Korean clinical practice guidelines on biologics for moderate to severe Crohn’s disease

Crohn’s disease (CD) is a relapsing and progressive condition characterized by diarrhea, abdominal pain, weight loss, and hematochezia that results in serious complications such as perforations, fistulas, and abscesses. Various medications, interventions, and surgical treatments have been used to treat CD. The Korean guidelines for CD management were distributed in 2012 and revised in 2017 by the Inflammatory Bowel Disease (IBD) Research Group of the Korean Association for the Study of Intestinal Diseases. Substantial progress in mucosal immunologic research has elucidated the pathophysiology of IBD, leading to development of biological agents for treatment of CD. The first developed biologic agent, tumor necrosis factor-α agents, were shown to be efficacious in CD, heralding a new era in management of CD. Subsequently, vedolizumab, a monoclonal antibody against integrin α4β7, and ustekinumab, a human monoclonal antibody that inhibits the common p40 subunit of interleukin-12 and interleukin-23, were both approved for clinical use and are efficacious and safe for both induction and maintenance of remission in moderate-to-severe CD patients. Moreover, a recent study showed the non-inferiority of CT-P13, an infliximab biosimilar, compared with infliximab in CD patients. The third Korean guidelines for CD management provide updated information regarding treatment of moderate-to-severe CD patients with biologic agents.

Difference in prognostic impact of lateral pelvic lymph node metastasis between pre- and post-neoadjuvant chemoradiotherapy in rectal cancer patients

Purpose@#The prognostic significance and treatment of lateral pelvic lymph node metastasis (mLPLN) in rectal cancer patients receiving neoadjuvant chemoradiotherapy (nCRT) are not well understood. In this study, we evaluated the impact of mLPLN identified in imaging modality on outcomes. @*Methods@#Between January 2008 and December 2016, 1,535 patients who underwent radical resection following nCRT were identified. The association between mLPLN and disease-free survival (DFS), overall survival (OS), local recurrencefree survival (LRFS), and pelvic recurrence-free survival (PRFS) was analyzed, along with risk factors associated with OS and DFS. @*Results@#Overall, 329 (21.4%) of the 1,535 patients experienced disease recurrence; 71 (4.6%) had local recurrence, 25 (1.6%) had pelvic recurrence, and 312 (20.3%) had distant recurrence. The pre- and post-nCRT mLPLN (–) groups had better DFS, LRFS, PRFS, and OS than the (+) groups. LPLN sampling (LPLNs) was implemented in 24.0% of the pre-nCRT mLPLN (+) group and in 28.8% of the post-nCRT mLPLN (+) group. There was no significant difference in OS and LRFS between LPLNs group and no LPLNs group in pre- and post-nCRT mLPLN (+) groups. Pre-nCRT mLPLN was associated with poor OS (hazard ratio [HR], 1.43; P = 0.009) and post-nCRT mLPLN was associated with poor DFS (HR, 1.49; P = 0.002). @*Conclusion@#Pre- and post-nCRT mLPLN (+) have different prognostic effects. Post-nCRT mLPLN appears to be more important for disease control. However, pre-nCRT mLPLN should not be disregarded when devising a treatment strategy since it is an independent risk factor for OS.

Efficacy of preoperative chemoradiotherapy in patients with cT2N0 distal rectal cancer

