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.

Simultaneous Laparoscopy-Assisted Resection for Colorectal Cancer and Metastases / 고신대학교의과대학학술지

With advancement of minimal invasive surgery, a simultaneous laparoscopy-assisted resection for colorectal cancer and metastasis has become feasible. Hence, we report three cases of simultaneous laparoscopic surgery for colorectal cancer with liver or lung metastasis. In the first case, laparoscopic right hemicolectomy and left lateral segmentectomy of liver was performed for ascending colon cancer and liver metastasis. In the second case, laparoscopic right hemicolectomy and wedge resection of right lower lung was performed for cecal cancer and lung metastasis. In the third case, laparoscopic right hemicolectomy and wedge resection of left lower lung was performed for ascending colon cancer and lung metastasis. In the first two cases, patients quickly returned to normal activity. In the third case, postoperative bleeding was observed, but spontaneously stopped. There was no postoperative mortality. Simultaneous laparoscopic surgery represents a feasible option for colorectal cancer with metastases on the other organs.

Long-term Outcomes of Laparoscopic versus Open Surgery for Rectal Cancer: A Singlecenter Retrospective Analysis / 대한소화기학회지

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 or =75 years vs. < or =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.

Simultaneous Laparoscopy-Assisted Resection for Synchronous Colorectal and Gastric Cancer / 고신대학교의과대학학술지

OBJECTIVES: The purpose of this study is to evaluate feasibility and safety of simultaneous laparoscopy-assisted resection for synchronous colorectal and gastric cancer. METHODS: From January 2001 to December 2013, a total of 29 patients underwent simultaneous resection for synchronous colorectal and gastric cancers. Medical records were reviewed, retrospectively. RESULTS: Eight patients (5 male) underwent laparoscopy-assisted resection (LAP group) and twenty one patients (17 male) underwent open surgery (Open group). In the both group, the mean age (65.2 vs. 63.7 years, p =0.481), body mass index (22.6 vs. 22.3, p = 0.896) was comparable, respectively. In LAP group, laparoscopy-assisted distal gastrectomy was performed for all eight patients. In Open group, subtotal gastrectomy with billroth I gastroduodenostomy was most common procedure (66.7%). The operation time, blood loss volume was similar between the two groups. Gas out was earlier (3.0 vs. 4.6 days p = 0.106), postoperative hospital stay was shorter (12.0 vs. 18.3 days, p = 0.245) in LAP group. The postoperative complications were an ileus, a wound seroma and a bile leakage in LAP group, pneumonia (10.0%), wound bleeding (5.0%) and leakage (5.0%) in Open group. CONCLUSIONS: The simultaneous laparoscopy-assisted resection for synchronous colorectal cancer and gastric cancer is a feasible and safe procedure.

Single-incision Laparoscopic Surgery for Simultaneous Appendectomy and Cholecystectomy

Single-incision laparoscopic surgery (SILS) has become popular due to the advantage of minimizing surgical. We report on two cases of simultaneous appendectomy and cholecystectomy using a single-incision laparoscopic technique. The patients were 49- and 50-year old females diagnosed with acute appendicitis with concomitant cholelithiasis. Body mass indices of the patients were 22.3 and 26.0. A 3 cm abdominal incision was made via the umbilicus, and a single port platform was created using a small wound retractor (ALEXIS(R) wound retractor S, Applied Medical, Santa Margarita, CA, USA) and a surgical glove. Cholecystectomy was performed first, followed by the appendectomy. The operation times were 165 and 280 minutes, and blood loss was 50 and 150 cc, respectively. The postoperative hospital stays were five and seven days, and one patient had a wound seroma as a surgical complication. We believe that SILS for simultaneous appendectomy and cholecystectomy is a feasible and safe minimally invasive procedure.

Single-incision Laparoscopic Surgery for Simultaneous Appendectomy and Cholecystectomy

Single-incision laparoscopic surgery (SILS) has become popular due to the advantage of minimizing surgical. We report on two cases of simultaneous appendectomy and cholecystectomy using a single-incision laparoscopic technique. The patients were 49- and 50-year old females diagnosed with acute appendicitis with concomitant cholelithiasis. Body mass indices of the patients were 22.3 and 26.0. A 3 cm abdominal incision was made via the umbilicus, and a single port platform was created using a small wound retractor (ALEXIS(R) wound retractor S, Applied Medical, Santa Margarita, CA, USA) and a surgical glove. Cholecystectomy was performed first, followed by the appendectomy. The operation times were 165 and 280 minutes, and blood loss was 50 and 150 cc, respectively. The postoperative hospital stays were five and seven days, and one patient had a wound seroma as a surgical complication. We believe that SILS for simultaneous appendectomy and cholecystectomy is a feasible and safe minimally invasive procedure.

