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Purpose The Korean Hereditary Tumor Registry, the first and one of the largest registries of hereditary tumors in Korea, has registered about 500 families with hereditary cancer syndromes. This study evaluates the temporal changes in clinicopathologic features and surgical patterns of Lynch syndrome (LS) patients. Materials and methods Data on 182 unrelated LS patients were collected retrospectively. The patients were divided into the period 1 group (registered in 1990-2004) and 2 (registered in 2005-2014). The clinical characteristics of the two groups were compared to identify changes over time. Results The period 1 group included 76 patients; the period 2 group, 106 patients. The mean ages at diagnosis were 45.1 years (range, 13 to 85 years) for group 1 and 49.7 years (range, 20 to 84 years) for group 2 (p=0.015). The TNM stage at diagnosis did not differ significantly-period 1 group: stage 0-I (n=18, 23.7%), II (n=37, 48.7%), III (n=19, 25.0%), and IV (n=2, 2.6%); period 2 group: stage 0-I (n=30, 28.3%), II (n=35, 33.0%), III (n=37, 34.9%), and IV (n=4, 3.8%). Extended resection was more frequently performed (55/76, 72.4%) in the period 1 group than period 2 (49/106, 46.2%) (p=0.001). Conclusion Colorectal cancer in patients with LS registered at the Korean Hereditary Tumor Registry is still diagnosed at an advanced stage, more than two decades after registry's establishment. Segmental resection was more frequently performed in the past decade. A prompt nationwide effort to raise public awareness of hereditary colorectal cancer and to support hereditary cancer registries is required in Korea.

Recently, media as well as academic societies have referred to GLOBOCAN 2012 to support the high incidence rate of colorectal cancer in Korea. According to GLOBOCAN 2012, colorectal cancer incidence ranked third for men and fifth for women, and the highest when both sexes were combined among 184 countries (Table 1) [1]. Because GLOBOCAN intended to provide the most recent estimates of cancer incidence, mortality, and prevalence for 28 cancers worldwide, the quality of country estimates varied from high quality national or regional data to no data [1]. Therefore, the accuracy of estimates are dependent on the availability and the accuracy of the data from each country [1]. Korean data is high quality national data with rates projected to 2012. The most recent incidence data used for GLOBOCAN estimates was for the year 2009 [2]. Indeed, the age-standardized incidence of colorectal cancer increased by 5.3% annually between 1999 and 2012 [3]. However, according to the Korea Central Cancer Registry data, the colorectal cancer incidence decreased for men and stabilized for women in 2012 [3]. Since projection used for GLOBOCAN 2012 applied trends until 2009, which was an annual percent change of 6.2% for both sexes [4], the GLOBOCAN estimates overestimated the incidence for the Korean population. Table 1. Estimated incidence of colorectal cancer, GLOBOCAN 2012 [1] We retrieved published incidence data of selected countries from 2008 to 2012 (or nearest year to 2012) (Table 2). In comparison of age-standardized incidence rates, Czech (2011), Slovakia (2008), and Slovenia (2011) showed higher incidence than Korea (2011 or 2012) in men. In women, most countries with recent data showed higher incidence compared to Korea. When both sexes were combined, incidence of Japan (2010), Netherlands (2012), Australia (2012), and New Zealand (2012) was higher than that of Korea. Table 2. Observed age-standardized incidence ratesa) of colorectal cancer from selected cancer registries In conclusion, the aim of GLOBOCAN 2012 is to provide worldwide estimates for cancer burden, and there are substantial differences between GLOBOCAN estimates and observed statistics due to methodology applied. Korea has experienced rapid transition in colorectal cancer epidemiology, therefore predicted estimates using past trends may not appropriately reflect the observed statistics. Although GLOBOCAN is useful for overviewing cancer burden, caution should be used in direct comparison or referring of the estimated incidence or mortality.

Purpose Lynch syndrome, the commonest hereditary colorectal cancer syndrome, is caused by germline mutations in mismatch repair (MMR) genes. Three recently developed prediction models for MMR gene mutations based on family history and clinical features (MMRPredict, PREMM(1,2,6), and MMRPro) have been validated only in Western countries. In this study, we propose validating these prediction models in the Korean population. Materials and methods We collected MMR gene analysis data from 188 individuals in the Korean Hereditary Tumor Registry. The probability of gene mutation was calculated using three prediction models, and the overall diagnostic value of each model compared using receiver operator characteristic (ROC) curves and area under the ROC curve (AUC). Quantitative test characteristics were calculated at sensitivities of 90%, 95%, and 98%. Results Of the individuals analyzed, 101 satisfied Amsterdam criteria II, and 87 were suspected hereditary nonpolyposis colorectal cancer. MMR mutations were identified in 62 of the 188 subjects (33.0%). All three prediction models showed a poor predictive value of AUC (MMRPredict, 0.683; PREMM(1,2,6), 0.709; MMRPro, 0.590). Within the range of acceptable sensitivity (> 90%), PREMM(1,2,6) demonstrated higher specificity than the other models. Conclusion In the Korean population, overall predictive values of the three models (MMRPredict, PREMM(1,2,6), MMRPro) for MMR gene mutations are poor, compared with their performance in Western populations. A new prediction model is therefore required for the Korean population to detect MMR mutation carriers, reflecting ethnic differences in genotype-phenotype associations.

Background There has been no comparative study of the long-term oncological outcomes of appendiceal cancer and colon cancer. We hypothesized that the oncological outcome is worse in appendiceal cancer because perforation is more frequent than in colon cancer. Methods Patients with stage I–III were selected from 5046 patients with appendiceal or colon cancer, between September 2001 and June 2010. The 5-year disease-free survival (DFS) was the primary endpoint. Multivariate analyses with Cox proportional hazards model for DFS and logistic regression model for perforation were conducted. A matching model was used to compensate for the heterogeneity between groups. Results The perforation rate was 44.7% in appendiceal cancer (n = 47), but 1.1% in colon cancer (n = 2828) ( p = 0.001). The 5-year DFS rate was lower in appendiceal cancer than in colon cancer (57.9% vs . 85.2%, p = 0.001; matching model, 54.2% vs . 78.4%, p = 0.038), with a higher rate of peritoneal seeding (25.5% vs . 2.5%, p = 0.001; matching model, 24.0% vs . 4.0%, p = 0.007). Multivariate Cox regression showed that appendiceal cancer was an independent prognostic factor for poor DFS (hazard ratio = 2.602, 95% confidence interval = 1.26–5.35, p = 0.009), and logistic regression confirmed that appendiceal cancer was the risk factor associated with perforation (odds ratio = 66.265, 95% confidence interval = 28.21–155.61, p = 0.001). Conclusions This study suggested that the long-term oncological outcomes are worse for appendiceal cancer than for colon cancer, attributed to higher perforation rate in appendiceal cancer.

