Nomogram Development and External Validation for Predicting the Risk of Lymph Node Metastasis in T1 Colorectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Predicting lymph node metastasis (LNM) risk is crucial in determining further treatment strategies following endoscopic resection of T1 colorectal cancer (CRC). This study aimed to establish a new prediction model for the risk of LNM in T1 CRC patients. MATERIALS AND METHODS: The development set included 833 patients with T1 CRC who had undergone endoscopic (n=154) or surgical (n=679) resection at the National Cancer Center. The validation set included 722 T1 CRC patients who had undergone endoscopic (n=249) or surgical (n=473) resection at Daehang Hospital. A logistic regression model was used to construct the prediction model. To assess the performance of prediction model, discrimination was evaluated using the receiver operating characteristic (ROC) curves with area under the ROC curve (AUC), and calibration was assessed using the Hosmer-Lemeshow (HL) goodness-of-fit test. RESULTS: Five independent risk factors were determined in the multivariable model, including vascular invasion, high-grade histology, submucosal invasion, budding, and background adenoma. In final prediction model, the performance of the model was good that the AUC was 0.812 (95% confidence interval [CI], 0.770 to 0.855) and the HL chi-squared test statistic was 1.266 (p=0.737). In external validation, the performance was still good that the AUC was 0.771 (95% CI, 0.708 to 0.834) and the p-value of the HL chi-squared test was 0.040. We constructed the nomogram with the final prediction model. CONCLUSION: We presented an externally validated new prediction model for LNM risk in T1 CRC patients, guiding decision making in determining whether additional surgery is required after endoscopic resection of T1 CRC.

Persistent Bleeding Following a Stapled Hemorrhoidopexy

A stapled hemorrhoidopexy (SH) is widely used for treatment of patients with grades III and IV hemorrhoids. The SH is easy to perform, is associated with less pain and allows early return to normal activities. However, complications, whether severe or not, have been reported. Here, we present the case of a female patient with persistent bleeding after a SH. The bleeding was caused by the formation of granulation tissue at the stapler line, diagnosed with sigmoidoscopy, and successfully treated via transanal excision (TAE) under spinal anesthesia. The biopsy showed inflammatory granulation tissue. After the TAE, her symptom was completely gone.

The Pathological and Clinical Effects of Preoperative Chemoradiation in Rectal Cancer / 대한방사선종양학회지

PURPOSE: To evaluate the pathological and clinical effects of preoperative chemoradiation (CCRT) in cases of locally advanced rectal cancer and to determine the predictive factors for tumor downstaging. MATERIALS AND METHODS: From March 2004 to August 2008, 33 patients with locally advanced rectal cancer were treated with preoperative CCRT. Twenty-eight patients (84.8%) were treated using a concomitant boost technique while five (15.2%) patients were treated using a cone down boost technique. All patients received 50.4 Gy of irradiation and concurrent chemotherapy with 5-fluorouracil. The median follow-up duration was 24.2 months (range, 9.8 to 64.7 months). RESULTS: Thirty-one (93.9%) patients underwent surgery. Twenty-four patients (72.7%) underwent anal sphincter-preserving surgery. The 3-year disease free survival (DFS) and overall survival rates were 63.4% and 78.8%, respectively. Post-operative factors were more important for DFS. Pathologic N stage, margin status, and pathologic differentiation were significant prognostic factors (p=0.001, 0.029, 0.030). Tumor size and lymphovascular invasion were also associated with marginal significance (p=0.081, 0.073). However, only pre-treatment T stage was a significant pre-operative factor (p=0.018). The complete pathological response rate was 9.1%. T-downstaging was observed in ten (30.3%) patients, whereas N-downstaging was found in 24 (72.7%) patients. Pre-treatment T stage and the interval between CCRT and operation were the predictive factors for downstaging in a univariate analysis (p=0.029, 0.027). Pre-treatment carcinoembryogenic antigen was also associated with marginal significance (p=0.068). CONCLUSION: The survival of rectal cancer patients can be better determined based on post-operative findings. Therefore, pre-operative CCRT for downstaging of the tumor seems to be important. Pre-treatment T stage and the interval between CCRT and operation can be used to predict downstaging.