The Safety of Elective Colorectal Surgery without Mechanical Bower Preparation / 고신대학교의과대학학술지

OBJECTIVES: To reduce the risk of postoperative infectious complications and anastomotic leakage in colorectal surgery, preoperative mechanical bowel preparation (MBP) is performed routinely. The aim of this study was to evaluate the safety of primary anastomosis in elective colorectal surgery without MBP. METHODS: From Jan. 2005 to Dec. 2006, three hundred and seventy-nine patients of elective colorectal surgery with primary anastomosis were performed with MBP in 352 cases (Prep group) and without MBP in 24 cases (Non-prep group). For preoperative MBP, 4 liters of polyethylene glycol solution was administered. Postoperative infectious complications and other morbidity were reviewed with medical records and prospectively collected data. RESULTS: Demographic, clinical and treatment characteristics did not differ significantly between the two groups. The overall rate of abdominal infectious complications (wound infection, anastomotic leak) was 2.9 % in the Prep group and 9 % in the Non-prep group (P > 0.05). Anastomotic leak occurred in nine patients (2.6%) in the Prep group and one (4.5%) in the Non-prep group. CONCLUSIONS: The incidence of infectious complications after elective colorectal surgery without MBP did not differ significantly compare to that with MBP. However, prospective, randomized clinical trial is needed to assess the safety of primary anastomosis in elective colorectal surgery without MBP.

The Learning Curve by Varied Operative Procedures in Laparoscopic Colorectal Surgery

PURPOSE: This study aimed at evaluation of the learning curve for laparoscopic colorectal surgery with varied operative procedures. METHODS: From June 2004 to May 2010, 269 consecutive patients underwent laparoscopic colorectal surgery. Patients were divided into four groups according to operative methods: right-side colectomy, left-side colectomy, rectal resection, and total colectomy group. Each group was divided into three-early, middle, and late-groups according to operation numbers. Learning curves were generated for each group using moving average methods. Prospective collection and retrospective review of data on operative outcomes, including open conversion, operation time, intra-operative blood loss, postoperative hospital stay, and postoperative complication were performed. RESULTS: Operations included 75 right-side colectomies, 12 left-side colectomies, 178 rectal resections, four total colectomies, and seven open conversions (2.6%). The mean operative time for right-side colectomy and rectal resection showed a significant decline from the early group to the middle and late groups, while the left-side colectomy group showed no significant difference. Operation time was platitude after 50 cases of whole laparoscopic colorectal surgery, 11 cases in the right-side colectomy group, eight cases in the left-side colectomy group, and 34 cases in the recto-sigmoid resection group. CONCLUSION: For the surgeon, laparoscopic colorectal surgery can be performed more independently after 50 cases. The learning curve may be determined according to the general skill of laparoscopic colorectal surgery. The question of whether the learning curve is determined by varied operative procedures has not yet been resolved.

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.

Clinicopathologic Factors for Prediction of Lymph Node Metastasis in Submucosally Invasive Colorectal Carcinoma

PURPOSE: The purpose of this study is to identify useful clinicopathologic factors for the prediction of lymph node metastasis in submucosally invasive colorectal carcinoma. METHODS: A total of fifty-four cases of colorectal carcinomas with submucosal invasion were included. The patients underwent curative resection with en bloc lymph node dissection. Clinical features such as age, gender, tumor size and tumor location were reviewed. Histopathologic examinations for tumor growth type, differentiation, depth of tumor invasion, lymphovascular invasion, neural invasion, tumor budding and peritumoral inflammation were performed. The expression of E-cadherin, beta-catenin, Smad4, p53 and Ki-67 were examined by immunohistochemistry. The correlation between the clinicopathologic factors and lymph node metastasis was evaluated. RESULTS: From the 54 patients with submucosally invasivecolorectal carcinoma, lymph node metastasis was identified in 13 cases (24.1%). The incidence of lymph node metastasis was significantly higher in cases positive for lymphovascular invasion (55.6% vs. 17.8%, P=0.028) and positive for tumor budding (47.4% vs. 11.45%, P=0.006). Cases negative for Smad4 had a higher tendency for incidence of lymph node metastasis (28.6% vs. 15.8%, P=0.341). Other clinicopathologic and immunohistochemical features were irrelevant to the lymph node status. In multivariate analysis, only tumor budding was an independent predictor of lymph node metastasis (P=0.051). CONCLUSION: Lymphovascular invasion and tumor budding were predictive factors of lymph node metastasis in submucosally invasive colorectal carcinoma. The incidence of lymph node metastasis of submucosally invasive colorectal carcinoma was not low. Careful selection for avoiding surgery in submuocally invasive colorectal carcinoma should be considered.