Purpose@#This study was designed to determine the feasibility of preoperative chemoradiotherapy (PCRT) in patients with clinical T2N0 distal rectal cancer. @*Methods@#Patients who underwent surgery for clinical T2N0 distal rectal cancer between January 2008 and December 2016 were included. Patients were divided into PCRT and non-PCRT groups. Non-PCRT patients underwent radical resection or local excision (LE) according to the surgeon’s decision, and PCRT patients underwent surgery according to the response to PCRT. Patients received 50.0 to 50.4 gray of preoperative radiotherapy with concurrent chemotherapy. @*Results@#Of 127 patients enrolled, 46 underwent PCRT and 81 did not. The mean distance of lesions from the anal verge was lower in the PCRT group (P=0.004). The most frequent operation was transanal excision and ultralow anterior resection in the PCRT and non-PCRT groups, respectively. Of the 46 patients who underwent PCRT, 21 (45.7%) achieved pathologic complete response, including 15 of the 24 (62.5%) who underwent LE. Rectal sparing rate was significantly higher in the PCRT group (11.1% vs. 52.2%, P<0.001). There were no significant differences in 3- and 5-year overall survival and recurrence-free survival regardless of PCRT or surgical procedures. @*Conclusion@#PCRT in clinical T2N0 distal rectal cancer patients increased the rectal sparing rate via LE and showed acceptable oncologic outcomes. PCRT may be a feasible therapeutic option to avoid abdominoperineal resection in clinical T2N0 distal rectal cancer.

Molecular characterization of dysplasia-initiated colorectal cancer with assessing matched tumor and dysplasia samples

Purpose@#Ulcerative colitis (UC) is known to have an association with the increased risk of colorectal cancer (CRC), and UC-associated CRC does not follow the typical progress pattern of adenoma-carcinoma. The aim of this study is to investigate molecular characteristics of UC-associated CRC and further our understanding of the association between UC and CRC. @*Methods@#From 5 patients with UC-associated CRC, matched normal, dysplasia, and tumor specimens were obtained from formalin-fixed paraffin-embedded (FFPE) samples for analysis. Genomic DNA was extracted and whole exome sequencing was conducted to identify somatic variations in dysplasia and tumor samples. Statistical analysis was performed to identify somatic variations with significantly higher frequencies in dysplasia-initiated tumors, and their relevant functions were investigated. @*Results@#Total of 104 tumor mutation genes were identified with higher mutation frequencies in dysplasia-initiated tumors. Four of the 5 dysplasia-initiated tumors (80.0%) have TP53 mutations with frequent stop-gain mutations that were originated from matched dysplasia. APC and KRAS are known to be frequently mutated in general CRC, while none of the 5 patients have APC or KRAS mutation in their dysplasia and tumor samples. Glycoproteins including mucins were also frequently mutated in dysplasia-initiated tumors. @*Conclusion@#UC-associated CRC tumors have distinct mutational characteristics compared to typical adenoma-carcinoma tumors and may have different cancer-driving molecular mechanisms that are initiated from earlier dysplasia status.

Effects of anchoring sutures at diverting ileostomy after rectal cancer surgery on peritoneal adhesion at following ileostomy reversal

Purpose@#During diverting ileostomy reversal for rectal cancer patients who underwent previous sphincter-saving surgery, the extent of adhesion formation around the ileostomy site affects operative and postoperative outcomes. Anchoring sutures placed at the time of the ileostomy procedure may reduce adhesions around the ileostomy. This study aimed to evaluate the effects of anchoring sutures on the degree of adhesion formation and the postoperative course at the time of ileostomy reversal. @*Methods@#Patients who underwent sphincter-saving surgery with diverting ileostomy for rectal cancer between January 2013 and December 2017 were enrolled. Variables including the peritoneal adhesion index (PAI) score, operation time, the length of resected small bowel, operative complications, and postoperative hospital stay were collected prospectively and compared between the anchoring group (AG) and non-anchoring group (NAG). @*Results@#A total of 90 patients were included in this study, with 60 and 30 patients in the AG and NAG, respectively. The AG had shorter mean operation time (46.88 ± 16.37 minutes vs. 61.53 ± 19.36 minutes, P = 0.001) and lower mean PAI score (3.02 ± 2.53 vs. 5.80 ± 2.60, P = 0.001), compared with the NAG. There was no significant difference in the incidence of postoperative complications between the AG and NAG (5.0% vs. 13.3%, respectively; P = 0.240). @*Conclusion@#Anchoring sutures at the formation of a diverting ileostomy could decrease the adhesion score and operation time at ileostomy reversal, thus may be effective in improving perioperative outcomes.

