Effects of prior endoscopic resection on recurrence in patients with T1 colorectal cancer who underwent radical surgery.

PURPOSE: Endoscopic resection (ER) is a reliable treatment for early colorectal cancer without lymph node metastasis. We aimed to examine the effects of ER performed prior to T1 colorectal cancer (T1 CRC) surgery by comparing long-term survival after radical surgery with prior ER to that after radical surgery alone. METHODS: This retrospective study included patients who underwent surgical resection of T1 CRC at the National Cancer Center, Korea, between 2003 and 2017. All eligible patients (n = 543) were divided into primary and secondary surgery groups. To ensure similar characteristics between the groups, 1:1 propensity score matching was used. Baseline characteristics, gross and histological features, along with postoperative recurrence-free survival (RFS) between the two groups were compared. Cox proportional hazard model was used to identify the risk factors affecting recurrence after surgery. Cost analysis was performed to examine the cost-effectiveness of ER and radical surgeries. RESULTS: No significant differences were observed in 5-year RFS between the two groups in matched data (96.9% vs. 95.5%, p = 0.596) and in the unadjusted model (97.2% vs. 96.8%, p = 0.930). This difference was also similar in subgroup analyses based on node status and high-risk histologic features. ER before surgery did not increase the medical costs of radical surgery. CONCLUSION: ER prior to radical surgery did not affect the long-term oncologic outcomes of T1 CRC or significantly increased the medical costs. Attempting ER first for suspected T1 CRC would be a good strategy to avoid unnecessary surgery without concerns of worsening cancer-related prognosis.

Subpopulation analysis of survival in high-risk T1 colorectal cancer: surgery versus endoscopic resection only.

BACKGROUND AND AIMS: This study aimed to assess the long-term survival of patients with T1 colorectal cancer (CRC) after local or surgical resection considering the type and number of risk factors for lymph node metastasis. METHODS: This study included patients with high-risk T1 CRC who underwent therapeutic resection at the National Cancer Center, Korea between January 2001 and December 2014. Risk factors included positive resection margin, high-grade histology, deep submucosal invasion, vascular invasion, budding, and no background adenoma (BGA). We statistically divided the population into favorable or unfavorable subpopulations. The favorable subpopulation included the following 5 combinations of risk factors: positive margin only or unconditional for margin status, deep submucosal invasion only, budding only, no BGA only, and budding + no BGA. We analyzed the survival rate according to the resection type (local or surgical) in the total cohort and in each subpopulation. RESULTS: Eighty-one and 466 patients underwent local and surgical resections, respectively. The distant recurrence-free survival (DRFS) and overall survival (OS) rates were significantly high in the surgical group (hazard ratio [HR], .20; 95% confidence interval [CI], .06-.61; P = .0045 and HR, .41; 95% CI, .25-.70; P = .0010, respectively). In the favorable subpopulation, both DRFS and OS rates were not significantly different between the surgical and local groups (HR, .26; 95% CI, .02-4.19; P = .3431 and HR, .58; 95% CI, .27-1.23; P = .1534, respectively). CONCLUSIONS: Intensive surveillance without additional surgery may be another option in selected cases after of high-risk T1 CRC endoscopic resection.

Factors associated with diet failure after colon cancer surgery.

BACKGROUND: Since the introduction of Enhanced Recovery After Surgery (ERAS), early diet after surgery has been emphasized and clinical outcomes have improved, though vomiting has been reported frequently. We defined diet failure based on clinical manifestation and images after colon cancer surgery and attempted to analyze underlying risk factors by comparing the early diet group with the conventional diet group. METHODS: All consecutive patients underwent colectomy with curative intent at a single institution between August 2015 and July 2017. The early diet group was started on soft diet on the second day after surgery, while the conventional group started the same after flatulence. The primary outcome was the difference in the incidence of diet failure between the two groups. Secondary outcomes were analyzed to determine risk factors for diet failure and readmission due to ileus. RESULTS: Overall, 293 patients were included in the conventional diet group and 231 in the early diet group. There were no significant differences between the two groups, except for shorter hospital stays in the early diet group (median 8 days, p < 0.001). A total of 46 patients (early diet, n = 20; conventional diet, n = 26, p = 1.000) had diet failure. Multivariate analysis showed that operation time (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.33-2.32) and side-to-side anastomosis compared with the end-to-end method (OR 4.41, 95% CI 2.10-9.24) were independent risk factors for diet failure. Sixteen patients were readmitted due to ileus that occurred within 2 months after surgical operation. Diet resumption time was not a risk factor for both diet failure and ileus. CONCLUSIONS: Early diet resumption does not increase diet failure and can reduce hospital stay. Anastomosis and operation time may be related to diet failure. Our study suggests that evaluation of surgical factors is important for postoperative recovery, and well-designed follow-up studies are needed.

