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Abstract Fluorescence-guided surgery has emerged as an innovative technique with promising applications in the treatment of various tumors, including colon cancer. Tumor-initiating probe yellow (TiY) has been discovered for identifying tumorigenic cells by unbiased phenotypic screening with thousands of diversity-oriented fluorescence library (DOFL) compounds in a patient-derived lung cancer cell model. This study demonstrated the clinical feasibility of TiY for tumor-specific fluorescence imaging in the tissues of patients with colorectal cancer (CRC). To evaluate the efficacy of TiY in tumor imaging, surgical specimens were obtained, consisting of 36 tissues from 18 patients with CRC, for ex vivo molecular fluorescence imaging, histology, and immunohistochemistry. Orthotopic and chemically induced CRC mice models were administered TiY topically, and distinct tumor lesions were observed in 10 min by real-time fluorescence colonoscopy and ex vivo imaging. In a hepatic metastasis mouse model using splenic injection, TiY accumulation was detected in metastatic liver lesions through fluorescence imaging. Correlation analysis between TiY intensity and protein expression, assessed via immunohistochemistry and Western blotting, revealed a positive correlation between TiY and vimentin and Zeb1, which are known as epithelial–mesenchymal transition (EMT) markers of cancers. A comparative analysis of TiY with other FDA-approved fluorescence probes such as ICG revealed greater quantitative differences in TiY fluorescence intensity between tumor and normal tissues than those observed with ICG. Altogether, these results demonstrated that TiY has a strong potential for visualizing CRC by fluorescence imaging in various preclinical models, which can be further translated for clinical use such as fluorescence-guided surgery. Furthermore, our data indicate that TiY is preferentially uptaken by cells with EMT induction and progression, and overexpressing vimentin and Zeb1 in patients with CRC.

Purpose Although partial mesorectal excision (PME) and total mesorectal excision (TME) is primarily indicated for the upper and lower rectal cancer, respectively, few studies have evaluated whether PME or TME is more optimal for middle rectal cancer. Methods This study included 671 patients with middle and upper rectal cancer who underwent robot-assisted PME or TME. The 2 groups were optimized by propensity score matching of sex, age, clinical stage, tumor location, and neoadjuvant treatment. Results Complete mesorectal excision was achieved in 617 of 671 patients (92.0%), without showing a difference between the PME and TME groups. Local recurrence rate (5.3% vs. 4.3%, P>0.999) and systemic recurrence rate (8.5% vs. 16.0%, P=0.181) also did not differ between the 2 groups, in patients with middle and upper rectal cancer. The 5-year disease-free survival (81.4% vs. 74.0%, P=0.537) and overall survival (88.0% vs. 81.1%, P=0.847) also did not differ between the PME and TME groups, confined to middle rectal cancer. Moreover, 5-year recurrence and survival rates were not affected by distal resection margins of 2 cm (P=0.112) to 4 cm (P>0.999), regardless of pathological stages. Postoperative complication rate was higher in the TME than in the PME group (21.4% vs. 14.5%, P=0.027). Incontinence was independently associated with TME (odds ratio [OR], 2.009; 95% confidence interval, 1.015–3.975; P=0.045), along with older age (OR, 4.366, P5 cm from the anal verge.

Abstract Peritoneal metastases (PM) in colorectal cancer (CRC) is associated with a dismal prognosis. Identifying and exploiting new biomarkers, signatures, and molecular targets for personalised interventions in the treatment of PM in CRC is imperative. We conducted transcriptomic profiling using RNA-seq data generated from the primary tissues of 19 CRC patients with PM. Using our dataset established in a previous study, we identified 1422 differentially expressed genes compared to non-metastatic CRC. The profiling demonstrated no differential expression in liver and lung metastatic CRC. We selected 12 genes based on stringent criteria and evaluated their expression patterns in a validation cohort of 32 PM patients and 84 without PM using real-time reverse transcription-polymerase chain reaction. We selected cartilage intermediate layer protein 2 (CILP2) because of high mRNA expression in PM patients in our validation cohort and its association with a poor prognosis in The Cancer Genome Atlas. Kaplan–Meier survival analysis in our validation cohort demonstrated that CRC patients with high CILP2 expression had significantly poor survival outcomes. Knockdown of CILP2 significantly reduced the proliferation, colony-forming ability, invasiveness, and migratory capacity and downregulated the expression of molecules related to epithelial-mesenchymal transition in HCT116 cells. In an in vivo peritoneal dissemination mouse knockdown of CILP2 also inhibited CRC growth. Therefore, CILP2 is a promising biomarker for the prediction and treatment of PM in CRC.

