Prediction of Microsatellite Instability in Colorectal Cancer Using a Machine Learning Model Based on PET/CT Radiomics

Purpose@#We investigated the feasibility of preoperative 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/ computed tomography (CT) radiomics with machine learning to predict microsatellite instability (MSI) status in colorectal cancer (CRC) patients. @*Materials and Methods@#Altogether, 233 patients with CRC who underwent preoperative FDG PET/CT were enrolled and divided into training (n=139) and test (n=94) sets. A PET-based radiomics signature (rad_score) was established to predict the MSI status in patients with CRC. The predictive ability of the rad_score was evaluated using the area under the receiver operating characteristic curve (AUROC) in the test set. A logistic regression model was used to determine whether the rad_score was an independent predictor of MSI status in CRC. The predictive performance of rad_score was compared with conventional PET parameters. @*Results@#The incidence of MSI-high was 15 (10.8%) and 10 (10.6%) in the training and test sets, respectively. The rad_score was constructed based on the two radiomic features and showed similar AUROC values for predicting MSI status in the training and test sets (0.815 and 0.867, respectively; p=0.490). Logistic regression analysis revealed that the rad_score was an independent predictor of MSI status in the training set. The rad_score performed better than metabolic tumor volume when assessed using the AUROC (0.867 vs. 0.794, p=0.015). @*Conclusion@#Our predictive model incorporating PET radiomic features successfully identified the MSI status of CRC, and it also showed better performance than the conventional PET image parameters.

Clinicopathologic characteristics and survival of patients with double primary malignancies: breast and colorectal cancer

Purpose@#This study aimed to investigate the clinicopathologic features and survival in patients with both breast cancer (BrC) and colorectal cancer (CRC). @*Methods@#Between 1996 and 2019, patients who were diagnosed with both BrC and CRC were evaluated retrospectively. Patients with distant metastasis, palliative resection, and previous cancer histories except for BrCs or CRCs were excluded. Altogether, 105 patients were divided into the B=C group (n=21), B-first group (n=40), and C-first group (n=44) according to the definition of synchronous and metachronous cancers. The clinicopathologic features and overall survival were evaluated. @*Results@#TNM stages and histologic types were comparable among the 3 groups (P=0.434). The interval of diagnosis was 67.1±40.4 and 59.3±47.2 months in the B- and C-first groups, respectively. The incidence of adjuvant chemotherapy in the B-first group was 57.5%, which was higher than the B=C and C-first groups (P<0.001). The estrogen receptor, progesterone receptor, Ki-67, and HER-2 molecular markers were not significantly different among the groups. The overall survival of the B-first group showed lower survival rates than the C-first group (P=0.039). In the logistic regression, HER-2 status (hazard ratio [HR], 11.9; P=0.032) and lymph node metastasis of CRC (HR, 5.8; P=0.036) were prognostic factors affecting overall survival. @*Conclusion@#B-first group had poorer survival outcomes than the C-first group in patients with the metachronous BrC and CRC. HER2 positivity and CRC lymph node metastasis may be prognostic factors that affect overall survival in these patients. The findings support that a colorectal cancer screening program should be included during BrC surveillance.

Machine Learning Model for Predicting Postoperative Survival of Patients with Colorectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Machine learning (ML) is a strong candidate for making accurate predictions, as we can use large amount of data with powerful computational algorithms. We developed a ML based model to predict survival of patients with colorectal cancer (CRC) using data from two independent datasets. @*Materials and Methods@#A total of 364,316 and 1,572 CRC patients were included from the Surveillance, Epidemiology, and End Results (SEER) and a Korean dataset, respectively. As SEER combines data from 18 cancer registries, internal validation was done using 18-Fold-Cross-Validation then external validation was performed by testing the trained model on the Korean dataset. Performance was evaluated using area under the receiver operating characteristic curve (AUROC), sensitivity and positive predictive values. @*Results@#Clinicopathological characteristics were significantly different between the two datasets and the SEER showed a significant lower 5-year survival rate compared to the Korean dataset (60.1% vs. 75.3%, p < 0.001). The ML-based model using the Light gradient boosting algorithm achieved a better performance in predicting 5-year-survival compared to American Joint Committee on Cancer stage (AUROC, 0.804 vs. 0.736; p < 0.001). The most important features which influenced model performance were age, number of examined lymph nodes, and tumor size. Sensitivity and positive predictive values of predicting 5-year-survival for classes including dead or alive were reported as 68.14%, 77.51% and 49.88%, 88.1% respectively in the validation set. Survival probability can be checked using the web-based survival predictor (http://colorectalcancer.pythonanywhere.com). @*Conclusion@#ML-based model achieved a much better performance compared to staging in individualized estimation of survival of patients with CRC.