Results of Screening Colonoscopy in Asymptomatic Average-risk Koreans at a Community-based Secondary Hospital / 대한소화기내시경학회지

BACKGROUND/AIMS: Colonoscopy has emerged as the dominant colorectal cancer screening strategy, yet the data on the results of performing screening colonoscopy in asymptomatic average risk Koreans is limited. The aim of this study is to determine the results of screening colonoscopy at a community-based single center in Korea. METHODS: A total of 13,743 individuals (5,935 males and 7,808 females, age: 50.6+/-11.8 years) who underwent screening colonoscopy at a community based hospital from April 2006 to March 2008 were analyzed. RESULTS: Of the 13,743 subjects, neoplasia, advanced neoplasia and early colon cancer were detected in 3,270 subjects (23.8%), 315 subjects (2.3%) and 60 subjects (0.5%), respectively. The prevalence of neoplasia and advanced neoplasia increased with age (p<0.001), and this was higher among males as compared to that of females (p<0.001). Of the 3,666 subjects with neoplasia, 1,440 subjects (38.3%) had multiple neoplasia. Old age and male gender were associated with multiple neoplasia. CONCLUSIONS: The overall prevalence of colorectal neoplasia in asymptomatic average-risk Koreans at a community based hospital is comparable with that in a health care setting or university hospitals. Old age and male gender are associated with a higher risk of colorectal neoplasia and having multiple neoplasia.

Anastomotic Leakage after Laparoscopic versus Open Resection for Rectal Cancer: A Retrospective Study

PURPOSE: This study is to compare the rate and pattern of anastomotic leakage (AL) for rectal cancer after laparoscopic vs. conventional open surgery at high and low rectal anastomosis and to evaluate whether the number of linear staples used for distal rectal resection is related to AL in laparoscopic group. RESULTS: One hundred ninety-seven patients who underwent a curative resection for rectal cancer between March 2002 and February 2006 were studied retrospectively (107 laparoscopic, 90 open). The proportions of patients with anastomosis above vs. below 5 cm from AV were not different between the laparoscopic and the open groups; (above/below: 54/53 and 41/49, respectively, P=0.57). The protective stoma rate, the overall rate of AL, the rate of AL according to the height of the anastomosis, and the number of distal linear staples were evaluated for both groups. RESULTS: Clinical AL occurred in 11 of 107 patients (10.3%) for the laparoscopic group and in 5 of 90 patients (5.6%) for the open group. The rates of AL in patients without protective stoma were not significantly different for high rectal anastomosis (6.0% for laparoscopic vs. 2.6% for open, P= 0.63) and for low rectal anastomosis (25.8% for laparoscopic vs. 12.1% for open, P=0.21). The risk of AL was 4.9 times higher when 3 linear staples were used than when 2 linear staples were used in the laparoscopic group. CONCLUSIONS: There was no statistical difference in AL between the laparoscopic group and the open group. The rate of AL could be reduced by using fewer linear staples for distal rectal resection in the laparoscopic group.

Therapeutic Results of Transanal Endoscopic Microsurgery and Radical Surgery for T1, T2 Rectal Cancer

PURPOSE: Transanal endoscopic microsurgery (TEM) has gained increasing acceptance as a treatment of choice for early rectal cancer. The purpose of this study was to compare the results of TEM and radical surgery in patients with T1 and T2 rectal cancer. METHODS: From October 1994 to December 2000, 74 patients with T1 and T2 rectal adenocarcinoma treated with TEM were compared with 100 patients with T1N0M0 and T2N0M0 rectal adenocarcinoma treated with radical surgery. Retrospective analysis was made regarding to recurrence and survival rate. Neither group received adjuvant chemo-radiation. There was no significant difference in age, gender, tumor location and follow-up period between two groups, except tumor size. RESULTS: Of 74 patients in TEM group, 52 patients were T1 (70.3%) and 22 patients were T2 (29.7%). Of 100 patients in radical surgery group, 17 patients were T1 (17.0%) and 83 patients were T2 (83.0%). Five-year local recurrence rates were 4.1% for T1, 19.5% for T2 after TEM, 0% for T1 and 9.4% for T2 after radical surgery. There was no statistical difference between T1 rectal cancer (P=0.95), but in T2 rectal cancer, it was higher after TEM than after radical surgery (P=0.04). Five-year disease free survival rates showed no statistical difference between two groups (TEM group: 95.9% for T1, 80.5% for T2, radical surgery group: 94.1% for T1, 83.3%for T2; P=0.35, P=0.12). Five-year survival rate were 100% for T1, 94.7% for T2 after TEM and 92.9% for T1, 96.1% for T2 after radical surgery. There were no significant statistical difference between two groups (P=0.07, P=0.48). CONCLUSIONS: In T1 rectal cancer, there were no difference in recurrence and five-year survival rate between TEM and radical surgery group. In T2 rectal cancer, five-year survival rate showed no statistical difference between two groups, but TEM carried higher risk of local recurrence. Therefore careful selection of the patients is required for TEM and when proper muscle invasion is proven after TEM, further treatment should be considered.

