Surgical management of colonic diverticular disease:Discrepancy between right- and left-sided diseases

AIM:To compare the outcome of the surgical management of left-sided and right-sided diverticular disease.METHODS:The medical records of 77 patients who were surgically treated for diverticular disease between 1999 and 2010 in a tertiary referral hospital were retrospectively reviewed.The study population was limited to cases wherein the surgical specimen was confirmed as diverticulosis by pathology.Rightsided diverticula were classified as those arising from the cecum,ascending colon,and transverse colon,and those from the descending colon,sigmoid colon,and rectum were classified as left-sided diverticulosis.To assess the changing trend of occurrence of diverticulosis,data were compared with two previous studies of 51 patients.RESULTS:The proportion of left-sided disease cases was significantly increased compared to the results of our previous studies in 1994 and 2001,(27.5%vs48.1%,P<0.05).Moreover,no differences in gender,body mass index,multiplicity of the diverticula,fever,or leukocytosis were noted between patients with rightsided and left-sided disease.However,patients with right-sided disease were significantly younger(50.9year vs 64.0 year,P<0.01).Furthermore,left-sided disease was significantly associated with a higher incidence of complicated diverticulitis(89.2%vs 57.5%,P<0.01),combined resection due to extensive inflammation(21.6%vs 5.0%,P<0.05),operative complications(51.4%vs 27.5%,P<0.05),and in-hospital mortality(10.8%vs 0%,P<0.05),along with longer post-operative hospitalization duration(21.3±10.2 d vs 10.6±8.1 d,P<0.05).CONCLUSION:Compared with right-sided diverticular disease,the incidence of left-sided disease in Korea has increased since 2001 and is associated with worse surgical outcomes.

Is colonic lavage a suitable alternative for left-sided colonic emergencies?

BACKGROUND The use of intra-operative colonic lavage(IOCL)with primary anastomosis remains controversial in the emergency left-sided large bowel pathologies,with alternatives including Hartmann’s procedure,manual decompression and subtotal colectomy.AIM To compare the peri-operative outcomes of IOCL to other procedures.METHODS Electronic databases were searched for articles employing IOCL from inception till July 13,2020.Odds ratio and weighted mean differences(WMD)were estimated for dichotomous and continuous outcomes respectively.Single-arm meta-analysis was conducted using DerSimonian and Laird random effects.RESULTS Of 28 studies were included in this meta-analysis,involving 1142 undergoing IOCL,and 634 other interventions.IOCL leads to comparable rates of wound infection when compared to Hartmann’s procedure,and anastomotic leak and wound infection when compared to manual decompression.There was a decreased length of hospital stay(WMD=-7.750;95%CI:-13.504 to-1.996;P=0.008)compared to manual decompression and an increased operating time.Single-arm meta-analysis found that overall mortality rates with IOCL was 4%(CI:0.03-0.05).Rates of anastomotic leak and wound infection were 3%(CI:0.02-0.04)and 12%(CI:0.09-0.16)respectively.CONCLUSION IOCL leads to similar rates of post-operative complications compared to other procedures.More extensive studies are needed to assess the outcomes of IOCL for emergency left-sided colonic surgeries.

Oncologic impact of colonic stents for obstructive left-sided colon cancer

Colonic stenting has had a significant positive impact on the management of obstructive left-sided colon cancer(OLCC) in terms of both palliative treatment and bridge-to-surgery(BTS). Notably, many studies have convincingly demonstrated the effectiveness of stenting as a BTS, resulting in improvements in shortterm outcomes and quality of life, safety, and efficacy in subsequent curative surgery, and increased cost-effectiveness, whereas the safety of chemotherapy after stenting and the long-term outcomes of stenting as a BTS are controversial. Several studies have suggested an increased risk of perforation in patients receiving bevacizumab chemotherapy after colonic stenting. In addition, several pathological analyses have suggested a negative oncological impact of colonic stenting. In contrast, many recent studies have demonstrated that colonic stenting for OLCC does not negatively impact the safety of chemotherapy or long-term oncological outcomes. The updated version of the European Society of Gastrointestinal Endoscopy guidelines released in 2020 included colonic stenting as a BTS for OLCC as a recommended treatment. It should be noted that the experience of endoscopists is involved in determining technical and clinical success rates and possibly oncological outcomes. This review discusses the positive and negative impacts of colonic stenting on OLCC treatment, particularly in terms of oncology.