Late Complications after Preoperative Chemoradiation for Rectal Cancers / 고신대학교의과대학학술지

OBJECTIVES: To compare the late complications after operations for rectal cancers with and without preoperative chemoradiation. METHODS: From January 2003 to December 2005, 55 patients underwent operation after preoperative chemoradiation for adenocarcinoma of the rectum. All of them received the full scheduled dose of radiation with concurrent chemotherapy. The interval between preoperative chemoradiation and surgery was 4-6 weeks. 47 patients who had tumors below 8 cm from the anal verge were enrolled into the study group (CRT group). During same period, we selected 153 patients who had adenocarcinoma of the rectum below 8cm from the anal verge, underwent surgery alone without postoperative radiotherapy non-CRT group). We compared the early and the late postoperative complications between the CRT group and the non-CRT group. RESULTS: Of the late complications, the incidence of anastomotic stricture was significantly higher in the CRT group (P = 0.018). The incidence of anal stricture was higher in the CRT group (P = 0.164). In the CRT group, 3 cases (17.6%) had failed to preserve the anal function due to moderate or severe anal stricture. Of the 3 cases, protective ileostomy was persistent in 2 cases, colostomy was performed in one case. Otherwise, the late complications of the CRT group were intestinal obstruction in 2 cases (4.3%), lymph edema in 2 cases (4.3%). CONCLUSION: In CRT group, failure of anal function preservation due to anastomotic stricture or anal stricture was more common and serious than non-CRT group. We emphasize the need for careful management for postoperative anal stricture after preoperative chemoradiation.

Dual Therapy and Triple Therapy of Prophylactic Antibiotics After Elective Colorectal Surgery: A Comparative Study

PURPOSE: The use of prophylactic antibiotics is the current standard of care after elective colorectal surgery. The aim of this study was to compare the efficacy of antibiotic prophylaxis with dual antibiotic therapy and triple antibiotic therapy after elective colorectal surgery. METHODS: We studied consecutive patients underwent elective colorectal surgery from January to June, 2007. Patients of triple-therapy group were administered second cephalosporin, metronidazole, and aminoglycoside for early 3 mo and dual-therapy group were administered second cephalosporin and metronidazole for next 3 mo. The prophylactic antibiotics were administered 2-3 doses for 24 hr after surgery. The surgery for diverticulitis, inflammatory bowel disease, and colon obstruction were excluded. Wound conditions were checked on alternate days during the hospital stay and follow up at least for 30 days after discharge. RESULTS: Over 6 mo, 110 patients were enrolled (59 dual-therapy group, 51 triple-therapy group). In two group, sex, age, American Society of Anesthesiology score, body mass index, combined diseases, and location of disease were similar. Wound infection rate were 1.7% in dual-therapy group and 2.0% in triple-therapy group (P=1.0). Anastomotic leakage rate were 5.1% in dual-therapy group and 2.0% in triple-therapy group (P=0.622). CONCLUSION: The addition of aminoglycoside to dual antibiotic therapy, second cephalosporin-metronidazole showed on advantage in prevention of postoperative wound complications. Further studies are required to establish appropriate guideline of antibiotic prophylaxis after elective colorectal surgery.

Comparison of a Straight, a Coloplasty, and a Colonic J-pouch Anastomosis after a Proctectomy for Rectal Cancer

