Jeong-Heum Baek

Single-port laparoscopic appendectomy versus conventional laparoscopic appendectomy: a prospective randomized controlled study.

Objective: To compare surgical outcomes and quality of life between single-port laparoscopic appendectomy (SPLA) and conventional laparoscopic appendectomy (CLA) in patients with acute appendicitis. Background: A prospective randomized single center study was performed to compare the outcome of SPLA and CLA in patients with acute appendicitis. Methods: A total of 248 patients were randomized, but because of 18 withdrawals, the outcome of 224 is analyzed, 116 in CLA and 114 in SPLA. Results: There was no significant difference in the overall complication rate (P = 0.470). There were no significant differences in infectious complications between the SPLA group and the CLA group (10.2% and 12.4%, respectively). The wound complication rate between the 2 groups was not significant (5.1% and 10.6%, respectively; P = 0.207). Cosmetic satisfaction score, 36-item short-form health survey, and postoperative pain scores were not significantly different between 2 groups. Conclusions: SPLA failed to show any advantages over CLA relative to pain and cosmesis. However, SPLA is as safe as CLA (RCT number 01348464).

The outcome after stent placement or surgery as the initial treatment for obstructive primary tumor in patients with stage IV colon cancer.

BACKGROUND It is still a matter of debate as to whether palliative resection of obstructive primary tumors may prolong the survival of patients with obstructive colon cancer and unresectable synchronous metastases. The main goal of this retrospective study was to compare the use of self-expanding metallic stents (SEMS) with open surgery for the palliation of patients with respect to survival, morbidity, and the time to start chemotherapy. METHODS Between January 2000 and January 2008, 88 consecutive patients (52 who underwent surgery and 36 who underwent SEMS insertion) with obstructive colon cancer and unresectable synchronous metastases were retrospectively evaluated. RESULTS The median hospital stay for all admissions was 7.2 days (range, 3-29 days) in the SEMS group and 12.3 days (range, 6-45 days) in the surgery group (P = .001). The incidence of stoma formation was significantly lower in the SEMS group than in the surgery group (16.7% vs 38.5%, respectively, P = .021). The median time to starting chemotherapy was significantly shorter in patients who underwent SEMS insertion compared with those who underwent surgery (8.1 vs 21.7 days, respectively, P = .001). The 1-year and 2-year survival rates were 44.2% and 21.27% in the surgery group and 16.7% and 2.8% in the SEMS group, respectively. The median survival for all patients was 15 months from the initiation of treatment (95% confidence interval, 6.0-19 months). CONCLUSIONS Both procedures can be safely performed, but the choice of treatment should be individualized and discussed with a multidisciplinary team.

The prognostic significant of percentage drop in serum CEA post curative resection for colon cancer

OBJECTIVE/BACKGROUND This study aimed to analyze the hypothesis that increased percentage drop in serum CEA post curative resection for colon cancer is associated with improved survival. METHODS Five hundred thirty three patients who underwent colon resection with a curative intent were retrospectively analyzed for their pre- and postoperative CEA levels. The disease-free and overall survival curves were calculated using Kaplan Meier analysis to evaluate cancer related outcomes. For multivariate analysis, the Cox regression model was used. RESULTS The estimated 5-year overall survival for the preoperative serum CEA > 5 ng/mL group with respect to a postoperative CEA level drop rate of 40%, 50% and 60% were 72.9%, 80.9% and 81.8%, respectively. The estimated 5-year overall survival for the preoperative serum CEA ≤ 5 ng/mL group with respect to each postoperative CEA level drop rate were 86.6%, 97.1% and 97.7%, respectively (P = 0.257, P = 0.092 and P = 0.073, respectively). The prognostic factors for poor survival were the depth of invasion (p = 0.042, hazard ratio: 2.617, 95% CI = 1.021-3.012) and lymph node metastasis (p = 0.008, hazard ratio: 2.249, 95% CI = 1.231-4.111). A 60% drop of the CEA level was an independent prognostic factor for survival (p = 0.001, hazard ratio: 2.954, 95% CI = 1.686-5.176) for patients with a preoperative CEA level > 5 ng/mL. CONCLUSION Determining the preoperative CEA level and the early postoperative percent drop of the serum CEA level may be a helpful factor for the prognosis of colon cancer patients. However, the percent drop from the pre to postoperative CEA level from the normal range was not associated with survival difference.