The number of operations on elderly colorectal cancer (CRC) patients has increased with the aging of the population. The aim of this study was to evaluate surgical outcomes in elderly patients who underwent laparoscopic or open surgery for CRC. We analyzed the data of 280 patients aged 80 or over who underwent surgery for CRC between January 2001 and December 2010. Seventy‐one pairs were selected after propensity score matching for laparoscopic or open surgery. Operative time, return to normal bowel function, length of hospital stay, postoperative complications, overall survival (OS), recurrence‐free survival (RFS), and prognostic factors affecting survival were investigated. In matched cohorts, operative time in the laparoscopic group was longer than in the open group (P

The seismic performance evaluation of a 49-story residential building under construction in Seoul, Korea is the subject of this paper. The building for this case study has an irregular plan and a deep basement shared with adjacent buildings. A series of nonlinear time history analyses were carried out for the Maximum Considered Earthquake (MCE) and Rare Earthquake (RE). Effects of modeling methods of the basement were studied. Modeling of the surrounding underground structure included transfer of torsional modes, which can easily be amplified by high frequency components of ground motions and result in localized damage at the upper part of building. Based on the analysis presented, the basement model with surrounding underground structures and non soil-structure interaction is recommended for a conservative design.

After curative resection of stage II colon cancer, adjuvant chemotherapy with 5-fluorouracil/leucovorin (FL) or capecitabine is selectively recommended. However, there is little evidence of the effect of capecitabine on oncologic outcome in geriatric patients with stage II colon cancer compared to that of FL. The aim of this study was to determine the difference in recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) in patients older than 70 years of age with stage II colon cancer receiving capecitabine and FL. Patients over 70 years of age diagnosed with primary pathologic stage II colon cancer at the Seoul National University Hospital from January 2005 to December 2015 were included. A prospectively collected database was analyzed retrospectively. Patients were separated into an FL group and a capecitabine group. The primary outcomes were RFS, CSS, and OS. Of the 154 included patients, 96 patients received FL and 58 patients received capecitabine. There was no difference between the two groups in RFS, CSS, or OS (p = 0.763, p = 0.221, and p = 0.470, respectively) as measured by Kaplan–Meier analysis with log-rank test. Administration of capecitabine as compared to FL was not a factor affecting RFS (hazard ratio [HR] 0.503, 95% confidence interval [CI] 0.145–1.745), CSS (HR 1.519, 95% CI 0.348–6.629), or OS (HR 0.941, 95% CI 0.290–3.053) on multivariable analysis. Capecitabine is a safe regimen in terms of oncologic outcomes compared with FL in older patients with stage II colon cancer.

Table S1. Mutation rate of 40 genes included in the study. Table S2. Mutation rate of critical pathways according to histology. Table S3. Survival after recurrence according to each gene mutation. (Genes with mutation rate over 5%). Table S4. Detailed profile of TGF-β pathway mutation. (DOCX 60 kb)

Background Perforated colon cancer is a rare complication, but has a high risk of recurrence. However, most studies have not distinguished sealed-off perforation from free perforation, and the prognosis is unclear. The aim of this study was to evaluate the oncologic outcome of colon cancer with sealed-off perforation. Methods Eighty-six consecutive patients who underwent resection for colon cancer with sealed-off or free perforation were included. We defined sealed-off perforation as a colon perforation with localized abscess identified on operative, computed tomography, or pathologic findings, with no evidence of free perforation, including fecal contamination and dirty fluid collection in the peritoneal cavity. Oncologic outcomes were compared between patients with colon cancer with sealed-off perforation and free perforation using a log-rank test and Cox regression analysis. Results The sealed-off perforation group included 62 patients, and 24 patients were in the free perforation group. TNM stage and lymphatic, venous, and perineural invasion were similar between the groups. The median follow-up period was 28.9 months (range 0–159). The sealed-off perforation group had better prognosis compared with the free perforation group in terms of progression-free survival (PFS) and overall survival (OS), although there were no statistically significant differences in PFS (5-year PFS 53.7% vs. 40.5%, p = 0.148; 5-year OS 53.6% vs. 22.9%, p = 0.001). However, in multivariable analysis using the Cox progression test, sealed-off perforation did not show a significant effect on cancer progression (p = 0.138) and OS (p = 0.727). Conclusions Colon cancer with sealed-off perforation showed no difference in prognosis compared with free perforation. Electronic supplementary material The online version of this article (10.1186/s12957-018-1530-3) contains supplementary material, which is available to authorized users.

The present study aimed to compare the surgical and oncological outcomes between young and older women with colorectal cancer (CRC).This retrospective study included 1815 women with CRC between 2010 and 2014. Participants were divided into a young group (under the age of 65 years) and an old group (65 years and older). The surgical and oncological outcomes were compared between the two groups using univariate and multivariate analyses.Around 45.1% (N = 819) patients were the older group. The old group had a higher comorbidity rate and a lower proportion of receiving postoperative chemotherapy. The old group also had a significantly higher blood loss (190 ± 611 mL vs. 145 ± 200 mL, p = 0.027) and a higher rate of intraoperative transfusion (5.4% vs. 3.0%, p = 0.011). They were found to develop more complications after surgery (11.7% vs. 7.8%, p = 0.015). The overall survival (OS) of the old group was lower than that of the young group (5-year OS rates: 72.8% vs. 83.8%, p 0.001; adjusted hazard ratio: 1.86, 95% confidence interval: 1.49-2.33). However, the cancer-specific survival (CSS) was not significantly different between the old and young groups (5-year CSS rates: 84.7% vs. 84.9%, p = 0.076).Older women with CRC had poorer OS than young women with CRC, but had similar CSS. Therefore, the management of comorbidities along with cancer treatment may be important in older women with CRC.

