摘要
Purpose@#This study aimed to evaluate the long-term clinical outcomes based on the ligation level of the inferior mesenteric artery (IMA) in patients with rectal cancer. @*Methods@#This was a retrospective analysis of a prospectively collected database that included all patients who underwent elective low anterior resection for rectal cancer between January 2013 and December 2019. The clinical outcomes included oncological outcomes, postoperative complications, and functional outcomes. The oncological outcomes included overall survival (OS) and relapse-free survival (RFS). The functional outcomes, including defecatory and urogenital functions, were analyzed using the Fecal Incontinence Severity Index, International Prostate Symptom Score, and International Index of Erectile Function questionnaires. @*Results@#In total, 545 patients were included in the analysis. Of these, 244 patients underwent high ligation (HL), whereas 301 underwent low ligation (LL). The tumor size was larger in the HL group than in the LL group. The number of harvested lymph nodes (LNs) was higher in the HL group than in the LL group. There were no significant differences in complication rates and recurrence patterns between the groups. There were no significant differences in 5-year RFS and OS between the groups. Cox regression analysis revealed that the ligation level (HL vs. LL) was not a significant risk factor for oncological outcomes. Regarding functional outcomes, the LL group showed a significant recovery in defecatory function 1 year postoperatively compared with the HL group. @*Conclusion@#LL with LNs dissection around the root of the IMA might not affect the oncologic outcomes comparing to HL; however, it has minimal benefit for defecatory function.
摘要
Purpose@#Whether to perform surgery or conservatively manage appendicitis in immunosuppressed patients is a concern for clinicians. This study aimed to compare the outcomes of these 2 treatment options for appendicitis in patients with cancer undergoing chemotherapy. @*Methods@#This retrospective study included 206 patients with cancer who were diagnosed with acute appendicitis between August 2001 and December 2021. Among them, patients who received chemotherapy within 1 month were divided into surgical and conservative groups. We evaluated the outcomes, including treatment success within 1 year, 1-year recurrence, and the number of days from the diagnosis of appendicitis to chemotherapy restart, between the 2 groups. @*Results@#Among the 206 patients with cancer who were diagnosed with acute appendicitis, 78 received chemotherapy within 1 month. The patients were divided into surgery (n = 63) and conservative (n = 15) groups. In the surgery group, the duration of antibiotic therapy (7.0 days vs. 16.0 days, P < 0.001) and length of hospital stay (8.0 days vs. 27.5 days, P = 0.002) were significantly shorter than conservative groups. The duration from the diagnosis of appendicitis to the restart of chemotherapy was shorter in the surgery group (20.8 ± 15.1 days vs. 35.2 ± 28.2 days, P = 0.028). The treatment success rate within 1 year was higher in the surgery group (100% vs. 33.3%, P < 0.001). @*Conclusion@#Surgical treatment showed a significantly higher success rate than conservative treatment for appendicitis in patients less than 1 month after chemotherapy. Further prospective studies will be needed to clinically determine treatment options.
摘要
Background@#The relationship between aspirin usage and the risk of colorectal cancer (CRC) among individuals with both hypertension (HTN) and diabetes mellitus (DM) remains unclear. This study aims to explore the impact of aspirin use on the site-specific CRC risk in patients with metabolic comorbidity. @*Methods@#A case-control study was conducted among 1,331 CRC patients and 2,771 controls recruited from the Nation Cancer Center in Korea. Multinomial logistic regression analyses were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for the association between aspirin use, metabolic disease status, and site-specific CRC risk. @*Results@#Among the 4,102 participants, 1,191 individuals had neither HTN nor DM, 2,044 were diagnosed with HTN, 203 with DM, and 664 presented with HTN and DM comorbidity.An increasing number of HTN and DM was associated with an increased risk of overall CRC (HTN or DM: OR, 1.70; 95% CI, 1.39–2.07; HTN and DM: OR, 8.43; 95% CI, 6.37–11.16), while aspirin use was associated with a decreased risk of overall CRC (OR, 0.31; 95% CI, 0.21–0.46).These results remained consistent across anatomical sites. Among individuals with HTN and DM comorbidity, aspirin use notably associated with lower risk of overall CRC (OR, 0.39; 95% CI, 0.21–0.72), proximal colon (OR, 0.32; 95% CI, 0.13–0.71) and rectal cancer (OR, 0.27;95% CI, 0.08–0.97), but not distal colon cancer (OR, 0.58; 95% CI, 0.27–1.24). @*Conclusion@#This study showed that aspirin use is negatively associated with overall and sitespecific CRC, even among individuals with HTN and DM comorbidity.