Analysis of 72 patients with colorectal high-grade neuroendocrine neoplasms from three Chinese hospitals

BACKGROUND Colorectal high-grade neuroendocrine neoplasms(HGNENs)are rare and constitute less than 1%of all colorectal malignancies.Based on their morphological differentiation and proliferation identity,these neoplasms present heterogeneous clinicopathologic features.Opinions regarding treatment strategies for and improvement of the clinical outcomes of these patients remain controversial.AIM To delineate the clinicopathologic features of and explore the prognostic factors for this rare malignancy.METHODS This observational study reviewed the data of 72 consecutive patients with colorectal HGNENs from three Chinese hospitals between 2000 and 2019.The clinicopathologic characteristics and follow-up data were carefully collected from their medical records,outpatient reexaminations,and telephone interviews.A survival analysis was conducted to evaluate their outcomes and to identify the prognostic factors for this disease.RESULTS According to the latest recommendations for the classification and nomenclature of colorectal HGNENs,61(84.7%)patients in our cohort had poorly differentiated neoplasms,which were categorized as high-grade neuroendocrine carcinomas(HGNECs),and the remaining 11(15.3%)patients had well differentiated neoplasms,which were categorized as high-grade neuroendocrine tumors(HGNETs).Most of the neoplasms(63.9%)were located at the rectum.More than half of the patients(51.4%)presented with distant metastasis at the date of diagnosis.All patients were followed for a median duration of 15.5 mo.In the entire cohort,the median survival time was 31 mo,and the 3-year and 5-year survival rates were 44.3%and 36.3%,respectively.Both the univariate and multivariate analyses demonstrated that increasing age,HGNEC type,and distant metastasis were risk factors for poor clinical outcomes.CONCLUSION Colorectal HGNENs are rare and aggressive malignancies with poor clinical outcomes.However,patients with younger age,good morphological differentiation,and without metastatic disease can have a relatively favorable prognosis.

Perivascular epithelioid cell neoplasm of the colon

A 17-year-old female presented with rectal bleeding from an ulcerated sigmoid mass in 1994.Initial pathological evaluation revealed a rare clear cell neoplasm of the colon,possibly originating from kidneys,adrenals,lung or a gynecologic source as a metastatic lesion.Extensive imaging studies were negative,and over the next 15 years,she remained well with no recurrence.The original resected neoplasm was reviewed and reclassified as a perivascular epithelioid cell neoplasm (PEComa).Although the long-term natural history of PEComas requires definition,increased clinical and pathological awareness should lead to increased recognition of an apparently rare type of colonic neoplasm that likely occurs more often than is currently appreciated.

Right- and left-sided colorectal cancersrespond differently to cetuximab

Introduction Right-sided colon cancer （RSCC） and left-sided colorectal cancer （LSCRC） differ with respect to theirbiology and genomic patterns. This study aimed to examine whether the primary tumor location is associated withthe response to cetuximab in patients with metastatic colorectal cancer （mCRC）.Methods： Patients with mCRC treated with cetuximab and standard chemotherapy as first- or second-line treatmentswere compared with randomly chosen patients who were treated with chemotherapy alone between 2005 and 2013.The main outcome measures were the overall response rate （ORR）, progression-free survival （PFS）, and overall survival （OS）.The differences in the outcome were analyzed by using the chi-squared test, Student＇s t test, and Kaplan-Meier method.Results： The treatment results of 206 patients with mCRC treated with cetuximab and standard chemotherapy asfirst- or second-line treatments were compared with those of 210 patients who were treated with chemotherapyalone. As a first-line treatment, cetuximab with chemotherapy was associated with a significantly higher ORR（49.4 % vs. 28.6 %, P = 0.005） as well as longer PFS （9.1 vs. 6.2 months, P = 0.002） and OS （28.9 vs. 20.1 months,P = 0.036） than chemotherapy alone in patients with LSCRC. However, cetuximab neither improved the ORR（36.4 % vs. 26.2 %, P = 0.349） nor prolonged PFS （5.6 vs. 5.7 months, P = 0.904） or OS （25.1 vs. 19.8 months, P = 0.553） inpatients with RSCC. As a second-line treatment, cetuximab exhibited a tendency to improve the ORR （23.5 % vs. 10.2 %,P = 0.087） and prolong PFS （4.9 vs. 3.5 months, P = 0.064）, and it significantly prolonged OS （17.1 vs. 12.4 months,P = 0.047） compared with chemotherapy alone in the patients with LSCRC. In contrast, as a second-line treatment,cetuximab neither improved the ORR （7.1 % vs. 11.4 %, P = 0.698） nor prolonged PFS （3.3 vs. 4.2 months, P = 0.761） orOS （13.4 vs. 13.0 months, P=0.652） in patients with RSCC.Conclusions： The addition of cetuximab to chemotherapy in both first- and second-line treatments of mCRC may onlybenefit patients with primary LSCRC.