Treatment Strategy for Perianal Fistulas in Crohn Disease Patients: The Surgeon’s Point of View

Perianal fistula is a frequent complication and one of the subclassifications of Crohn disease (CD). It is the most commonly observed symptomatic condition by colorectal surgeons. Accurately classifying a perianal fistula is the initial step in its management in CD patients. Surgical management is selected based on the type of perianal fistula and the presence of rectal inflammation; it includes fistulotomy, fistulectomy, seton procedure, fistula plug insertion, video-assisted ablation of the fistulous tract, stem cell therapy, and proctectomy with stoma creation. Perianal fistulas are also managed medically, such as antibiotics, immunomodulators, and biologics including anti-tumor necrosis factor-alpha agents. The current standard treatment of choice for perianal fistula in CD patients is the multidisciplinary approach combining surgical and medical management; however, the rate of long-term remission is low and is reported to be 50% at most. Therefore, the optimum management strategy for perianal fistulas associated with CD remains controversial. Currently, the goal of management for CD-related perianal fistulas are controlling symptoms and maintaining long-term anal function without proctectomy, while monitoring progression to anorectal carcinoma. This review evaluates perianal fistula in CD patients and determines the optimal surgical management strategy based on recent evidence.

Beware of Early Relapse in Rectal Cancer Patients Treated With Preoperative Chemoradiotherapy

Purpose@#Recurrence patterns in rectal cancer patients treated with preoperative chemoradiotherapy (PCRT) are needed to evaluate for establishing tailored surveillance protocol. @*Methods@#This study included 2,215 patients with locally-advanced mid and low rectal cancer treated with radical resection between January 2005 and December 2012. Recurrence was evaluated according to receipt of PCRT; PCRT group (n = 1,258) and no-PCRT group (n = 957). Early recurrence occurred within 1 year of surgery and late recurrence after 3 years. The median follow-up duration was 65.7 ± 29 months. @*Results@#The overall recurrence rate was similar between the PCRT and no-PCRT group (25.8% vs. 24.9%, P = 0.622). The most common initial recurrence site was the lungs in both groups (50.6% vs. 49.6%, P = 0.864), followed by the liver, which was more common in the no-PCRT group (22.5% vs. 33.6%, P = 0.004). Most of the recurrence occurred within 3 years after surgery in both groups (85.3% vs. 85.8%, P = 0.862). Early recurrence was more common in the PCRT group than in the no-PCRT group (43.1% vs. 32.4%, P = 0.020). Recurrence within the first 6 months after surgery was significantly higher in the PCRT group than in the no-PCRT group (18.8% vs. 7.6%, P = 0.003). Lung (n = 27, 44.3%) and liver (n = 22, 36.1%) were the frequent the first relapsed site within 6 months after surgery in PCRT group. @*Conclusion@#Early recurrence within the first 1 year after surgery was more common in patients treated with PCRT. This difference would be considered for surveillance protocols and need to be evaluated in further studies.

Beware of Early Relapse in Rectal Cancer Patients Treated With Preoperative Chemoradiotherapy

Purpose@#Recurrence patterns in rectal cancer patients treated with preoperative chemoradiotherapy (PCRT) are needed to evaluate for establishing tailored surveillance protocol. @*Methods@#This study included 2,215 patients with locally-advanced mid and low rectal cancer treated with radical resection between January 2005 and December 2012. Recurrence was evaluated according to receipt of PCRT; PCRT group (n = 1,258) and no-PCRT group (n = 957). Early recurrence occurred within 1 year of surgery and late recurrence after 3 years. The median follow-up duration was 65.7 ± 29 months. @*Results@#The overall recurrence rate was similar between the PCRT and no-PCRT group (25.8% vs. 24.9%, P = 0.622). The most common initial recurrence site was the lungs in both groups (50.6% vs. 49.6%, P = 0.864), followed by the liver, which was more common in the no-PCRT group (22.5% vs. 33.6%, P = 0.004). Most of the recurrence occurred within 3 years after surgery in both groups (85.3% vs. 85.8%, P = 0.862). Early recurrence was more common in the PCRT group than in the no-PCRT group (43.1% vs. 32.4%, P = 0.020). Recurrence within the first 6 months after surgery was significantly higher in the PCRT group than in the no-PCRT group (18.8% vs. 7.6%, P = 0.003). Lung (n = 27, 44.3%) and liver (n = 22, 36.1%) were the frequent the first relapsed site within 6 months after surgery in PCRT group. @*Conclusion@#Early recurrence within the first 1 year after surgery was more common in patients treated with PCRT. This difference would be considered for surveillance protocols and need to be evaluated in further studies.