Comparison of endoscopic submucosal dissection and transanal endoscopic microsurgery for T1 rectal neuroendocrine tumors: a propensity score-matched study.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) are the most effective endoscopic resection methods for T1 rectal neuroendocrine tumors (NETs). We aimed to compare the efficacy and safety of ESD and TEM for rectal NETs ≤20 mm. METHODS: Patients with rectal NETs ≤20 mm who underwent ESD or TEM were enrolled in this retrospective observational study. ESD and TEM groups were matched for pathologic tumor size and EMR history. We evaluated between-group differences in R0 resection rate, adverse event rate, procedure time, and hospital stay. RESULTS: We included 285 patients (ESD = 226, TEM = 59) in the final cohort, with 104 patients in the matched groups (ESD = 52, TEM = 52). The R0 resection rate was significantly higher for TEM (ESD 71.2% vs TEM 92.3%, P = .005). However, the median procedure time (ESD 22 [range, 11-65] vs TEM 35 [17-160] minutes, P < .001) and hospital stay (ESD 2.5 range 1-5] vs TEM 4 [3-8] days, P < .001) were significantly shorter for ESD. In the subgroup analysis of patients divided by tumor size <10 mm (ESD = 218, TEM = 49) and 10 to 20 mm (ESD = 8, TEM = 10)], there was no significant between-group difference in the R0 resection rate (83.5% vs 93.9%, P = .063 and 37.5% vs 80%, P = .145, respectively) or the rate of recurrence. CONCLUSIONS: Although TEM showed a better overall R0 resection rate for rectal NETs ≤20 mm, ESD could be a viable treatment modality concerning adverse events, procedure time, and hospital stay for rectal NETs <10 mm with similar R0 resection rates in comparison with TEM.

Comparison of underwater endoscopic mucosal resection and endoscopic submucosal dissection of rectal neuroendocrine tumors (with videos).

BACKGROUND AND AIMS: The first choice of treatment for rectal neuroendocrine tumors (NETs) ≤10 mm in size is endoscopic resection. However, because rectal NETs usually invade the submucosal layer, achieving R0 resection is difficult. Endoscopic submucosal dissection (ESD) has a high R0 resection rate, and underwater endoscopic mucosal resection (UEMR) was recently introduced to ensure a negative resection margin easily and safely. The aim of this study was to evaluate the efficacy and safety of UEMR versus ESD for rectal NETs ≤10 mm in size. METHODS: This retrospective observational study enrolled 115 patients with rectal NETs ≤10 mm in size who underwent ESD or UEMR between January 2015 and July 2019 at the National Cancer Center, Korea. The differences in R0 resection rate, adverse event rate, and procedure time between the ESD and UEMR groups were evaluated. RESULTS: Of the 115 patients, 36 underwent UEMR and 79 underwent ESD. The R0 resection rate was not different between the UEMR and ESD groups (UEMR vs ESD, 86.1% vs 86.1%, P = .996). The procedure time was significantly shorter with UEMR (UEMR vs ESD, 5.8 ± 2.9 vs 26.6 ±13.4 minutes, P < .001). Two patients (2.5%, 2/79) experienced adverse events in the ESD group and but there were no adverse events in the UEMR group; however, this difference was not statistically significant. CONCLUSION: UEMR is a safe and effective technique that should be considered when removing small rectal NETs. Further studies are warranted to define its role compared with ESD.

Analysis of metachronous colorectal neoplasms and survival following segmental or extended resection in patients with hereditary non-polyposis colorectal cancer.