Incidence of colorectal neoplasms among male pilots

AIM: To assess the prevalence of colorectal neoplasms (adenomas, advanced adenomas and colorectal cancers) among Israeli military and commercial airline pilots.

Pan-immune-inflammation value as a prognostic biomarker for colon cancer and its variation by primary tumor location

BACKGROUND A growing body of research indicates significant differences between left-sided colon cancers(LCC)and right-sided colon cancers(RCC).Pan-immune-inflammation value(PIV)is a systemic immune response marker that can predict the prognosis of patients with colon cancer.However,the specific distinction between PIV of LCC and RCC remains unclear.AIM To investigate the prognostic and clinical significance of PIV in LCC and RCC patients.METHODS This multicenter retrospective cohort study included 1510 patients with colon cancer,comprising 801 with LCC and 709 with RCC.We used generalized lifting regression analysis to evaluate the relative impact of PIV on disease-free survival(DFS)in these patients.Kaplan-Meier analysis,as well as univariate and multivariate analyses,were used to examine the risk factors for DFS.The correlation between PIV and the clinical characteristics was statistically analyzed in these patients.RESULTS A total of 1510 patients{872 female patients(58%);median age 63 years[interquartile ranges(IQR):54-71];patients with LCC 801(53%);median follow-up 44.17 months(IQR 29.67-62.32)}were identified.PIV was significantly higher in patients with RCC[median(IQR):214.34(121.78-386.72)vs 175.87(111.92-286.84),P<0.001].After propensity score matching,no difference in PIV was observed between patients with LCC and RCC[median(IQR):182.42(111.88-297.65)vs 189.45(109.44-316.02);P=0.987].PIV thresholds for DFS were 227.84 in LCC and 145.99 in RCC.High PIV(>227.84)was associated with worse DFS in LCC[PIV-high:Adjusted hazard ratio(aHR)=2.39;95%confidence interval:1.70-3.38;P<0.001]but not in RCC(PIV-high:aHR=0.72;95%confidence interval:0.48-1.08;P=0.114).CONCLUSION These findings suggest that PIV may predict recurrence in patients with LCC but not RCC,underscoring the importance of tumor location when using PIV as a colon cancer biomarker.

Malignant myopericytoma originating from the colon: A case report

BACKGROUND Myopericytoma is a benign tumor that typically occurs within subcutaneous tissue and most often involves the distal extremities,followed by the proximal extremities,neck,thoracic vertebrae and oral cavity.Complete resection is often curative.Malignant myopericytoma is extremely rare and has a poor prognosis.Here,we report for the first time a case of malignant myopericytoma originating from the colon.CASE SUMMARY A 69-year-old male was admitted to our hospital with right upper quadrant pain for five days.Imaging suggested a liver mass with hemorrhage.A malignant hepatic tumor was the initial diagnosis.Surgical resection was performed after a complete preoperative work up.Initial postoperative pathology suggested that the mass was a malignant myoblastoma unrelated to the liver.Four months after the first surgery,an enhanced computed tomography(CT)scan revealed a recurrence of the tumor.The diagnosis of malignant myopericytoma derived from the colon was confirmed on histopathological examination of the specimen from the second surgery.The patient did not return to the hospital regularly for surveillance.The first postoperative abdominal CT examination six months after the second surgery demonstrated multiple liver metastases.Survival time between the diagnosis of the tumor to death was approximately one year.CONCLUSION Malignant myopericytoma is a rare cancer.Preoperative diagnosis may be difficult.Due to a lack of treatment options,prognosis is poor.

