Different lymph node staging systems for predicting the prognosis of colorectal neuroendocrine neoplasms

BACKGROUND Colorectal neuroendocrine neoplasms(NENs)are a rare malignancy that primarily arises from the diffuse distribution of neuroendocrine cells in the colon and rectum.Previous studies have pointed out that the status of lymph node may be used to predict the prognosis.AIM To investigate the predictive values of lymph node ratio(LNR),positive lymph node(PLN),and log odds of PLNs(LODDS)staging systems on the prognosis of colorectal NENs treated surgically,and compare their predictive values.METHODS This cohort study included 895 patients with colorectal NENs treated surgically from the Surveillance,Epidemiology,and End Results database.The endpoint was mortality of patients with colorectal NENs treated surgically.X-tile software was utilized to identify most suitable thresholds for categorizing the LNR,PLN,and LODDS.Participants were selected in a random manner to form training and testing sets.The prognosis of surgically treating colorectal NENs was examined using multivariate cox analysis to assess the associations of LNR,PLN,and LODDS with the prognosis of colorectal NENs.C-index was used for assessing the predictive effectiveness.We conducted a subgroup analysis to explore the different lymph node staging systems’predictive values.RESULTS After adjusting all confounding factors,PLN,LNR and LODDS staging systems were linked with mortality in patients with colorectal NENs treated surgically(P<0.05).We found that LODDS staging had a higher prognostic value for patients with colorectal NENs treated surgically than PLN and LNR staging systems.Similar results were obtained in the different G staging subgroup analyses.Furthermore,the area under the receiver operating characteristic curve values for LODDS staging system remained consistently higher than those of PLN or LNR,even at the 1-,2-,3-,4-,5-and 6-year follow-up periods.CONCLUSION LNR,PLN,and LODDS were found to significantly predict the prognosis of patients with colorectal NENs treated surgically.

Colonoscopy plays an important role in detecting colorectal neoplasms in patients with gastric neoplasms

BACKGROUND Gastric cancer(GC)and colorectal cancer(CRC)are the fifth and third most common cancer worldwide,respectively.Nowadays,GC is reported to have a potential predictive value for CRC,especially for advanced CRC.AIM To evaluate the necessity of colonoscopy for gastric neoplasm(GN)patients.METHODS Four databases,including PubMed,EMBASE,the Cochrane Library,and Ovid,were used to perform the search strategy on May 2,2023.The prevalence of colorectal neoplasms(CRN)and baseline characteristics were compared between the neoplasm group and the control group.Continuous variables are expressed as the mean difference and standard deviation.Relationships of categorical variables in the two groups are expressed as odds ratios(OR)and 95%confidence intervals(95%CIs).Subgroup analysis according to different kinds of GNs was conducted for more in-depth analysis.The results of this study are represented by forest plots.Publication bias was evaluated by a funnel plot.All data analyses were performed by STATA SE 16.0 software.RESULTS A total of 3018 patients with GNs and 3905 healthy controls(age and sex matched)were enrolled for analysis.After comparing the prevalence of CRNs between the two groups,CRNs were detected significantly more frequently in GN patients than in controls(OR=1.69,95%CI=1.28 to 2.23,I^(2)=85.12%,P=0.00),especially in patients with GC(OR=1.80,95%CI=1.49 to 2.18,I^(2)=25.55%,P<0.1).Moreover,other risk factors including age(OR=1.08,95%CI=1.00 to 1.17,I^(2)=90.13%,P=0.00)and male sex(OR=2.31,95%CI=1.26 to 4.22,I^(2)=87.35%,P=0.00),were related to the prevalence of CRNs.For patients in the GN group,body mass index(BMI,OR=0.88,95%CI=0.80 to 0.98,I^(2)=0.00%,P=0.92)and smoking(OR=1.03,95%CI=1.01 to 1.05,I^(2)=0.00%,P=0.57)were protective and risk factors for CRNs,respectively.CONCLUSION Patients are recommended to undergo colonoscopy when diagnosed with GNs,especially GC patients with a low BMI and a history of smoking.