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

Abstract Background Early‐onset colorectal cancer (EOCRC) has been increasing in incidence worldwide but its genomic pathogenesis is mostly undetermined. This study aimed to identify robust EOCRC‐specific gene expression patterns in non‐familial adenomatous polyposis (FAP) and non‐hereditary nonpolyposis colorectal cancer syndrome (HNPCC) EOCRC. Method We first performed gene expression profiling analysis using RNA sequencing of discovery cohort comprised of 49 EOCRC (age 70) specimens. To obtain robust gene expression data from this analysis, we validated differentially expressed genes (DEGs) through TCGA cohort (EOCRC:59 samples, LOCRC:229 samples) and our validation cohort (EOCRC:72 samples, LOCRC:43 samples) using real‐time RT‐PCR. After the validation of DEGs, we validated the selected gene at protein levels using Western blotting. To identify whether genomic methylation regulates the expression of a particular gene, we selected methylation sites using The Cancer Genome Atlas (TCGA) datasets and validated them by pyrosequencing in our validation cohort. Results The EOCRC patients included in this study had significantly more prominent family history of cancer than the LOCRC patients (23 [46.9%] vs. 13 [26%], p = 0.050). Alanyl aminopeptidase (ANPEP) was significantly downregulated in the EOCRC tissues (FC = 1.78, p = 0.0007) and was also commonly downregulated in the TCGA cohort (FC = −1.08, p = 0.0021). Moreover, the ANPEP mRNA and protein expression levels were significantly downregulated in the EOCRC tissues of our validation cohort (p = 0.037 and 0.027). In comparisons of the normal and tumor tissues in public datasets, the ANPEP level was significantly lower in the tumor tissue in the TCGA dataset (p

Abstract The albumin–bilirubin (ALBI) score was created to assess the severity of liver dysfunction and to predict prognosis of hepatocellular carcinoma. Purpose of this study was to investigate the prognostic value of the ALBI score in patients with stage III colon cancer using propensity score matching (PSM) analysis. This study analyzed 510 patients with stage III colon cancer who had surgery between 2014 and 2015. The ALBI score was calculated as follows: (log10 bilirubin (μmol/L) $$\times$$ × 0.66) + (albumin (g/L) $$\times$$ × −0.0852), and the optimal cut-off value was determined using a receiver operating characteristic analysis and the Youden Index. According to the calculated cut-off value, patients were divided into two groups: Group A (ALBI ≤ − 2.54) and Group B (ALBI > − 2.54). The average ALBI score was − 2.68 (from − 3.39 to − 0.69). Group A had a significantly higher 5-year disease-free survival rate (85.5% vs 75.7%, p = 0.02), 5-year cancer-specific survival rate (93.7% vs 84.4%, p = 0.02), and 5-year overall survival rate (90.6% vs 77.4%, p = 0.01) than Group B. High ALBI scores were found to be an independent risk factor for both disease-free survival (HR 1.68, p = 0.048) and cancer-specific survival (HR 2.24, p = 0.028). The preoperative ALBI score was found to be a promising prognostic indicator for predicting recurrence and survival in patients with stage III colon cancer in this study. Because the ALBI score is simple and inexpensive to obtain, it has the potential to be a useful clinical marker for colon cancer patients.

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.

Objective: This study was designed to assess the demographic characteristics of patients with Crohn's perianal fistula (CPF) who were treated at a tertiary referral institution. Surgical outcomes were compared in groups of patients who underwent seton placement, fistulotomy, and stem cell therapy. Methods: Patients who underwent surgery for CPF between 2015 and 2017 at Asan Medical Center, Seoul, Korea, were retrospectively evaluated. Patients were divided into groups who underwent seton placement, fistulotomy, and stem cell therapy. Their clinical variables and closure rates were compared. Results: This study included 156 patients who underwent a total of 209 operations. More than half of the operations consisted of seton placement (67%), followed by stem cell therapy (18%) and fistulotomy (15%) patients. Of the 209 fistulas, 153 (73%) were complex, with an overall closure rate of 38% during a median follow-up of 29 months. Closure rates following fistulotomy, stem cell therapy, and seton placement were 90%, 70%, and 18%. Seton placement was more significantly frequently used than the other procedures in patients with complex fistula and those with abscesses. Of the 79 fistulas that achieved complete closure, 11 (14%) recurred. The recurrence rates did not differ among the various techniques. Conclusion: Surgical treatment of CPF is dependent on lesion type. Seton placement was the primary draining procedure for complex fistulas and abscesses, resulting in low closure rates. Fistulotomy was the definite procedure for low type and simple fistula. Stem cell therapy showed high closure rates as definitive treatment, even for complex fistulas.