PURPOSE Stage-IIIC colon cancer is an advanced disease; however, its oncologic outcomes and prognostic factors remain unclear. In this study, we aimed to determine the predictors of disease-free survival (DFS) in patients with stage-IIIC colon cancer. METHODS From a multicenter database, we retrospectively enrolled 611 patients (355 men and 256 women) who had undergone a potentially curative resection for a stage-IIIC colon adenocarcinoma between 2003 and 2011. The primary end-point was the 5-year DFS. RESULTS The median age was 62 years; 213 and 398 patients had right-sided colon cancer (RCC) and left-sided colon cancer (LCC), respectively. The 5-year DFS in all patients was 52.0%; median follow-up time was 35 months (range, 1-134 months). A multivariate Cox regression revealed that female sex (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.19-1.90; P < 0.01), right-sided tumor location (HR, 1.65; 95% CI, 1.29-2.11; P < 0.01), lymphatic invasion (HR, 1.52; 95% CI, 1.08-2.15; P < 0.01) and a high (≥0.4) metastatic lymph node ratio (HR, 3.72; 95% CI, 2.63-5.24; P < 0.01) were independent predictors of worse 5-year DFS. Female patients with RCC were 1.79 fold more likely to experience recurrence than male patients with LCC. CONCLUSION Female sex and right-sided tumor location are associated with higher tumor recurrence rates in patients with stage-IIIC colon cancers. Aggressive treatment and close surveillance should be planned for patients in these groups.

It is important to take into account potential prognostic factors to select patients with brain metastasis from colorectal cancer (CRC) who will benefit from active neurosurgical treatment. Therefore, we experimentally investigated our single institutional data to develop a novel CRC-specific graded prognostic assessment (GPA) and to help clinicians determine the optimal management. We retrospectively reviewed the records of 107 patients with brain metastases from CRC who received any kind of treatment in our hospital and had sufficient clinical information. The median overall survival was 5.2 months, and the 1- and 2-year overall survival rates were 23.7 and 6.6%, respectively. Multivariate analysis revealed that the number of brain metastases ≥ 6, presence of neurologic symptoms, and elevated serum carcinoembryonic antigen (≥ 30 ng/ml) were the independent prognostic factors for poor overall survival, while performance status was not. Based on this, we developed the CRC-specific GPA index and stratified patients into three categories. The median overall survival for patients with GPA scores of 0–0.5, 1.0–1.5, and 2.0–2.5 was 2.3, 4.3, and 12.7 months, respectively (p

A laparoscopic approach can be attempted for pathologic T4 (pT4) colon cancer. Our aim was to evaluate the clinico-oncologic outcomes following laparoscopic versus open surgery for right and left-sided pT4 colon cancer. From a multicentric collaborative database, we enrolled 245 patients with right-sided colon cancer (RCC, 128 laparoscopy and 117 open) and 338 with left-sided colon cancer (LCC, 176 laparoscopy and 162 open). All patients underwent intended curative surgery for histologically proven T4 adenocarcinoma, between 2004 and 2013. The primary end-point of our analysis was the oncologic outcome, including the 5-year disease-free survival (5 year-DFS) and the 5-year overall survival (5 year-OS). The secondary end-points included the R0 resection rate and postoperative complications. Our study group included 224 T4N0 and 359 T4N+ tumors. The median follow-up was 53 months. For patients with RCC, the rate of postoperative morbidities was lower for the laparoscopy than that for the open surgery group (12.5 vs. 22.2%, p = 0.044). There was no difference in the R0 resection rate (94.5 vs. 96.6%, p = 0.425) between the groups. The 5 year-DFS and 5 year-OS rates were lower for the laparoscopy than that in the open group (48.9% vs. 59.2%, p = 0.093; 60.0% vs. 70.0%, p = 0.284, respectively), but this difference was not statistically significant. Among patients with LCC, there were no differences in the rate of postoperative complication and R0 resection (15.3 vs. 21.0%, p = 0.307; 96.0 vs. 95.7%, p = 0.875, respectively). Both groups had comparable 5 year-DFS and 5 year-OS rates (62.7% vs. 61.1%, p = 0.552; 72.0% vs. 71.8%, p = 0.611, respectively). Laparoscopic surgery appears to be a safe procedure for patients with pT4 LCC, but requires careful consideration for patients with pT4 RCC.

There is a close link between Fusobacterium nucleatum and colorectal cancer (CRC) tumorigenesis and chemoresistance. However, the genetic characteristics and clinical significance of CRC related with F. nucleatum remains unclear. This study evaluated the relationship between F. nucleatum, pathway mutation, and patient prognosis. Fusobacterium nucleatum amount in the tumor tissue and adjacent normal tissue were measured by quantitative polymerase chain reaction in adjuvant (N = 128) and metastatic (N = 118) cohorts. Patients were divided into binary (F. nucleatum-high and F. nucleatum-low) according to F. nucleatum amount. Targeted next-generation sequencing of 40 genes included in the 5 critical pathways (WNT, P53, RTK-RAS, PI3 K, and TGF-β) was performed in the adjuvant cohort. Patients with MSI-H and CIMP-H had higher amount of F. nucleatum in tumor tissue. Fusobacterium nucleatum-high patients had higher rates of transition mutation and C to T (G to A) nucleotide change regardless of MSI status. In addition, mutation rate of AMER1 and ATM genes, and TGF-β pathway was higher in F. nucleatum-high patients. Fusobacterium nucleatum-high was associated with poor overall survival (OS) in the palliative cohort (26.4 vs. 30.7 months, p = 0.042). Multivariate analysis revealed F. nucleatum-high as an independent negative prognostic factor for OS [adjusted hazard ratio of 1.69 (95% confidence interval 1.04–2.75), p = 0.034]. However, F. nucleatum amount was not associated with recurrence in the adjuvant cohort. F. nucleatum-high was associated with poor survival in metastatic CRC. In addition, we identified mutational characteristics of colorectal cancer according to F. nucleatum amount.

Transanal total mesorectal excision (taTME) is expected to provide benefits in the removal of the complete mesorectum for low rectal lesions, and several clinical studies regarding this technique have been reported. However, a transanal platform has not yet been standardized, and diverse transanal endoluminal surgery access devices have been used, based on individual surgeon preferences. In the present study, we performed laparoscopy-assisted taTME in cadavers and compared the characteristics of four different platforms.Between January 2013 and April 2015, laparoscopy-assisted taTME was performed on six fresh cadavers. Flexible [SILS™ Port (Covidien), GelPOINT(®) Path Transanal Access Platform (Applied Medical)] and rigid [TEO(®) (Karl Storz Endoskope), TEM (Richard Wolf)] transanal access platforms were used on three cadavers each.All cadavers were male, with a mean age of 69.2 (range 57-86) years. The mean operation time was 146.3 (range 140-155) min with flexible platforms and 206.7 (range 150-260) min with rigid platforms. The mean specimen length was 23 (range 18-26) cm. Complete or nearly complete mesorectal specimens were obtained in all cases, except for one case using the TEM platform. Flexible platforms (SILS and GelPOINT) provided a short set-up time, relatively atraumatic retraction, and easy application of familiar laparoscopic instruments; a narrow operative field was its limitation. The rigid platforms (TEO and TEM) enabled larger and more stable operative fields and space than did the SILS platform, but they were limited by a narrow view, prolonged set-up time, rigidity, and long channels relative to the short distance from the anus to the rectal closure site.In this preliminary study, laparoscopy-assisted taTME was a feasible and safe procedure using both rigid and soft platforms, despite some limitations of each platform.