Risk factors for bleeding after endoscopic submucosal dissection of colorectal neoplasms

AIM: To investigate the risk factors for delayed bleeding following endoscopic submucosal dissection (ESD) treatment for colorectal neoplasms.

Endoscopic submucosal dissection for colorectal neoplasms

Although endoscopic submucosal dissection(ESD) gains acceptance as one of the standard treatments for esophageal and stomach neoplasms in Japan,it is still in the developing stage for colorectal neoplasms.In terms of indications,little likelihood of nodal metastasis and technical resectability are principally considered.Some of intramucosal neoplasms,carcinomas with minute submucosal invasion,and carcinoid tumors,which are technically unresectable by conventional endoscopic treatments,may become good candidates for ESD,considering substantial risks and obtained benefits.ESD as a staging measure to obtain histological information of the invasion depth and lymphovascular infiltration is acceptable because preoperative prediction is difficult in some cases.In terms of techniques,advantages of ESD in comparison with other endoscopic treatments are to be controllable in size and shape,and to be resectable even in large and fibrotic neoplasms.The disadvantages may be longer procedure time,heavier bleeding,and higher possibility of perforation.However,owing to refinement of the techniques,invention of devices,and the learning curve,acceptable technical safety has been achieved.Colorectal ESD is very promising and become one of the standard treatments for colorectal neoplasms in the near future.

CYP1A1,CYP2E1 and EPHX1 polymorphisms in sporadic colorectal neoplasms

AIM To investigate the contribution of polymorphisms in the CYP1A1, CYP2E1 and EPHX1 genes on sporadic colorectal cancer(SCRC) risk. METHODS Six hundred forty-one individuals(227 patients with SCRC and 400 controls) were enrolled in the study. The variables analyzed were age, gender, tobacco and alcohol consumption, and clinical and histopathological tumor parameters. The CYP1A1 *2A, CYP1A1 *2C CYP2E1 *5B and CYP2E1 *6 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). The EPHX1 Tyr113 His, EPHX1 His139 Arg and CYP1A1 *2C polymorphisms were detected by real-time PCR. Chisquared test and binary logistic regression were used in the statistical analysis. Haplotype analysis was conducted using the Haploview program, version 2.05.RESULTS Age over 6 2 years was a risk factor for SCRC development(OR = 7.54, 95%CI: 4.94-11.50, P < 0.01). Male individuals were less susceptible to SCRC(OR = 0.55, 95%CI: 0.35-0.85, P < 0.01). The CYP2E1*5B polymorphism was associated with SCRC in the codominant(heterozygous genotype: OR = 2.66, 95%CI: 1.64-4.32, P < 0.01), dominant(OR = 2.82, 95%CI: 1.74-4.55, P < 0.01), overdominant(OR = 2.58, 95%CI: 1.59-4.19, P < 0.01), and log-additive models(OR = 2.84, 95%CI: 1.78-4.52, P < 0.01). The CYP2E1*6 polymorphism was associated with an increased SCRC risk in codominant(heterozygous genotype: OR = 2.81, 95%CI: 1.84-4.28, P < 0.01; homozygous polymorphic : OR = 7. 3 2, 9 5 % C I : 1.85-28.96, P < 0.01), dominant(OR = 2.97, 95%CI: 1.97-4.50, P < 0.01), recessive(OR = 5.26, 95%CI: 1.35-20.50, P = 0.016), overdominant(OR = 2.64, 95%CI: 1.74-4.01, P < 0.01), and log-additive models(OR = 2.78, 95%CI: 1.91-4.06, P < 0.01). The haplotype formed by the minor alleles of the CYP2E1*5B(C) and CYP2E1*6(A) polymorphisms was associated with SCRC(P = 0.002). However, the CYP1A1 *2A, CYP1A1 *2C, EPHX1 Tyr113 His and EPHX1 His139 Arg polymorphisms were not associated with SCRC.CONCLUSION In conclusion, the results demonstrated that CYP2E1*5B and CYP2E1*6 minor alleles play a role in the development of SCRC.

Stage at diagnosis of colorectal cancer through diagnostic route:Who should be screened?