PURPOSE: The high incidence of metachronous colorectal tumours in patients with hereditary non-polyposis colorectal cancer (HNPCC) encourages extended resection (ER); however, the optimal surgical approach remains unclear. We evaluated the incidences of metachronous colorectal neoplasms following curative colorectal cancer segmental resection (SR) vs ER in patients with HNPCC and investigated patients' oncologic outcomes according to surgical modality and mismatch repair status. METHODS: We retrospectively investigated medical records of patients with HNPCC (per the Amsterdam II criteria) treated for primary colon cancer at our institution between 2001 and 2017. All patients underwent intensive endoscopic surveillance. RESULTS: We included 87 patients (36 who underwent SR and 51 who underwent ER). The cumulative incidence of metachronous adenoma was higher in the SR group. One patient in the SR group (2.8%) and 3 in the ER group (5.9%) developed metachronous colon cancer; the difference was not significant (P = 0.693). Four patients in the SR group (11.1%) and 1 in the ER group (2.0%) developed distant recurrences; again, the difference was not significant (P = 0.155). Moreover, no significant differences were observed in the 5-year overall survival rates of patients in the SR and ER groups (88.2% vs 95.5%, P = 0.446); the same was true for 5-year disease-free survival rates (79.5% vs 91.0%, P = 0.147). CONCLUSION: The incidence of metachronous cancer was not significantly different between the ER and SR groups; however, that of cumulative metachronous adenoma was higher in the SR group. Hence, intensive surveillance colonoscopy may be sufficient for patients with HNPCC after non-extensive colon resection.

Favorable short-term oncologic outcomes following laparoscopic surgery for small T4 colon cancer: a multicenter comparative study.

BACKGROUND: Laparoscopic surgery for T4 colon cancer may be safe in selected patients. We hypothesized that small tumor size might preoperatively predict a good laparoscopic surgery outcome. Herein, we compared the clinicopathologic and oncologic outcomes of laparoscopic and open surgery in small T4 colon cancer. METHODS: In a retrospective multicenter study, we reviewed the data of 449 patients, including 117 patients with tumors ≤ 4.0 cm who underwent surgery for T4 colon cancer between January 2014 and December 2017. We compared the clinicopathologic and 3-year oncologic outcomes between the laparoscopic and open groups. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate analyses were performed using the Cox proportional hazards model. A p < 0.05 was considered statistically significant. RESULTS: Blood loss, length of hospital stay, and postoperative morbidity were lower in the laparoscopic group than in the open group (median [range], 50 [0-700] vs. 100 [0-4000] mL, p < 0.001; 8 vs. 10 days, p < 0.001; and 18.0 vs. 29.5%, p = 0.005, respectively). There were no intergroup differences in 3-year overall survival or disease-free survival (86.6 vs. 83.2%, p = 0.180, and 71.7 vs. 75.1%, p = 0.720, respectively). Among patients with tumor size ≤ 4.0 cm, blood loss was significantly lower in the laparoscopic group than in the open group (median [range], 50 [0-530] vs. 50 [0-1000] mL, p = 0.003). Despite no statistical difference observed in the 3-year overall survival rate (83.3 vs. 78.7%, p = 0.538), the laparoscopic group had a significantly higher 3-year disease-free survival rate (79.2 vs. 53.2%, p = 0.012). CONCLUSIONS: Laparoscopic surgery showed similar outcomes to open surgery in T4 colon cancer patients and may have favorable short-term oncologic outcomes in patients with tumors ≤ 4.0 cm.

Preoperative endoscopic clipping for rectal tumor localization in laparoscopic anterior resection.

Background: Increasing the number of rectal tumors undergoing preoperative chemoradiotherapy or endoscopic resection has increased the importance of accurate tumor localization. This study describes the preoperative endoscopic clipping method for the localization of rectal tumors and evaluated the feasibility of this technique.Material and methods: A total of 109 patients underwent preoperative endoscopic clipping to localize non-palpable rectal adenocarcinomas, which were located within 10 cm from the anal verge. Two endoscopic clips were attached to both lateral sides of the tumor's distal edge. For confirming the distal margin of tumors during surgery, attempts were made to palpate the clips by digital rectal examination.Results: In all 109 cases, endoscopic clips applied to targeted rectal lesions were easily palpable in the operating room. None of the tumors showed involvement at the distal resection margins (median 1.5 cm) in histopathology.Conclusion: Preoperative endoscopic clipping methods can be useful for localizing non-palpable rectal tumors.