Objective The objective of this study was to evaluate the psychometric properties of the Smart Management Strategy for Health Assessment Tool (SAT), which we developed to enable cancer patients to assess their self-management (SM) strategies of health by themselves. Patients and methods The development of the questionnaire included four phases: item generation, construction, pilot testing, and field testing. To assess the instrument's sensitivity and validity, we recruited 300 cancer patients from three Korean hospitals who were 18 or more years old and accustomed to using the Internet or email. Using the appropriate and priority criteria for pilot and field testing, we tightened the content and constructed the first version of the SAT. Results We developed the core strategies with 28 items, preparation strategies with 30 items, and implementation strategies with 33 items. Factor analysis of data from 300 patients resulted in core strategies with four factors, preparation strategies with five factors, and implementation strategies with six factors. All the SAT subscales demonstrated a high reliability with good internal consistency. The total scores of the three SAT sets differentiated participant groups well according to their stage of goal implementation and proportions of action of the 10 Rules for Highly Effective Health Behavior. Each factor of the three SAT sets correlated positively with the scores for additional assessment tool. Conclusion The SAT is a three-set, 16-factor, 91-item tool that assesses the SM strategies of health that patients use to overcome a crisis. Patients can use the SAT to assess their SM strategies of health and obtain feedback from clinicians in the practice setting. Copyright © 2015 John Wiley & Sons, Ltd.

Visceral obesity has been known to be more pathogenic than body mass index (BMI). There have been a few reports about the association between visceral obesity and surgical outcomes in laparoscopic surgery. The aim of this study was to evaluate the effect of visceral obesity on surgical outcomes undergoing laparoscopic colorectal surgery.Between January 2005 and December 2012, a total of 543 patients who underwent laparoscopic resection for colorectal cancer and had available computed tomography (CT) scans were included in this retrospective study. Visceral fat volumes (VFVs) were measured in preoperative CT scans from S1 to 12.5 cm above. Patients were divided into an obese group and a non-obese group according to VFV and BMI. Obesity was defined by VFV ≥1.92 dm(3) (75% value of VFV) or BMI ≥25 kg/m(2).There were 136 (25.0%) and 150 (27.6%) obese patients according to VFV and BMI, respectively. The high VFV group had a longer operative times (165.2 ± 84.4 vs. 146.1 ± 58.9 min; P = 0.016), higher blood loss during surgery (132.5 ± 144.8 vs. 98.3 ± 109.6 ml; P = 0.012), more frequent conversion to laparotomy (5.9 vs. 1.5%; P = 0.010), and more frequent major complications (Dindo score ≥3; 11.0 vs. 4.7%; P = 0.008), whereas there was no significant difference between the high and low BMI groups. High VFV was a significant independent risk factor for open conversion (odds ratio 4.964, 95% confidence interval 1.336-18.438, P = 0.017).Visceral obesity can be a more clinically useful predictor than BMI in predicting surgical outcomes for laparoscopic colorectal cancer surgery.

Table S1 Clinicopathologic characteristics after propensity score matching. Table S2 Risk factors associated with cancer progression after propensity score matching. Table S3 Risk factors for overall survival after propensity score matching. (DOCX 21 kb)

To save the sphincter, understanding the anatomy of anal sphincter complex is essential. The anal canal extends from the level of the levator ani muscle to the anal verge. The muscularis propria of the rectum is consisted of the inner circular and outer longitudinal smooth muscle layer. The internal and external sphincters together can maintain anal continence. Intersphincteric groove lies between the subcutaneous external anal sphincter and the internal anal sphincter. This is one of the landmarks for intersphincteric resection. In the middle and low rectal cancer, total mesorectal excision should be performed. For distal rectal cancer, a 1-cm distal margin may be acceptable. To avoid positive circumferential resection margin, the surgeons should follow the principles of total mesorectal excision and perform en bloc resection of contiguous tissues when clinically indicated.

The aim of this study was to develop and validate a short form (SF) of the Smart Management Strategy for Health Assessment Tool (SAT) for cancer patients. Data for item reduction were derived from cancer patient data (n = 300) previously used to develop the original SAT. We used regression methods to select and score the new SAT-SF. To assess the instrument’s reliability and validity, we recruited another 354 cancer patients from the same hospitals who were older than 18 years and accustomed to using the web. All results were compared with that of the long-form SAT (original SAT). The SAT-SF used is the shorter version, a 30-item (from the original 91-item) instrument, to measure cancer patient’s health. The 30-item SAT-SF explained 97.7% of total variance of the full 91-item long-form SAT. All SAT-SF subscales demonstrated a high reliability with good internal consistency compared with the original SAT. The total short-form scores of the three SAT sets (SAT-Core, SAT-Preparation, SAT-Implementation) differentiated participant groups according to their stage of goal implementation and percentage of actions taken in the 10 Rules for Highly Effective Health Behavior. We found acceptable correlations between the three SAT-SF sets and the additional assessment tools compared with the original SAT. The 30-item SAT-SF had a satisfactory internal consistency and validity for cancer patients with minimal loss of information compared with the original SAT.

This study aimed to evaluate the efficacy of post-operative oral nutrition supplementation after major gastrointestinal surgery.A prospective randomized controlled trial was conducted to evaluate 174 subjects who were discharged within 2 weeks after major gastrointestinal surgery. The subjects in the study group were prescribed 400 ml/day of Encover® from the day of discharge for 8 weeks, but no supplementation was allowed in the control group. The primary endpoint was the weight loss rate at 8 weeks after discharge compared with the pre-operative weight, and the secondary endpoints included changes in body weight, body mass index, Patient-Generated Subjective Global Assessment score/grade, hematological/ biochemical parameters, and adverse events evaluated at 2, 4, and 8 weeks after discharge.The weight loss rate at 8 weeks after discharge did not differ between two groups (4.23±5.49% vs 4.80±4.84%, p=0.481). The total lymphocyte count, the level of total cholesterol, total protein, and albumin were significantly higher in the study group after discharge. Diarrhea was the most frequent adverse event, and the incidence of adverse events with a severity score of=3 did not differ between groups (2.3% vs 1.2%).The utility of routine oral nutritional support after major gastrointestinal surgery was not proven in terms of weight loss at 8 weeks after discharge. However, it can be beneficial for early recovery of biochemical parameters.