Short-term Results of Radiofrequency Ablation for Liver Metastasis of Colorectal Cancer

PURPOSE: Radiofrequency ablation (RFA) is emerging as a new therapeutic method for the management of hepatic malignancy. We report our experience on the use of his technique for the management of liver metastasis of colorectal cancer. METHODS: All 32 colorectal cancer patients with synchronous or metachronous liver metastasis treated with RFA from May 1999 to May 2001 were reviewed using retrospective method including chart review and telephone interview. All patients were followed up postoperatively to assess complications, complete necrosis, local recurrence, and survival rate. RESULTS: Forty-one RFA sessions were performed on 70 metastatic tumors in 32 patients. There were no treatment- related death. Two complications related with RFA treatment, one intrahepatic bleeding and one intrahepatic abscess, occurred in 41 sessions of RFA (6.2%). With a median follow-up of 13.5 months, tumors recurred in 7 of 70 lesions (10.0%) from 5 patients due to incomplete necrosis and intrahepatic new lesion or distant metastasis in 13 patients of 27 patients (51.9%) after complete necrosis. There were 5 deaths and the 2 year survival rate was 80.9%. Disease free survival was 90.1%, 75%, 26.4% in 6 months, 12 months and 24 months, respectively. Seven patients underwent liver resections successfully with the application of RFA for the residual lesions in the remaining contralateral lobe. In these patients, with 9.0 months median follow up, the disease recurred in 2 patients due to incomplete necrosis, while recurring in 2 patients after complete necrosis and 3 patients were survived without recurrence or distant metastasis. CONCLUSIONS: Radiofrequency ablation is a safe, well-tolerated, and effective treatment for liver metastasis in colorectal cancer patients. The procedure can be used to treat the residual tumor load in the contralateral lobe following liver resection in those considered unresectable at first presentation. This new therapeutic strategy seems to increase surgical resectability in patients whose mass is determined unresectable. To approve the efficacy of RFA, more long- term follow up should be attempted.

Oncological Safety of Flexible Rectal Stent Insertion in Obstructive Colorectal Cancer: Short Term Result

PURPOSE: Flexible rectal stent for obstructive colorectal cancer has an advantage of elective one stage operation after decompression. But, forceful expansion of stent may increase the possibility of tumor cell dissemination through lymph nodes and blood vessels. We studied the oncological safety of stent insertion in obstructive colorectal cancer. METHODS: From June 1996 to August 2001, the patients with stent insertion for obstructive colorectal cancer at Samsung Medical Center were retrospectively evaluated. Seventy- one patients had stent insertion for palliation or curative resection. Among these patients 15 patients underwent curative surgery after stent insertion (stent group). During the same period 25 patients underwent multi-staged operation after the decompressing colostomy or Hartman operation. (staged operation group). Statistical methods such as Fisher's exact test, 2-test, Kaplan-Meier method were used. RESULTS: There was no significant difference between two groups in terms of age, gender, tumor location, and stage. The median follow-up period was 21 months in stent insertion group and 29 months in staged operation group. Overall recurrence rate was 33.3% in stent insertion group and 32.0% in staged operation group. The 5-year survival rate in stent insertion group was higher than in staged operation group (75.8% vs. 48.3%). But there was no statistical significance (P>0.05 ). Disease free survival was 22.4 (6~51) months in stent insertion group and 27.8 (5~71) months in staged operation group. There was no significant difference either. CONCLUSIONS: There was no significant difference between two groups in survival rate, recurrence rate in short term result. Flexible rectal stent insertion can be considered as oncologically safe and useful treatment of obstructive colorectal cancer. But we think long term follow up and much more cases will be necessary to make a conclusion more definitively.