BACKGROUND Colorectal cancer(CRC)is a global health concern,with advanced-stage diagnoses contributing to poor prognoses.The efficacy of CRC screening has been well-established;nevertheless,a significant proportion of patients remain unscreened,with>70%of cases diagnosed outside screening.Although identifying specific subgroups for whom CRC screening should be particularly recommended is crucial owing to limited resources,the association between the diagnostic routes and identification of these subgroups has been less appreciated.In the Japanese cancer registry,the diagnostic routes for groups discovered outside of screening are primarily categorized into those with comorbidities found during hospital visits and those with CRC-related symptoms.AIM To clarify the stage at CRC diagnosis based on diagnostic routes.METHODS We conducted a retrospective observational study using a cancer registry of patients with CRC between January 2016 and December 2019 at two hospitals.The diagnostic routes were primarily classified into three groups:Cancer screening,follow-up,and symptomatic.The early-stage was defined as Stages 0 or I.Multivariate and univariate logistic regressions were exploited to determine the odds of early-stage diagnosis in the symptomatic and cancer screening groups,referencing the follow-up group.The adjusted covariates were age,sex,and tumor location.RESULTS Of the 2083 patients,715(34.4%),1064(51.1%),and 304(14.6%)belonged to the follow-up,symptomatic,and cancer screening groups,respectively.Among the 2083 patients,CRCs diagnosed at an early stage were 57.3%(410 of 715),23.9%(254 of 1064),and 59.5%(181 of 304)in the follow-up,symptomatic,and cancer screening groups,respectively.The symptomatic group exhibited a lower likelihood of early-stage diagnosis than the follow-up group[P<0.001,adjusted odds ratio(aOR),0.23;95%confidence interval(95%CI):0.19-0.29].The likelihood of diagnosis at an early stage was similar between the follow-up and cancer screening groups(P=0.493,aOR for early-stage diagnosis in the cancer screening group vs follow-up group=1.11;95%CI=0.82-1.49).CONCLUSION CRCs detected during hospital visits for comorbidities were diagnosed earlier,similar to cancer screening.CRC screening should be recommended,particularly for patients without periodical hospital visits for comorbidities.

Non-participation of asymptomatic candidates in screening protocols reduces early diagnosis and worsens prognosis of colorectal cancer

The Agatsuma et al’s study shows that despite the evidence of the benefits of an early colorectal cancer(CRC)diagnosis,through screening in asymptomatic subjects,up to 50%of candidates reject this option and many of those affected are diagnosed later,in advanced stages.The efficacy of screening programs has been well-established for several years,which reduces the risk of CRC morbidity and mortality,without taking into account the test used for screening,or other tools.Nevertheless,a significant proportion of patients remain unscreened,so understanding the factors involved,as well as the barriers of the population to adherence is the first step to possibly modify the participation rate.These barriers could include a full range of social and political aspects,especially the type of financial provision of each health service.In Japan,health services are universal,and this advantageous situation makes it easier for citizens to access to these services,contributing to the detection of various diseases,including CRC.Interestingly,the symptomatic CRC group had a lower early-stage diagnosis rate than the patients detected during follow-up for other comorbidities,and symptomatic and cancer screening groups showed similar early-stage diagnosis.

Different risk factors for advanced colorectal neoplasm in young adults

AIM: To compare the risk of developing advanced colorectal neoplasm(ACRN) according to age in Koreans.METHODS: A total of 70428 Koreans from an occupational cohort who underwent a colonoscopy between 2003 and 2012 at Kangbuk Samsung Hospital were retrospectively selected. We evaluated and compared odds ratios(OR) for ACRN between the young-adults(YA < 50 years) and in the older-adults(OA ≥ 50 years). ACRN was defined as an adenoma ≥ 10 mm in diameter, adenoma with any component of villous histology, high-grade dysplasia, or invasive cancer.RESULTS: In the YA group, age(OR = 1.08, 95%CI: 1.06-1.09), male sex(OR = 1.26, 95%CI: 1.02-1.55), current smoking(OR = 1.37, 95%CI: 1.15-1.63), family history of colorectal cancer(OR = 1.46, 95%CI: 1.01-2.10), diabetes mellitus related factors(OR = 1.27, 95%CI: 1.06-1.54), obesity(OR = 1.23, 95%CI: 1.03-1.47), CEA(OR = 1.04, 95%CI: 1.01-1.09) and low-density lipoprotein-cholesterol(OR = 1.01, 95%CI: 1.01-1.02) were related with an increased risk of ACRN. However, age(OR = 1.08, 95%CI: 1.06-1.09), male sex(OR = 2.12, 95%CI: 1.68-2.68), current smoking(OR = 1.38, 95%CI: 1.12-1.71), obesity(OR = 1.34, 95%CI: 1.09-1.65) and CEA(OR = 1.05, 95%CI: 1.01-1.09) also increased the risk of ACRN in the OA group.CONCLUSION: The risks of ACRN differed based on age group. Different colonoscopic screening strategies are appropriate for particular subjects with risk factors for ACRN, even in subjects younger than 50 years.