Rectovaginal fistulas are difficult to treat completely, especially when patients present with a history of multiple surgeries and radiation therapy. We aimed to evaluate the efficacy of gracilis muscle flap transposition to treat rectovaginal fistula. We performed a retrospective chart review of all gracilis muscle transposition cases and other procedures between January 2009 and July 2016. Total 53 cases were reviewed. A total of 11 patients underwent gracilis muscle flap transposition for rectovaginal fistula repair, with 8 patients showing good results without recurrence (total success rate, 72.7%). Comparison of this patient group with patients who had undergone other surgical procedures for rectovaginal fistula repair showed that those who received a gracilis transposition flap had significantly higher average number of previous surgeries (2.18 ± 1.17 vs. 1.1 ± 1.25) and had previously undergone radiotherapy at a significantly higher rate (63.6 vs. 26.2%). Furthermore, none of our patients complained of donor site discomfort. Based on these results, we recommend using the gracilis muscle flap for rectovaginal fistula repair in cases where there is a history of radiotherapy and had surgical failure more than twice.

To evaluate chemoradiotherapy (CRT)-induced changes in the expression levels of programmed death-ligand 1 (PD-L1) and CD8We performed a paired analysis using pre-CRT biopsies and the corresponding post-CRT resected tissues of 123 rectal cancer patients undergoing preoperative CRT followed by surgery between 2005 and 2012. Immunohistochemistry of PD-L1 and CD8 was analyzed for the specimens.The expression levels of PD-L1 and density of CD8This study verified the CRT-induced immunologic shift toward increases in PD-L1 expression and density of CD8

Purpose The number of international visiting scholars has been on the increase in Korea and we aim to investigate the program's current situation. Methods This cross-sectional study is based on an online survey questionnaire responded by international visiting scholars in surgical departments of 8 Korean hospitals between 2014 and 2018 about their experiences and satisfaction with the visiting scholar program. Results A total of 1,496 international scholars from 80 countries visited various surgical departments in 8 Korean hospitals between 2014 and 2018. The numbers have been on the increase over the years. Out of 355 visiting scholars in 2018, 71 replied to the online survey, of whom 52 were male and 19 female, and mostly in their 30s and 40s. Information about the program was accessed mostly through friends or colleagues (42.3%) and international conferences (36.6%). The commonest funding source was private (35.2%) and more than half stayed for less than 3 months. The visiting scholar's main roles were mostly observation or participation in surgery and clinical research. All but 1 were satisfied with the program (98.6%) and would recommend it to friends and colleagues, although the language barrier was identified as an inconvenience. Those aged 20-39 years with governmental or institutional funding were associated with stays of more than 1 year. Conclusion The number of international visiting scholars at surgical departments in Korean hospitals has been on the increase with high satisfaction levels. Improvements need to be made on funding sources and lengthening visiting period to maximize the benefits of the program.

Purpose: Recently, survival after recurrence (SAR) has been one of the major concerns after recurrence of colorectal carcinoma. To identify the risk factors about SAR is important as much as to identify the risk factors about recurrence. It provides us useful information for treatment strategy to know which patient will be expected with long term survival after recurrence. This study was aimed to identify the risk factors about overall SAR in recurred colorectal carcinoma. Methods: Between January 2002 and December 2005, two hundred twenty one patients, who had recurrence of colorectal carcinoma after initial curative resection at Seoul National University Hospital, were included. Clinicopathologic characteristics and survival outcomes were retrospectively reviewed. Survival analysis was performed to identify the risk factors for SAR. Results: Median recurrence time after initial curative resection was 22.5 months (range, 0?93.0 month). Median follow-up time after recurrence was 34.8 months (range, 0?130.0 month). In univariate analysis, low body mass index, preoperative elevated carcinoembryonic antigen (CEA) level, high grade histology, metastatic disease and perineural invasion were significant associated with poor SAR. In multivariate analysis, preoperative elevated CEA (hazard ratio [HR], 1.517; 95% confidence interval [CI], 1.088?2.114; P=0.014), high grade histology (HR, 2.307; 95% CI, 1.343?3.961; P=0.002) and treatment after recurrence (HR, 2.755; 95% CI, 1.374?5.524; P=0.004) were significant associated with poor SAR. Conclusion: Preoperative elevated CEA, high grade histology and treatment after recurrence were independent risk factors for SAR.

This study proposes a two-phase non-inverting buck-boost converter that uses a coupled inductor. The multi-phase converter has many advantages over single-phase counterparts, such as reduced output current ripple and conduction loss in switching devices and passive elements. Although the output current ripple of the multi-phase converter is reduced significantly because of the interleaved effect, the inductor current ripple is not reduced in multi-phase converters. One of the solutions to this problem is to use a coupled inductor. A 4 kW prototype converter is built and tested to verify the performance of the proposed converter.

Background and Objectives Reoperation is recommended for resectable retroperitoneal sarcoma (RS) recurrence; however, the long-term overall survival (OS) benefit varies. Although histologic grade is an important OS predictor after primary tumor resection, its prognostic value tends to diminish with subsequent reoperations. The objective of this study was to identify prognostic factors of OS after reoperation for recurrent RS. Methods The medical records of 95 patients who underwent resection for RS at Seoul National University Hospital between January 1999 and July 2011 were retrospectively reviewed. Of the 95 patients, 50 patients underwent second resection for recurrence, and 26 of these patients underwent third resection. Prognostic factors were analyzed at each reoperation. Results Higher histologic grade and gross residual disease were poor prognostic factors of OS after first resection. After second resection, higher histologic grade and time since previous operation of within 1 year were poor prognostic factors. After third resection, only contiguous organ resection was a significant independent prognostic factor. Conclusions The significance of prognostic factors changes with repetitive reoperations for RS recurrence. The prognostic value of histologic grade diminishes after the third resection, whereas other clinical factors such as time since previous operation and contiguous organ resection achieve significance. J. Surg. Oncol. 2015 111:165–172. © 2014 Wiley Periodicals, Inc.