LASSO-Based Machine Learning Algorithm for Prediction of Lymph Node Metastasis in T1 Colorectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The role of tumor-infiltrating lymphocytes (TILs) in predicting lymph node metastasis (LNM) in patients with T1 colorectal cancer (CRC) remains unclear. Furthermore, clinical utility of a machine learning–based approach has not been widely studied. @*Materials and Methods@#Immunohistochemistry for TILs against CD3, CD8, and forkhead box P3 in both center and invasive margin of the tumor were performed using surgically resected T1 CRC slides. Three hundred and sixteen patients were enrolled and categorized into training (n=221) and validation (n=95) sets via random sampling. Using clinicopathologic variables including TILs, the least absolute shrinkage and selection operator (LASSO) regression model was applied for variable selection and predictive signature building in the training set. The predictive accuracy of our model and the Japanese criteria were compared using area under the receiver operating characteristic (AUROC), net reclassification improvement (NRI)/integrated discrimination improvement (IDI), and decision curve analysis (DCA) in the validation set. @*Results@#LNM was detected in 29 (13.1%) and 12 (12.6%) patients in training and validation sets, respectively. Nine variables were selected and used to generate the LASSO model. Its performance was similar in training and validation sets (AUROC, 0.795 vs. 0.765; p=0.747). In the validation set, the LASSO model showed better outcomes in predicting LNM than Japanese criteria, as measured by AUROC (0.765 vs. 0.518, p=0.003) and NRI (0.447, p=0.039)/IDI (0.121, p=0.034). DCA showed positive net benefits in using our model. @*Conclusion@#Our LASSO model incorporating histopathologic parameters and TILs showed superior performance compared to conventional Japanese criteria in predicting LNM in patients with T1 CRC.

LASSO-Based Machine Learning Algorithm for Prediction of Lymph Node Metastasis in T1 Colorectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The role of tumor-infiltrating lymphocytes (TILs) in predicting lymph node metastasis (LNM) in patients with T1 colorectal cancer (CRC) remains unclear. Furthermore, clinical utility of a machine learning–based approach has not been widely studied. @*Materials and Methods@#Immunohistochemistry for TILs against CD3, CD8, and forkhead box P3 in both center and invasive margin of the tumor were performed using surgically resected T1 CRC slides. Three hundred and sixteen patients were enrolled and categorized into training (n=221) and validation (n=95) sets via random sampling. Using clinicopathologic variables including TILs, the least absolute shrinkage and selection operator (LASSO) regression model was applied for variable selection and predictive signature building in the training set. The predictive accuracy of our model and the Japanese criteria were compared using area under the receiver operating characteristic (AUROC), net reclassification improvement (NRI)/integrated discrimination improvement (IDI), and decision curve analysis (DCA) in the validation set. @*Results@#LNM was detected in 29 (13.1%) and 12 (12.6%) patients in training and validation sets, respectively. Nine variables were selected and used to generate the LASSO model. Its performance was similar in training and validation sets (AUROC, 0.795 vs. 0.765; p=0.747). In the validation set, the LASSO model showed better outcomes in predicting LNM than Japanese criteria, as measured by AUROC (0.765 vs. 0.518, p=0.003) and NRI (0.447, p=0.039)/IDI (0.121, p=0.034). DCA showed positive net benefits in using our model. @*Conclusion@#Our LASSO model incorporating histopathologic parameters and TILs showed superior performance compared to conventional Japanese criteria in predicting LNM in patients with T1 CRC.