Inhibitory effect of sulindac against chemically induced primary colonic tumours by N methyl N nitrosourea in mice

AIM To investigate the chemopreventive effect of sulindac, one of the nonstroidal anti inflammatory drugs (NSAIDs), on the growth of N methyl N nitrosourea (MNU) induced mouse colonic tumors.

Prevention of metastasis to liver by using 5-FU intraperitoneal chemotherapy in nude mice inoculated with human colonic cancer cells

AIMS Using a new approach of regional adjuvant chemotherapy to prevent cancer cells hepatic metasta- sis after radical surgery of large bowel cancer. METHODS A model of liver with metastasis of hu- man colonic cancer (HCC) cells in nude mice was used to observe the effect in prevention of metastasis of HCC cells inoculated via spleen applied with early postoper- ative intraperitoneal (IP) chemotherapy using large dose of 5-FU. RESULTS The incidence of metastasis to liver was decreased by 40%,the mean number of metastatic liv- er nodules in each animal was reduced by 50.89% and the mean survival times of each animal was prolonged by 48.21% by using 5-FU 40 mg/NS 40 ml/kg IP for two consecutive days as compared with the controls. CONCLUSIONS IP is a new and more effective re- gional adjuvant chemotheraputic approach in the pre- vention of liver metastasis HCC cells after radical surgery of large bowel cancer.

Patterns of lymph node metastasis are different in colon and rectal carcinomas

AIM:To describe patterns of lymph node metastasis in invasive colon and rectal carcinomas.METHODS:Clinical data of 2340 patients with colorectal carcinoma(stageⅠ to Ⅲ) who received radical resection,was retrospectively reviewed.Of the 2340 patients,1314 patients suffered from rectal carcinoma and 1026 from colon carcinoma.Patients with rectal cancer who received neoadjuvant chemoradiation therapy were excluded.Statistical analysis was performed using MannWhitney,χ 2 and Cochran's and Mantel-Haenszel tests(SPSS 15.0).A two-tailed P < 0.05 was considered statistically significant.RESULTS:Lymph node retrieval in the rectal carcinoma group was significantly lower than that in the colon carcinoma group(P < 0.001),while positive lymph node retrieval in the rectal carcinoma group was significantly higher than that in the colon carcinoma group(P < 0.001).The proportion of lymph node positive(N+) cases was higher(patients with one or more positive lymph nodes) in the rectal carcinoma group(P = 0.004).The number of N+ cases was compared at different T stages(T1-T4) to eliminate background bias and the results were confirmed(P < 0.001).In addition,the lymph node ratio(the ratio of number of positive lymph nodes over the number of lymph nodes examined) of stage Ⅲ cases in the rectal carcinoma group was significantly higher than that in the colon carcinoma group(P < 0.001).CONCLUSION:Rectal carcinomas seem more prone to metastasize to the lymph nodes than colon carcinomas,which may be of potential clinical significance.

Tumor growth inhibition effect of hIL-6 on colon cancer cells transfected with the target gene by retroviral vector

AIM To observe the tumor inhibitory effects bytransfecting IL-6 cDNA into colon cancer cell lineHT-29 with retroviral vector pZIP cDNA.METHODS Human IL-6 gene was reconstructedin retrovirus vector and transfected into incasingcells PA317 by lipofectamine mediated method,the clones of the cells transferred with hlL-6were selected by G418,and targeted HT-29 cellswere infected with the virus granules secretedfrom PA317 and also selected by G418.Test genetranscription and expression level byhybridization,ELISA and MTT assay,etc.Analyze tumor inhibitory effects according to thecell growth curve,plating forming rate andtumorigenicity in nude mice.RESULT Successfully constructed andtransfected recombinant expressing vectorspZIPIL-6 cDNA and got positive transfected celllines.The colon cancer cell line(HT-29 IL-5)transfected with the hlL-5 gene by retroviralvector was established.The log proliferationperiod and the doubling time of this cell line wasbetween 4 to 7 days and 2.5 days according tothe direct cell count,the cell proliferation wasobviously inhibited with MTT assay,the platinginhibitory rate was 50% by plating efficiencytest.When HT-29 IL-6 cells were inoculated intothe nude mice subcutaneously,carcinogenicactivity of the solid tumor was found superior tothe control group and the size of tumor was notsignificantly enlarged.Injection of combinationvirus fluid containing 11.-6 gene intotransplantation tumors could inhibit the growthand development of the tumor.CONCLUSION IL-6 could inhibit the growth andproliferation of colon cancer cells by retroviralvector-mediated transduction.