Poly[1-(cholesteryloxyhexyloxy)ethylene] (PHET) and poly[1-(cholesteryloxycarbonyl-hexyloxy)ethylene] (PHES) were prepared by reacting poly(vinyl alcohol) with cholesteryloxyhexyloxy bromides (CHB) or cholesteryloxycarbonylhexyloxy bromides (CEHB), and their thermal and optical properties were investigated. PHET and PHES exhibited monotropic cholesteric phases; however, their thermal behaviours depended on the cholesteryl groups and alkylene spacers with different chemical structures. PHET did not display reflection colours over its entire cholesteric range, whereas PHES did display reflection colours. These results suggested that the thermal stability and helical twisting power (HTP) of these polymers strongly depend on the difference in the chemical structures of the flexible spacer via cholesterol. The mesophase properties of PHET and PHES differed substantially from those of poly(cholesteryl-ω-acryloyloxyalkanoates). The results indicate that the mode of chemical linkage between the side-chain group a...

Compared with open resection, laparoscopic resection of rectal cancers is associated with improved short-term outcomes, but high-level evidence showing similar long-term outcomes is scarce. We aimed to compare survival outcomes of laparoscopic surgery with open surgery for patients with mid-rectal or low-rectal cancer.The Comparison of Open versus laparoscopic surgery for mid or low REctal cancer After Neoadjuvant chemoradiotherapy (COREAN) trial was an open-label, non-inferiority, randomised controlled trial done between April 4, 2006, and Aug 26, 2009, at three centres in Korea. Patients (aged 18-80 years) with cT3N0-2M0 mid-rectal or low-rectal cancer who had received preoperative chemoradiotherapy were randomly assigned (1:1) to receive either open or laparoscopic surgery. Randomisation was stratified by sex and preoperative chemotherapy regimen. Investigators were masked to the randomisation sequence; patients and clinicians were not masked to the treatment assignments. The primary endpoint was 3 year disease-free survival, with a non-inferiority margin of 15%. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00470951.We randomly assigned 340 patients to receive either open surgery (n=170) or laparoscopic surgery (n=170). 3 year disease-free survival was 72·5% (95% CI 65·0-78·6) for the open surgery group and 79·2% (72·3-84·6) for the laparoscopic surgery group, with a difference that was lower than the prespecified non-inferiority margin (-6·7%, 95% CI -15·8 to 2·4; p0·0001). 25 (15%) patients died in the open group and 20 (12%) died in the laparoscopic group. No deaths were treatment related.Our results show that laparoscopic resection for locally advanced rectal cancer after preoperative chemoradiotherapy provides similar outcomes for disease-free survival as open resection, thus justifying its use.National Cancer Center, South Korea.

Although lateral pelvic node dissection (LPND) is recommended for rectal cancer with clinically metastatic lateral pelvic lymph nodes (LPNs), LPNs may respond to neoadjuvant chemoradiotherapy (nCRT). Our aim was to determine the optimal indication for LPND after nCRT for mid/low rectal cancer. Of 2,263 patients with clinical stage II/III mid/low rectal cancer who were managed at three tertiary referral hospitals, 66 patients underwent curative surgery including LPND after nCRT were included in this study. Risk factors for LPN metastasis were retrospectively analyzed and oncologic outcomes determined according to LPN response to nCRT. Persistent LPNs greater than 5 mm on post-nCRT magnetic resonance imaging were significantly associated with residual tumor metastasis, unlike responsive LPN after nCRT (short-axis diameter ≤5 mm) (pathologically, 61.1 % [22 of 36] vs. 0 % [0 of 30], P

OBJECTIVE: To evaluate outcomes and toxicity profiles after re-irradiation in patients with pelvic recurrence of anorectal cancer. METHODS: 25 anorectal cancer patients who received re-irradiation for pelvic recurrence between 2005 and 2015 were included. For initial treatment, all patients underwent surgical resection and preoperative or postoperative radiotherapy. RESULTS: The median follow-up duration was 21.5 months (range, 2.9–84.4). After a median of 43.3 months (range, 11.7–218.5), patients received re-irradiation with a median dose of 45 Gy (range, 36–60). The equivalent dose in 2 Gy fractions (EQD2) of re-irradiation—calculated using α/β = 10 Gy—ranged from 34.5 to 84.0 Gy (median, 46.4). Surgical resection was performed for 11 patients, and 14 patients received concurrent chemotherapy with re-irradiation. The 3-year local progression-free survival was 29.7%. The 3-year overall survival was 49.7%. Concurrent chemotherapy with re-irradiation and re-irradiation doses >50 Gy EQD2(α/β=10) were significant prognostic factors for local progression free survival and overall survival according to multivariate analysis. 90% (9 of 10) of patients with symptoms had improvement after re-irradiation. Among 23 patients available for evaluation of late toxicity, 12 developed late toxicities. There were no Grade 4 late toxicities, and 6 patients had Grade 3 late toxicities (small bowel obstruction, bowel perforation and fistula). CONCLUSION: Re-irradiation for pelvic recurrence of anorectal cancer improved symptoms of patients but the rate of late toxicity was high. Further investigation for patient selection is required. ADVANCES IN KNOWLEDGE: Re-irradiation could be considered as a possible option for pelvic recurrence of anorectal cancer in selected patients.

The circumferential resection margin (CRM) is a strong prognostic factor in rectal cancer. The purpose of this study was to investigate the relationship between CRM distance and recurrence in patients with locally advanced rectal cancer who received preoperative chemoradiotherapy (CRT).We analyzed data for 561 patients who underwent preoperative CRT and curative surgery for locally advanced rectal cancer between August 2001 and December 2008. CRM was divided into four groups: group 1, CRM2 mm; group 2, 1.1-2.0 mm; group 3, 0.1-1.0 mm; and group 4, 0 mm. We assessed the associations of CRM with local recurrence and disease-free survival.Groups 1, 2, 3, and 4 comprised 487, 36, 20, and 18 patients, respectively. The local recurrence rate was highest and the disease-free survival rate was lowest in group 4, followed by groups 3, 2, and 1. Survival was similar between groups 2 and 1. Local recurrence rates were lower in groups 3, 2, and 1 than in group 4 [hazard ratio (HR) 0.28, 95 % confidence interval (CI) 0.09-0.91, P = 0.035; HR 0.11, 95 % CI 0.03-0.46, P = 0.002; HR 0.18, 95 % CI 0.08-0.42, P0.0001, respectively]. Disease-free survival rates were higher in groups 3, 2, and 1 than in group 4 (HR 0.32, 95 % CI 0.13-0.75, P = 0.009; HR 0.24, 95 % CI 0.10-0.54, P = 0.001; HR 0.26, 95 % CI 0.14-0.48, P0.0001, respectively).After preoperative CRT, CRM distance provides useful information for risk stratification in the recurrence of rectal cancer.