Abstract Background Perianal fistula is one of the most common complications in Crohn’s disease, and various medical and surgical treatments are being tried. The aim of this study was to compare the perianal fistula closure rates following treatment with anti-tumor necrosis factor (TNF) agents or autologous adipose tissue-derived stem cell (auto-ASC) transplantation with Crohn’s disease (CD). Methods CD patients who underwent seton placement for perianal fistula from January 2015 to December 2019 at a tertiary referral center were retrospectively reviewed. Patients were divided into two groups, one that received sequential treatments with anti-TNF agents (anti-TNF group) and the other that underwent auto-ASC transplantation (stem cell group). Clinical variables and fistula closure rates were compared in the two groups. Results Of the 69 patients analyzed, 39 were treated with anti-TNF agents and 30 underwent auto-ASC transplantation. Compared with the stem cell group, patients in the anti-TNF group were older (p=0.028), were more frequently male (p=0.019), had fistulas with more penetrating behavior (p=0.002), had undergone surgery more frequently (p=0.010), and had a shorter interval from seton placement to intended treatment (p

Summary: Background: Pseudomyxoma peritonei (PMP) is a rare disease characterized by mucinous ascites and deposits on the peritoneal surfaces. The study aimed to assess PMP patients according to the Peritoneal Surface Oncology Group International (PSOGI) classification, as a part of standardization of this rare disease. Methods: This retrospective study analyzed PMP patients who underwent surgery between January 2007 and December 2017. All histologic slides were re-evaluated and the clinical data were collected. According to the PSOGI, PMP was retrospectively classified into three categories: low-grade (LG-PMP), high-grade (HG-PMP), and signet-ring cells (SRC-PMP). The extent of peritoneal involvement was quantified by the peritoneal cancer index (PCI). The completeness of cytoreduction (CCR) was dichotomized as complete or incomplete. Results: Fifty-seven patients were included in this study, consisted of 39 patients with LG-PMP (74.0%), 14 with HG-PMP (20.8%), and 4 with SRC-PMP (5.2%). There was no operative mortality and major complications occurred in 24 patients (31.2%). The 5-year overall survival was 56.2% ± 8.1% for LG-PMP, 37.5% ± 12.1% for HG-PMP, and 25.0% ± 21.7% for SRC-PMP. Concerning CCR, the 5-year overall (complete: 59.5% ± 8.4% vs. incomplete: 12.7% ± 8.1%, p = 0.001) and disease-free survival (complete: 38.6% ± 8.9% vs. incomplete: 7.7% ± 6.8%, p = 0.001) were significantly different. In a multivariable analysis, PSOGI classification and CCR independently correlated with survival (p = 0.011 and 0.018, respectively). Conclusions: The PSOGI classification provides prognostic stratification, hopefully requiring further validation including every single case of PMP established as a standard criteria.

Purpose Carcinoma arising from Crohn disease (CD) is rare, and there is no clear guidance on how to properly screen for at-risk patients and choose appropriate care. This study aimed to evaluate the clinicopathological characteristics, treatment, and oncologic outcomes of CD patients diagnosed with colorectal cancer (CRC). Methods Using medical records, we retrospectively enrolled a single-center cohort of 823 patients who underwent abdominal surgery for CD between January 2006 and December 2015. CD-associated CRC patients included those with adenocarcinoma, lymphoma, or neuroendocrine tumors of the colon and rectum. Results Nineteen patients (2.3%) underwent abdominal surgery to treat CD-associated CRC. The mean duration of CD in the CD-associated CRC group was significantly longer than that in the benign CD group (124.7±77.7 months vs. 68.9±60.2 months, P = 0.006). The CD-associated CRC group included a higher proportion of patients with a history of perianal disease (73.7% vs. 50.2%, P = 0.035) and colonic location (47.4% vs. 6.5%, P = 0.001). Among 19 CD-associated CRC patients, 17 (89.5%) were diagnosed with adenocarcinoma, and of the 17 cases, 15 (88.2%) were rectal adenocarcinoma. On multivariable analyses for developing CRC, only colonic location was a risk factor (relative risk, 7.735; 95% confidence interval, 2.862–20.903; P = 0.001). Conclusion Colorectal malignancy is rare among CD patients, even among patients who undergo abdominal surgery. Rectal adenocarcinoma accounted for most of the CRC, and colonic location was a risk factor for developing CRC.