Comparison of HER2 expression between primary colorectal cancer and their corresponding metastases

The aim of this study was to compare human epidermal growth factor 2 (HER2) status in primary colorectal cancer and paired liver or lung metastasis. Gene amplification of HER2 has been intensively evaluated in contemporary oncology, especially in breast and stomach cancer. The knowledge of HER2 status in primary and metastatic sites may be of potential value for therapeutic decision making in metastatic colon cancer. The HER2 status was assessed by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) in 94 colorectal cancer with corresponding liver or lung metastases. HER2 amplification was present in 19 of the 188 (10.1%) of both primary and metastases combined. Four (4.6%) patients showed HER2 amplification in the metastasis and 10 (10.6%) patients showed HER2 amplification in the primary tumor. In 14 cases (14.8%), the HER2 status of the primary lesions was different from that of the associated metastases. The presence of HER2 overexpression in KRAS mutant colon cancer was found in 5.3%. No relationship was found between HER2 expression and KRAS status (P = 0.486). The evidence of HER2 positive metastatic lesion and primary colorectal cancer suggest that HER2 assessment might be considered in selected cases when this may help change the therapeutic decision.

Comparison of the surgical outcomes of laparoscopic versus open surgery for colon perforation during colonoscopy

Purpose Colonoscopy is a safe and commonly used method for the screening of colon cancer, but sometimes major complications, such as, colonic perforation or hemorrhage occur during the procedure. The aim of this study was to compare the surgical outcomes of laparoscopic and open surgery for colon perforation after colonoscopy. Methods A retrospective review of patient records was performed on 25 patients with iatrogenic colon perforation during colonoscopy during the 7-year period from January 2005 to June 2012. Demographic data, operative procedures, operation times, postoperative complications, hospital course, and morbidities in the laparoscopic surgery group (LG) and open surgery group (OG) were compared. Results Seventeen of the 25 patients underwent laparoscopic surgery (68%) and 8 patients open surgery (32%). The most common surgical methods were primary repair in the LG, and Hartmanns operation in the OG. Average time to first flatus was 2.9 days in the LG and 4.5 days in the OG, and average times to first meals were 4.5 days and 5 days, respectively. Mean hospital stays were 10.8 days in the LG and 17 days in the OG. After surgery, complications occurred in two patients in the LG, but no complication occurred in the OG. Conclusion Laparoscopic repair for iatrogenic colonic perforation during colonoscopy seems to be useful and safe surgical method in early period after perforation. However, open surgery is also needed for the delayed cases after perforation.

Chemoradiotherapy Followed by Surgery in Rectal Cancer: Improved Local Control Using a Moderately High Pelvic Radiation Dose