Association of Body Composition with Long-Term Survival inNon-metastatic Rectal Cancer Patients / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#We evaluated the association of body composition with long-term oncologic outcomes innon-metastatic rectal cancer patients. @*Materials and Methods@#We included 1,384 patients with stage(y)0-III rectal cancer treated at Asan Medical Centerbetween January 2005 and December 2012. Body composition at diagnosis was measuredusing abdomino-pelvic computed tomography (CT). Sarcopenia, visceral obesity (VO), andsarcopenic obesity (SO) were defined using CT measured parameters such as skeletal muscleindex (total abdominal muscle area, TAMA), visceral fat area (VFA), and VFA/TAMA. Inflammatorystatus was defined as a neutrophil-lymphocyte ratio of ! 3. Obesity was categorizedby body mass index (! 25 kg/m2). @*Results@#Among the 1,384 patients, 944 (68.2%) had sarcopenia and 307 (22.2%) had SO. The5-year overall survival (OS) rate was significantly lower in sarcopenic patients (no sarcopeniavs. sarcopenia; 84% vs. 78%, p=0.003) but the 5-year recurrence-free survival (RFS) ratewas not different (77.3% vs. 77.9% p=0.957). Patients with SO showed lower 5-year OS(79.1% vs. 75.5% p=0.02) but no difference in 5-year RFS (p=0.957). Sarcopenia, SO, VO,and obesity were not associated with RFS. However, obesity, SO, age, sex, inflammatorystatus, and tumor stage were confirmed as independent factors associated with OS on multivariateanalysis. In subgroup analysis, association of SO with OS was more prominent inpatients with (y)p stage 0-2 and no inflammatory status. @*Conclusion@#The presence of SO and a low body mass index at diagnosis are negatively associated withOS in non-metastatic rectal cancer patients.

Early Postoperative Anastomotic Obstruction Due to an Intraluminal Blood Clot After Laparoscopic Anterior Resection: A Case Report

Early postoperative anastomotic obstruction after colorectal surgery rarely develops. Herein, we present a case of a 50-year-old healthy woman who had an early postoperative anastomotic obstruction which was revealed caused by a blood clot and successfully managed by endoscopic approach. The patient was discharged after laparoscopic anterior resection and visited the emergency department one day after because of abdominal pain. Computed tomography showed that the anastomosis site was obstructed with low-density material. Intraoperative endoscopy was performed under general anesthesia and blood clot filling the lumen were identified. As the scope was advanced to the blood clot with air inflation, the blood clot was evacuated. The anastomosis site could be obstructed by blot clot with mucous debris albeit it is a rare condition. An endoscopic approach seems to be the first option in the diagnosis and treatment of postoperative obstruction at the anastomosis site and it could prevent unnecessary laparotomy.

Short-term Outcomes of Elective 2-Stage Restorative Proctocolectomy for Ulcerative Colitis in Korea: Does Laparoscopy Have Benefits?