摘要
Purpose@#Most predictive factors for lymph node metastasis in rectal neuroendocrine tumors (NETs) have been based on local and endoscopic resection. We aimed to evaluate the risk factors for lymph node metastasis in patients who underwent radical resection for rectal NETs and stratify the risk of lymph node metastasis. @*Methods@#Sixty-four patients who underwent radical resection for rectal NETs between January 2001 and January 2018 were included. We investigated the risk factors of lymph node metastasis using clinicopathologic data. We also performed a risk stratification for lymph node metastases using the number of previously known risk factors. For oncologic outcomes, the 5-year overall survival and recurrence-free survival were evaluated in both groups. @*Results@#Among the patients who underwent radical surgery, 32 (50.0%) had lymph node metastasis and 32 (50.0%) had non–lymph node metastasis. In the multivariable analysis, only the male sex was identified as a risk factor for lymph node metastasis (odds ratio, 3.695; 95% confidence interval, 1.128–12.105; P=0.031). When there were 2 or more known risk factors, the lymph node metastasis rate was significantly higher than when there were one or no risk factors (odds ratio, 3.667; 95% confidence interval, 1.023–13.143; P=0.046). There was also no statistical difference between the 2 groups in 5-year overall survival (P=0.431) and 5-year recurrence-free survival (P=0.144). @*Conclusion@#We found that the rate of lymph node metastasis increased significantly when the number of known risk factors is 2 or more.
摘要
Purpose@#Minimally invasive surgery (MIS) is currently the standard treatment for rectal cancer. However, its limitations include complications and incomplete total mesorectal resection (TME) due to anatomical features and technical difficulties. Transanal TME (TaTME) has been practiced since 2010 to improve this, but there is a risk of local recurrence and intra-abdominal contamination. We aimed to analyze samples obtained through lavage to compare laparoscopic TME (LapTME) and TaTME. @*Methods@#From June 2020 to January 2021, 20 patients with rectal cancer undergoing MIS were consecutively and prospectively recruited. Samples were collected at the start of surgery, immediately after TME, and after irrigation. The samples were analyzed for carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20) through a quantitative real-time polymerase chain reaction. The primary outcome was to compare the detected amounts of CEA and CK20 immediately after TME between the surgical methods. @*Results@#Among the 20 patients, 13 underwent LapTME and 7 underwent TaTME. Tumor location was lower in TaTME (7.3 cm vs. 4.6 cm, P=0.012), and negative mesorectal fascia (MRF) was more in LapTME (76.9% vs. 28.6%, P=0.044). CEA and CK20 levels were high in 3 patients (42.9%) only in TaTME. There was 1 case of T4 with incomplete purse-string suture and 1 case of positive MRF with dissection failure. All patients were followed up for an average of 32.5 months without local recurrence. @*Conclusion@#CEA and CK20 levels were high only in TaTME and were related to tumor factors or intraoperative events. However, whether the detection amount is clinically related to local recurrence remains unclear.