BACKGROUND To determine complete resection and sphincter preservation rates, down-staging, local control and survival associated with concurrent chemoradiotherapy (CCRT) using a moderately high pelvic radiation dose before surgery in rectal cancer. METHODS Fifty-seven patients with histologically proven adenocarcinoma of the mid to lower rectum were treated using preoperative CCRT and surgery. Median radiation dose to the pelvis was 5400 cGy (5040-5580 cGy). CCRT was administered during the first and fifth weeks of radiotherapy with bolus intravenous 5-fluorouracil (5-FU) 400 mg/m(2)/day and leucovorin (LV) 20 mg/m(2)/day for 5 days. Surgery was attempted 4-8 weeks after completing preoperative CCRT. Post-operative chemotherapy was then added for up to four cycles of intravenous 5-FU and LV. RESULTS Toxicities during CCRT were generally mild and manageable: Grade 1/2 anemia, 3.5%; Grade 1/2 leukopenia, 45.6%; Grade 3 leukopenia, 3.5%; Grade 1/2 diarrhea, 22.8%; Grade 1/2 abdominal discomfort, 7%; and perianal skin reaction, 5.3%. No late complication requiring surgical intervention occurred. Complete surgical resection with a negative resection margin was achieved in 98.2% of patients, and the down-staging rate was 52.6% (30/57; 95% CI 39.6-65.6%). Complete pathologic response was obtained in 5.3% patients (3/57; 95% CI 0-11.1%) and in other 2 patients only sporadic tumor cells nests were noted in surgical specimens. The sphincter preservation rate was 77.2% (44/57; 95% CI 66.3-88.1%). Of 30 patients with tumors located within 5 cm from the anal verge, sphincter preservation was possible in 18 patients (60.0%; 95% CI 47.3-72.7%). With a median follow-up duration of 40 months, overall and disease-free survival (DFS) rates over 3 years were 91.8% (95% CI 85.5-98.2%) and 79.7% (95% CI 71.2-88.2%), respectively. At univariate analysis, significant factors for DFS was LN involvement status (P = 0.024). Local and distant failure rates over the same period were 5.3 and 21.1%, respectively. CONCLUSIONS Preoperative CCRT produced encouraging down-staging rates and was found to facilitate complete resection and sphincter saving in distal rectal cancer with acceptable toxicity. Further studies are warranted using this moderately high radiation dose to the pelvis to improve the local control.

Surgical failure after colonic stenting as a bridge to surgery

AIM To identify risk factors for surgical failure after colonic stenting as a bridge to surgery in left-sided malignant colonic obstruction. METHODS The medical records of patients who underwent stent insertion for malignant colonic obstruction between February 2004 and August 2012 were retrospectively reviewed. Patients with malignant colonic obstruction had overt clinical symptoms and signs of obstruction. Malignant colonic obstruction was diagnosed by computed tomography and colonoscopy. A total of 181 patients underwent stent insertion during the study period; of these, 68 consecutive patients were included in our study when they had undergone stent placement as a bridge to surgery in acute left-sided malignant colonic obstruction due to primary colon cancer. RESULTS Out of 68 patients, forty-eight (70.6%) were male, and the mean age was 64.9 (range, 38-89) years. The technical and clinical success rates were 97.1% (66/68) and 88.2% (60/68), respectively. Overall, 85.3% (58/68) of patients underwent primary tumor resection and primary anastomosis. Surgically successful preoperative colonic stenting was achieved in 77.9% (53/68). The mean duration, defined as the time between the SEMS attempt and surgery, was 11.3 d (range, 0-26 d). The mean hospital stay after surgery was 12.5 d (range, 6-55 d). On multivariate analysis, the use of multiple self-expanding metal stents (OR = 28.872; 95%CI: 1.939-429.956, P = 0.015) was a significant independent risk factor for surgical failure of preoperative stenting as a bridge to surgery. Morbidity and mortality rates in surgery after stent insertion were 4.4% (3/68) and 1.5% (1/68), respectively. CONCLUSION The use of multiple self-expanding metal stents appears to be a risk factor for surgical failure.

Docosahexaenoic acid inhibits insulin-induced activation of sterol regulatory-element binding protein 1 and cyclooxygenase-2 expression through upregulation of SIRT1 in human colon epithelial cells

Multiple lines of compelling evidence from clinical and population-based studies support that hyperinsulinemia often accompanying obesity-associated insulin insensitivity promotes colon carcinogenesis. Insulin can acetylate, thereby activating sterol regulator element-binding protein 1 (SREBP-1), a prime transcription factor responsible for expression of genes involved in lipogenesis. Moreover, SREBP-1 upregulates cyclooxygenase-2 (COX-2), a key player in inflammatory signaling. Docosahexaenoic acid (DHA), a representative omega-3 polyunsaturated fatty acid, has been known to negatively regulate SREBP-1, but the underlying molecular mechanism is not fully clarified yet. This prompted us to investigate whether DHA could inhibit insulin-induced activation of SREBP-1 and COX-2 expression in the context of its potential protective effect on obesity-induced inflammation and carcinogenesis. SIRT1, a NAD(+)-dependent histone/non-histone protein deacetylase, has been reported to inhibit intracellular signaling mediated by SREBP-1 through deacetylation of this transcription factor. We found that DHA induced SIRT1 expression in CCD841CoN human colon epithelial cells. DHA abrogated insulin-induced acetylation as well as expression of SREBP-1 and COX-2 upregulation. Insulin-induced stimulation of CCD841CoN cell migration was also inhibited by DHA. These effects mediated by DHA were attenuated by pharmacologic inhibition of SIRT1. Hyperinsulinemia or insulin resistance is considered to be associated with obesity-associated inflammation. Genetically obese (ob/ob) mice showed higher colonic expression levels of both SREBP-1 and COX-2 than did normal lean mice. Likewise, expression of SREBP-1 and COX-2 was elevated in human colon tumor specimens compared with surrounding normal tissues. In conclusion, DHA may protect against obesity-associated inflammation and colon carcinogenesis by suppressing insulin-induced activation of SREBP-1 and expression of COX-2 through up-regulation of SIRT1.