Purpose@#This study aimed to compare the short-term outcomes of the open and laparoscopic approaches to 2-stage restorative proctocolectomy (RPC) for Korean patients with ulcerative colitis (UC). @*Methods@#We retrospectively analyzed the medical records of 73 patients with UC who underwent elective RPC between 2009 and 2016. Patient characteristics, operative details, and postoperative complications within 30 days were compared between the open and laparoscopic groups. @*Results@#There were 26 cases (36%) in the laparoscopic group, which had a lower mean body mass index (P = 0.025), faster mean time to recovery of bowel function (P = 0.004), less intraoperative blood loss (P = 0.004), and less pain on the first and seventh postoperative days (P = 0.029 and P = 0.027, respectively) compared to open group. There were no deaths, and the overall complication rate was 43.8%. There was no between-group difference in the overall complication rate; however, postoperative ileus was more frequent in the open group (27.7% vs. 7.7%, P = 0.043). Current smoking (odds ratio [OR], 44.4; P = 0.003) and open surgery (OR, 5.4; P = 0.014) were the independent risk factors for postoperative complications after RPC. @*Conclusion@#Laparoscopic RPC was associated with acceptable morbidity and faster recovery than the open approach. The laparoscopic approach is a feasible and safe option for surgical treatment for UC in selective cases.

Clinical Characteristics and Postoperative Outcomes of Patients Presenting With Upper Gastrointestinal Tract Crohn Disease

Purpose@#Upper gastrointestinal (GI) tract involvement in Crohn disease (CD) is rare and effectiveness of surgical treatment is limited. The aim of this study was to evaluate characteristics and surgical outcomes of upper GI CD. @*Methods@#Medical records of 811 patients who underwent intestinal surgery for CD between January 2006 and December 2015 at a single institution were reviewed. Upper GI CD was defined by involvement of the stomach to the fourth portion of duodenum, with or without concomitant small/large bowel CD involvement according to a modification of the Montreal classification. @*Results@#We identified 24 patients (21 males, 3 females) who underwent surgery for upper GI CD. The mean age at diagnosis was 27 ± 12 years, the mean age at surgery was 33 ± 11 years, and the mean duration of CD was 73.6 ± 56.6 months.Fifteen patients (62.5%) had history of previous perianal surgery. Ten patients (41.7%) had duodenal or gastric stricture and 14 patients (58.3%) had penetrating fistula; patients with fistula were significantly more likely to develop complications (57.1% vs. 20.0%, P = 0.035). One patient with stricture had surgical recurrence. In seven patients with fistula, fistula was related to previous anastomosis. Patients with fistula had significantly longer hospital stays than those with stricture (16 days vs. 11 days, P = 0.01). @*Conclusion@#Upper GI CD is rare among CD types (2.96%). In patients with upper GI CD, penetrating fistula was associated with longer hospital stay and more complications.

Prognostic Implications of Extranodal Extension in Relation to Colorectal Cancer Location / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Extranodal extension (ENE) is closely associated with the aggressiveness of both colon and rectal cancer. This study evaluated the clinicopathologic significance and prognostic impact of ENE in separate populations of patients with colon and rectal cancers. MATERIALS AND METHODS: The medical records of 2,346 patients with colorectal cancer (CRC) who underwent curative surgery at our institution between January 2003 and December 2011 were clinically and histologically reviewed. RESULTS: ENE was associated with younger age, advanced tumor stage, lymphovascular invasion (LVI), and perineural invasion (PNI) in both colon and rectal cancer. ENE rates differed significantly in patients with right colon (36.9%), left colon (42.6%), and rectal (48.7%) cancers (right vs. left, p=0.037; left vs. rectum, p=0.009). The 5-year disease-free survival (DFS) rate according to ENE status and primary tumor site differed significantly in patients with ENE-negative colon cancer (80.5%), ENE-negative rectal cancer (77.4%), ENE-positive colon cancer (68.6%), and ENE-positive rectal cancer (64.2%) (p<0.001). Multivariate analysis showed that advanced tumor stage, ENE, LVI, PNI, and absence of adjuvant chemotherapy were independently prognostic of reduced DFS in colon and rectal cancer patients. CONCLUSION: ENE is closely associated with the aggressiveness of colon and rectal cancers, with its frequency increasing from the right colon to the left colon to the rectum. ENE status is a significant independent predictor of DFS in CRC patients irrespective of tumor location. ENE might be more related with distally located CRC.