Risk of recurrence after endoscopic resection of early colorectal cancer with positive margins.

BACKGROUND AND STUDY AIM: Additional surgery is recommended if an endoscopically resected T1 colorectal cancer (CRC) specimen shows a positive resection margin. We aimed to investigate the significance of a positive resection margin in endoscopically resected T1 CRC. PATIENTS AND METHODS: We enrolled 265 patients with T1 CRC who underwent endoscopic resection between January 2001 and December 2016. The inclusion criteria were: 1) complete resection by endoscopy, and 2) pathology of a positive margin. Among the 265 patients, 213 underwent additional surgery and 52 did not. In the additional surgery group, various clinicopathological factors were evaluated with respect to the presence or absence of residual tumor. The follow-up results were assessed in the group that did not undergo additional surgery. RESULTS: In the 213 patients who underwent additional surgery, residual tumor was detected in 13 patients (6.1 %), and none of the clinicopathological factors was significantly associated with the presence of residual tumor. Among the 52 patients who did not undergo additional surgery, recurrence was detected in 4 (7.7 %), and all 4 underwent salvage surgery. Among these four patients, three had no risk factors for lymph node metastasis and recurrence was at the previous resection site; pathology was high grade dysplasia, rpT3N0M0, and rpT1N0M0, respectively. CONCLUSIONS: A positive resection margin in endoscopically resected T1 CRC is related to a relatively low incidence of residual tumor (6.1 %). Although current guidelines recommend additional surgery for such cases, surveillance and timely salvage surgery could be another option in selected cases.

Phase II Clinical Trial to Evaluate the Efficacy of Transanal Endoscopic Total Mesorectal Excision for Rectal Cancer.

BACKGROUND: Total mesorectal excision has become the standard treatment for rectal cancer, and several investigators have shown that a transanal approach is a feasible option. OBJECTIVE: This study aimed to evaluate the efficacy of transanal endoscopic total mesorectal excision in patients with rectal cancer. DESIGN: This study was a prospective, single-arm phase II trial. It was registered on clinicaltrials.gov under identifier NCT02406118. SETTINGS: Inpatients at a hospital specializing in oncology were selected. PATIENTS: This prospective study enrolled 49 patients with rectal cancer located 3 to 12 cm from the anal verge who were scheduled to undergo radical surgery. INTERVENTIONS: Laparoscopy-assisted transanal total mesorectal excision was performed. MAIN OUTCOME MEASURES: The primary end point was total mesorectal excision quality and circumferential resection margin. Secondary end points included the number of harvested lymph nodes, operation time, and 30-day postoperative complications. RESULTS: From March 2015 to April 2016, 32 men and 17 women with rectal cancer were enrolled. The mean age was 61.2 years, and mean BMI was 23.3 kg/m. The mean operating time was 158 minutes, and the mean estimated blood loss was 89.3 mL. There were no intraoperative complications and no conversions to open surgery. Successful treatment based on total mesorectal excision quality and circumferential resection margin was achieved in 45 patients (91.8%). Fifteen patients (30.6%) had 30-day postoperative complications, including 7 (14.3%) with anastomotic dehiscence, 5 (10.2%) with urinary retention, 2 (4.1%) with abdominal wound complications, and 1 (2.0%) with ileus. There was no postoperative mortality. LIMITATIONS: This was a noncomparative single-arm trial conducted at a single institution. CONCLUSIONS: Transanal endoscopic total mesorectal excision showed acceptable results based on perioperative and short-term oncologic outcomes. Further investigations are necessary to show the benefits and long-term outcomes of this procedure. See Video Abstract at http://links.lww.com/DCR/A563.

Risk Factors Associated With Incomplete Colonoscopy Based on the Analysis of Computed Tomographic Colonography Findings.