摘要
Purpose@#Anastomotic bleeding after colorectal surgery is a rare, mostly self-limiting, postoperative complication that could lead to a life-threatening condition. Therefore, prompt management is required. This study aimed to evaluate the efficacy and safety of endoscopic clipping for acute anastomotic bleeding after colorectal surgery. @*Methods@#We retrospectively reviewed the data of patients pathologically diagnosed with colorectal cancer at National Cancer Center, Korea from January 2018 to November 2020, which presented with anastomotic bleeding within the first postoperative week and were endoscopically managed with clips. @*Results@#Nine patients had anastomotic bleeding, underwent endoscopic management, and, therefore, were included in this study. All patients underwent laparoscopic (low/ultralow) anterior resection with mechanical double-stapled anastomosis. Anastomotic bleeding was successfully managed through a colonoscopy with clips on the first trial in all patients. Hypovolemic shock occurred in one patient, following anastomotic breakdown. @*Conclusion@#Endoscopic clipping seems to be an effective and safe treatment for anastomotic bleeding with minimal physiologic stress, easy accessibility, and scarce postoperative complications. However, a surgical backup should always be considered for massive bleeding.
摘要
Purpose@#Oral sulfate tablets are abundantly used for bowel preparation before colonoscopy. However, their efficiency and safety for bowel preparation before colorectal surgery remain ill-defined. Herein, we aimed to compare the surgical site infection rates and efficiency between oral sulfate tablets and sodium picosulfate. @*Methods@#We designed a prospective, randomized, phase 2 clinical trial. Patients with colorectal cancer aged 19–75 years who underwent elective bowel resection and anastomosis by minimally invasive surgery were administered oral sulfate tablets or sodium picosulfate. Eighty-three cases were analyzed from October 2020 to December 2021. Surgical site infection within 30 days after surgery was considered the primary endpoint. Postoperative morbidities, the degree of bowel cleansing, and tolerability were the secondary endpoints. @*Results@#Surgical site infection was detected in 1 patient (2.5%) in the oral sulfate tablet group and 2 patients (4.7%) in the sodium picosulfate group, indicating no significant difference between the 2 groups. Postoperative morbidity and the degree of bowel cleansing bore no statistically significant differences. Furthermore, none of the investigated tolerability criteria, namely bloating, pain, nausea, vomiting, and discomfort, differed significantly between the 2 groups. The patients’ willingness to reuse the drug was also not significantly different between the 2 groups. @*Conclusion@#Although we could not establish the noninferiority of oral sulfate tablets to sodium picosulfate, we found no evidence suggesting that oral sulfate tablets are less safe or tolerable than sodium picosulfate in preoperative bowel preparation.
摘要
Purpose@#Local excision (LE) is an alternative initial treatment for clinical T1 rectal cancer, and has avoided potential morbidity. This study aimed to evaluate the clinical outcomes of LE compared with total mesorectal excision (TME) for clinical T1 rectal cancer. @*Methods@#Between January 2000 and December 2011, we retrospectively reviewed from multicenter data in patients with clinically suspected T1 rectal cancer treated with either LE or TME. Of 1,071 patients, 106 were treated with LE and 965 were treated with TME. The data were analyzed using propensity score matching, with each group comprising 91 patients. @*Results@#After propensity score matching, the median follow-up time was 60.8 months (range, 0.6–150.6 months). After adjustment for the necessary variables, patients who underwent LE showed a significantly higher local recurrence rate than did those who underwent TME; however, there were no differences in disease-free survival and overall survival. In the multivariate analysis, age (hazard ratio [HR], 9.620; 95% confidence interval [CI], 3.415–27.098; P<0.001) and angiolymphatic invasion (HR, 3.63; 95% confidence interval, 1.33–9.89; P=0.012) were independently associated with overall survival. However, LE was neither associated with overall survival nor disease-free survival. @*Conclusion@#LE for clinical T1 rectal cancer yielded a higher local recurrence rate than did TME. Nevertheless, LE provided comparable overall survival rate and can be proposed as an optional treatment in terms of organ-preserving strategies.