Sensitivity of Various Evaluating Modalities for Predicting a Pathologic Complete Response After Preoperative Chemoradiation Therapy for Locally Advanced Rectal Cancer

PURPOSE: We investigated the sensitivity of various evaluating modalities in predicting a pathologic complete response (pCR) after preoperative chemoradiation therapy (PCRT) for locally advanced rectal cancer (LARC). METHODS: From a population of 2,247 LARC patients who underwent PCRT followed by surgery at Asan Medical Center, Seoul, Korea from January 2007 to June 2016, we retrospectively analyzed 313 patients (14.1%) who showed a pCR after surgery. Transrectal ultrasound (TRUS), high-resolution magnetic resonance imaging (MRI), abdominopelvic computed tomography (AP-CT), and endoscopy were performed within 2 weeks prior to surgery. RESULTS: Of the 313 patients analyzed, 256 (81.8%) had a pCR after radical surgery and 57 (18.2%) showed total regression after local excision. Preoperative TRUS, MRI, and AP-CT were performed in 283, 305, and 139 patients, respectively. Among these 3 groups, a prediction of a pCR of the primary tumor was made in 41 (14.5%), 51 (16.7%), and 27 patients (19.4%), respectively, before surgery. A prediction of a clinical N0 stage was made in 204 patients (88.3%) using TRUS, 130 (52.2%) using MRI, and 78 (65.5%) using AP-CT. Of the 211 patients who underwent endoscopy, 87 (41.2%) had a mention of clinical CR in their records. A prediction of a pathologic CR was made for 124 patients (39.6%) through at least one diagnostic modality. CONCLUSION: The various evaluation methods for predicting a pCR after PCRT show a predictive sensitivity of 0.15–0.41 for primary tumors and 0.52–0.88 for lymph nodes. Endoscopy is a relatively superior modality for predicting the pCR of the primary tumor of LARC patients.

Long-term Transanal Excision Outcomes in Patients With T1 Rectal Cancer: Comparative Analysis of Radical Resection

PURPOSE: Transanal excision (TAE) is an alternative surgical procedure for early rectal cancer. This study compared long-term TAE outcomes, in terms of survival and local recurrence (LR), with total mesorectal excision (TME) in patients with pathologically confirmed T1 rectal cancer. METHODS: T1 rectal adenocarcinoma patients who underwent surgery from 1990 to 2011 were retrospectively reviewed. Patients that were suspected to have preoperative lymph node metastasis were excluded. Demographics, recurrence, and survival were analyzed based on TAE and TME surgery. RESULTS: Of 268 individuals, 61 patients (26%) underwent TAE, which was characterized by proximity to the anus, submucosal invasion depth, and lesion infiltration, compared with TME patients (P < 0.001–0.033). During a median follow-up of 10.4 years, 12 patients had systemic and/or LR. Ten-year cancer-specific survival in the TAE and TME groups was not significantly different (98% vs. 100%). However, the 10-year LR rate in the TAE group was greater than that of TME group (10% vs. 0%, P < 0.001). Although 5 of the 6 TAE patients with LR underwent salvage surgery, one of the patients eventually died. The TAE surgical procedure (hazard ratio, 19.066; P = 0.007) was the only independent risk factor for LR. CONCLUSION: Although long-term survival after TAE was comparable to that after TME, TAE had a greater recurrence risk than TME. Thus, TAE should only be considered as an alternative surgical option for early rectal cancer in selected patients.