Multivariate Analysis of Risk Factors Associated With the Nonreversal Ileostomy Following Sphincter-Preserving Surgery for Rectal Cancer.

Purpose A loop ileostomy is used to protect an anastomosis after anal sphincter-preserving surgery, especially in patients with low rectal cancer, but little information is available concerning risk factors associated with a nonreversal ileostomy. The purpose of this study was to identify risk factors of ileostomy nonreversibility after a sphincter-saving resection for rectal cancer. Methods Six hundred seventy-nine (679) patients with rectal cancer who underwent sphincter-preserving surgery between January 2004 and December 2011 were evaluated retrospectively. Of the 679, 135 (19.9%) underwent a defunctioning loop ileostomy of temporary intent, and these patients were divided into two groups, that is, a reversal group (RG, 112 patients) and a nonreversal group (NRG, 23 patients) according to the reversibility of the ileostomy. Results In 23 of the 135 rectal cancer patients (17.0%) that underwent a diverting ileostomy, stoma reversal was not possible for the following reasons; stage IV rectal cancer (11, 47.8%), poor tone of the anal sphincter (4, 17.4%), local recurrence (2, 8.7%), anastomotic leakage (1, 4.3%), radiation proctitis (1, 4.3%), and patient refusal (4, 17.4%). The independent risk factors of the nonreversal group were anastomotic leakage or fistula, stage IV cancer, local recurrence, and comorbidity. Conclusion Postoperative complications such as anastomotic leakage or fistula, advanced primary disease (stage IV), local recurrence and comorbidity were identified as risk factors of a nonreversal ileostomy. These factors should be considered when drafting prudential guidelines for ileostomy closure.

What does absence of lymph node in resected specimen mean after neoadjuvant chemoradiation for rectal cancer

BackgroundThe effect of insufficient node sampling in patients with rectal cancer managed by neoadjuvant chemoradiation followed by surgery has not been clearly determined. We evalulated the impact of insufficient sampling or even abscence of lymph nodes in the specimen on survival in patients at high-risk (T3, T4 or node positive) for rectal cancer.MethodsWe conducted a single institution, retrospective analysis of all patients who underwent surgical rectal resection following neoadjuvant chemoradiation for treatment of mid to lower rectal cancer between 1997 and 2009. ypNX was defined as the absence of lymph nodes retrieved in the resected specimen.ResultsA total of 132 patients underwent resection for treatment of rectal cancer following neoadjuvant chemoradiation. Ninety four patients (71.2%) were considered as having node-negative disease, including ypNx and ypN0. In 38 patients (28.8%), the primary tumor was associated with regional lymph node metastases (ypNpos). The mean number of retrieved nodes per specimen was 14.2, respectively. The five-year overall survival from initial operation for the ypNx group was 100%, respectively. The estimated five-year overall survival for ypN0 and ypNpos was 84.0% and 60.3%, respectively (P =0.001). No significant differences in overall survival were observed between the ypNx and ypN0 group (P =0.302).ConclusionAbsence of recovered LN in resected specimens after neoadjuvant chemoradiation was observed in 7.6% of specimens. Absence of LN should not be regarded as a risk factor for poor survival or as a sign of less radical surgery.