Screening for Lung Cancer Using Low-dose Chest Computed Tomography in Korean Long-term Colorectal Cancer Survivors

BACKGROUND: The National Lung Screening Trial (NLST) and NELSON trial showed that low-dose chest computed tomography (LDCT) screening significantly reduced the mortality form lung cancer. Although cancer survivors are known to have high risk for second malignant neoplasm (SMN), the usefulness of LDCT screening for lung cancer in cancer survivors is not clear. METHODS: Between August 2016 and August 2017, 633 long-term colorectal cancer (CRC) survivors visited the survivorship clinic in Cancer Prevention Center, Yonsei Cancer Center, Seoul, Republic of Korea. We surveyed the smoking status and recommended LDCT screening to ever-smoking CRC survivors aged 55–80 years. The participants were classified into three risk groups: risk group 1 (RG1) who met the NLST criteria (Age 55–74 years, ≥ 30 pack-years of smoking, smoking cessation < 15 years); risk group 2 (RG2) who would not meet the NLST criteria but were at increased 6-year risk of lung cancer (PLCOM2012 ≥ 0.0151); risk group 3 (RG3) who did not meet any of the criteria above. RESULTS: Among 176 ever-smoking CRC survivors, 173 (98.3%) were male, 32 (18.2%) were current-smoker, and median age was 66 years (range, 55–79 years). We found 38 positive findings (non-calcified nodule ≥ 4 mm), 8 clinically significant findings, 66 minor abnormalities, and 64 negative findings on LDCT. Positive findings were identified in 15 of 79 (19.0%) of RG1, in 9 of 36 (25%) of RG2, and in 14 of 61 (23.0%) of RG3. Second primary lung cancers were found in 2 patients of RG2, and in 1 patient of RG3. SMN was most frequently found in RG2 (11 of 36 patients, 30.6%), compared with RG1 (12.7%) or RG3 (9.8%) (P = 0.016). CONCLUSIONS: LDCT screening for lung cancer in Korean CRC survivors is feasible. Well-designed clinical trial for defining high risk patients for lung cancer among CRC survivors is needed.

Robotic Surgery for Rectal Cancer and Cost-Effectiveness

Robotic surgery is considered as one of the advanced treatment modality of minimally invasive surgery for rectal cancer. Robotic rectal surgery has been performed for three decades and its application is gradually expanding along with technology development. It has several technical advantages which include magnified three-dimensional vision, better ergonomics, multiple articulated robotic instruments, and the opportunity to perform remote surgery. The technical benefits of robotic system can help to manipulate more meticulously during technical challenging procedures including total mesorectal excision in narrow pelvis, lateral pelvic node dissection, and intersphincteric resection. It is also reported that robotic rectal surgery have been shown more favorable postoperative functional outcomes. Despite its technical benefits, a majority of studies have been reported that there is rarely clinical or oncologic superiority of robotic surgery for rectal cancer compared to conventional laparoscopic surgery. In addition, robotic rectal surgery showed significantly higher costs than the standard method. Hence, the cost-effectiveness of robotic rectal surgery is still questionable. In order for robotic rectal surgery to further develop in the field of minimally invasive surgery, there should be an obvious cost-effective advantages over laparoscopic surgery, and it is crucial that large-scale prospective randomized trials are required. Positive competition of industries in correlation with technological development may gradually reduce the price of the robotic system, and it will be helpful to increase the cost-effectiveness of robotic rectal surgery.