摘要
Purpose@#Colonoscopy is an effective method of screening for colorectal cancer (CRC), and it can prevent CRC by detection and removal of precancerous lesions. The most important considerations when performing colonoscopy screening are the safety and satisfaction of the patient and the diagnostic accuracy. Accordingly, the Korean Society of Coloproctology (KSCP) herein proposes an optimal level of standard performance to be used in endoscopy units and by individual colonoscopists for screening colonoscopy. These guidelines establish specific criteria for assessment of safety and quality in screening colonoscopy. @*Methods@#The Colonoscopy Committee of the KSCP commissioned this Position Statement. Expert gastrointestinal surgeons representing the KSCP reviewed the published evidence to identify acceptable quality indicators and indicators that lacked sufficient evidence. @*Results@#The KSCP recommends an optimal standard list for quality control of screening colonoscopy in the following 6 categories: training and competency of the colonoscopist, procedural quality, facilities and equipment, performance indicators and auditable outcomes, disinfection of equipment, and sedation and recovery of the patient. @*Conclusion@#The KSCP recommends that endoscopy units performing CRC screening evaluate 6 key performance measures during daily practice.
摘要
Purpose@#This study was performed to evaluate the risk of readmission in the first year after low anterior resection (LAR) for patients with rectal cancer and to identify the contributing factors for readmission related to dehydration specifically. @*Methods@#This was a retrospective analysis of 570 patients who underwent LAR for rectal cancer at National Cancer Center, Republic of Korea. A diverting loop ileostomy was performed in 357 (62.6%) of these patients. Readmission was defined as an unplanned visit to the emergency room or admission to the ward. The reasons for readmission were reviewed and compared between the ileostomy (n = 357) and no-ileostomy (n = 213) groups. The risk factors for readmission and readmission due to dehydration were analyzed using multivariable logistic and Cox proportional hazard model. @*Results@#Dehydration was the most common cause of readmission in both groups (ileostomy group, 6.7%, and no-ileostomy group, 4.7%, P = 0.323). On multivariable analysis, risk factors for readmission were an estimated intraoperative blood loss of ≥400 mL (odds ratio [OR], 1.757; 95% confidence interval [CI], 1.058–2.918; P = 0.029), and postoperative chemotherapy (OR, 2.914; 95% CI, 1.824–4.653; P < 0.001). On multivariable analysis, postoperative chemotherapy, and not a diverting loop ileostomy, was an independent risk factor for dehydration-related readmission (OR, 5.102; 95% CI, 1.772–14.688; P = 0.003). @*Conclusion@#The most common cause of readmission after LAR for rectal cancer was dehydration, as reported previously. Postoperative chemotherapy, not the creation of a diverting ileostomy, was identified as the risk factor associated with readmission related to dehydration.
摘要
Purpose@#The effect of transanal total mesorectal excision (TaTME) on patients’ quality of life and functional outcomes is not fully understood. This study aimed to compare the quality of life and bowel, anorectal, and urogenital functions after laparoscopic and TaTME. @*Methods@#Laparoscopic or TaTME was performed for 202 propensity score-matched patient pairs with rectal cancer between January 2014 and December 2017 at the National Cancer Center, Korea. The outcomes for all patients were assessed using anorectal manometry, the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) and Colorectal Cancer-Specific Quality of Life Questionnaire (QLQ-CR38), low anterior resection syndrome (LARS) score, Fecal Incontinence Severity Index, and International Prostate Symptom Score (IPSS). This retrospective comparative study included patients who completed anorectal manometry and the questionnaires before treatment and at 1 year after surgery. @*Results@#The EORTC QLQ-C30 and QLQ-CR38 showed comparable outcomes regarding the quality of life in both groups. More patients experienced major LARS in the transanal group at 1 year postoperatively (31.0% vs. 6.8% in the laparoscopic group, P = 0.004). Multivariable analysis revealed no significant difference in the LARS score between the groups at 1 year postoperatively (odds ratio, 2.30; 95% confidence interval, 0.79–6.72; P = 0.127). Significant differences in the IPSS were not noted between the groups. @*Conclusion@#The quality of life and functional outcomes were comparable between the laparoscopic and transanal approaches; however, our findings suggest a higher rate of LARS after TaTME.