This single-blind, prospective, randomized controlled trial was designed to evaluate the effects of a culturally responsive health promotion program for elderly Korean (CHP-K) survivors of gastrointestinal (GI) cancers. The program consisted of 8 weeks of Qi exercise and face-to-face counseling on physical and psychological factors. A total of 63 Korean GI cancer survivors, aged ≥65 years, who had completed their active cancer treatment, were recruited from a cancer center in South Korea. Outcomes included the amount of exercise, body weight, BMI, the Patient Generated Subjective Global Assessment scale, the M.D. Anderson Symptom Inventory, and self-efficacy and self-esteem scales. Repeated measures MANCOVA revealed a significant difference over time between the groups (Wilks' Lambda F1,62 = 5.361, p = 0.007). Univariate RM-ANCOVA for each outcome measure revealed statistically significant differences between groups. These results suggested that the participation in the CHP-K may have enhanced the health of elderly Korean GI cancer survivors.

Postoperative adhesions appear to be less common following laparoscopic surgery than after conventional open surgery. The purpose of this study was to compare the impact of laparoscopic and conventional open rectal surgery on peristomal adhesion formation. We enrolled 97 subjects who were participants in a trial comparing open versus laparoscopic surgery for mid and low rectal cancer after neoadjuvant chemoradiotherapy. These patients had undergone rectal cancer surgery with ileostomy formation. Peristomal adhesions were assessed during ileostomy takedown using an adhesion grading system: (1) no adhesions or fine, filmy adhesions separable by blunt dissection; (2) dense adhesions, separable by sharp dissection; (3) very dense adhesions, resulting in enterotomy and/or requiring extension of the abdominal wall incision. A total of 57 patients underwent laparoscopic resection (group A) and 40 underwent open resection (group B). Operating time for ileostomy dissection was shorter in group A than in group B (14.6 vs. 19.8 min, respectively; p = 0.047). Dense adhesions (grades 2 and 3) were more common in group B (22/40, 55 %) than in group A (12/57, 21 %; p

Background: There have been controversies in prognostic impact of mucinous histology on colorectal cancer, and its implication in patients treated with adjuvant 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) is unclear. Methods: Stage II and III colorectal cancer patients who underwent curative resection followed by adjuvant FOLFOX were included. Patients were grouped according to the mucinous content: >50%, mucinous adenocarcinoma (MAC)

Background: We aimed to determine the role of palliative resection in metastatic colorectal cancer (mCRC) and ascertain which patient populations would benefit most from this treatment. Methods: A total of 1015 patients diagnosed with mCRC at Seoul National University Hospital between 2000 and 2009 were retrospectively studied. Results: Of the 1015 patients, 168 patients with only liver and/or lung metastasis received curative resection. The remaining 847 patients were treated with palliative chemotherapy and/or palliative resection combined with best supportive care. Palliative resection was performed in 527 (62.2%) cases (complete resection with negative margin (R0) in 93, R1/2 in 434). Resected patients had a more prolonged median overall survival (OS) than unresected patients (21.3 vs 14.1 months; P

Colorectal cancer (CRC) develops through the alteration of several critical pathways. This study was aimed at evaluating the influence of critical pathways on survival outcomes for patients with CRC.Targeted next-generation sequencing of 40 genes included in the 5 critical pathways of CRC (WNT, P53, RTK-RAS, phosphatidylinositol-4,5-bisphosphate 3-kinase [PI3K], and transforming growth factor β [TGF-β]) was performed for 516 patients with stage III or high-risk stage II CRC treated with surgery followed by adjuvant fluoropyrimidine and oxaliplatin chemotherapy. The associations between critical pathway mutations and relapse-free survival (RFS) and overall survival were analyzed. The associations were further analyzed according to the tumor location.The mutation rates for the WNT, P53, RTK-RAS, PI3K, and TGF-β pathways were 84.5%, 69.0%, 60.7%, 30.0%, and 28.9%, respectively. A mutation in the PI3K pathway was associated with longer RFS (adjusted hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.36-0.99), whereas a mutation in the RTK-RAS pathway was associated with shorter RFS (adjusted HR, 1.60; 95% CI, 1.01-2.52). Proximal tumors showed a higher mutation rate than distal tumors, and the mutation profile was different according to the tumor location. The mutation rates of Kirsten rat sarcoma viral oncogene homolog (KRAS), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA), and B-Raf proto-oncogene serine/threonine kinase (BRAF) were higher in proximal tumors, and the mutation rates of adenomatous polyposis coli (APC), tumor protein 53 (TP53), and neuroblastoma RAS viral oncogene homolog (NRAS) were higher in distal tumors. The better RFS with the PI3K pathway mutation was significant only for proximal tumors, and the worse RFS with the RTK-RAS pathway mutation was significant only for distal tumors.A PI3K pathway mutation was associated with better RFS for CRC patients treated with adjuvant chemotherapy, and an RTK-RAS pathway mutation was associated with worse RFS. The significance of the prognostic impact differed according to the tumor location. Cancer 2017;123:3513-23. © 2017 American Cancer Society.

Purpose This study was conducted to validate the prognostic influence of treatment response among patients with positive circumferential resection margin for locally advanced rectal cancer. Materials and Methods Clinical data of 197 patientswith positive circumferentialresection margin defined as ≤ 2 mm after preoperative chemoradiotherapy followed by total mesorectal excision between 2004 and 2009were collected forthis multicenter validation study. All patients underwent median 50.4Gy radiationwith concurrentfluoropyrimidine based chemotherapy. Treatmentresponse was dichotomized to good response, including treatmentresponse of grade 2 or 3, and poor response, including grade 0 or 1. Results After 52 months median follow-up, 5-year overall survival (OS) for good responders and poor responders was 79.1% and 48.4%, respectively (p < 0.001). In multivariate analysis, circumferential resection margin involvement and treatment response were a prognosticator for OS and locoregional recurrence-free survival. In subgroup analysis, good responders with close margin showed significantly better survival outcomes for survival. Good responders with involved margin and poor responders with close margin shared similar results, whereas poorresponderswith involved margin hadworst survival (5-year OS, 81.2%, 57.0%, 50.0%, and 32.4%, respectively; p < 0.001). Conclusion Among patients with positive circumferential resection margin after preoperative chemoradiotherapy, survival of the good responders was significantly better than poor responders. Subgroup analysis revealed that definition of positive circumferential resection margin may be individualized as involvement for good responders, whereas ≤ 2 mm for poor responders.