Which Patients with Isolated Para-aortic Lymph Node Metastasis Will Truly Benefit from Extended Lymph Node Dissection for Colon Cancer? / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The prognosis of patientswith colon cancer and para-aortic lymph node metastasis (PALNM) is poor. We analyzed the prognostic factors of extramesenteric lymphadenectomy for colon cancer patients with isolated PALNM. MATERIALS AND METHODS: We retrospectively reviewed 49 patients with PALNM who underwent curative resection between October 1988 and December 2009. RESULTS: In univariate analyses, the 5-year overall survival (OS) and disease-free survival (DFS) rates were higher in patients with ≤ 7 positive para-aortic lymph node (PALN) (36.5% and 27.5%) than in those with > 7 PALN (14.3% and 14.3%; p=0.010 and p=0.027, respectively), and preoperative carcinoembryonic antigen (CEA) level > 5 was also correlated with a lower 5-year OS and DFS rate of 21.5% and 11.7% compared with those with CEA ≤ 5 (46.3% and 41.4%; p=0.122 and 0.039, respectively). Multivariate analysis found that the number of positive PALN (hazard ratio [HR], 3.291; 95% confidence interval [CI], 1.309 to 8.275; p=0.011) was an independent prognostic factor for OS and the number of positive PALN (HR, 2.484; 95% CI, 0.993 to 6.211; p=0.052) and preoperative CEA level (HR, 1.953; 95% CI, 0.940 to 4.057; p=0.073) were marginally independent prognostic factors for DFS. According to our prognostic model, the 5-year OS and DFS rate increased to 59.3% and 53.3%, respectively, in patients with ≤ 7 positive PALN and CEA level ≤ 5. CONCLUSION: PALN dissection might be beneficial in carefully selected patients with a low CEA level and less extensive PALNM.

Protective effect of Korean red ginseng on oxaliplatin-mediated splenomegaly in colon cancer

PURPOSE: This study investigated how adding Korean red ginseng extract (KRG) to folinic acid, fluorouracil and oxaliplatin (FOLFOX) chemotherapy affected the rate of splenomegaly in colon cancer. METHODS: This retrospective study analyzed 42 patients who were randomly assigned to receive a FOLFOX regimen with or without KRG. Spleen volume change was assessed by computed tomography scans measured before surgery (presurgery volume) and 3 weeks after cessation of the 12th cycle of FOLFOX (postchemotherapy volume). RESULTS: All patients showed increased spleen volume. No difference was observed in median presurgery and postchemotherapy volume between the KRG and control groups. However, a ratio defined as postchemotherapy volume divided by presurgery volume was significantly lower in the KRG group than the control group (median, 1.38 [range, 1.0–2.8] in KRG group vs. median, 1.89 [range, 1.1–3.0] in control group, P = 0.028). When splenomegaly was defined as a >61% increase in spleen volume, the rate of splenomegaly was significantly lower in the KRG group than the control group (28.6% vs. 61.9%, P = 0.03). KRG consumption was inversely associated with developing splenomegaly in multivariate analysis. CONCLUSION: Adding KRG during FOLFOX chemotherapy for colon cancer might protect against oxaliplatin-induced splenomegaly. The protective effect of Korean red ginseng should be investigated with further research.

Single Center Experience With Hyperthermic Intraperitoneal Chemotherapy

PURPOSE: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been proposed for controlling peritoneal seeding metastasis in some kinds of cancers, including those of colorectal origin, but their safety and oncological benefits are subjects of debate. We present our early experience with those procedures. METHODS: Data were retrospectively collected from all patients with peritoneal carcinomatosis (PC) and pseudomyxoma peritonei (PMP) treated using CRS and HIPEC at Yonsei Cancer Center between July 2014 and July 2015. Short-term outcomes and risk factors for postoperative complications were analyzed. RESULTS: Twenty-three patients with PC (n = 18) and PMP (n = 5) underwent CRS and HIPEC. Median follow-up and age were 2 months and 54 years, respectively. The median peritoneal carcinomatosis index score was 15, and CC0-1 was achieved in 78.3% of all patients. The median operation time and bleeding loss were 590 minutes and 570 mL, respectively. Grade-IIIa/grade-IIIb complications occurred in 4.3% (n = 1)/26.1% (n = 6) of the patients within 30 days postoperatively, and no 30-day mortalities were reported. Factors related to postoperative complications with CRS and HIPEC were number of organ resection (P = 0.013), longer operation time (P < 0.001), and amount of blood loss (P = 0.003). All patients treated with cetuximab for recurred colorectal cancer had grade-III postoperative complication. CONCLUSION: Our initial experience with CRS and HIPEC presented about 30% grade-III postoperative complications. Therefore, expert surgeons need to perform those procedures with great caution in selected patients who might benefit from it.