Clinical significance of type V_I pit pattern subclassification in determining the depth of invasion of colorectal neoplasms

AIM: To clarify whether subclassification of the type VI pit pattern on the basis of magnifying colonoscopy findings is useful in determining the type and depth of invasion of colorectal neoplasms.METHODS: We retrospectively analyzed 272 colorectal neoplasms (117 dysplasias and 155 submucosal invasive carcinomas; 228 patients) with a type V pit pattern [type VI, n = 202; type VN, n = 70 (Kudo and Tsuruta classification system)]. We divided lesions with a type VI pit pattern into two subclasses, mildly irregular lesions and severely irregular lesions, according to the prominent and detailed magnifying colonoscopy findings. We examined the relation between these two subclasses and histology/invasion depth.RESULTS: One hundred and four lesions (51.5%) were judged to be mildly irregular, and 98 lesions (48.5%) were judged to be severely irregular. Ninety-seven (93.3%) mildly irregular lesions showed dysplasias or submucosal invasion of less than 1000 μm (SM < 1000 μm). Fifty-five (56.1%) severely irregular lesions showed submucosal invasion equal to or deeper than 1000 μm (SM ≥ 1000 μm). Mild irregularity was found significantly more often in dysplasias or lesions with SM < 1000 μm than in lesions with SM ≥ 1000 μm (P < 0.01).CONCLUSION: Subclassification of the type VI pit pattern is useful for identifying dysplasias or lesions with SM < 1000 μm.

Intraductal papillary mucinous neoplasm of the ileal heterotopic pancreas in a patient with hereditary non-polyposis colorectal cancer: A case report

We report a case of intraductal papillary mucinous neoplasm(IPMN) originating from the ileal heterotopic pancreas in a patient with hereditary non-polyposis colorectal cancer(HNPCC). A 49-year-old woman had a past history of total colectomy and total hysterectomy with bilateral salpingo-oophorectomy due to colonic adenocarcinoma and endometrial adenocarcinoma 11 years ago. Her parents died from colonic adenocarcinoma and her sister died from colonic adenocarcinoma and endometrial adenocarcinoma. The clinician found an ileal mass with necrotic change and the mass increased in size from 1.7 cm to 2.2 cm during the past 2 years on computed tomography. It was surgically resected. Microscopically, the ileal mass showed heterotopic pancreas with IPMN high grade dysplasia. Immunohistochemical staining revealed positive reactivity for MLH1/PMS2 and negative reactivity for MSH2/MSH6. This is the first report of IPMN originating from the ileal heterotopic pancreas in a patient with HNPCC in the English literature.

Prediction rule for estimating advanced colorectal neoplasm risk in average-risk populations in southern Jiangsu Province

Objective：The aim of this study was to establish the risk scoring system towards the advanced colorectal neoplasm （CN） risk in the average-risk populations in the southern Jiangsu Province,and to evaluate the screening efficacy.Methods：Totally 905 cases of the average-risk populations who received the colonoscopy were selected as the objective.The multivariate logistic regression analysis method was used to establish the scoring system towards the occurrence risk of the advanced tumor,and its screening efficacy was evaluated through the prediction consistency,distinguishing ability and screening accuracy.Results：The scoring system consisted of five variables,namely age,gender,coronary heart disease,egg intake and stool frequency.The results revealed that it had good prediction consistency （P=0.205） and distinguishing ability [the area under the receiver operating characteristic （ROC） curve was 0.75,with 95％ confidence interval （95％ CI） of 0.69-0.82].Thus,2.5 points was set as the screening cutoff value,and its sensitivity,specificity,accuracy,positive predictive value,negative predictive value,positive likelihood ratio and negative likelihood ratio were 93.8 ％,47.6％,50.1％,9.1％,99.3％,1.79 and 0.13,respectively.Conclusions：The established scoring system had good screening efficacy,and can be used as the screening tool applying to the CN screening within the average-risk populations in the southern Jiangsu Province.