Abstract We aimed to evaluate the clinical feasibility of a new visual grading system. We included 50 patients who underwent resection of primary colorectal cancer. Before anastomosis, the marginal vessel was cut and the perfusion status was assessed by a visual grading system. The visual grading system is comprised of five grades according to the bleeding from the marginal vessel and is categorized into 4 groups: good (grade A and B), moderate (grade C), poor (grade D) and none (grade E). Colorectal anastomosis was performed only in the good and moderate groups. We compared postoperative outcomes between the good and moderate groups and analysed the factors affecting the perfusion grade. Among the patients, 48% were grade A, 12% were grade B, and 40% were grade C. There was no anastomotic leakage. Only one patient with grade C showed ischemic colitis and needed reoperation. Age was the only factor correlated with perfusion grade in multivariate analysis (OR 1.080, 95% CI 1.006–1.159, p = 0.034). The perfusion grades were significantly different between > 65 and 65, A 29.2% B 12.5% C 58.3% vs.

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.

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.

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.

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.

Summary: Objective: We aimed to evaluate oncological outcomes after repeat metastasectomies in patients having undergone previous resections for colorectal cancer metastases. Methods: We examined 248 patients who underwent metastasectomies for lung and/or liver metastases at our center during a 7-year period, from January 2005 to December 2011. Recurrence-free survival 1 (RFS1) after the metastasectomy for the initial recurrence, recurrence-free survival 2 (RFS2) after the second, and recurrence-free survival 3 (RFS3) after the third repeated resections for recurrence were assessed. The overall survival (OS) rate after the first metastasectomy for the first recurrence (OS) was also assessed. Results: Sites of recurrence of the first metastasectomy were the liver, lung, and liver and lung in 115, 117, and 16 cases, respectively, and 133 patients had a second recurrence (133/248, 53.6%). Twenty-seven patients had a third recurrence (27/52, 51.9%), of whom 14 underwent a third metastasectomy. The 5-year and 10-year OS rates were 74.8% and 57.9%, respectively. The 1-year RFS1, RFS2, and RFS3 rates were 76%, 75%, and 39%, respectively. The hazard ratios for RFS were 1.142 and 2.590 for the first and second repeat surgeries, when compared to the first metastasectomy. The third metastasectomy showed significantly lower RFS than did the second metastasectomy. Conclusion: A second metastasectomy should be considered the optimal treatment for a second recurrence. However, careful considerations should be made before performing a third metastasectomy. Keywords: Colorectal cancer, Metastasectomy, Oncologic outcome, Repeated resection

Few radiation-induced bowel perforations have been reported to date. Furthermore, perforation after ileal restoration in asymptomatic patients is rare. We report the case of a 61-year-old man who was administered preoperative chemoradiotherapy for advanced rectal cancer. The patient underwent ultra-low anterior resection with ileal diversion, followed by ileal restoration. Perforation was detected 9 days after restoration, and he underwent a right hemicolectomy. The histologic evaluation indicated ileal perforation caused by acute radiation enteritis.

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.

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.

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.