摘要
Purpose@#This study was performed to evaluate the risk of readmission in the first year after low anterior resection (LAR) for patients with rectal cancer and to identify the contributing factors for readmission related to dehydration specifically. @*Methods@#This was a retrospective analysis of 570 patients who underwent LAR for rectal cancer at National Cancer Center, Republic of Korea. A diverting loop ileostomy was performed in 357 (62.6%) of these patients. Readmission was defined as an unplanned visit to the emergency room or admission to the ward. The reasons for readmission were reviewed and compared between the ileostomy (n = 357) and no-ileostomy (n = 213) groups. The risk factors for readmission and readmission due to dehydration were analyzed using multivariable logistic and Cox proportional hazard model. @*Results@#Dehydration was the most common cause of readmission in both groups (ileostomy group, 6.7%, and no-ileostomy group, 4.7%, P = 0.323). On multivariable analysis, risk factors for readmission were an estimated intraoperative blood loss of ≥400 mL (odds ratio [OR], 1.757; 95% confidence interval [CI], 1.058–2.918; P = 0.029), and postoperative chemotherapy (OR, 2.914; 95% CI, 1.824–4.653; P < 0.001). On multivariable analysis, postoperative chemotherapy, and not a diverting loop ileostomy, was an independent risk factor for dehydration-related readmission (OR, 5.102; 95% CI, 1.772–14.688; P = 0.003). @*Conclusion@#The most common cause of readmission after LAR for rectal cancer was dehydration, as reported previously. Postoperative chemotherapy, not the creation of a diverting ileostomy, was identified as the risk factor associated with readmission related to dehydration.
摘要
Purpose@#The effect of transanal total mesorectal excision (TaTME) on patients’ quality of life and functional outcomes is not fully understood. This study aimed to compare the quality of life and bowel, anorectal, and urogenital functions after laparoscopic and TaTME. @*Methods@#Laparoscopic or TaTME was performed for 202 propensity score-matched patient pairs with rectal cancer between January 2014 and December 2017 at the National Cancer Center, Korea. The outcomes for all patients were assessed using anorectal manometry, the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) and Colorectal Cancer-Specific Quality of Life Questionnaire (QLQ-CR38), low anterior resection syndrome (LARS) score, Fecal Incontinence Severity Index, and International Prostate Symptom Score (IPSS). This retrospective comparative study included patients who completed anorectal manometry and the questionnaires before treatment and at 1 year after surgery. @*Results@#The EORTC QLQ-C30 and QLQ-CR38 showed comparable outcomes regarding the quality of life in both groups. More patients experienced major LARS in the transanal group at 1 year postoperatively (31.0% vs. 6.8% in the laparoscopic group, P = 0.004). Multivariable analysis revealed no significant difference in the LARS score between the groups at 1 year postoperatively (odds ratio, 2.30; 95% confidence interval, 0.79–6.72; P = 0.127). Significant differences in the IPSS were not noted between the groups. @*Conclusion@#The quality of life and functional outcomes were comparable between the laparoscopic and transanal approaches; however, our findings suggest a higher rate of LARS after TaTME.
摘要
Purpose@#Although many studies have evaluated the association between intestinal microorganisms and the risk of colorectal cancer (CRC), only a few studies have investigated the changes in microorganisms following curative treatment for CRC. The current study analyzed changes in intestinal microbiota following curative surgery in CRC patients. @*Methods@#Stool samples were collected before and 6 months after surgery, from 11 patients with clinical stage III CRC, who underwent curative surgery between May 2017 and June 2017. Next, 16S rRNA gene sequencing was performed. Operational taxonomic units (OTUs) and alpha diversity were evaluated using the Shannon index. The bacterial compositions of the stools were analyzed according to taxonomic rank at genus and phylum levels. @*Results@#OTUs and alpha diversity were significantly decreased following surgery (P < 0.001 and P = 0.019, respectively). The compositions of several bacterial taxa changed after surgery. At genus level, proportions of pathogens such as Campylobacter, Fusobacterium, Haemophilus, Porphyromonas, and Prevotella, decreased after surgery (adjusted P < 0.05). At phylum level, the proportion of Fusobacteria decreased after surgery (adjusted P < 0.001). @*Conclusion@#Significant changes in intestinal microbial communities were noted following curative resection of CRC patients. Especially, decreases in pathogenic bacterial populations, such as Fusobacterium and Prevotella, which are known to be associated with CRC development, were detected even though OTUs and alpha diversity were decreased following curative resection. To determine and validate the clinical significance of these findings, large scale, prospective studies that include cancer prognoses are required.