Association between white opaque substance under magnifying colonoscopy and lipid droplets in colorectal epithelial neoplasms

AIM To examine the association between white opaque substance(WOS) and histologically verified lipiddroplets in colorectal epithelial neoplasms.METHODS We reviewed colonoscopy records at our institution from 2014 to 2016 and identified cases of endoscopically or surgically resected colorectal epithelial neoplasms observed by magnifying narrow-band imaging(M-NBI) colonoscopy. Immunohistochemistry was used to stain tumors with a monoclonal antibody specific to adipophilin as a marker of lipids. The expression and distribution of adipophilin were compared between WOS-positive and WOS-negative lesions and among tumors classified by histologic type and depth of invasion.RESULTS Under M-NBI colonoscopy, 81 lesions were positive for WOS and 48 lesions were negative for WOS. The rate of adipophilin expression was significantly higher in WOS-positive lesions(95.1%) than in WOS-negative lesions(68.7%)(P = 0.0001). The incidence of deep adipophilin expression was higher in WOS-positive lesions(24.7%) than in WOS-negative lesions(4.2%)(P = 0.001). The incidence of deep expression was predominant among cancers with massive submucosal invasion(62.5%) compared to adenoma(7.2%) and high-grade dysplasia or cancers with slight submucosal invasion(12.7%)(P = 0.0001).CONCLUSION The distribution of lipid droplets may be closely associated with the visibility of WOS under M-NBI colonoscopy, and with histologic grade and depth of tumor invasion.

Incidence and localization of lymphoid follicles in early colorectal neoplasms

AIM： TO investigate the incidence and Iocalizations of lymphoid follicles （LFs） in early colorectal neoplasms in human beings. METHODS： From July 1992 to September 1999, a total of 1 324 early colorectal neoplasms were removed endoscopically or surgically at our hospital; 1 031 （77.9%） were available for analysis in this study. Localization of LFs was defined histologically： as submucosal LFs, if located under the muscularis mucosa; and as intramucosal LFs, if located across or over the muscularis RESULTS： Histologically, the materials included 903 intramucosal neoplasms and 128 submucosal cancers. Overall incidence of LFs was 27.2% （280/1 031）. The incidence of LFs was significantly higher in females （33.6% vs 24.9%, P = 0.0064）, the right-sided colon （32.2% vs 25.6%, P = 0.0403） and in flat or depressed type lesions （34.6% vs 25.2%, P〈O.O001） as compared to males, left-sided colon and protruding type lesions, respectively. The incidences of intramucosal neoplasms and submucosal cancers were 24.3% and 43.8%, respectively （P〈O.O001）. Localizations of LFs （intramucosal LF/submucosal LF） in depressed, flat, and protruding types were 1/24, 14/36, and 131/74, respectively. CONCLUSION： The incidence of LFs in early human colorectal neoplasms significantly differs by gender, location, macroscopic type, and histology. Moreover,localization significantly differs by macroscopic type.

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.

Synchronous manifestation of colorectal cancer and intraductal papillary mucinous neoplasms

High rates of extrapancreatic malignancies,in particular colorectal cancer(CRC),have been detected in patients with intraductal papillary mucinous neoplasm(IPMN).So far,there is no distinct explanation in the literature for the development of secondary or synchronous malignancies in patients with IPMN.In the past few years,some data related to common genetic alterations in IPMN and other affiliated cancers have been published.This review elucidated the association between IPMN and CRC,shedding light on the most relevant genetic alterations that may explain the possible relationship between these entities.In keeping with our findings,we suggested that once the diagnosis of IPMN is made,special consideration of CRC should be undertaken.Presently,there are no specific guidelines regarding colorectal screening programs for patients with IPMN.We recommend that patients with IPMNs are at high-risk for CRC,and a more rigorous colorectal surveillance program should be implemented.