Multiple Myeloma Mimics Bone Metastasis From a Rectal Adenocarcinoma

A presumptive diagnosis of bone metastasis can be easily made when a patient with a history of colorectal cancer develops bone lesions that are seen on follow-up imaging. In this case report, we describe a patient whose multiple bone lesions were wrongly attributed to a recurrence of rectal cancer rather than being identified as multiple myeloma lesions. When clinicians detect new, abnormal, bony lesions in a patient with a previous history of cancer, they should consider diseases such as multiple myeloma in their differential diagnosis.

Laparoscopic and Robotic Surgeries for Patients With Colorectal Cancer Who Have Had a Previous Abdominal Surgery

PURPOSE: The impact of previous abdominal surgery (PAS) on surgical outcomes from laparoscopic and robot surgeries is inconclusive. This study aimed to investigate the impact of PAS on perioperative outcomes from laparoscopic and robotic colorectal surgeries. METHODS: From March 2007 to February 2014, a total of 612 and 238 patients underwent laparoscopic and robotic surgeries, respectively. Patients were divided into 3 groups: those who did not have a PAS (NPAS), those who had a major PAS, and those who had a minor PAS. We further divided the patients so that our final groups for analysis were: patients with NPAS (n = 478), major PAS (n = 19), and minor PAS (n = 115) in the laparoscopy group, and patients with NPAS (n = 202) and minor PAS (n = 36) in the robotic surgery group. RESULTS: In the laparoscopy group, no differences in the conversion rates between the 3 groups were noted (NPAS = 1.0% vs. major PAS = 0% vs. minor PAS = 1.7%, P = 0.701). In the robotic surgery group, the conversion rate did not differ between the NPAS group and the minor PAS group (1.0% vs. 2.8%, P = 0.390). Among the groups, neither the operation time, blood loss, days to soft diet, length of hospital stay, nor complication rate were affected by PAS. CONCLUSION: PAS did not jeopardize the perioperative outcomes for either laparoscopic or robotic colorectal surgeries. Therefore, PAS should not be regarded as an absolute contraindication for minimally invasive colorectal surgeries.

Oncologic outcomes of squamous cell carcinoma of the anal canal after chemoradiation therapy

PURPOSE: The aim of this study is to analyze the oncological outcomes of squamous cell carcinoma (SCC) of the anal canal after chemoradiation therapy (CRT) in a single institution.METHODS: Fifty-one patients with anal SCC who had been treated with CRT between January 2000 and December 2010 were analyze data single center in Korea.RESULTS: Forty-eight patients exhibited clinical complete response. After a median follow-up of 42.1 months, 13 patients (25.5%) showed recurrence. The disease-free survival (DFS) rate was 63.4% at 5 and 10 years. The overall survival (OS) rates were 83.6% (5 years) and 75.2% (10 years). Stage I: DFS, 100%; OS, 100%; stage II: DFS, 85.7%; OS, 100%; stage IIIA: DFS, 68.6%; OS, 87.5%; stage IIIB: DFS, 34.7%; OS, 48.4%; and stage IV: DFS and OS, 0%. The local recurrence patterns were as follows: pelvic node (n=4, 7.8%), inguinal node (n=1, 2.0%), and inguinal and pelvic node (n=1, 2.0%). The systemic recurrence patterns were as follows: lung (n=2, 3.9%), para-aortic node (n=1, 2.0%), and extrapelvic site (n=2, 3.9%). N-stage represented a single independent prognostic factor for recurrence (P<0.05).CONCLUSION: CRT for SCC of the anal canal is effective for oncological outcomes and sphincter preservation. The initial nodal status may affect the oncological outcome.