Oncologic Outcomes of Organ Preserving Approaches in Patients With Rectal Cancer Treated With Preoperative Chemoradiotherapy

PURPOSE: We evaluated the oncologic outcomes of organ-preserving strategies in patients with rectal cancer treated with preoperative chemoradiotherapy (PCRT). METHODS: Between January 2008 and January 2013, 74 patients who underwent wait-and-watch (WW) (n = 42) and local excision (LE) (n = 32) were enrolled. Organ-preserving strategies were determined based on a combination of magnetic resonance imaging, sigmoidoscopy, and physical examination 4–6 weeks after completion of PCRT. The rectum sparing rate, 5-year recurrence-free survival (RFS), and overall survival (OS) were evaluated. RESULTS: The rectum was more frequently spared in the LE (100% vs. 87.5%, P = 0.018) at last follow-up. Recurrence occurred in 9 (28.1%) WW and 7 (16.7%) LE (P = 0.169). In the WW, 7 patients had only luminal regrowth and 2 had combined lung metastasis. In the LE, 2 (4.8%) had local recurrence only, 4 patients had distant metastasis, and 1 patient had local and distant metastasis. Among 13 patients who indicated salvage surgery (WW, n = 7; LE, n = 11), all in the WW received but all of LE refused salvage surgery (P = 0.048). The 5-year OS and 5-year RFS in overall patients was 92.7% and 76.9%, respectively, and were not different between WW and LE (P = 0.725, P = 0.129). CONCLUSION: WW and LE were comparable in terms of 5-year OS and RFS. In the LE group, salvage treatment was performed much less among indicated patients. Therefore, methods to improve the oncologic outcomes of patients indicated for salvage treatment should be considered before local excision.

Does the Different Locations of Colon Cancer Affect the Oncologic Outcome? A Propensity-Score Matched Analysis

PURPOSE: We evaluate the prognostic value of primary tumor location for oncologic outcomes in patients with colon cancer (CC). METHODS: CC patients treated with curative surgery between 2009 and 2012 were classified into 2 groups: right-sided colon cancer (RCC) and left-sided colon cancer (LCC). Recurrence-free survival (RFS) and overall survival (OS) were examined based on tumor stage. Propensity scores were created using eight variables (age, sex, T stage, N stage, histologic grade, presence of lymphovascular invasion/perineural invasion, and microsatellite instability status). RESULTS: Overall, 2,329 patients were identified. The 5-year RFSs for RCC and LCC patients were 89.7% and 88.4% (P = 0.328), respectively, and their 5-year OSs were 90.9% and 93.4% (P = 0.062). Multivariate survival analyses were carried out by using the Cox regression proportional hazard model. In the unadjusted analysis, a marginal increase in overall mortality was seen in RCC patients (hazard ratio [HR], 1.297; 95% confidence interval [CI], 0.987–1.704, P = 0.062); however, after multivariable adjustment, similar OSs were observed in those patients (HR, 1.219; 95% CI, 0.91–1.633; P = 0.183). After propensity-score matching with a total of 1,560 patients, no significant difference was identified (P = 0.183). A slightly worse OS was seen for stage III RCC patients (HR, 1.561; 95% CI, 0.967–2.522; P = 0.068) than for stage III LCC patients. The 5-year OSs for patients with stage III RCC and stage III LCC were 85.5% and 90.5%, respectively (P = 0.133). CONCLUSION: Although the results are inconclusive, tumor location tended to be associated with OS in CC patients with lymph node metastasis, but it was not related to oncologic outcome.

Variation in the Height of Rectal Cancers According to the Diagnostic Modalities

PURPOSE: Although the height of a rectal tumor above the anal verge (tumor height) partly determines the treatment strategy, no practical standard exists for reporting this. We aimed to demonstrate the differences in tumor height according to the diagnostic modality used for its measurement. METHODS: We identified 100 patients with rectal cancers located within 15 cm of the anal verge who had recorded tumor heights measured by using magnetic resonance imaging (MRI), colonoscopy, and digital rectal examination (DRE). Tumor height measured by using MRI was compared with those measured by using DRE and colonoscopy to assess reporting inconsistencies. Factors associated with differences in tumor height among the modalities were also evaluated. RESULTS: The mean tumor heights were 77.8 ± 3.3, 52.9 ± 2.3, and 68.9 ± 3.1 mm when measured by using MRI, DRE, and colonoscopy, respectively (P < 0.001). Agreement among the 3 modalities in terms of tumor sublocation within the rectum was found in only 39% of the patients. In the univariate and the multivariate analyses, clinical stage showed a possible association with concordance among modalities, but age, sex, and luminal location of the tumor were not associated with differences among modalities. CONCLUSION: The heights of rectal cancer differed according to the diagnostic modality. Tumor height has implications for rectal cancer’s surgical planning and for interpreting comparative studies. Hence, a consensus is needed for measuring and reporting tumor height.