Abstract Background Preoperative chemoradiotherapy (pre-CRT) followed by total mesorectal excision (TME) is currently a standard therapy for locally advanced mid-to-low rectal cancer. Less aggressive, organ-preserving option such as local excision (LE) or watchful wait can alternatively be used for patients who respond well to pre-CRT. High-resolution rectal magnetic resonance imaging (MRI) is one of the most useful methods to assess pre-CRT response, and the MERCURY group has shown that the MR tumor regression grade (mrTRG) correlated with the pathologic TRG. The aim of this study is to compare postoperative complication and oncologic outcomes between LE and TME in mid-to-low rectal cancer patients whose tumors are mrTRG grade 1 (radiological complete remission) or 2 (predominant fibrosis; near-complete remission) after pre-CRT. Methods A prospective, double-arm, randomized, open-labeled, single center, clinical trial will be conducted in patients with mid-to-low rectal cancer whose tumors are mrTRG 1/2 after pre-CRT at the Asan Medical Center, Seoul, Korea, after approval from the Institution Review Board. Patient medical records will be de-identified using a serial number to protect personal information. Inclusion criteria will include rectal adenocarcinoma with an inferior border 20, and provision of informed consent. Postoperative complications will be assessed by Clavien-Dindo Classification Grade. Oncologic and functional outcomes will be collected and risk factors related to these outcomes will be investigated. Discussion We believed that the rate of postoperative complication of LE will be comparable to that of TME in mid-to-low advanced rectal cancer patients with a favorable response after pre-CRT. Trial registration KCT0002579 (https://cris.nih.go.kr) Dec-2017.

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.

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.

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 (

Purpose Colorectal cancer (CRC) is generally considered a disease of old age. Most CRCs are diagnosed at age 50 and over. CRC rarely occurs in teenagers, and the clinical features and prognosis of CRC are not clear in this population. The aim of this study was to uncover the clinicopathologic characteristics of teenage sporadic CRC. Methods Of the 21,042 patients who underwent operation for primary CRC at Asan Medical Center between July 1989 and December 2014, 19 cases (0.09%) without a familial history of CRC before 20 years of age at diagnosis were enrolled in this study. The clinicopathologic features of the teenage sporadic CRC patients were retrospectively reviewed. Results Of the 19 patients, 16 patients (84.2%) were male. The most common primary site was the left colon (descending colon & sigmoid colon) in nine patients. With respect to histologic type, adenocarcinoma represented 57.8% of cases, mucinous adenocarcinoma, 31.5%, and signet ring cell carcinoma, 10.5%. Six (31.5%) patients showed peritoneal seeding at presentation. In survival analysis, the 5-year overall survival rate of the patients who underwent curative surgery was 71.3%. Conclusion Teenage sporadic CRC is a very rare disease and the proportion of patients with a poor histologic subtype is high, but early detection and radical treatment can lead to favorable survival rates.

Abstract We aimed to assess utility weight of health states associated with colorectal cancer (CRC) that reflect the societal preference of the Korean population and to estimate the quality-adjusted life year (QALY) loss with CRC. We recruited 607 individuals from the Korean population; they were surveyed via face-to-face computer-assisted interviews. The participants evaluated each CRC-associated health state using standard gamble. Utility weight for each health state was calculated as the possibility of full health restoration. Moreover, we estimated total QALY loss due to CRC in Korean individuals aged ≥30 years in 2013. To calculate QALY due to morbidity, we yielded utility weights and used epidemiologic data of CRC on severity from the National Cancer Control Institute. QALY loss due to mortality was calculated using mortality of CRC and life expectancy data from the Korean Statistical Information Service. The highest and lowest utility weights were assigned to “adenomatous polyps” and “metastatic colon cancer”, respectively. Total QALY loss due to CRC in Korea was 173,662; these patients were more likely to be men or be included in the 70–74-year age group. These utility weights may be useful for conducting cost-utility studies of cancer screening for CRC and for measuring disease burden with QALY.

Purpose We compared oncologic outcomes between surgery and radiofrequency ablation (RFA) in patients with metachronous isolated hepatic metastases from colorectal cancer. Methods We retrospectively analyzed 123 patients treated with hepatic resection and 82 patients treated with RFA for metachronous hepatic metastases between April 2000 and October 2011. Re-recurrence pattern and 3-year re-recurrence free survival (RFS) rate compared between groups. Factors associated with RFS were evaluated. Results The patients in the two groups were similar in age, gender, location of primary tumor, disease-free interval to hepatic metastasis, pathological stage of primary disease, number of metastatic lesions. The mean diameter of the biggest hepatic metastatic lesion was significantly larger in the resection group than in the RFA group. The RFS rate after hepatic metastasis treatment was significantly higher in the resection group than in the RFA group (48.6% vs. 33.7%, respectively; P=0.015). Marginal recurrence at the RFA site was observed in 14 of the 82 patients (17.1%). The size and number of metastatic lesions, stage of primary disease, disease-free interval to hepatic metastasis, and modality of treatment were confirmed as re-recurrence-associated factors after hepatic metastasis treatment. Among patients with solitary metastases of ≤3 cm, the RFS rate was not different between the resection and RFA groups (52.4% vs. 53.4%, respectively; P=0.491). Conclusion Surgical resection for metachronous hepatic metastases achieved higher RFS and lower local recurrence rates. However, the RFS rate in patients with a solitary hepatic metastasis of ≤3 cm was similar between the resection and RFA groups.