OBJECTIVE: This study aimed to identify the computed tomographic colonography (CTC) findings of incomplete colonoscopy compared with those of complete colonoscopy. METHODS: The clinical data and CTC imaging data from January 2004 to December 2012 were retrospectively obtained at 2 different institutions and reviewed by the central review system. A total of 71 patients who underwent both videocolonoscopy and CTC were included in this study. The CTC findings and clinical data were evaluated for the completeness of colonoscopy. RESULTS: In the CTC analysis, differences in total colon length, abdominal circumference, and sigmoid colon diameter were statistically significant between both groups (P < 0.05). Body mass index (BMI) and height were identified as significant clinical factors influencing the completeness of colonoscopy. In multiple logistic regression tests, only BMI and sigmoid colon diameter were independent factors (P < 0.05). CONCLUSIONS: High BMI larger diameter of sigmoid colon was associated with incomplete colonoscopy based on CTC.

Helicobacter pylori infection is an independent risk factor for colonic adenomatous neoplasms.

PURPOSE: Helicobacter pylori infection is considered to have a positive association with colorectal neoplasms. In this study, we evaluated the association between H. pylori infection and colorectal adenomas, based on the characteristics of these adenomas in Korea, where the prevalence of H. pylori infection is high and the incidence of colorectal cancer continues to increase. METHODS: The study cohort consisted of 4,466 subjects who underwent colonoscopy and esophagogastroduodenoscopy during screening (1,245 colorectal adenomas vs. 3,221 polyp-free controls). We compared the rate of H. pylori infection between patients with adenoma and polyp-free control cases, using multivariable logistic regression analysis. RESULTS: The overall rate of positive H. pylori infection was higher in adenoma cases than in polyp-free control cases (55.0 vs. 48.5%, p < 0.001). The odds ratio (OR) of positive H. pylori infection in patients with adenoma compared to polyp-free controls was 1.28 (95% CI 1.11-1.47). The positive association of H. pylori infection with colorectal adenomas was more prominent in advanced adenomas (OR 1.84, 95% CI 1.25-2.70) and multiple adenomas (OR 1.72, 95% CI 1.26-2.35). Based on the location of these adenomas, the OR was significant only in patients with colonic adenomas (OR 1.31, 95% CI 1.13-1.52) and not in those with rectal adenoma (OR 0.85, 95% CI 0.58-1.24). CONCLUSION: Helicobacter pylori infection is an independent risk factor for colonic adenomas, especially in cases of advanced or multiple adenomas, but not for rectal adenomas.

Visceral Adipose Tissue Volume and the Occurrence of Colorectal Adenoma in Follow-up Colonoscopy for Screening and Surveillance.

Whether obesity accelerates adenoma recurrence is not yet clear; therefore, we analyzed the risk factors for adenoma occurrence at follow-up colonoscopy, with a focus on visceral adiposity. In total, 1516 subjects underwent index colonoscopy, computed tomography, and questionnaire assessment from February to May 2008; 539 subjects underwent follow-up colonoscopy at the National Cancer Center at least 6 mo after the index colonoscopy. The relationships between the presence of adenoma at follow-up colonoscopy and anthropometric obesity measurements, including body mass index (BMI), waist circumference (WC), visceral adipose tissue (VAT) volume, and subcutaneous adipose tissue (SAT) volume, were analyzed. 188 (34.9%) had adenomatous polyps at follow-up colonoscopy. Multivariate analysis revealed that VAT volume ≥ 1000 cm3 and BMI ≥ 30 kg/m2 were related to the presence of adenoma at follow-up colonoscopy (VAT volume 1000-1500 cm3: odds ratio [OR] = 2.13(95% confidence interval, CI = 1.06-4.26), P = 0.034; VAT volume ≥ 1000 cm3: OR = 2.24(95% CI = 1.03-4.88), P = 0.043; BMI ≥ 30 kg/m2: OR = 4.22(95% CI = 1.12-15.93), P = 0.034). In contrast, BMI 25-29.9 kg/m2, SAT volume, and WC were not associated with the presence of adenoma at follow-up colonoscopy. In conclusion, excess VAT can contribute to the development and growth of new colorectal adenomas, and is a better predictor of colorectal adenoma occurrence at follow-up colonoscopy than BMI, WC, and SAT volume.