Malignant schwannoma of the pancreas involving transversal colon treated with en-bloc resection

Pancreatic schwannoma is a very uncommon tumor of the pancreas,with only 27 cases reported.Most pancreatic schwannomas are benign,with only four malignant tumors reported.We describe a case of giant malignant schwannoma of the pancreatic body and tail,which involved the transverse colon.The tumor was treated successfully with en bloc distal splenopancreatectomy and colon resection.This is believed to be the first reported radical operation for malignant schwannoma of the pancreatic body,with infiltration of the transverse colon,with excellent longterm results.The patient is alive and well 28 mo after the operation.The authors conclude that pancreatic schwannomas should be considered in the differential diagnosis of cystic neoplasms of the pancreas,although the diagnosis can only be confirmed by microscopic examination.In the case of the benign tumors,local excision is adequate,but in the case of malignant schwannoma,oncological standards must be fulfilled.

Inhibitory effect of modified citrus pectin on liver metastases in a mouse colon cancer model

AIM: To discuss the expression of glactin-3 in liver metastasis of colon cancer and its inhibition by modi- fied citrus pectin (MCP) in mice. METHODS: Seventy-five Balb/c mice were randomly di- vided into negative control group (n = 15), positive con- trol group (n = 15), low MCP concentration group (n = 15), middle MCP concentration group (n = 15) and high MCP concentration group (n = 15). CT26 colon cancer cells were injected into the subcapsule of mouse spleen in positive control group, low, middle and high MCP concentrations groups, except in negative control, to set up a colon cancer liver metastasis model. The concen- tration of MCP in drinking water was 0.0%, 0.0%, 1.0%, 2.5% and 5.0% (wt/vol), respectively. Liver metastasis of colon cancer was observed after 3 wk. Enzyme-linked immunosorbent assay (ELISA) was used to detect the concentration of galectin-3 in serum. Expression of ga- lectin-3 in liver metastasis was detected by immunohis- tochemistry. RESULTS: Except for the negative group, the percent- age of liver metastasis in the other 4 groups was 100%, 80%, 73.3% and 60%, respectively. The number of liver metastases in high MCP concentration group was significantly less than that in positive control group (P = 0.008). Except for the negative group, the median volume of implanted spleen tumor in the other 4 groups was 1.51 cm3, 0.93 cm3, 0.77 cm3 and 0.70 cm3, respec- tively. The volume of implanted tumor in middle and high MCP concentration groups was significantly smaller than that in positive control group (P = 0.019; P = 0.003). The concentration of serum galectin-3 in positive control and MCP treatment groups was significantly higher than that in the negative control group. However, there was no significant difference between them. Except for the negative control group, the expression of galectin-3 in liver metastases of the other 4 groups showed no sig- nificant difference. CONCLUSION: Expression of galetin-3 increases sig- nificantly in liver metastasis of colon cancer, which can be effectively inhibited by MCP.

Efficacy of cap-assisted colonoscopy according to lesion location and endoscopist training level