Background and Aim. Ultralow anterior resection (uLAR) is a sphincter-saving procedure for very low-lying rectal cancers. This procedure, however, has complications related to defecation which can aggravate the patient’s quality of life postoperatively. In this study, we compared the anthropometric and nutritional parameters after uLAR and abdominoperineal resection (APR). Methods. We retrospectively reviewed the data of patients who underwent either uLAR or APR in 2012 for rectal cancers within 3 cm from the anal verge. Data including body weight, body mass index (BMI), levels of total protein, albumin, and hemoglobin and lymphocyte count were analyzed. We compared the changes of these parameters before operations to 3 years after discharge between uLAR and APR groups by ANOVA for repeated measures and Bonferroni comparison method. Results. After 3 years of discharge, the body weight and BMI of the APR group were fully recovered to the preoperative levels; however, those of the uLAR group did not. The hemoglobin level in the APR group was recovered to the preoperative level within 3 months of discharge; however, that in the uLAR group was recovered after 1 year of discharge. Conclusions. Recovery of anthropometric and nutritional status of patients was more stable after APR than after uLAR. These findings might indirectly reflect the low anterior syndrome effect of uLAR and help colorectal surgeons in selecting better surgical methods and in better counseling patients with very low-lying rectal cancer.

The present study aimed to identify molecules associated with lymphovascular invasion (LVI) and perineural invasion (PNI) and to examine their biological behavior in colorectal cancer (CRC). LVI- and PNI-associated molecules were identified and verified using sequential processes including (1) identification of 117 recurrence-associated genes differentially expressed on RNA-seq analysis using primary cancer tissues from 130 CRC patients with and without systemic recurrence; (2) analysis of molecules associated with LVI and PNI; (3) assessment of biological properties by measuring proliferation, anoikis, invasion/migration, epithelial-mesenchymal transition and autophagy flux; and (4) verification of disease-free survival using public datasets. Gelsolin (GSN) and 2'-5'-oligoadenylate synthetase 2 (OAS2) were associated with PNI and LVI, respectively. Invasion potential was >2-fold greater in GSN-overexpressing LoVo cells than in control cells (p

Purpose: Preoperative chemoradiotherapy (PCRT) has been widely adopted. However, benefit of PCRT for patients with clinically T3N0 (cT3N0) rectal cancer is doubtful. We analyzed oncologic outcome in patients with magnetic resonance image (MRI) staged cT3N0 rectal cancer according to receipt of PCRT. Methods: Between January 2006 and December 2010, one hundred twenty four patients were MRI-based T3N0 rectal cancer. In patients who received PCRT the median dose of given radiotherapy was 5,040 Gy, and either 5-fluorouracil/leucovorin, capecitabine or S-1/oxaliplatin was delivered. The 3-year disease free survival rate (DFS) and sphincter preservation were compared. Results: Sixty four patients received and sixty patients did not receive PCRT. Rate of complete remission was obtained in 17.2% of PCRT group. Sphincter-preserving surgery was performed in 79.7% of PCRT group and 88.3% of non-PCRT group (P=0.194). In patients with low-lying rectal cancer, sphincter-preservation was also not different; PCRT 70.5% and non-PCRT 66.7% (P=0.761). Overall recurrence occurred in 21.9% in PCRT group and 15.0% in non-PCRT group (P=0.327). Three-year DFS was comparable between PCRT (76.5%) and non-PCRT group (79.7%) (P=0.330). Conclusion: Preoperative chemoradiotherapy in MRI-based cT3N0 rectal cancer had no benefit on sphincter preservation and did not improve DFS. Therefore, the routine use of PCRT in cT3N0 rectal cancer should not be warranted.