Comparative Evaluation of the Efficacy of Polyethylene Glycol With Ascorbic Acid and an Oral Sulfate Solution in a Split Method for Bowel Preparation: A Randomized, Multicenter Phase III Clinical Trial.

BACKGROUND: An adequate level of bowel preparation before colonoscopy is important. The ideal agent for bowel preparation should be effective and tolerable. OBJECTIVE: The purpose of this study was to compare the clinical efficacy and tolerability of polyethylene glycol with ascorbic acid and oral sulfate solution in a split method for bowel preparation. DESIGN: This was a prospective, multicenter, randomized controlled clinical trial. SETTINGS: Outpatients at the specialized clinics were included. PATIENTS: A total of 186 subjects were randomly assigned. After exclusions, 84 subjects in the polyethylene glycol with ascorbic acid group and 83 subjects in the oral sulfate solution group completed the study and were analyzed. INTERVENTIONS: Polyethylene glycol with ascorbic acid or oral sulfate solution in a split method was the included intervention. MAIN OUTCOME MEASURES: The primary end point was the rate of successful bowel preparation, which was defined as being excellent or good on the Aronchick scale. Tolerability and adverse events were also measured. RESULTS: Success of bowel preparation was not different between 2 groups (91.7% vs 96.4%; p = 0.20), and the rate of adverse GI events (abdominal distension, pain, nausea, vomiting, or abdominal discomfort) was not significantly different between the 2 groups. In contrast, the mean intensity of vomiting was higher in the oral sulfate solution group than in the polyethylene glycol with ascorbic acid group (1.6 ± 0.9 vs 1.9 ± 1.1; p = 0.02). LIMITATIONS: All of the colonoscopies were performed in the morning, and the subjects were offered enhanced instructions for bowel preparation. In addition, the results of tolerability and adverse effect may have a type II error, because the number of cases was calculated for confirming the efficacy of bowel preparation. CONCLUSIONS: Oral sulfate solution is effective at colonoscopy cleansing and has acceptable tolerability when it is compared with polyethylene glycol with ascorbic acid. The taste and flavor of oral sulfate solution still need to be improved to enhance tolerability.

Early Outcomes of Endoscopic Submucosal Dissection for Colorectal Neoplasms According to Clinical Indications.

BACKGROUND: Although endoscopic submucosal dissection has been shown to be safe and effective for colorectal tumors, its clinical outcomes vary. OBJECTIVE: The aim of this study is to assess the outcomes of endoscopic submucosal dissection according to clinical indications. DESIGN: This is a prospective, multicenter, single-arm study. SETTING: The study was conducted at special hospitals for colorectal diseases and cancers. PATIENTS: The study population included consecutive patients aged 20 to 80 years who underwent colorectal endoscopic submucosal dissection for 1) early colorectal cancer, 2) laterally spreading tumors ≥2 cm in diameter, and 3) submucosal tumors. INTERVENTIONS: Procedures were performed by experienced colonoscopists. MAIN OUTCOME MEASURES: The primary end points were en bloc and curative resection rates. En bloc resection was defined as endoscopic one-piece resection without tumor fragmentation. Curative resection was defined as en bloc resection and no pathologic requirement for additional surgery. Secondary end points included procedure time, complications, and hospital stay. RESULTS: Of 321 patients, 317 (98.8%) underwent en bloc resection and 231 (72.0%) underwent curative resection. The mean procedure time was 46.2 minutes. Mean hospital stay after the procedure was 3.1 days. Perforation occurred in 2 patients (0.6%), and bleeding occurred in 10 (3.1%) patients. All patients with complications were treated by endoscopic clipping or nonoperative management. Fifteen patients (4.7%) underwent additional radical surgery owing to the risks of lymph node metastasis. Although tumor size was smaller and procedure time shorter in the submucosal tumor group than in the laterally spreading tumor or early colorectal cancer group, there were no differences in clinical outcomes including en bloc and curative resection rates. Submucosal fibrosis was the only factor affecting endoscopic submucosal dissection procedure-related complications. LIMITATIONS: Early outcomes in a limited population and the potential for selection bias were limitations of this study. CONCLUSIONS: Outcomes of colorectal endoscopic submucosal dissection were acceptable in selected patients, with no difference in outcomes according to clinical indications. Because submucosal fibrosis can increase complications, it should be minimized before endoscopic submucosal dissection.