Single-Port Laparoscopic Total Extraperitoneal Inguinal Hernia Repair without Fixation of the Mesh

PURPOSE: Single-port laparoscopic surgery has been used increasingly in treatment of a variety of conditions, and one recently introduced technique is single-port laparoscopic total extraperitoneal (SPLTEP) hernia repair. The aim of this study was to evaluate the safety and technical feasibility of SPLTEP hernia repair without fixation of the mesh. METHODS: From June 2010 to October 2012, 112 consecutive patients underwent SPLTEP hernia repair. RESULTS: We performed 129 inguinal hernia repairs in 112 patients, 17 were bilateral and 95 unilateral. There were 107 indirect hernias (83.0%), 20 direct hernias, and 2 hernias had both of types. Successful SPLTEP hernia repair was performed in 110 patients, with two conversions to an open surgical approach. Median operative times for unilateral and bilateral hernias were 70 minutes (40~145 minutes) and 90 minutes (67~135 minutes), respectively, and the hospital stay was 1 day (1~5 days). Postoperative complications included 10 patients with wound seromas or hematomas, 2 with urinary retention, 4 with groin pain, and 1 with bleeding from the incision site. There were 3 early recurrences (2.4%) during a median follow-up period of 42 months (range, 6~55). CONCLUSION: SPLTEP inguinal hernia repair without fixation of the mesh is both safe and technically feasible, and provides acceptable operative outcomes. Conduct of a prospective randomized study with long-term follow-up is needed to confirm the benefit of this technique in patients with inguinal hernia.

Xanthogranulomatous Appendicitis Mimicking Residual Burkitt's Lymphoma After Chemotherapy

The case of a 23-year-old female treated with aggressive high-dose therapy for Burkitt's lymphoma is reported. A positron emission tomography and computed tomography scan after completion of chemotherapy revealed a residual hypermetabolic lesion in the right pelvic cavity. A pelvic magnetic resonance imaging scan showed circumferential wall thickening at the tip of the appendix. A laparoscopic exploration and appendectomy were performed, and a pathologic examination of the resected appendix revealed xanthogranulomatous appendicitis. This is a rare case of a xanthogranulomatous appendicitis mimicking remnant Burkitt's lymphoma after completion of chemotherapy.

Novel Methods for Clinical Risk Stratification in Patients with Colorectal Liver Metastases / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Colorectal cancer patients with liver-confined metastases are classified as stage IV, but their prognoses can differ from metastases at other sites. In this study, we suggest a novel method for risk stratification using clinically effective factors. MATERIALS AND METHODS: Data on 566 consecutive patients with colorectal liver metastasis (CLM) between 1989 and 2010 were analyzed. This analysis was based on principal component analysis (PCA). RESULTS: The survival rate was affected by carcinoembryonic antigen (CEA) level (p < 0.001; risk ratio, 1.90), distribution of liver metastasis (p=0.014; risk ratio, 1.46), and disease-free interval (DFI; p < 0.001; risk ratio, 1.98). When patients were divided into three groups according to PCA score using significantly affected factors, they showed significantly different survival patterns (p < 0.001). CONCLUSION: The PCA scoring system based on CEA level, distribution of liver metastasis, and DFI may be useful for preoperatively determining prognoses in order to assist in clinical decisionmaking and designing future clinical trials for CLM treatment.

Is Low-Dose-Rate Endorectal Brachytherapy a New Treatment Method for Locally Advanced Distal Rectal Cancer?

No abstract available.