摘要
Gastrointestinal graft-versus-host disease (GVHD) is a common complication after hematopoietic stem cell transplantation. Concomitant cytomegalovirus (CMV) enteritis worsens the prognosis of this condition. We report a case of small bowel perforation associated with gastrointestinal GVHD and CMV enteritis in a patient with leukemia who was successfully treated surgically. A 39-year-old man presented with intestinal perforation necessitating emergency surgical intervention. He was diagnosed with T-cell acute lymphoblastic leukemia and developed severe gastrointestinal GVHD and CMV enteritis after hematopoietic stem cell transplantation. His terminal ileum showed a perforation with diffuse wall thinning, and petechiae were observed over long segments of the distal ileum and the proximal colon. Small bowel segmental resection and a subtotal colectomy with a double-barreled ileocolostomy were performed. The patient recovered uneventfully after the operation. Based on reports described in the literature, surgery plays a minor role in the management of gastrointestinal GVHD; however, timely surgical intervention could be effective in selected patients.
摘要
Purpose@#This study aimed to assess the evaluation of clinical outcomes and consequences of complications after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for the peritoneal carcinomatosis (PC) from colorectal cancer. @*Methods@#A total 26 patients underwent CRS and HIPEC for PC from colorectal cancer between March 2009 and April 2018. All the patients underwent CRS with the purpose of complete or near-complete cytoreduction. Intraoperative HIPEC was performed simultaneously after the CRS. Mitomycin C was used as chemotherapeutic agent for HIPEC. @*Results@#Median disease-free survival was 27.8 months (range, 13.4–42.2 months). Median overall survival was 56.0 months (range, 28.6–83.5 months). The mean peritoneal cancer index (PCI) was 8.73 ± 5.54. The distributions thereof were as follows: PCI <10, 69.23%; PCI 10–19, 23.08%; and PCI ≥20, 7.69%. The completeness of cytoreduction was 96.2% of patients showed CC-0, with 3.8% achieved CC-1. The mean operation time was 8.5 hours, and the mean postoperative hospital stay was 21.6 days. The overall rate of early postoperative complications was 88.5%; the rate of late complications was 34.6%. In the early period, most complications were grades I–II complications (65.4%), compared to grades III–V (23.1%). All late complications, occurring in 7.7% of patients, were grades III–V. There was no treatment-related mortality. @*Conclusion@#Although the complication rate was approximately 88%, but the rate of severe complication rate was low. In selective patients with peritoneal recurrence, more aggressive strategies for management, such as CRS with HIPEC, were able to be considered under the acceptable general condition and life-expectancy.
摘要
Purpose@#Minute T1 colorectal cancer (CRC) lesions (≤5 mm) are rare; however, little is known about their characteristics and aggressiveness. In this study, we evaluated the characteristics of minute T1 CRC in relevance to pathology and treatment. @*Methods@#This retrospective study included 849 patients with T1 CRC endoscopically or surgically treated between January 2001 and December 2016. The patients were stratified into 4 groups according to tumor size; minute group (≤5 mm), small group (6–10 mm), medium group (11–20 mm), and large group (≥21 mm). Clinicopathological variables were evaluated with respect to tumor size. @*Results@#The incidence of the minute T1 CRC was 2.4% (20 of 849). Minute T1 CRC was significantly associated with flat type (minute, 25%; small, 12.6%; medium, 8.8%; large, 12.6%; P = 0.016), right-sided cancer (30%, 15.4%, 15.4%, 15.1%, P = 0.002) and the absence of background adenoma (BGA) (50%, 40.7%, 32.8%, 18.1%, P < 0.001). In patients who underwent surgery, lymph node metastasis (LNM) was significantly higher in the minute group (36.4%, 15.9%, 15.7%, 9.2%, P = 0.029). @*Conclusion@#Minute T1 CRC is significantly associated with flat type, right-sided cancers, as well as with the absence of BGA and LNM. These results suggested the minute T1 CRC lesions are often aggressive and are likely to be missed during colonoscopy.
