with ileal pouch-anal anastomosis is one of the surgical treatments of choice for patients with familial adenomatous polyposis. Although the risk of cancer developing in an ileal pouch is not yet clear, a few cases of adenocarcinoma arising in an ileal pouch have been reported. We report a case of adenocarcinoma in ileal pouch after proctocolectomy with ileal pouch-anal anastomosis. A 56-yr-old woman was diagnosed as having familial adenomatous polyposis. Total colectomy with ileorectal anastomosis was performed. Six years later, she underwent completion-proctectomy with ileal J pouch-anal anastomosis including anorectal mucosectomy for rectal cancer. After 7 yr, she presented with anal spotting. Endoscopic biopsies revealed adenocarcinoma at the ileal pouch. Resection of the ileal pouch and permanent ileostomy were performed. The risk of cancer in an ileal pouch and its prevention with regular surveillance must be emphasized.

Multiple primary cancers in extracolonic sites with colorectal cancer.

PURPOSE: The present study was undertaken to clarify the clinical and pathological features of multiple primary cancers, especially those at extracolonic sites, in patients with colorectal cancers. METHODS: We reviewed the records of 2,176 patients who underwent surgery for colorectal cancers in our institute from January 1997 to December 2006. A synchronous multiple primary cancer was defined as extracolonic cancer detected within 6-month interval before and after the detection of colorectal cancer. Any metastasis from colorectal cancers was excluded. RESULTS: Synchronous multiple primary cancers were identified in 32 patients. The stomach is the most common organ for synchronous multiple primary cancer development in patients with colorectal cancers (0.9%, 20/2,176). CONCLUSIONS: Gastric cancer is the most common synchronous multiple primary cancers occurring concomitantly with colorectal cancers. Careful preoperative screening is necessary for the detection of multiple primary cancers in extracolonic sites in patients with colorectal cancers.

Clinical characteristics of multiple primary colorectal cancers.

PURPOSE: Although multiple primary colorectal cancer has been recognized as a significant clinical entity, its clinical and pathological features and its prognosis are still controversial. The purpose of this study was to clarify clinical and pathological features of multiple primary colorectal cancer. MATERIALS AND METHODS: Among 1669 patients who underwent surgery for primary colorectal cancer from January 1997 to June 2005, 26 patients (1.6%) with multiple primary colorectal cancer were identified. We reviewed clinical characteristics including diagnostic interval, lesions, operating methods, and TNM stage, and we defined the index lesion as the most advanced lesion among the synchronous lesions. For the purposes of the study, the colon and rectum were classified into three segments. The right-side colon included the appendix, cecum, ascending colon, hepatic flexure, and transverse colon, and the left-side colon included the splenic flexure, descending colon, and sigmoid colon. RESULTS: Of the 26 patients with multiple primary colorectal cancers, nineteen patients were male and seven patients were female, with a mean age of 61.5 years. Nineteen patients had synchronous colorectal cancers and seven patients had metachronous colorectal cancers. In the metachronous cases, the mean diagnostic interval was 36.8 months. The site of the first lesion in metachronous colorectal cancers was the right colon in five cases (71.4%) and the left colon in two cases (28.6%), and the site of the second lesion was the rectum in six cases (55.5%), the right colon in three cases (33.3%), and the left colon in one case. The TNM stage of the second lesions in the metachronous colorectal cancers was stage II in four cases (57.1%), stage III in one case (14.3%), and stage IV in one case (14.3%). For the synchronous colorectal cancers, the operation methods were single-segment resection combined with endoscopic mucosal resection in five cases (26.3%), single-segment resection alone in six cases, two-segment resection in six cases, and total colectomy in two cases. CONCLUSION: In metachronous colorectal cancers, the secondary lesions were later-stage cancer. Therefore, careful postoperative follow-up is necessary for patients who have undergone surgery for colorectal cancers. Further study of therapeutic modalities is important for synchronous colorectal cancers.

Intestinal perforation in colorectal cancers treated with bevacizumab (Avastin).

Bevacizumab is a monoclonal antibody that targets vascular endothelial growth factor (VEGF), and it has shown promise as a clinical agent against metastatic colorectal cancer, and particularly in combination with chemotherapy. Bowel perforation is a known risk that's associated with bevacizumab use, but the etiology is unknown. Here we report on two cases of metastatic colorectal cancer in which the patients suffered from intestinal perforation after chemotherapy with bevacizumab. For the first case, a 47 year-old man had rectal cancer with concurrent liver and lung metastasis. He underwent chemotherapy with 5-fluorouracil, irinotecan and bevacizumab. Fever and abdominal pain developed seven days later, and rectal perforation was identified upon exploration 13 days later. For the second case, a 48 year-old woman had sigmoid colon cancer with peritoneal and ovary metastases. After seven days of chemotherapy with 5-fluorouracil, oxaliplatin and bevacizumab, exploratory surgery revealed a perforation at the ileum.