AIM: To evaluate the efficacy of cap-assisted colonoscopy(CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training level.METHODS: Patients 20 years or older, who underwent their first screening colonoscopy in a single tertiary center from May 2011 to December 2012 were enrolled in this study. All patients underwent either CAC or standard colonoscopy(SC), and all of the procedures were performed by 11 endoscopists(8 trainees and 3 experts). All procedures were performed with highdefinition colonoscopes and narrow band imaging. The eight trainees had experiences of performing 150 to 500 colonoscopies, and the three experts had experiences of performing more than 3000 colonoscopies. A 4-mmlong transparent cap was attached to the end of a colonoscope in the CAC group. We retrospectively evaluated the number of polyps and adenomas, polyp detection rate(PDR), and the number of adenomas and adenoma detection rate(ADR) according to the lesion location and endoscopist training level between CAC and SC. We also evaluated the number of polyps and adenomas according to their size between CAC and SC.RESULTS: Overall, PDR and ADR using CAC were significantly higher than those using SC for both whole colon(48.5% vs 40.7%, P = 0.012; 35.7% vs 28.3%, P = 0.012) and right-side colon(35.3% vs 26.6%, P = 0.002; 27.0% vs 16.9%, P < 0.001). The number of polyps and adenomas per patient using CAC was significantly higher than that using SC for both the whole colon(1.07 ± 1.59 vs 0.82 ± 1.31, P = 0.008; 0.72 ± 1.32 vs 0.50 ± 1.01, P = 0.003) and right-side colon(0.66 ± 1.18 vs 0.41 ± 0.83, P < 0.001; 0.46 ± 0.97 vs 0.25 ± 0.67, P < 0.001). In the trainee group, the PDR and ADR using CAC were significantly higher than those using SC for both the whole colon(46.7% vs 39.7%, P = 0.040; 33.9% vs 26.0%, P =0.012) and right-side colon(34.2% vs 26.5%, P = 0.015; 25.3% vs 15.9%, P = 0.001). In the expert group, the PDR and ADR using CAC were significantly higher than those using SC only for the right-side colon(42.1% vs 27.0%, P =0.035; 36.8% vs 21.0%, P = 0.020).CONCLUSION: CAC is more effective than SC for detection of colorectal polyps and adenomas, especially when performed by trainees and when the lesions are located in the right-side colon.

Effect of gastrin on protein kinase C and its subtype in human colon cancer cell line SW480

INTRODUCTIONGastrin is atrophic gastrointestinal hormone whichis secreted by G cell.Gastrin has long beenconsidered a growth stimulatory hormone formucosa of the gastrointestinal tract.The growthresponses of certain colorectal cancer cells,andxenografts,can be stimulated by endogenousgastrin.Protein kinase C (PKC) is a family ofisozymes that plays a crucial role in transducingsignals of many hormones,growth peptides,

Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum

AIM: To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series.

Prognostic significance of computed tomography-detected extramural vascular invasion in colon cancer

AIM: To compare disease-free survival(DFS) between extramural vascular invasion(EMVI)-positive and-negative colon cancer patients evaluated by computed tomography(CT).METHODS: Colon cancer patients(n = 194) undergoing curative surgery between January 2009 and December 2013 were included. Each patient's demographics, cancer characteristics, EMVI status, pathological status and survival outcomes were recorded. All included patients had been routinely monitored until December 2015. EMVI was defined as tumor tissue within adjacent vessels beyond the colon wall as seen on enhanced CT. Disease recurrence was defined as metachronous metastases, local recurrence, or death due to colon cancer. Kaplan-Meier analyses were used to compare DFS between the EMVI-positive and-negative groups. Cox's proportional hazards models were used to measure the impact of confounding variables on survival rates.RESULTS: EMVI was observed on CT(ct EMVI) in 60 patients(30.9%, 60/194). One year after surgery, there was no statistically significant difference regarding the rates of progressive events between EMVI-positive and-negative patients [11.7%(7/60) and 6.7%(9/134), respectively; P = 0.266]. At the study endpoint, the EMVI-positive patients had significantly more progressive events than the EMVI-negative patients [43.3%(26/60) and 14.9%(20/134), respectively; oddsratio = 4.4, P < 0.001]. Based on the Kaplan-Meier method, the cumulative 1-year DFS rates were 86.7%(95%CI: 82.3-91.1) and 92.4%(95%CI: 90.1-94.7) for EMVI-positive and EMVI-negative patients, respectively. The cumulative 3-year DFS rates were 49.5%(95%CI: 42.1-56.9) and 85.8%(95%CI: 82.6-89.0), respectively. Cox proportional hazards regression analysis revealed that ctE MVI was an independent predictor of DFS with a hazard ratio of 2.15(95%CI: 1.12-4.14, P = 0.023). CONCLUSION: ctE MVI may be helpful when evaluating disease progression in colon cancer patients.