Supplemental Digital Content is available in the text, The role of pelvic radiotherapy (RT) in stage IV rectal cancer with total mesorectal excision (TME) has not been defined. We evaluated the impact of RT on oncologic outcomes among patients with stage IV rectal cancer who underwent TME and performed a meta-analysis of published studies. The records of stage IV rectal cancer patients who underwent TME between August 2001 and December 2011 were reviewed. Patients who received pelvic RT (RT group) and those who did not (non-RT group) were matched using a propensity score. Oncologic outcomes were compared between the groups. A systematic literature search and meta-analysis was conducted. One hundred seventy-six patients were matched with propensity score matching, resulting in 39 patients in each group. The local recurrence-free survival (LRFS) of the RT group was significantly higher than that of the non-RT group (2-year LRFS: 100% vs 83.6%, respectively, P = 0.038). The overall survival, disease-free survival, and systemic recurrence were not significantly different between the groups. In the meta-analysis, the RT group had a reduced risk for loco-regional recurrence than the non-RT group (RR: 0.48, 95% confidence interval: 0.29–0.79). Pelvic RT might have benefits for loco-regional control in patients with stage IV rectal cancer who undergo TME.

This study was performed to evaluate whether fluorine-18 fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) could predict treatment outcome of regorafenib in metastatic colorectal cancer (mCRC).Previously treated refractory mCRC patients were enrolled into a prospective biomarker study of regorafenib. For this sub-study, the results of FDG PET/CT scans at baseline and after two cycles of treatment were analyzed. Various metabolic parameters obtained from PET images were analyzed in relation to treatment outcome.A total of 40 patients were evaluable for PET image analysis. Among various PET parameters, total lesion glycolysis (TLG) measured in the same target lesions for RECIST 1.1 analysis were the most significant in predicting prognosis, with the lowest p-value observed in TLG calculated using the margin threshold of 40 % (TLGMeasurement of TLG can predict treatment outcome of regorafenib in mCRC.

Background Preoperative chemoradiotherapy (CRT) has become a widely used treatment for improving local control of disease and increasing survival rates of rectal cancer patients. We aimed to identify a set of genes that can be used to predict responses to CRT in patients with rectal cancer. Methods Gene expression profiles of pre-therapeutic biopsy specimens obtained from 77 rectal cancer patients were analyzed using DNA microarrays. The response to CRT was determined using the Dworak tumor regression grade: grade 1 (minimal, MI), grade 2 (moderate, MO), grade 3 (near total, NT), or grade 4 (total, TO). Results Top ranked genes for three different feature scores such as a p-value (pval), a rank product (rank), and a normalized product (norm) were selected to distinguish pre-defined groups such as complete responders (TO) from the MI, MO, and NT groups. Among five different classification algorithms, supporting vector machine (SVM) with the top 65 norm features performed at the highest accuracy for predicting MI using a 5-fold cross validation strategy. On the other hand, 98 pval features were selected for predicting TO by elastic net (EN). Finally we combined TO- and MI-finder models to build a three-class classification model and validated it using an independent dataset of rectal cancer mRNA expression. Conclusions We identified MI- and TO-finders for predicting preoperative CRT responses, and validated these data using an independent public dataset. This stepwise prediction model requires further evaluation in clinical studies in order to develop personalized preoperative CRT in patients with rectal cancer. Electronic supplementary material The online version of this article (doi:10.1186/s13014-016-0623-9) contains supplementary material, which is available to authorized users.

Background: The association between the CpG island methylator phenotype (CIMP) and clinical outcomes in metastatic colorectal cancer remains unclear. We investigated the prognostic impact of CIMP in patients with metastatic colorectal cancer treated with systemic chemotherapy. Methods: Eight CIMP-specific promoters (CACNA1G, IGF2, NEUROG1, RUNX3, SOCS1, CDKN2A, CRABP1, and MLH1) were examined. The CIMP status was determined by the number of methylated promoters as high (⩾5), low (1–4), and negative (0). Results: A total of 153 patients were included (men/women, 103/50; median age, 61 years; range, 22–80 years). The CIMP status was negative/low/high in 77/ 69/7 patients, respectively. Overall survival (OS) was significantly different among the three CIMP groups, with median values of 35.7, 22.2, and 9.77 months for the negative, low, and high groups, respectively (P

More than half of all rectal cancers are T3 lesions, but they are classified as a single-stage category.The aim of this study was to validate prognostic significance of mesorectal extension depth in T3 rectal cancer.This study is a retrospective analysis of oncologic outcomes of patients with T3 rectal cancer grouped by mesorectal extension depth (T3a,1 mm; T3b, 1-5 mm; T3c, 5-15 mm; T3d,15 mm).This study was conducted at a tertiary referral cancer hospital.From 2003 to 2009, 291 patients who underwent a curative surgery were included.Oncologic outcomes in terms of disease-free survival were analyzed.The 5-year disease-free survival rate according to T3 subclassification was 86.5% for T3a, 74.2% for T3b, 58.3% for T3c, and 29.0% for T3d. It was significantly higher in T3a,b tumors than that in T3c,d tumors (77.6% vs 55.2%, p0.001). On univariate and multivariate analysis, prognostic factors affecting recurrence were preoperative CEA level ≥ 5 ng/mL (HR 2.617, 95% CI 1.620-4.226), lymph node metastasis (HR 3.347, 95% CI 1.834-6.566), and mesorectal extension depth5 mm (HR 1.661, 95% CI 1.013-2.725). In subgroup analysis, independent prognostic factors were preoperative CEA level and mesorectal extension depth5 mm for 200 patients with ypT3 rectal cancer and preoperative CEA level and lymph node metastasis for 91 patients with pT3 rectal cancer.This study lacks quality of surgery plane evaluation because of its retrospective nature. Moreover, pathologic examination was not done with a whole-mount section.Depth of mesorectal extension5 mm is a significant prognostic factor in patients with T3 rectal cancer. Depth of mesorectal extension especially may be more important than the nodal status in predicting the oncologic outcome for patients who had received preoperative chemoradiotherapy.

We synthesized polyimide (based on ODA-PMDA) and polyimide foam and polyimide/clay foam that pore size was uniform about 1㎛. We identified that the clay layers are well dispersed in polyimide matrix and achieved exfoliation structure by X-ray diffraction. And we compared thermal conductivity of PI, PI foam, PI/clay foam. Thermal conductivity decreased up to maximum 28 % by introducing both pores and clay layers. Exfoliated structure of clay leads to decrease of thermal conductivity by thermal barrier effect. Also, the presence of clay could considerably reinforce the poor mechanical properties of polyimide by foam because of interfacial interaction between clay layers and polymer matrix. Through the this results, it has shown that this study may provide an effective method to prepare polymer/clay nanocomposite foams having exfoliation structure, and can be used as insulating material having low thermal conductivity.