摘要
Purpose@#Mutation of the Kirsten Ras (KRAS) oncogene is present in 30%-40% of colorectal cancers and has prognostic significance in rectal cancer. In this study, we examined the ability of radiomics features extracted from T2-weighted magnetic resonance (MR) images to differentiate between tumors with mutant KRAS and wild-type KRAS. @*Materials and Methods@#Sixty patients with primary rectal cancer (25 with mutant KRAS, 35 with wild-type KRAS) were retrospectively enrolled. Texture analysis was performed in all regions of interest on MR images, which were manually segmented by two independent radiologists. We identified potentially useful imaging features using the two-tailed t test and used them to build a discriminant model with a decision tree to estimate whether KRAS mutation had occurred. @*Results@#Three radiomic features were significantly associated with KRASmutational status (p < 0.05). The mean (and standard deviation) skewness with gradient filter value was significantly higher in the mutant KRAS group than in the wild-type group (2.04±0.94 vs. 1.59±0.69). Higher standard deviations for medium texture (SSF3 and SSF4) were able to differentiate mutant KRAS (139.81±44.19 and 267.12±89.75, respectively) and wild-type KRAS (114.55±29.30 and 224.78±62.20). The final decision tree comprised three decision nodes and four terminal nodes, two of which designated KRAS mutation. The sensitivity, specificity, and accuracy of the decision tree was 84%, 80%, and 81.7%, respectively. @*Conclusion@#Using MR-based texture analysis, we identified three imaging features that could differentiate mutant from wild-type KRAS. T2-weighted images could be used to predict KRAS mutation status preoperatively in patients with rectal cancer.
摘要
Purpose@#Although many studies have evaluated the association between intestinal microorganisms and the risk of colorectal cancer (CRC), only a few studies have investigated the changes in microorganisms following curative treatment for CRC. The current study analyzed changes in intestinal microbiota following curative surgery in CRC patients. @*Methods@#Stool samples were collected before and 6 months after surgery, from 11 patients with clinical stage III CRC, who underwent curative surgery between May 2017 and June 2017. Next, 16S rRNA gene sequencing was performed. Operational taxonomic units (OTUs) and alpha diversity were evaluated using the Shannon index. The bacterial compositions of the stools were analyzed according to taxonomic rank at genus and phylum levels. @*Results@#OTUs and alpha diversity were significantly decreased following surgery (P < 0.001 and P = 0.019, respectively). The compositions of several bacterial taxa changed after surgery. At genus level, proportions of pathogens such as Campylobacter, Fusobacterium, Haemophilus, Porphyromonas, and Prevotella, decreased after surgery (adjusted P < 0.05). At phylum level, the proportion of Fusobacteria decreased after surgery (adjusted P < 0.001). @*Conclusion@#Significant changes in intestinal microbial communities were noted following curative resection of CRC patients. Especially, decreases in pathogenic bacterial populations, such as Fusobacterium and Prevotella, which are known to be associated with CRC development, were detected even though OTUs and alpha diversity were decreased following curative resection. To determine and validate the clinical significance of these findings, large scale, prospective studies that include cancer prognoses are required.
摘要
The incidence of rectal neuroendocrine tumors (NETs) has increased worldwide, including in Korea. Rectal NETs are usually single lesions, but synchronous multiple lesions are reported in 2–4.5% of patients. Small rectal NETs (≤ 10 mm) are usually confined to the submucosal layer and rarely give rise to lymph node or distant metastases. Here we describe the case of a 54-year-old woman referred to National Cancer Center for the management of two rectal subepithelial tumors. Because computed tomography revealed a small hepatic nodule suggesting atypical hemangioma rather than metastasis, endoscopic submucosal dissection was performed. However, the size of the nodules increased during follow-up. The pathologic results of a liver biopsy confirmed metastatic NET. This case was unusual in that synchronous small rectal NETs and distant liver metastasis occurred in the absence of any risk factors for metastasis. Thus, patients with rectal NETs should be carefully evaluated, especially for the possibility of metastasis.