Study on Proteomics in Hepatic Metastasis of Colorectal neoplasms

Colorectal cancer is one of the most frequent cancers in the world. Hepatic metastasis is the most common site metastatic disease and dominant cause of death in colorectal cancer patients. In the large majority of cases, cell dysfunction in CRC results from multiple rather than single, gene interactions, so to be able to predict occurrence of disease and treatment outcome, more studies on comparative proteomics are needed both in sporadic and in hereditary colorectal cancer. This article is about the proteomic study on hepatic metastasis of colorectal cancer which helps to identify the specific proteins that play important roles in hepatic metastasis. The study of protein molecules with their expressions correlated to the metastatic process would help to understand the metastatic mechanisms and thus facilitate the development of strategies for the therapeutic interventions and clinical markagement of cancer.

Expenditure and financial burden for the diagnosis and treatment of colorectal cancer in China:a hospital.based,multicenter,cross-sectional survey

Background: The increasing prevalence of colorectal cancer(CRC) in China and the paucity of information about relevant expenditure highlight the necessity of better understanding the financial burden and effect of CRC diagnosis and treatment. We performed a survey to quantify the direct medical and non-medical expenditure as well as the resulting financial burden of CRC patients in China.Methods: We conducted a multicenter, cross-sectional survey in 37 tertiary hospitals in 13 provinces across China between 2012 and 2014. Each enrolled patient was interviewed using a structured questionnaire. All expenditure data were inflated to the 2014 Chinese Yuan(CNY; 1 CNY = 0.163 USD). We quantified the overall expenditure and financial burden and by subgroup(hospital type, age at diagnosis, sex, education, occupation, insurance type, household income, clinical stage, pathologic type, and therapeutic regimen). We then performed generalized linear modeling to determine the factors associated with overall expenditure.Results: A total of 2356 patients with a mean age of 57.4 years were included, 57.1 % of whom were men; 13.9% of patients had stage I cancer; and the average previous-year household income was 54,525 CNY.The overall average direct expenditure per patient was estimated to be 67,408 CNY, and the expenditures for stage Ⅰ, Ⅱ, Ⅲ, and Ⅳ disease were 56,099 CNY, 59,952 CNY, 67,292 CNY, and 82,729 CNY, respectively. Non-medical expenditure accounted for 8.3%of the overall expenditure. The 1-year out-of-pocket expenditure of a newly diagnosed patient was 32,649 CNY, which accounted for 59.9% of their previous-year household income and caused 75.0% of families to suffer an unmanageable financial burden. Univariate analysis showed that financial burden and overall expenditure differed in almost all subgroups(P < 0.05), except for sex. Multivariate analysis showed that patients who were treated in specialized hospitals and those who were diagnosed with adenocarcinoma or diagnosed at a later stage were likely to spend more,whereas those with a lower household income and those who underwent surgery spent less(all P < 0.05).Conclusions: For patients in China, direct expenditure for the diagnosis and treatment of CRC seemed catastrophic,and non-medical expenditure was non-ignorable. The financial burden varied among subgroups, especially among patients with different clinical stages of disease, which suggests that, in China, CRC screening might be cost-effective.

Hepatectomy vs radiofrequency ablation for colorectal liver metastasis:A propensity score analysis

AIM:To compare outcomes from radiofrequency ablation(RFA) and hepatectomy for treatment of colorectal liver metastasis(CRLM).METHODS:From January 2000 to December 2009,408 patients underwent curative intent treatment for CRLM.We excluded patients using the criteria:size of CRLM > 3 cm,number of CRLM ≥ 5,percutaneous RFA,follow-up period < 12 mo,double primary cancer,or treatment with both RFA and hepatectomy.We matched 51 patients who underwent RFA with 102 patients who underwent hepatectomy by propensity scores.RESULTS:The median follow-up period was 45 mo(range,12 mo to 158 mo).Hepatic recurrence was more frequent in the RFA than the hepatectomy group(P = 0.021) although extrahepatic recurrence curves were similar(P = 0.716).Survival curves of hepatectomy group were better than that of RFA for multiple,large(> 2 cm) CRLM(P = 0.034).However,survival curves were similar for single or small(≤ 2 cm) CRLM(P = 0.714,P = 0.740).CONCLUSION:Hepatectomy is better than RFA for the treatment of CRLM.However,RFA might be suitable for selected patients with single,small(≤ 2 cm) CRLM.