Difference in Time to Locoregional Recurrence Between Patients With Right-Sided and Left-Sided Colon Cancers.

BACKGROUND: Locoregional recurrence rates after curative resection for colon cancer vary widely. Identification of factors associated with locoregional recurrence may help in patient management. OBJECTIVE: The purpose of this study was to compare time to locoregional recurrence and distribution of locoregional recurrence after curative resection of colon cancer according to primary tumor location and to investigate risk factors for locoregional recurrence of colon cancer. DESIGN: This was a retrospective observational study. SETTINGS: This study was conducted at a single institution. PATIENTS: This study analyzed 1632 patients with colonic adenocarcinoma without distant metastasis who underwent curative resection at the National Cancer Center in Korea between January 2001 and December 2009. The primary end point of the study was time from surgery to locoregional recurrence. The Kaplan-Meier method was used to estimate the cumulative incidence of locoregional recurrence, and the log-rank test was used to test the difference in time to locoregional recurrence between patient subgroups. Cox proportional hazards models were used to investigate the risk factors for locoregional recurrence. MAIN OUTCOME MEASURES: The time from surgery to locoregional recurrence was compared between patients with right-sided and left-sided colon cancers. RESULTS: The time to locoregional recurrence was significantly different between patients with right-sided and left-sided colon cancers (HR = 2.35 for right-sided; p < 0.001). The overall 5-year locoregional recurrence rate was 5.7%, and that in patients with right-sided and left-sided colon cancers was 8.5% and 4.1%. Multivariable analysis demonstrated that right-sided location, female sex, T4 disease, lymph node metastasis, and perineural invasion were independent risk factors for locoregional recurrence of colon cancer. LIMITATIONS: This was a retrospective design and single-institution study. CONCLUSIONS: Patients with right-sided colon cancers presented with significantly increased risk of locoregional recurrence. Right-sided location, female sex, T4 disease, lymph node metastasis, and perineural invasion are independent risk factors for locoregional recurrence of colon cancer.

Randomized clinical trial comparing reduced-volume oral picosulfate and a prepackaged low-residue diet with 4-liter PEG solution for bowel preparation.

BACKGROUND: Reduced-volume bowel preparation with a low-residue diet prior to colonoscopy would result in better patient compliance and sufficient bowel preparation. OBJECTIVE: To compare the clinical efficacy of reduced-volume sodium picosulfate and a prepackaged low-residue diet with that of the standard bowel preparation using 4 L of PEG solution. DESIGN: Prospective, single center, single blind, active control, randomized study (NCCCTS-12-619, KCT0000470). SETTING: Ambulatory outpatient clinic at the National Cancer Center, Republic of Korea. PATIENTS: A total of 194 subjects were randomly assigned for this study, 97 in each group. After exclusions, 94 subjects in the Picolight group and 90 in the PEG group completed the study and were analyzed. INTERVENTIONS: Sodium picosulfate with a prepackaged low-residue, one-day diet or 4-L PEG for bowel preparation. MAIN OUTCOME MEASURES: Success rate of the bowel preparation, tolerability, adverse events, cecal intubation time, polyp detection rate and adenoma detection rate. RESULTS: The bowel preparation success rate was significantly higher (91.5% vs. 81.1%, p = 0.04) and the rates of adverse events, including abdominal distension, pain, nausea, vomiting and abdominal discomfort, were significantly lower in the picosulfate group than the PEG group. Cecal intubation times and the polyp and adenoma detection rates were similar in the 2 groups. LIMITATIONS: Single center, limited population, all colonoscopies were performed in the morning. CONCLUSIONS: Bowel preparation with low-volume oral picosulfate and a prepackaged low-residue diet enhances colon cleansing and is better tolerated than the standard bowel preparation.

Treatment for appendicitis in cancer patients on chemotherapy: a retrospective cohort study.

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.