Colon Stricture After Ischemia Following a Robot-Assisted Ultra-Low Anterior Resection With Coloanal Anastomosis

Four consecutive cases of a colonic stricture following a da Vinci robot-assisted ultra-low anterior resection (LAR) with coloanal anastomosis and diverting ileostomy for the treatment of rectal cancer are reported. The colonic strictures developed after early proximal colonic ischemia without anastomotic site leakage or disruption. All patients were treated with preoperative chemoradiation therapy. During the postoperative recovery period, patients developed colonic ischemia, presenting with a high, spiking fever, but without any symptoms of peritonitis. Patients were treated with conservative management (antibiotic therapy) and discharged after two weeks when in good condition. Several months after discharge, all four patients developed a long-segment colonic stricture from the anastomosis site to the distal colon. Management of the colon strictures, including the anastomotic site, involved colonic dilation with a Hegar dilator in an outpatient clinic for several months. The ileostomies in three patients could not be closed.

Reduced-Port Laparoscopic Surgery for a Tumor-Specific Mesorectal Excision in Patients With Colorectal Cancer: Initial Experience With 20 Consecutive Cases

PURPOSE: Single-port plus one-port, reduced-port laparoscopic surgery (RPLS) may decrease collisions between laparoscopic instruments and the camera in a narrow, bony, pelvic cavity while maintaining the cosmetic advantages of single-incision laparoscopic surgery. The aim of this study is to describe our initial experience with and to assess the feasibility and safety of RPLS for tumor-specific mesorectal excisions (TSMEs) in patients with colorectal cancer. METHODS: Between May 2010 and August 2012, RPLS for TSME was performed in 20 patients with colorectal cancer. A single port with four channels through an umbilical incision and an additional port in the right lower quadrant were used for RPLS. RESULTS: The median operation time was 231 minutes (range, 160-347 minutes), and the estimated blood loss was 100 mL (range, 50-500 mL). We transected the rectum with one laparoscopic stapler in 17 cases (85%). The median time to soft diet was 4 days (range, 3-6 days), and the length of hospital stay was 7 days (range, 5-45 days). The median total number of lymph nodes harvested was 16 (range, 7-36), and circumferential resection margin involvement was found in 1 case (5%). Seven patients (35%) developed postoperative complications, and no mortalities occurred within 30 days. During the median follow-up period of 20 months (range, 12-40 months), liver metastasis occurred in 1 patient 10 months after surgery, and local recurrence was nonexistent. CONCLUSION: RPLS for TSME in patients with colorectal cancer is technically feasible and safe without compromising oncologic safety. However, further studies comparing RPLS with a conventional, laparoscopic low-anterior resection are needed to prove the advantages of the RPLS procedure.

Operative Outcomes of Open versus Laparoscopic Total Proctocolectomy with Ileal Pouch Anal Anastomosis in Ulcerative Colitis

PURPOSE: During the course of disease, nearly 30% of ulcerative colitis patients receive surgical therapy. Total proctocolectomy with ileal pouch anal anastomosis is a standard procedure. However, the effectiveness of laparoscopic surgery in ulcerative colitis has not yet been proven. We aimed to evaluate the clinical course of both laparoscopic and open surgeries of a total proctocolectomy with ileal pouch anal anastomosis. METHODS: We reviewed charts of 34 patients who underwent a total proctocolectomy with ileal pouch anal anastomosis between April 2005 and April 2014. The laparoscopic group (n=21) and the open group (n=13) were compared retrospectively in accordance with patients' demographics, clinical features, operative data, and postoperative complications within and after 30 days after the operation. RESULTS: Patient characteristics were not significantly different between the two groups. The laparoscopic group had a longer duration of disease before the operation (42.3+/-48.5 vs. 105+/-97.6, p=0.019). The operative results, including operation time and estimated blood loss, were not different in both groups. The postoperative outcomes of laparoscopic surgery were not different from those of open surgery in postoperative complications within and after 30 postoperative days. The rate of reoperation and readmission was not different, and the days until first gas passing and soft diet were not significantly different. CONCLUSION: Laparoscopic surgery in ulcerative colitis is a feasible and safe procedure. Laparoscopic surgery may provide an alternative approach to open surgery in carefully selected ulcerative colitis patients.