Chemoprevention of tea on colorectal cancer induced by dimethylhydrazine in Wistar rats

AIM To investigate the chemopreventiveeffects of green tea and tea pigment on 1,2-dimethylhydrazine(DMH)-induced rat colorectalcarcinogenesis.METHODS Male weaning Wistar rats wererandomly allocated into four groups.Rats in thepositive control group were given s.c.injectionof DMH,once a week for ten weeks;rats in tea-treated groups,with the same DMH treatment asin the positive group,received 2% green tea and0.1% tea pigments;rats in the negative controlgroup were given s.c.injection of the samevolume of saline as well as DMH in the positivegroup.Animals were sacrified and necropsied atthe end of week 16 and week 32.RESULTS Aberrant cryptic foci(ACF)wereformed in animals in DMH-treated groups at theend of week 16.Compared to the DMH group,green tea and tea pigments groups had less ACF(148.25 and 204.25,respectively,P【0.01).Atthe end of week 32,all rats in DMH groupdeveloped large intestinal tumors.The resultsalso showed that DMH increased labeling index(LI)of proliferating cell nuclear antigen(PCNA)of intestinal mucosa and the expression of ras-p21.However,in the tea-treated groups,PCNA-LI was significantly reduced as compared withthe positive control group(36.63 and 40.36 inthe green tea group and tea pigment group,respectively,at the end of the experiment,P【0.01).ras-p21 expression was alsosignificantly reduced(2.07 and 2.36 in the colontumors of rats in the green tea group and teapigments group,respectively at the end of theexperiment,P【0.01).Furthermore,green tea and tea pigment inhibited the expression of Bcl-2protein(2,5,1,0 and 2,4,1,0,respectively,at the end of the experiment P【0.01),andinduced expression of Bax protein(0,1,3,4and 0,1,4,3,respectively,P【0.01).CONCLUSION Chinese green tea drinkinginhibited ACF and colonic tumors formation inrats,which showed that tea had a significantchemopreventive effect on DMH-inducedcolorectal carcinogenesis.Such effects may bedue to suppression of cell proliferation andinduction of apoptosis in the intestinal crypts.

Comparative analysis of radiofrequency ablation and resection for resectable colorectal liver metastases

AIM:To evaluate the therapeutic efficacy of radiofrequency ablation(RFA)for resectable colorectal liver metastases(CRLM)compared with that of resection.METHODS:Between June 2004 and June 2009,we retrospectively analyzed 29 patients with resectable CRLMs;17 patients underwent RFA,and 12 underwent hepatic resection.All of the patients were informed about the treatment modalities and were allowed to choose either of them.RFA including an intraoperative approach was performed by a radiologist;otherwise,hepatic resection was performed by a surgeon.Comparative analysis of the two groups was performed,including comparisons of gender,age,and clinical outcomes,such as primary tumor stage and survival rates.RESULTS:The mean tumor size was significantly larger in the resection group(3.59 cm vs 2.02 cm,P<0.01),and the 5-year overall survival(OS)rate for all patients was 44.7%.There was no difference in the 5-year OS rates between the RFA and resection groups(37.8%vs66.7%).Univariate analysis indicated significantly lower5-year OS rates for patients with a tumor size>3cm.The 5-year disease-free survival(DFS)rates were17.6%and 22.2%in the RFA and resection groups,respectively(P=0.119).Univariate analysis revealed that in cases of male gender,age>65 years,T stage<Ⅳ,absence of lymphatic metastasis,and tumor size>3 cm,RFA resulted in significantly inferior 5-year DFS rates compared with surgical resection.CONCLUSION:Surgical resection revealed superior outcomes in the treatment of resectable CRLMs,particularly in cases with a hepatic tumor size>3 cm.