PURPOSE: Colonic pouches have been used to improve the reservoir function of the neorectrum after a ultra-low anterior resection for treatment of rectal cancer. The purpose of this study was to compare the safety and the functional outcome between a straight anastomosis, an anastomosis using coloplasty, and that using a colonic J-pouch in patients who had undergone an ultralow anterior resection. METHODS: From 2004 through 2006, 60 patients underwent a coloanal straight (straight group: n=23), coloplasty (coloplasty group: n=19), or colonic J-pouch (J-pouch group: n=18) anastomosis to the anal canal after a total mesorectal excision of the rectal cancer. We retrospectively reviewed the medical records of those patients for clinical outcomes according to the reservoir type. The median follow-up interval was 23.7 (4.4-40.9) mo. RESULTS: The anastomotic leakage rate was higher in the coloplasty group (21.1%) than in the straight group (8.7%) or in the J-pouch group (0%), but the difference was not significant (P=0.1). The mean number of bowel movements per day was significantly lower in the coloplasty group (3.6) and in the pouch group (3.1) than in the straight group (6.2) (P=0.015). No statistically significant differences were found among the three groups regarding other functional outcomes, including use of antidiarrheal drugs (P=0.971), gas incontinence (P=0.256), fecal incontinence (P=0.544), use of pads (P=0.782), difficulty of evacuation (P=0.496), and use of enemas (P=0.712). CONCLUSION: Reconstruction with a coloplasty or a colonic J-pouch in patients undergoing a low colorectal or coloanal anastomosis after rectal cancer surgery seems to decrease the number of daily bowel movements compared to a straight anastomosis. However, the anastomotic leakage rate of coloplasty group was higher than that of the straight-anastomosis group.

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.

ERRATUM:Dual Therapy and Triple Therapy of Prophylactic Antibiotics After Elective Colorectal Surgery: A Comparative Study

he conclusion should be corrected as The addition of aminoglycoside to dual antibiotic therapy, second cephalosporinmetronidazole showed no advantage in prevention of postoperative wound complications. Journal of The Korean Society of Coloproctology apologizes to the readers for this error.

Efficacy of 24 Hour-Administration of Antibiotic Prophylaxis after Elective Colorectal Surgery

PURPOSE: Although the two or three-postoperative doses of prophylactic antibiotics are recommended, the tendency for surgeons to prolong the administration of prophylactic antibiotics after colorectal surgery is a well-known fact. The aim of this study was to assess the prophylactic efficacy of two or three-doses of prophylactic antibiotics over a 24 hour period after elective colorectal surgery. METHODS: We reviewed the surgical complications in 69 patients who underwent elective colorectal surgery from April to Jun, 2006. All patients had preoperative mechanical bowel cleansing performed. As antibiotic prophylaxis, oral metronidazole was administered 2~3 times on the day before surgery and second generation cephalosporin were administered intravenously 30 minutes before surgical incision. After surgery, second generation cephalosporin, aminoglycoside and metronidazole were given to all the patients, at 2~3 doses for 24 hours. Wound conditions were checked on alternate days during the hospital stay and the patients were followed up for at least 30 days after discharge. RESULTS: In 69 patients, the diseases were cancer in 64 cases (92.8%). The procedures were anterior resection or lower anterior resection in 38 cases (55.1%), hemicoloectomy in 16 cases (23.2%), segmental resection in 9 cases, and abdomino-perineal resection or Hartmann's procedure in 6 cases. The wound complications were wound seroma in 3 cases (4.3%), wound dehiscence in 3 cases (4.3%) and anastomotic leakage in 1 case (1.4%). CONCLUSION: The wound complication rate was not high after antibiotic prophylaxis for 24 hours in patients who underwent elective colorectal surgery. Further studies are required to establish appropriate guidelines for antibiotic prophylaxis after elective colorectal surgery.

Positron Emission Tomography (PET)-Computed Tomography (CT) for Preoperative Staging of Colorectal Cancers

PURPOSE: The purpose of this study is to evaluate the usefulness of positron emission tomography (PET)-computed tomography (CT) for preoperative tumor staging in cases of colorectal cancer. METHODS: Between July 2006 and September 2007, seventy-six patients with a diagnosis of colorectal cancer (43 males and 33 females; mean age: 60.4+/-10.13 years; range: 34~82 years) selected prospectively were studied for staging by using Chest X-ray, abdominal CT and PET-CT. RESULTS: The sensitivities and the specificities for N-staging were 76.9% and 35.1% for CT, 61.8% and 66.7% for PET-CT, and both procedures showed a relatively low diagnostic accuracy (CT 57.9%, PET-CT 61.8%). In the PET-CT alone, six distant metastatic lesions and four multiple primary malignancies were found. The locations of the distant metastases were the liver, the axillary node, the common iliac node, the subclavicular node, the peritoneum, and the lung. The locations of the multiple primary maligancies in extracolonic sites were 3 in the thyroid and 1 in the nasopharynx. CONCLUSIONS: For N-staging, preoperative PET-CT is no more useful than CT, but PET-CT is required before surgery to find lesions that cannot be found with conventional studies.

Clinical Characteristics of Multiple Primary Colorectal Cancers / Journal of the Korean Cancer Association, 대한암학회지

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 diagnosticinterval 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.