Utility of BRAF VE1 Immunohistochemistry as a Screening Tool for Colorectal Cancer Harboring BRAF V600E Mutation

BACKGROUND: BRAF mutation has been recognized as an important biomarker of colorectal cancer (CRC) for targeted therapy and prognosis prediction. However, sequencing for every CRC case is not cost-effective. An antibody specific for BRAF V600E mutant protein has been introduced, and we thus examined the utility of BRAF VE1 immunohistochemistry for evaluating BRAF mutations in CRC. METHODS: Fifty-one BRAF-mutated CRCs and 100 age and sexmatched BRAF wild-type CRCs between 2005 and 2015 were selected from the archives of Asan Medical Center. Tissue microarrays were constructed and stained with BRAF VE1 antibody. RESULTS: Forty-nine of the 51 BRAF-mutant CRCs (96.1%) showed more than moderate cytoplasmic staining, except for two weakly stained cases. Six of 100 BRAF wild-type cases also stained positive with BRAF VE1 antibody; four stained weakly and two stained moderately. Normal colonic crypts showed nonspecific weak staining, and a few CRC cases exhibited moderate nuclear reactivity (3 BRAF-mutant and 10 BRAF wild-type cases). BRAF-mutated CRC patients had higher pathologic stages and worse survival than BRAF wild-type patients. CONCLUSIONS: BRAF VE1 immunohistochemistry showed high sensitivity and specificity, but occasional nonspecific staining in tumor cell nuclei and normal colonic crypts may limit their routine clinical use. Thus, BRAF VE1 immunohistochemistry may be a useful screening tool for BRAF V600E mutation in CRCs, provided that additional sequencing studies can be done to confirm the mutation in BRAF VE1 antibody-positive cases.

Trephine Transverse Colostomy Is Effective for Patients Who Have Previously Undergone Rectal Surgery

PURPOSE: Colostomy creation is an essential procedure for colorectal surgeons, but the preferred method of colostomy varies by surgeon. We compared the outcomes of trephine colostomy creation with open those for the (laparotomy) and laparoscopic methods and evaluated appropriate indications for a trephine colostomy and the advantages of the technique. METHODS: We retrospectively evaluated 263 patients who had undergone colostomy creation by trephine, open and laparoscopic approaches between April 2006 and March 2016. We compared the clinical features and the operative and postoperative outcomes according to the approach used for stoma creation. RESULTS: One hundred sixty-three patients (62%) underwent colostomy surgery for obstructive causes and 100 (38%) for fistulous problems. The mean operative time was significantly shorter with the trephine approach (trephine, 46.0 ± 1.9 minutes; open, 78.7 ± 3.9 minutes; laparoscopic, 63.5 ± 5.0 minutes; P < 0.001), as was the time to flatus (1.8 ± 0.1 days, 2.1 ± 0.1 days, 2.2 ± 0.3 days, P = 0.025). Postoperative complications (<30 days) were not different among the 3 approaches (trephine, 4.3%; open, 1.2%; laparoscopic, 0%; P = 0.828). In patients who underwent rectal surgery, a trephine colostomy was feasible for a diversion colostomy (P < 0.001). CONCLUSION: The trephine colostomy is safe and can be implemented quickly in various situations, and compared to other colostomy procedures, the patient's recovery is faster. Previous laparotomy history was not a contraindication for a trephine colostomy, and a trephine transverse colostomy is feasible for patients who have undergone previous rectal surgery.